Tesi: "Plant's biology"

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Rohloff, Jens. "Cultivation of Herbs and Medicinal Plants in Norway - Essential Oil Production and Quality Control". Doctoral thesis, Norwegian University of Science and Technology, Department of Biology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-415.

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Essential oils (EO) are plant secondary metabolites that are known for their fragrance and food flavour properties. They consist of a complex mixture of mono- and sesquiterpenes, phenyl propanoids and oxygenated compounds. EOs can be present in different plant organs and materials, and their storage is related to specialised secretory structures. The yield of EOs from plant raw materials by distillation or pressing may on average vary from 0.1 – 1%, thus restricting the major EO production to the plant group of aromatic plants. Due to their function as signalling compounds between different types of organisms and diverse biological systems, their general antimicrobial and antioxidative effects and medicinal activity, EOs offer a promising potential for future applications within the fields of agriculture, medicine, pharmaceutical industry and biotechnology.

Changed consumer demands and raised interest in natural product compounds, especially essential oils, have formed the basis for initiating the research project “Norwegian Herb Production (Norsk Urteproduksjon NUP)” to encourage the cultivation, processing, marketing and distribution of aromatic and medicinal plants. The production, composition and quality characteristics of EOs (yield and terpene composition) from chamomile, lemon balm, oregano, peppermint, sachalinmint, thyme and yarrow have been investigated in the project period between 1994-1998.

Much focus has been put on the application of solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) for the analysis of EO volatiles from various aromatic and medicinal plants. SPME is a fast, solvent-free and non- destructive sample preparation technique where the analytes are extracted from fluid or solid matrices by headspace (HS) or direct immersion sampling (DI). Apart from EO isolation by common distillation, the applicability and sensitivity of the SPME fibre has made it feasible to carry out qualitative and semi-quantitative HS analyses of aromatic plants with regard to changes of EO metabolism during ontogenesis and plant development.

Based on NUP-results from field trials in the period between 1995-1996, the mint species peppermint (Mentha × piperita L.) and sachalinmint (Mentha sachalinensis (Briq.) Kudô) have been studied in detail (Papers B, D and E). Comparative analyses by applying distillation sampling and SPME have been carried out in order to study the advantages and disadvantages of both techniques (Papers B and E). It could be shown, that SPME offers a fast and reliable method for detecting quality-impact compounds from the p-menthane group (menthol, menthone, neomenthol, isomenthone and menthyl acetate). A distinct increase in the menthol/menthone ratio in the basipetal direction could be detected for peppermint and sachalinmint by applying SPME, thus revealing within-plant quality differences according to pharmacopeial requirements. Taking the increase of EO production from the vegetative to the generative growth stage into account, the harvest of mint plants in bloom will result in better EO yield and quality with regard to higher amounts of menthol.

When applying HS-SPME on complex EO volatile matrices such as known for yarrow (Achillea millefolium L.; Paper C), one might deal with fibre-partitioning effects of the different mono- and sesquiterpenes due to their physical and chemical properties. Despite these disadvantages, HS-SPME appears to be a sensitive extraction method for the screening of EO volatiles from complex sample matrices. Comparative analyses of volatiles from rose root rhizomes (Rhodiola rosea L.) have been carried out in order to characterize the rose-like odour compounds (Paper F). A total of 75 and 59 compounds have been identified by distillation sampling and HS-SPME, respectively, thus underscoring the excellent extraction properties and applicability of the SPME fibre.

Paper A gives a brief overview of EO biosynthesis and chemical structures, plant sources and methods of EO production. Before leading over to the main topic of HS-SPME applications by referring to numerous examples from the research work at The Plant Biocenter in the past 5 years, an introduction of solid-phase microextraction with regard to devices, procedures and extraction parameters is given.

The advantages and disadvantages of distillation vs. SPME are outlined on the background of comparative analyses of peppermint, chamomile, basil and dill. Furthermore, the utilization of HS-SPME for quantitative studies with regard to extraction time and analyte concentration is being highlighted. Examples for the screening of chemotypes (hops −Humulus lupulus L.) and cultivars (dill – Anethum graveolens L.) and ontogenetic studies are given (Mentha species; arnica −Arnica montana L.). Finally, the applicability of HS-SPME for the quality assessment of processed herbs (sweet basil −Ocimum basilicum L.) and phytomedicinal preparations (red coneflower – Echinacea purpurea L.) is being discussed.

The advantages of HS-SPME over classical distillation and headspace applications are impressive due to drastically reduced analysis time and will introduce new frontiers in plant volatile research with regard to secondary metabolism, plant-insect interactions and in vivo studies. The user-friendliness of operating SPME will initiate the development of future applications and equipment for the monitoring of volatiles for plant biological and environmental studies, extraction automation, on-site sampling and on-fibre storage of analytes.

Paper VI reprinted with kind permission of Elsevier, Sciencedirect, www.sciencedirect.com

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Hadj, Amor Khaoula. "Classification et inférence de réseaux de gènes à partir de séries temporelles très courtes : application à la modélisation de la mémoire transcriptionnelle végétale associée à des stimulations sonores répétées". Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSES037.

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Les avancées des nouvelles technologies de séquençage ont ouvert l'accès aux données d'expression dynamique des gènes à l'échelle du génome. Les approches ensemblistes classiques, habituellement utilisées en biologie, ne permettent pas la compréhension des mécanismes moléculaires complexes sous-jacents. Par conséquent, le développement de méthodes analytiques permettant d'appréhender de manière plus satisfaisante ce type de données représente un défi majeur pour la biologie contemporaine. Cependant, les coûts techniques et expérimentaux associés aux données de transcriptomiques limitent la dimension des jeux de données réels et, par conséquent, leurs méthodes d'analyse. Au cours de ma thèse, à l'interface entre les mathématiques appliquées et la biologie végétale, j'ai travaillé sur la mise en place d'une méthode d'inférence de réseaux de régulations dynamiques adaptée à un jeu de données réelles et originales décrivant l'effet de stimulations sonores répétées sur l'expression des gènes d'Arabidopsis thaliana. J'ai ainsi proposé une méthode de classification adaptée aux séries temporelles très courtes qui regroupe les gènes par variations temporelles, permettant d'ajuster la dimension des données à l'inférence de réseau. La comparaison de cette méthode aux méthodes classiques a permis de montrer qu'elle était la plus adaptée aux séries temporelles très courtes avec un pas de temps irrégulier. Pour l'inférence de réseau dynamique, j'ai proposé un modèle qui prend en compte la variabilité intra-classe et qui intègre un terme constant décrivant explicitement la stimulation externe du système. L'évaluation de ces méthodes de classification et d'inférence a été effectuée sur des données de séries temporelles simulées et réelles, ce qui a permis d'établir la bonne qualité des performance en terme de précision, de rappel et d'erreur de prédiction. L'implémentation de ces méthodes a permis d'étudier le priming de la réponse immunitaire d'Arabidopsis thaliana par des ondes sonores répétées. Nous avons montré l'existence de la formation d'une mémoire transcriptionnelle associée aux stimulations qui fait passer la plante d'un état naïf à un état primé et plus résistant en 3 jours. Cet état résistant, entretenu d'une part par les stimulations et d'autre part par des cascades de facteurs de transcription, augmente la résistance immunitaire de la plante en déclenchant l'expression de gènes de résistance chez la plante saine, en diversifiant le nombre de gènes participant à la réponse immunitaire et en intensifiant l'expression de nombreux gènes de résistance. L'inférence du réseau décrivant la mémoire transcriptionnelle associée aux stimulations sonores répétées nous a permis d'identifier les propriétés qu'elle confère à la plante. Ces prédictions, validées expérimentalement, ont montré par exemple que l'augmentation de la cadence entre stimulations ne permettait pas d'obtenir un gain de résistance plus conséquent et que la mémoire transcriptionnelle ne dure que 1.5 jours après la dernière stimulation
Advancements in new sequencing technologies have paved the way for accessing dynamic gene expression data on a genome-wide scale. Classical ensemble approaches traditionally used in biology fall short of comprehending the underlying the complex molecular mechanisms. Consequently, developing analytical methods to understand further such data poses a significant challenge for current biology. However, the technical and experimental costs associated with transcriptomic data severely limit the dimension of real datasets and their analytical methods. Throughout my thesis, at the intersection of applied mathematics and plant biology, I focused on implementing an inference method for dynamic regulatory networks tailored to a real and original dataset describing the effect of repeated acoustic stimulations on genes expressions of Arabidopsis thaliana. I proposed a clustering method adapted to very-short time series that groups genes based on temporal variations, adjusting the data dimension for network inference. The comparison of this method with classical methods showed that it was the most suitable for very-short time series with irregular time points. For the network inference, I proposed a model that takes into account intra-class variability and integrates a constant term explicitly describing the external stimulation of the system. The evaluation of these classification and inference methods was conducted on simulated and real-time series data, which established their high performance in terms of accuracy, recall, and prediction error. The implementation of these methods to study the priming of the immune response of Arabidopsis thaliana through repeated sound waves. We demonstrated the formation of a transcriptional memory associated with stimulations, transitioning the plant from a naïve state to a primed and more resistant state within 3 days. This resistant state, maintained by stimulations and transcription factor cascades, enhances the plant's immune resistance by triggering the expression of resistance genes in healthy plants, diversifying the number of genes involved in the immune response, and intensifying the expression of numerous resistance genes. The inference of the network describing the transcriptional memory associated with repeated sound stimulations allowed us to identify the properties conferred to plants. Experimentally validated predictions showed that increasing the frequency between stimulations does not result in a more significant resistance gain, and the transcriptional memory lasts only 1.5 days after the last stimulation

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Sakamoto, Tetsu. "The tomato RLK superfamily: phylogeny and functional predictions about the role of the LRRII- RLK subfamily in antiviral defense". Universidade Federal de Viçosa, 2012. http://locus.ufv.br/handle/123456789/4804.

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Fundação de Amparo a Pesquisa do Estado de Minas Gerais
Receptores cinases (RLKs) compõem uma grande famíla de proteínas transmembrânicas que possuem funções importantes na propagação e percepção de sinais celulares nas plantas. Em Arabidopsis thaliana, a superfamília de RLK é composta de mais de 600 membros e vários destes, principalmente aqueles que possuem repetições ricas em leucina (LRR), são considerados excelentes alvos para manipulação molecular em cultivares superiores no intuito de aumentar a produtividade e a resistência contra estresses bióticos e abióticos. A subfamília LRRII é particularmente relevante neste aspecto uma vez que seus membros apresentam funções duplas tanto no desenvolvimento quanto na resposta de defesa da planta. Apesar da relevância desta superfamília e da recente finalização do sequenciamento do genoma de tomateiro, a superfamília de RLK de tomate ainda não se encontra caracterizada e são poucos os trabalhos que analisaram a função biológica de seus membros. Neste trabalho, foi construído um inventário completo dos membros da superfamília de RLK de tomate. Para identificar os membros da superfamília RLK em tomate, foi realizado uma análise filogenética utilizando a superfamília de RLK de Arabidopsis como modelo. Um total de 647 RLKs foram recuperados do genoma de tomate e estes encontravam- se organizados no mesmo clado das subfamílias de RLKs de Arabidopsis. Apenas oito das 58 subfamílias exibiram expansão/redução específica no número de menbros comparado com Arabidopsis e apenas seis RLKs foram específicos em tomate, indicando que os RLKs de tomate compartilham aspectos funcionais e estruturais com os RLKs de Arabidopsis. Também foi caracterizado a subfamília LRRII através de análises filogenéticos, genômico, expressão gênica e interação com o fator de virulência de begomovírus, o nuclear shuttle protein (NSP). Os membros da subfamília LRRII de tomate e Arabidopsis demonstraram-se altamente conservados tanto em sequência quanto em estrutura. No entanto, a maioria dos pares ortólogos não mostraram conservados em relação à expressão gênica, indicando que estes ortólogos tenham se divergido na função após a especiação do ancestral comum entre o tomate e Arabidopsis. Baseado no fato de que membros de RLKs de Arabidopsis (NIK1, NIK2, NIK3 e NsAK) interagem com o NSP de begomovirus, foi verificado se ortólogos de NIKs, BAK1 e NsAK interagem com o NSP de Tomato Yellow Spot Virus (ToYSV). Os ortólogos dos genes que interagem com o NSP em tomate, SlNIKs e SlNsAK, interagiram especificamente com NSP na levedura e demonstraram um padrão de expressão consistente com o padrão de infecção de geminivírus. Além de sugerir uma analogia funcional entre estes ortólogos, estes resultados confirmam a observação anterior de que as interações NSP-NIK não são específicos para um vírus ou para um hospedeiro. Portanto, a sinalização antiviral mediado por NIK provavelmente ocorre em tomate, sugerindo que NIKs de tomate sejam alvos potenciais para manipular a resistência contra begomovírus que infectam esta planta.
Receptor-like kinases (RLKs) represent a large family of transmembrane proteins that play important roles in cellular signaling perception and propagation in plants. In Arabidopsis thaliana, the RLK superfamily is made-up of over 600 proteins and many of these RLKs, mainly those bearing leucine-rich repeats (LRR), have been considered as excellent targets for engineering superior crops with enhancement of yield and resistance to biotic and abiotic stresses. The LRRII-RLK subfamily is particularly relevant due to the dual function of its members in both development and defense. In spite of the relevance of the RLK family and the completion of the tomato genome sequencing, the tomato RLK family has not been characterized and a framework for functional predictions of the members of the family is lacking. In this investigation we disclosed a complete inventory of the members of the tomato RLK family. To generate a complete list of all members of the tomato RLK superfamily, we performed a phylogenetic analysis using the Arabidopsis RLKs as a template. A total of 647 RLKs were identified in the tomato genome, which were organized into the same RLK subfamily clades as Arabidopsis. Only eight of 58 RLK subfamilies exhibited specific expansion/reduction compared to their Arabidopsis counterparts and only six proteins were lineage-specific in tomato, indicating that the tomato RLKs share functional and structural conservation with Arabidopsis. We also characterized the LRRII-RLK family by phylogeny, genomic analysis, expression profile and interaction with the virulence factor from begomoviruses, the nuclear shuttle protein (NSP). The LRRII subfamily members from tomato and Arabidopsis were highly conserved in both sequence and structure. Nevertheless, the majority of the orthologous pairs did not display similar conservation in the gene expression profile, indicating that these orthologs may have diverged in function after speciation of tomato and Arabidopsis common ancestor. Based on the fact that members of the Arabidopsis RLK superfamily (NIK1, NIK2, NIK3 and NsAK) interact with the begomovirus nuclear shuttle protein (NSP), we examined whether the tomato orthologs of NIK, BAK1 and NsAK genes interacted with NSP of Tomato Yellow Spot Virus (ToYSV). The tomato orthologs of NSP interactors, SlNIKs and SlNsAK, interacted specifically with NSP in yeast and displayed an expression pattern consistent with the pattern of geminivirus infection. In addition to suggesting a functional analogy between these phylogenetically classified orthologs, these results expand our previous observation that NSP-NIK interactions are neither virus-specific nor host-specific. Therefore, NIK-mediated antiviral signalling is also likely to operate in tomato, suggesting that tomato NIKs may be good targets for engineering resistance against tomato-infecting begomoviruses.

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Firetti-Leggieri, Fabiana. "Biossistematica das especies do complexo Anemopaegma arvense (Vell.) Stellf. ex de Souza (Bignoniaceae, Bignonieae) = aspectos anatomicos, citologicos, moleculares, morfologicos e reprodutivos". [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315193.

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Orientadores: João Semir, Lucia Garcez Lohmann
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O complexo Anemopaegma arvense é constituído por espécies e variedades de difícil delimitação. As opiniões dos taxonomistas, baseadas em caracteres morfológicos, são controversas em considerálas uma única espécie altamente polimórfica ou separá-las. Com o intuito de auxiliar na circunscrição de tais táxons, realizou-se um estudo biossistemático que englobou os seguintes assuntos: morfologia e morfometria de caracteres vegetativos e reprodutivos, anatomia da lâmina foliolar, contagem cromossômica, aplicação de marcadores AFLP para a delimitação genética, fenologia, biologia floral e polinização, sistema reprodutivo e hibridação e, poliembrionia em espécies do gênero com distintos níveis de ploidia. As morfoespécies do complexo diferem principalmente na morfologia foliar, sendo os táxons de Anemopaegma acutifolium caracterizados por folíolos elípticos a estreitamente oblanceolados com razão comprimento/largura do folíolo 3,5 a 18,5, os de A. arvense por folíolos lineares a estreitamente oblanceolados (razão 22,2 a 45,5) e, A. glaucum por folíolos largamente oblanceolados, oblongos a obovados (razão entre 1,69 e 3,9). A partir de caracteres morfológicos, como crescimento indeterminado dos ramos, exclui-se A. scabriusculum do complexo. O estudo morfométrico de caracteres foliares se mostrou útil para a separação das espécies. Já a morfometria de caracteres reprodutivos não foi informativa para a delimitação de tais táxons. Anatomicamente, as espécies e morfoespécies do complexo diferem quanto à disposição dos estômatos, tipo de epiderme constituição do sistema vascular da nervura mediana e composição da bainha dos feixes vasculares das nervuras laterais. Dentre as morfoespécies de A. acutifolium, A. acutifolium "típica" difere das demais por possuir folíolos anfiestomáticos e A. acutifolium "sarmentosa" por apresentar epiderme da face adaxial com desdobramentos pontuais. Já A. arvense é caracterizada pela ausência de cordões floemáticos no sistema vascular da nervura mediana e por possuir a margem destituída de parênquima fundamental subepidérmico. As morfoespécies de A. glaucum, "típica" da Bahia e "não glauca", são diferenciadas das demais pela ausência de calotas de fibras sobre o xilema nas nervuras laterais de grande e médio calibre. A. scabriusculum difere das outras espécies por possuir extensão de bainha nos feixes vasculares de grande e médio calibre e estômatos agrupados nas regiões internervurais com câmaras subestomáticas unidas. A contagem cromossômica revelou a condição poliplóide das espécies e morfoespécies do complexo, tendo estas 2n = 80. Os marcadores AFLP, apesar de serem bastante utilizados para a separação de táxons em nível infra-específico, não se mostraram eficientes para a delimitação das espécies do complexo Anemopaegma arvense. Quanto ao comportamento fenológico, A. acutifolium, A. arvense e A. glaucum apresentaram eventos anuais de brotamento, floração e frutificação. Já os indivíduos de A. scabriusculum têm dois a três eventos de floração e frutificação por ano. As flores das espécies são bastante semelhantes quanto à morfologia e recursos produzidos e são polinizadas pelas mesmas espécies de abelhas. Através de polinizações controladas constatou-se que tais espécies são auto-compatíveis e interférteis, havendo, portanto, alta probabilidade de formação de híbridos em populações simpátricas destas espécies. Notou-se uma relação positiva entre poliploidia e poliembrionia nas espécies do gênero aqui abordadas, tendo as sementes das espécies poliplóides mais de um embrião e as da espécie diplóide, A. album, somente um embrião.
Abstract: Anemopaegma arvense complex is constituted by species and varieties of difficult delimiting. Taxonomists opinions based upon morphologic features are controversial as to considering them either an only highly polymorphic species or separating them into different taxa. In order to help with the circumscription of such taxa, a biosystematic study was conducted which included the following subjects: morphology and morphometry of vegetative and reproductive features, leaflet blade anatomy, chromosome counting, AFLP markers application for genetic delimitation, phenology , floral biology and pollination, reproductive system and hybridization and polyembryony of the genus species with different ploidy levels .The morphs of the complex differ mainly in leaf morphology where the Anemopaegma acutifolium taxa are characterized by elliptical leaflets with the lengh / width ratio of leaflet falling within the range 3,5 to 18,5; A. arvense characterized by linear leaflets to narrowly oblanceolate (ratio between 22,2 and 45,5) and, A. glaucum by leaflets broadly oblanceolate, from oblong to obovate (ratio between 1,69 and 3,9).Taking into account morphologic features such as undetermined growth of the branches, A. scabriusculum may be excluded off the complex. The morphometric study of the leaf features has been found useful for species separation. However, the morphometry of reproductive features were not informative enough for the delimitation of such taxa. Anatomically, the species and morphs of the complex differ from one another as to the stomata disposition, epidermis type, vascular system constitution of the midrib and, composition of the vascular bundle of the lateral veins. Among the A. acutifolium morphs, A. acutifolium "típica" differs from the others for possessing anphistomatic leaflets and, A. acutifolium "sarmentosa" for presenting the adaxial face epidermis with punctual unfoldings. As for A. arvense, it is characterized by the absence of phloematic strings in the midrib vascular system and parenchyma absent in the marginal region. As for the two morphs, A. glaucum "típica" of Bahia and "não glauca", they are differentiated from the others by the absence of fibers caps on the xilem on the lateral ribs of large and medium caliber. A. scabriusculum differs from the other species for possessing extension sheath in the vascular bundles of large and medium caliber and, stomata grouped between vascular bundles presenting substomatic cameras linked to one another. The chromosome counting revealed polyploidy condition of the species and the morphs of the complex, those presenting 2n = 80. The AFLP markers, in spite of being quite utilized for taxa separation in an infraspecific level, were not found efficient for the species delimitation of Anemopaegma arvense complex. With relation to the phenologic behavior, A. acutifolium, A. arvense and A. glaucum presented annual events of sprouting, blooming and fructification. However, A. scabriusculumindividuals presented two to three blooming and fructification events a year. The flowers of the species are very similar to one another as to their morphology and to the resources provided by them and are pollinated by the same species of bees. Through controlled pollinations, it could be verified, that such species are self- ompatible and inter fertile, bearing, therefore, high probability of hybrid formation in sympatric populations of those species. A positive relationship between polyploidy and polyembryony in the species of the genus studied here was observed, as well as the fact that more than one embryo were found for polyploidy species seeds whereas for diploid species, A. album, only one embryo has been registered.
Doutorado
Doutor em Biologia Vegetal

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Brickman, Jacklyn E. "Experiments in Biological Planet Formation and Plants: Nourishing Bodies, Nourishing Planets". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595340630648528.

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Carvalho, Paula Andréa Sampaio de Vasconcelos [UNESP]. "Concentração de resveratrol e expressão de resveratrol sintase em espécies de Arichis". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/108549.

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O resveratrol é uma fitoalexina produzida em função de estresses bióticos e abióticos e foi encontrado em um número limitado de espécies de plantas, incluindo o amendoim (Arachis hypogaea) e seus parentes silvestres. Este tem também propriedades antioxidantes e em função disso é um promissor antitumoral, cardioprotetor e neuroprotetor. O amendoim é um alotetraploide de constituição genômica AB sendo A. ipaënsis e A. duranensis os doadores de seus genomas B e A, respectivamente. Estudos prévios demonstraram que algumas espécies silvestres do gênero Arachis produzem resveratrol e que ampla variabilidade genética para diferentes características existe entre acessos das espécies silvestres, incluindo ampla variação nos níveis de resistência a doenças fúngicas e nematoides. Portanto, a avaliação de um maior número do gênero e a investigação da variação da produção de resveratrol também entre acessos é fundamental para uma exploração mais adequada das espécies silvestres do gênero Arachis. O melhor entendimento das causas da variação na produção de resveratrol sem dúvida contribuirá para o uso das mesmas e o primeiro passo para esse entendimento sem duvida passa pela identificação do padrão de expressão da resveratrol sintase (RS). Este trabalho tem como objetivos avaliar a variação na produção de resveratrol entre espécies (A. hypogaea, A. stenosperma, A. valida, A. wiliamsii, A. duranensis, A. ipaënsis e um anfidiploide sintético proveniente do cruzamento artificial entre A. duranensis e A. ipaënsis) e entre acessos de duas espécies(A. hypogaea e A. stenosperma) por meio de HPLC e avaliar a expressão relativa da resveratrol sintase por meio de RT-qPCR em A. hypogaea, A. duranensis, A. ipaënsis e um anfidiploide sintético. Folhas foram coletadas de plantas cultivadas em casa de vegetação para os grupos teste e controle e três repetições biológicas ...
Resveratrol is a phytoalexin produced under biotic and abiotic stresses. It has been found in a restricted number of plant species including peanut (Arachis hypogaea) and its wild relatives. This phytochemical has antioxidant properties, being considered a promising antitumour, cardioprotective and neuroprotective agent. Peanut is an allotetraploid specie with an AABB genomic constitution. Arachis ipaënsis and A. duranensis are the donors of the B genome and the A genome, respectively. Previous studies have shown that wild species of the genus Arachis can produce resveratrol. Therefore, the evaluation of other species of thus genus and the analysis of the variation in the production of resveratrol between accessions is essential for better exploitation of wild species in the genus Arachis. It also important the understanding of the variation in resveratrol concentration between species and accessions and that could be reached through the better understating of the role resveratrol synthase.. . The aims of this work were to evaluate the variation in resveratrol production between species (A. hypogaea, A. stenosperma, A. valida, A. wiliamsii, A. duranensis, A. ipaënsis and in a synthetic amphidiploid derived from these two wild species A. duranensis and A. ipaënsis) and between accessions of the same specie (A. hypogaea and A. stenosperma) through HPLC, and to quantify the expression of resveratrol synthase by RT-qPCR in A. hypogaea, A. duranensis, A. ipaënsis and in a synthetic amphidiploid. Leaves for the test and control groups were collected from plants cultivated in a greenhouse and three biological replicates were evaluated for each specie. The synthesis of resveratrol in leaves was induced by treatment with UV for 2 hours and thirty minutes and then the difference in the concentration of resveratrol between species and between the accessions and cultivars of the same species was analyzed. We found new ...

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Carvalho, Paula Andréa Sampaio de Vasconcelos. "Concentração de resveratrol e expressão de resveratrol sintase em espécies de Arichis /". Botucatu, 2013. http://hdl.handle.net/11449/108549.

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Orientador: Marcos Aparecido Gimenes
Coorientador: Tânia da Silveira Agostini Costa
Coorientador: Ana Cristina Miranda Brasileiro
Banca: Marcia Ortiz Mayo Marques
Banca: Edvaldo Aparecido Amaral da Silva
Resumo: O resveratrol é uma fitoalexina produzida em função de estresses bióticos e abióticos e foi encontrado em um número limitado de espécies de plantas, incluindo o amendoim (Arachis hypogaea) e seus parentes silvestres. Este tem também propriedades antioxidantes e em função disso é um promissor antitumoral, cardioprotetor e neuroprotetor. O amendoim é um alotetraploide de constituição genômica AB sendo A. ipaënsis e A. duranensis os doadores de seus genomas B e A, respectivamente. Estudos prévios demonstraram que algumas espécies silvestres do gênero Arachis produzem resveratrol e que ampla variabilidade genética para diferentes características existe entre acessos das espécies silvestres, incluindo ampla variação nos níveis de resistência a doenças fúngicas e nematoides. Portanto, a avaliação de um maior número do gênero e a investigação da variação da produção de resveratrol também entre acessos é fundamental para uma exploração mais adequada das espécies silvestres do gênero Arachis. O melhor entendimento das causas da variação na produção de resveratrol sem dúvida contribuirá para o uso das mesmas e o primeiro passo para esse entendimento sem duvida passa pela identificação do padrão de expressão da resveratrol sintase (RS). Este trabalho tem como objetivos avaliar a variação na produção de resveratrol entre espécies (A. hypogaea, A. stenosperma, A. valida, A. wiliamsii, A. duranensis, A. ipaënsis e um anfidiploide sintético proveniente do cruzamento artificial entre A. duranensis e A. ipaënsis) e entre acessos de duas espécies(A. hypogaea e A. stenosperma) por meio de HPLC e avaliar a expressão relativa da resveratrol sintase por meio de RT-qPCR em A. hypogaea, A. duranensis, A. ipaënsis e um anfidiploide sintético. Folhas foram coletadas de plantas cultivadas em casa de vegetação para os grupos teste e controle e três repetições biológicas ...
Abstract: Resveratrol is a phytoalexin produced under biotic and abiotic stresses. It has been found in a restricted number of plant species including peanut (Arachis hypogaea) and its wild relatives. This phytochemical has antioxidant properties, being considered a promising antitumour, cardioprotective and neuroprotective agent. Peanut is an allotetraploid specie with an AABB genomic constitution. Arachis ipaënsis and A. duranensis are the donors of the B genome and the A genome, respectively. Previous studies have shown that wild species of the genus Arachis can produce resveratrol. Therefore, the evaluation of other species of thus genus and the analysis of the variation in the production of resveratrol between accessions is essential for better exploitation of wild species in the genus Arachis. It also important the understanding of the variation in resveratrol concentration between species and accessions and that could be reached through the better understating of the role resveratrol synthase.. . The aims of this work were to evaluate the variation in resveratrol production between species (A. hypogaea, A. stenosperma, A. valida, A. wiliamsii, A. duranensis, A. ipaënsis and in a synthetic amphidiploid derived from these two wild species A. duranensis and A. ipaënsis) and between accessions of the same specie (A. hypogaea and A. stenosperma) through HPLC, and to quantify the expression of resveratrol synthase by RT-qPCR in A. hypogaea, A. duranensis, A. ipaënsis and in a synthetic amphidiploid. Leaves for the test and control groups were collected from plants cultivated in a greenhouse and three biological replicates were evaluated for each specie. The synthesis of resveratrol in leaves was induced by treatment with UV for 2 hours and thirty minutes and then the difference in the concentration of resveratrol between species and between the accessions and cultivars of the same species was analyzed. We found new ...
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8

Jin, Xin. "Isoprenoid and flavonoid biosynthesis and regulation in higher plants". Doctoral thesis, Universitat de Lleida, 2019. http://hdl.handle.net/10803/667579.

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Aquesta tesi es centra principalment en l'anàlisi funcional i la caracterització dels gens que codifiquen per a alguns metabòlits secundaris i en l’estudi de la seva regulació en les plantes. Els objectius generals varen ser (a) entendre millor la regulació transcripcional del gen de la biosíntesi dels carotenoids, la β-carotè hidroxilasa 2 (BCH2) en el blat de moro i (b) l'anàlisi funcional de les dues isopentenil difosfat isomerasas (OsIPPI) d'arròs i determinar la seva localització subcel·lular. Simultàniament, es va estudiar com la llum afecta la via metabòlica i a la producció de pelargonidina en l'arròs; es van identificar també els gens essencials de la seva biosíntesi en Gentiana lutea L. var. aurantiaca. Les plantes de blat de moro i arròs es varen transformar amb els gens dels factors de transcripció ZmMYB i ZmPBF. Es va analitzar l’expressió gènica transitòria i es va realitzar transformació estable. Els resultats obtinguts indiquen que tant ZmPBF com ZmGAMYB poden transactivar l'expressió de ZmBCH2 a l’endosperm del blat de moro, i ZmPBF i ZmGAMYB transactiven independentment el promotor de ZmBCH2 en arròs. Els dos paràlegs de IPPI (OsIPPI1 i OsIPPI2) aïllats prèviament en arròs varen tenir un patró d'expressió diferent; l'ARNm de OsIPPI1 va ser més abundant que l'ARNm de OsIPPI2 en tots els teixits. Es va usar la microscòpia de fluorescència confocal i microscòpia inmunoelectrónica per determinar la localització de les dues proteïnes. Aquestes es localitzen en el reticle endoplasmàtic (RE), així com en els peroxisomes i les mitocòndries, mentre que només es va detectar OsIPPI2 en els plastidis. La detecció d'ambdues isoformes en el RE indica que DMAPP es pot sintetitzar de novo en aquest compartiment. Diferents tècniques com UPLC, GC-MS i qRT-PCR també es varen utilitzar per perfilar els metabòlits primaris i secundaris i l'expressió gènica relacionada en plàntules d'arròs des-etioladas. Els resultats varen revelar que el metabolisme primari i secundari i els gens corresponents estan regulats per la llum, especialment en la biosíntesi d'isoprenoides en fulles d'arròs. Onze derivats de pelargonidina es varen identificar en els pètals de G. lutea i es varen perfilar els gens de la seva via de biosíntesi, revelant que DFR, ANS i 3GT afecten principalment a l'acumulació dels glucòsids de pelargonidina. Tots aquests resultats suggereixen la idea que la biosíntesi dels carotenoids en plantes superiors és regulada a diferents nivells.
Esta tesis se centra principalmente en el análisis funcional y en la caracterización de los genes que codifican para algunos metabolitos secundarios y en el estudio de su regulación en las plantas. Los objetivos generales fueron (a) profundizar en el conocimiento de la regulación transcripcional del gen de la biosíntesis de los carotenoides, la β-caroteno hidroxilasa 2 (BCH2) en el maíz, y (b) analizar la función de las dos isopentenil difosfato isomerasas (OsIPPI) de arroz, determinando además su localización subcelular. Simultáneamente, se estudió cómo la luz afecta a la vía metabólica y a la producción de pelargonidina en el arroz; se identificaron también los genes esenciales de su biosíntesis en Gentiana lutea L. var. aurantiaca. Las plantas de maíz y arroz se transformaron con los genes de los factores de transcripción ZmMYB y ZmPBF. Se analizó la expresión génica transitoria y se realizó transformación estable. Los resultados obtenidos indicaron que tanto ZmPBF como ZmGAMYB pueden transactivar la expresión de ZmBCH2 en endospermo de maíz, y ZmPBF y ZmGAMYB transactivar independientemente el promotor de ZmBCH2 en arroz. Los dos parálogos de IPPI (OsIPPI1 y OsIPPI2) aislados previamente en arroz tuvieron un patrón de expresión diferente; el ARNm de OsIPPI1 fue más abundante que el ARNm de OsIPPI2 en todos los tejidos. Se usó la microscopía de fluorescencia confocal y microscopía inmunoelectrónica para determinar la localización de ambas proteínas. Estas se localizan en el retículo endoplásmico (RE), así como en los peroxisomas y las mitocondrias, mientras que solo se detectó OsIPPI2 en los plastidios. La detección de ambas isoformas en el RE indica que DMAPP se puede sintetizar de novo en este compartimiento. Diferentes técnicas como UPLC, GC-MS y qRT-PCR también se utilizaron para perfilar los metabolitos primarios y secundarios y la expresión génica en plántulas de arroz des-etioladas. Los resultados revelaron que los genes involucrados en la en el metabolismo primario y secundario están regulados por la luz, especialmente en la biosíntesis de isoprenoides en hojas de arroz. Once derivados de pelargonidina se identificaron en los pétalos de G. lutea y se perfilaron los genes de la vía de biosíntesis, revelando que DFR, ANS y 3GT afectan principalmente a la acumulación de los glucósidos de pelargonidina. Todos estos resultados contribuyen al conocimiento, a diferentes niveles, de la regulación de las rutas biosinteticas de los carotenoides en plantas superiores.
This thesis mainly focuses on functional analysis and characterization of a number of secondary metabolite biosynthetic genes and the regulation of the corresponding secondary metabolite biosynthetic pathway in plants. The overall aims were to elucidate the transcriptional regulation of β-carotene hydroxylase 2 gene (BCH2) in maize, the functional analysis of rice isopentenyl diphosphate isomerases (OsIPPI), and determine their subcellular localization. Simultaneously, the influence of light on the metabolic pathway in rice was studied and the pelargonidin quantification and essential pelargonidin biosynthesis genes in Gentiana lutea L. var. aurantiaca were identified. Maize and rice plants were transformed with transcription factor genes ZmMYB and ZmPBF, via transient gene expression and stable transformation respectively. The results indicated that both ZmPBF and ZmGAMYB can transactivate ZmBCH2 expression in maize endosperm and ZmPBF and ZmGAMYB independently transactivate the ZmBCH2 promoter in rice. The two IPPI paralogs (OsIPPI1 and OsIPPI2) isolated previously in rice had a different expression pattern; OsIPPI1 mRNA was more abundant than OsIPPI2 mRNA in all tissues. Confocal fluorescence microscopy and immuno-electron microscopy were used to determine the localization of both proteins. These localized to the endoplasmic reticulum (ER) as well as peroxisomes and mitochondria, whereas only OsIPPI2 was detected in plastids. The detection of both isoforms in the ER indicates that DMAPP can be synthesized de novo in this compartment. UPLC, GC-MS and qRT-PCR were used to profile the primary and secondary metabolites and gene expression in de-etioleted rice seedlings. The results revealed both primary and secondary metabolism and the corresponding genes are regulated by light, especially isoprenoids biosynthesis in rice leaves. Eleven pelargonidin derivatives were identified in the petals of G. lutea and the biosynthetic pathway genes were profiled, revealing DFR, ANS and 3GT mainly affect the accumulation of pelargonidin glucosides. Collectively my results provide novel insights of the regulation of carotenoid and flavonoid biosynthesis in higher plants at different levels.

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Smith, Madeleine Joy. "The biology and molecular biology of Polymyxa species and their interactions with plants and viruses". Thesis, University of Warwick, 2008. http://wrap.warwick.ac.uk/3792/.

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Polymyxa graminis and Polymyxa betae are obligate, intracellular, root-infecting organisms of cereals (P. graminis) and members of the Chenopodiacae (P. betae). Between the two species, they transmit approximately 15 economically important plant viruses. These include Soil-borne cereal mosaic virus, Barley yellow mosaic virus and Beet necrotic yellow vein virus and together, cover a world-wide distribution. Recent ribosomal DNA (rDNA) sequence data has shown that temperate isolates of P. graminis belong to two groups or ‘ribotypes’ based on sequence differences in the internal transcribed spacer region. P. betae sequences belong to a third group. These ribotypes appear to differ in host range and ability to transmit viruses. It has been suggested that particular ribotypes have different host specificities or preferences and are involved in the transmission of specific viruses. There were three major areas of work. Firstly the determination of host-virusribotype associations. One approach was to inoculate plants containing virus with specific ribotypes and monitor onward transmission of the virus to a susceptible host. Another approach used plants grown in infested soils to bait any Polymyxa present, then plants were tested for the Polymyxa ribotypes and viruses present. This work confirmed the association between ribotype II and SBCMV and SBWMV, using viruses from a wider range of geographic locations. It also identified a previously unknown role for transmission of Furoviruses by P. graminis ribotype I. Examination of the phylogenetic relationships of Polymyxa ribotypes using rDNA sequences revealed two new ribotype groups. Whilst ribotype groups II, IV and V always form a clade together, the relationship of the other P. graminis ribotypes and P. betae is still not well resolved. Finally, for the first time, infection of Arabidopsis by Polymyxa (P. betae and P. graminis) was demonstrated, showing that this model system could be used to study Polymyxa-host interactions.

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Almeida, Juliana Dantas de. "Origem, evolução e direcionamento da proteína THI1 em plantas". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11137/tde-03082004-152655/.

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THI1 é provavelmente uma proteína bifuncional, uma vez que está envolvida na biossíntese de tiamina e na estabilidade do DNA organelar, notadamente o mitocondrial. Interessantemente, a biossíntese de tiamina ocorre em compartimentos distintos em plantas (cloroplastos) e em leveduras (mitocôndrias). Ensaios de complementação funcional mostraram que o gene thi1 de Arabidopsis thaliana é capaz de complementar uma cepa mutante de levedura para o gene ortólogo. A proteína THI1 de Arabidopsis thaliana é codificada por um único gene. Uma análise detalhada da região N-terminal da proteína, responsável pela sua localização na células, revelou a presença de duas sequências de direcionamento adjacentes. Na extremidade N-terminal encontra-se um peptídeo de trânsito cloroplástico seguida por uma região capaz de formar uma α-hélice anfifílica, tipicamente encontrada em pré-sequências de direcionamento mitocondriais. Com o objetivo de avaliar se a localização final de THI1 pode apresentar um tipo de regulação temporal ou espacial, foram obtidas plantas transgênicas expressando a proteína THI1 fundida a GFP ("green fluorescent protein"). Análises dessas plantas por meio de microscopia confocal revelaram que THI1 está presente majoritariamente em cloroplastos e raramente em mitocôndrias. Ao contrário do que acontece em Arabidopsis thaliana, em cana de açúcar foram encontrados pelo menos três isoformas/parálogos de thi1. O alinhamento da seqüência de aminoácidos dessas isoformas com a THI1 de Arabidopsis thaliana revelou alta similaridade, inclusive na seqüência de direcionamento. Com o intuito de avaliar o padrão de direcionamento dessas isoformas de cana de açúcar foram obtidas construções gênicas contendo ou a seqüência de direcionamento completa ou o peptídeo de trânsito cloroplástico ou a pré-seqüência mitocondrial, fundidas a GFP sob o comando do promotor 35S. A expressão transiente dessas construções em epiderme de cebola, revelou que no caso das construções contendo a seqüência de direcionamento completa ou o peptídeo de trânsito, o direcionamento ocorreu apenas para os cloroplastos. No caso das construções contendo somente a seqüência de direcionamento mitocondrial a GFP permaneceu difundida no citoplasma. Além do aspecto do direcionamento, THI1 foi avaliada sob o ponto de vista filogenético. As análises filogenéticas mostram que thi1 é raramente encontrado em bactérias mas é amplamente distribuído em Archaea. As distâncias genéticas indicam que provavelmente os eucariontes herdaram thi1 de Archaea. As poucas bactérias que possuem esse gene provavelmente obtiveram-no por meio de herança horizontal.
THI1 is probably a bifunctional protein, since it is involved in thiamin biosynthesis and organelar genome stability mainly the mitochondrial. Interestingly, the thiamin biosynthesis occurs at different compartments in plants (chloroplasts) and yeasts (mitochondria). Functional complementation assays showed that Arabidopsis thaliana thi1 gene is able to complement a yeast mutant strain for the hortolog gene. The Arabidopsis thaliana THI1 is encoded by a single copy gene. A detailed analysis of the THI1 N-terminal region, that is responsible for its targeting in cells, reveled the presence of two in tanden directing sequences. At N-terminal region there is a chloroplastic transit peptide followed by a region able to form an anfifilic α-helix frequently present in mitochondrial presequences. Aiming to evaluate if the THI1 final localization could present a temporal or spacial regulation, transgenic plants expressing THI1 fused to GFP ("green fluorescent protein") where obtained. Confocal microscopy analysis of these transgenic plants showed that THI1 is mainly found in chloroplasts and barely found in mitochondrias. Different from what happens in Arabidopsis thaliana, in sugar cane where founded at least three thi1 isoforms/paralogs. The amino acids sequence alignment of these isoforms with the thi1 one, reveled high similarity including the targeting sequence. To evaluate the directing standard of these sugarcane isoforms, gene constructions made by the complete targeting sequence or the chloroplastic transit peptide or the mitochondrial presequence, fused to GFP under the guidance of 35S promotor, where obtained. A transient expression of these gene constructios in epidermal onion cells prove that in the case of the constructions containing either the complete targeting sequence or the chloroplastic transit peptide the directing occurred only to chloroplasts. On the other hand, the constructions containing the mitochondrial pre sequence, GFP were kept defused in the citoplasm. Besides the directing aspect, THI1 were evaluated under the filogenetic point of view. Filogenetic analysis showed that thi1 is rarely found in bacteria but is widely distributed in Archaea. The genetic distances pointed out that probably eucaryotes THI1 came from Archaea. This gene in a few bacterias probably were inherited by lateral transference.

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Amaral, Ingrid. "Biologia e tabela de vida de Brevipalpus yothersi (Acari: Tenuipalpidae) oriundos de diferentes regiões citrícolas do Estado de São Paulo /". Jaboticabal, 2016. http://hdl.handle.net/11449/137926.

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Orientador: Daniel Junior de Andrade
Banca: Marineide Rosa Vieira
Banca: Renato Beozzo Bassanezi
Resumo: O ácaro Brevipalpus yothersi Baker é vetor da leprose dos citros, principal doença viral da citricultura mundial. Informações sobre a biologia de B. yothersi são essenciais para compreender a dinâmica populacional do ácaro no campo e inferir se mudanças no manejo do pomar em função da região pode alterar a biologia do ácaro. O objetivo do trabalho foi determinar a biologia e elaborar a tabela de vida de fertilidade de B. yothersi coletados em diferentes regiões citrícolas do estado de São Paulo. Os experimentos foram realizados no Laboratório de Acarologia, pertencente à Faculdade de Ciências Agrárias e Veterinárias - FCAV/UNESP, Jaboticabal - SP. Os ácaros foram coletados em pomares cítricos das regiões de Barretos, Jales e Santa Cruz do Rio Pardo, posteriormente, em laboratório, foram multiplicados em frutos de laranja. Os parâmetros biológicos avaliados foram duração das fases de desenvolvimento, oviposição, período de incubação, viabilidade dos ovos, longevidade, taxa líquida de reprodução (Ro), tempo médio de geração (T), taxa intrínseca de crescimento populacional (rm) e taxa finita de crescimento populacional (λ). Estes parâmetros foram avaliados em dois experimentos, o primeiro consistiu na biologia de B. yothersi em frutos isentos de resíduos de produtos fitossanitários à 23±1ºC e o segundo sob frutos com resíduo de espirodiclofeno à 25±1ºC. As observações foram realizadas diariamente, pela manhã e ao fim da tarde. A duração do desenvolvimento, longevidade, período d... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The mite Brevipalpus yothersi Baker is the vector of the citrus leprosis, major viral disease of citrus worldwide. Information about B. yothersi's biology are essential to understanding the population dynamics of the mite in the field and infer whether changes in orchard management by region can change the mite biology. The objective was to determine the biology and prepare the fertility life table of B. yothersi collected in different citrus regions of São Paulo state. The experiments were performed in Acarology Laboratory, belonging to the Faculty of Agricultural and Veterinary Sciences - FCAV/UNESP, Jaboticabal - SP. The mites were collected in citrus orchards in the regions of Barretos, Jales and Santa Cruz do Rio Pardo, later in the laboratory were multiplied in orange fruits. The biological parameters assessed were duration of the stages of development, oviposition, incubation period, egg viability, longevity, net reproductive rate (Ro), mean generation time (T), intrinsic rate of increase (rm) and finite rate increase (λ). These parameters were evaluated in two experiments, the first consisted the biology of B. yothersi in fruits free of residues of pesticides at 23 ± 1°C and the second consisting of the biology of B. yothersi under fruit with spirodiclofen residue at 25 ± 1°C . The observations were performed daily, in the morning and in the afternoon. The duration of the development, longevity, pre-oviposition period, oviposition rate and number of B. yothersi eggs s... (Complete abstract click electronic access below)
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12

Runguphan, Weerawat. "Reprogramming alkaloid biosynthesis in Catharanthus roseus : synthetic biology in plants". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65274.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011.
Vita. Cataloged from PDF version of thesis.
Includes bibliographical references.
The medicinal plant Madagascar periwinkle (Catharanthus roseus) produces over 130 monoterpene indole alkaloid (MIA) natural products. Many of these compounds have pharmaceutical value, such as the anticancer agents vinblastine and vincristine. Unnatural modifications can impart novel bioactivity to the parent natural product. Advances in synthetic biology and microbial engineering have allowed overproduction of natural products and their analogs in non-native organisms such as yeast and E. coli. However, re-engineering of plant pathways to yield "novel" products has been limited, particularly when compared to the successes achieved in prokaryotic systems. This thesis describes several strategies to re-engineer MIA biosynthesis in periwinkle to produce novel alkaloids. The first strategy involves the introduction of a biosynthetic enzyme with redesigned substrate specificity into periwinkle. The resulting transgenic plant culture produces a variety of unnatural alkaloid compounds when co-cultured with precursors that the re-engineered enzyme has been designed to accept. The second strategy improves upon this work by enabling periwinkle to autonomously synthesize precursor analogs in situ. Specifically, the prokaryotic halogenation machinery was introduced into the genome of periwinkle, which lacks the biosynthetic ability to produce halogenated compounds. These halogenases function within the context of the plant cell to generate halogenated precursor, which is then shuttled into MIA metabolism to yield halogenated alkaloids. Altogether, a new functional group-an organohalide-was introduced into plant secondary metabolism in a regioselective and predictable manner. The third strategy involves RNAi-mediated suppression of MIA biosynthesis in periwinkle. Alkaloid production was obliterated in the resulting transgenic plant culture. The silenced plant culture produces a variety of fluorinated alkaloids when co-cultured with fluorinated starting substrate. The yields of some unnatural alkaloids were improved since the natural precursor was absent. Finally, the fourth strategy describes chemical functionalization of halogenated MIAs. Postbiosynthetic chemical derivatizations of halogenated MIAs using palladium-catalyzed Suzuki-Miyaura cross-coupling reactions robustly afforded aryl and heteroaryl analogs of MIAs. Altogether, the work described in this thesis demonstrates the versatility of medicinal plants in the generation of unnatural alkaloids. Thus, despite their genetic complexity, plants are a viable platform for synthetic biology efforts.
by Weerawat Runguphan.
Ph.D.

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13

Ohlsson, Åse. "Do plants change their defence strategy from a structural defence to a chemical one as a response to heavier herbivory?" Thesis, Södertörn University College, School of Life Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-310.

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To the main part, this paper is the result of a literature survey and to the minor part of a field survey. The study is found on the question of, if and why unpalatable plant species invade heavily grassed rangelands and if plants change their defence strategy from a mechanical defence to a chemical defence if the herbivory pressure increase. I conclude that defended plants do invade heavily grassed rangelands if the rangelands lose essential recourses (often nutrients) and/or the defended plants are strongly avoided by mammalian herbivores. I also conclude that plants do go from a mechanical defence strategy to a chemical strategy if their environment loses essential recourses under a threshold. This firstly depends on that mechanical defended plants can not develop a complete defence if they suffer from a shortage in the nutrient supply, and secondly of that plants in resources rich environments often have lager possibilities of responding to herbivory with regrowth. They do not therefore have to defend them self as hard as plants in environments with low supply of recourses.

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Filipski, Jules. "Reproductive biology of the endangered plant, Phlox hirsuta (E.E. Nelson)". View full-text version online, 2005. http://soda.sou.edu/awdata/060221b1.pdf.

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Thesis (M.S.) --Southern Oregon University, 2005.
"A thesis submitted to the Department of Biology and the Graduate School of Southern Oregon University in partial fulfillment of the requirements for the degree of Master of Science in Science." Includes bibliographical references (p. 69-75) Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.

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Albrecht, Matthew A. "Reproductive Biology of Medicinal Woodland Herbs Indigenous to the Appalachians". Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1163427974.

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16

Jobson, Richard William. "Molecular phylogenetics and evolutionary processes in the carnivorous plant family Lentibulariaceae (Asteridae:Lamiales) /". [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16812.pdf.

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17

Fank-de-Carvalho, Suzane Margaret. "Contribuição ao conhecimento da anatomia, micromorfologia e ultraestrutura foliar de Amaranthaceae do Cerrado". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317998.

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Orientador: Sonia Nair Bao
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A família Amaranthaceae no sensu lato, incluindo Chenopodiaceae, é formada por cerca de 2.360 espécies, 145 delas encontradas no Brasil; 94 espécies subsistem em diversas fitofisionomias do Bioma Cerrado, 71 são endêmicas de diferentes regiões e biomas brasileiros e 27 aparecem em listas regionais de espécies ameaçadas de extinção. Visando contribuir para o conhecimento das espécies dessa família, foram estudados aspectos ecológicos, micromorfológicos, anatômicos e ultraestruturais de folhas de Amaranthaceae nativas do Brasil, com ênfase nos gêneros Alternanthera, Gomphrena, Froelichiella, Hebanthe e Pfaffia. As espécies nativas de regiões abertas de cerrado apresentam adaptações que favorecem a sobrevivência em condições adversas (seca e fogo), tais como raízes tuberosas ou lenhosas e xilopódios, hábito herbáceo e/ou subarbustivo, pilosidade densa nas porções aéreas, senescência de ramos aéreos durante as fases mais secas, dependência de fogo ou chuva para rebrotação e/ou floração, frutificação rápida seguida de dispersão anemocórica, epidermes com cutículas bem desenvolvidas e metabolismo fotossintético C4. O comportamento pirofítico das espécies favorece o estabelecimento pioneiro das mesmas, principalmente nas áreas abertas do Cerrado. As superfícies foliares de algumas espécies do gênero Gomphrena apresentam cristais de cera epicuticular do tipo plaquetas, orientadas paralelamente, aspecto anteriormente descrito apenas em espécies de Chenopodiaceae. Em duas espécies foram encontrados fungos Ascomyceto colonizando folhas, cujos aspectos ultraestruturais foram descritos. A anatomia Kranz foi caracterizada em seis espécies do gênero Gomphrena, que também possuem cloroplastos dimórficos, demonstrando estrutura foliar compatível com o metabolismo fotossintético C4. Na análise das duas espécies do gênero Alternanthera (uma C3 e outra intermediária C3-C4) verificou-se que a posição das organelas nas células da bainha pode ser um elemento chave na determinação do tipo metabólico. As espécies de Froelichiella, Hebanthe e Pfaffia possuem anatomia e ultraestrutura compatíveis com o metabolismo C3. A anatomia foliar e a ultraestrutura das espécies estudadas apresentam um padrão já descrito para outras espécies da família Amaranthaceae, exceto para os gêneros Hebanthe e Froelichiella, cuja descrição anatômica e ultraestrutural foi realizada pela primeira vez. A evolução do metabolismo C4 pode estar relacionada, pelo menos em parte, ao desenvolvimento da anfiestomia associada à maior espessura do limbo foliar em espécies herbáceas. Plastoglóbulos bem desenvolvido foram encontrados em cloroplastos de algumas das espécies do Cerrado e parecem associados aos mecanismos de defesa, além do metabolismo de lipídios. A família Amaranthaceae pode ser um bom marcador da biodiversidade de dicotiledôneas de pequeno porte e da capacidade de regeneração das áreas de campos rupestres, campos úmidos e outros tipos de vegetação aberta dos cerrados. A riqueza de informações obtidas durante o estudo de espécies dessa família ilustram a importância da ampliação das pesquisas básicas e aplicadas em suas espécies, especialmente as que ocorrem naturalmente no Cerrado. A ampliação do conhecimento relativo à anatomia e à especialização das organelas de diferentes gêneros para o metabolismo fotossintético pode contribuir para o entendimento da evolução da via C4 e do ambiente onde as plantas se especializaram. O estudo do Bioma Cerrado pretende ampliar as justificativas para esforços de preservação de sua biodiversidade.
Abstract: The Amaranthaceae family sensu lato, including Chenopodiaceae, is comprised of approximately 2,360 species, 145 of them found in Brazil. 94 species exist in various vegetation types of the Cerrado, 71 are endemic to different regions and Brazilian biomes, and 27 appear in regional lists of endangered species. To contribute to the knowledge of this family species the ecological aspects, micromorphology, anatomy and ultrastructure of leaves of brazilian Amaranthaceae were studied, with emphasis on the genera Alternanthera, Gomphrena, Froelichiella, Hebanthe and Pfaffia. The native species of open areas of Cerrado (a savannah-like vegetation) exhibit adaptations that promote survival in adverse conditions (drought and fire), such as tuberous or woody roots, xylopodium, herbaceous or subshrub habit, dense pubescence in aerial portions, senescence of shoots and leaves during the driest season, dependence on rain or fire to resprout and/or flowering, fruiting followed by rapid wind dispersion, tick cuticle on epidermis and C4 photosynthetic metabolism. The species' fire behavior favors their establishment as pioneers, especially in open areas of the Cerrado. Leaf surfaces of some species of the genus Gomphrena present epicuticular wax crystals in platelet form, oriented in parallel, an aspect previously described only in Chenopodiaceae species. In two of the species studied Ascomycete fungi were found colonizing its leaves, and ultrastructural aspects were described. Kranz anatomy was found in six species of the genus Gomphrena, which also have dimorphic chloroplasts, showing leaf structure compatible with the C4 photosynthetic metabolism. In the analysis of two species of Alternanthera (a C3 and a C3-C4 intermediate) showed that besides the Kranz anatomy, the position of organelles in bundle sheath cells can be a key element in determining the metabolic type. The Froelichiella, Hebanthe and Pfaffia species have leaf anatomy and ultrastructure consistent with C3 metabolism. The leaf anatomy and ultrastructure have a pattern already described for other species of the Amaranthaceae family, except for the genera Hebanthe and Froelichiella, whose anatomical and ultrastructural aspects were described for the first time. The evolution of C4 metabolism may be related, at least in part, to the development of amphystomy associated with increased leaf thickness in herbaceous species. Large plastoglobuli were found in chloroplasts of some Cerrado species and appear associated with defense mechanisms, and lipid metabolism. The Amaranthaceae family can be a good marker of the biodiversity of nonwoody Eudicotyledons with ability to regenerate areas of rocky fields, wet grasslands and other open vegetation of the cerrado. These results illustrate the importance of expansion of basic and applied research in Amaranthaceae species, especially those that occur naturally in Brazilian cerrados. The expansion of knowledge concerning the anatomy and the specialization of organelles of different genera to perform its photosynthetic metabolism may contribute to understanding of the evolution of C4 pathway and the environment where plants specialize. The study of Cerrado Biome aims to broaden the justification for efforts to preserve its biodiversity.
Doutorado
Biologia Celular
Doutor em Biologia Celular e Estrutural

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18

Mildén, Mikael. "Local and regional dynamics of Succisa pratensis". Doctoral thesis, Stockholms universitet, Botaniska institutionen, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-762.

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Land use change is considered to be one of the biggest threat to global species diversity. In Sweden, abandonment of grazing is one of the most common reasons for decline in species richness in semi-natural grasslands. Today semi-natural grasslands often occur as more or less isolated fragments. The result for species that benefits from grazing is a smaller area of suitable habitat and higher extinction risks and a lowered ability to colonize new areas. Succisa pratensis is a long-lived perennial plant that benefits from grazing and is common in Swedish semi-natural grasslands. I have assessed the performance of Succisa pratensis at various spatial and temporal scales, in a Swedish rural landscape. I performed demographic matrix modelling of populations at grazed and ungrazed sites. A regional level was then added, by incorporating data collected from a large number of populations and habitat types into the matrix models and extinction risks over 50 years were calculated. A dynamic metapopulation model was created and the regional dynamics, in terms of colonisations resulting from long distance dispersal and population extinctions were examined. The effects of management history were incorporated into the model by using historical maps. In addition, I made an analysis of the impact of management history on the distribution and performance of four grassland species, using vegetation maps from 1945 and 2001. Local dynamics of Succisa pratensis was negatively affected by abandonment of grazing. Recorded population sizes were ten times higher in grazed sites than in ungrazed. The turnover rate of the system was estimated to about one extinction or colonisation per year. Both the simulation study and the analyses of vegetation maps suggested a pronounced legacy of management history in Succisa pratensis in the study landscape. Overall, the results of this thesis demonstrate the importance of management history for species in the rural landscape.

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Blanc, Patrick. "Biologie des plantes des sous-bois tropicaux". Paris 6, 1989. http://www.theses.fr/1989PA066054.

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Apres avoir expose les caracteristiques mesologiques des sous-bois de forets tropicales, l'auteur montre les particularites des plantes vasculaires effectuant leur cycle complet en sous-bois: faible activite cambiale, persistance des individus par emission de rejets basaux, faible ramification des tiges aeriennes et constance de l'ensemble assimilateur tout au long de la vie des individus. Les modes de croissance sont tres diversifies mais les plantes n'adoptent qu'un nombre limite de formes globales, chacune des 9 formes de bases reconnues montrent des convergences remarquables entre fougeres, monocotyledones et dicotyledones. Les feuilles des plantes de sous-bois presentant des caracteristiques dont la valeur adaptative est discutee: couleur, pilosite, succulence, hydathodes marginaux. La multiplication vegetative est tres diversifiee et permet la persistance, et meme le deplacement des individus, grace au bouturage de feuilles. La floraison repetitive caracterise de nombreuses especes et montre que les axes sexuels, comme les axes vegetatifs, peuvent presenter une croissance indefinie. Les graines, suivant leurs dimensions, germent sur support incline ou sur le sol forestier, cette difference etant a l'origine de corteges floristiques propres a chacun de ces types de support. Des conclusions phylogeniques sont degagees: les angiospermes, avec leur feuille large, seraient apparues en sous-bois puis se seraient diversifiees en milieu ouvert, essentiellement dans leurs parties aeriennes grace a l'activite cambiale. Les premieres dicotyledones seraient proches des chloranthaceae et les premieres monocoledones des convallariaceae. L'origine des angiospermes serait a rechercher parmi les sphenophytes

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20

Baron, Daniel [UNESP]. "Estudo da compatibilidade de atemoia ((Annona cherimola Mill. X Annona squamosa L. CV. 'THOMOSON') enxertada em araticum-de-terra-fria [Annona emarginata (Schltdl.) H. Rainer variedade terra-fria] e biribá [[Annona mucosa (Bai.) H. Rainer]". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/123795.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A enxertia é utilizada de maneira eficaz para o cultivo de espécies frutíferas comercias, uma vez que é necessário garantir as caraterísticas genéticas de espécies produtivas com o emprego de clones selecionados. Apesar da enxertia ser técnica comum e amplamente difundida, os mecanismos de compatibilidade em frutíferas lenhosas ainda não estão bem elucidados. Desta forma, o objetivo desta tese foi estudar a restabelecimento da atemoieira (Annona cherimola Mill. x A. squamosa L. cv. 'Thompson') enxertada em atemoieira (A. cherimola Mill. x A. squamosa L. cv. 'Thompson'), araticum-mirim [A. emarginata (Schltdl.) H. Rainer variedade mirim, araticum-de-terra-fria [A. emarginata (Schltdl.) H. Rainer variedade terra-fria e biribá [A. mucosa (Bail.) H. Rainer]. Após a enxertia foram realizadas avaliações das trocas gasosas; de crescimento vegetal; análises da concentração iônica de elementos minerais no tecido foliar e radicular; determinações das concentrações de compostos fenólicos totais e atividade da peroxidase; expressão do gene UGP e atividade enzimática da UDP-glicose pirofosforilase. Os porta-enxertos modularam as trocas gasosas alterando a eficiência de carboxilação e a transpiração. Variações no crescimento e nas concentrações de elementos essenciais em folhas e raízes também foram observadas em função das combinações copa/porta-enxerto. Em relação a atividade da peroxidase, observou-se aumento no porta-enxerto araticum-mirim em relação às demais espécies. Por outro lado, não foram verificadas diferenças nas concentrações de compostos fenólicos nas regiões enxertadas, no entanto tais concentrações foram maiores do que nos péfrancos. A enxertia alterou a expressão do gene UGP, o que indica a possibilidade de maior formação de tecido de parede celular, sendo que a combinação atemoia enxertada ...
Grafting is used efficiently for the commercial cultivation of fruit species, because it is necessary to ensure the genetic characteristics of productive species with the use of selected clones. Although grafting is common and widespread technique, mechanisms for compatibility in woody fruit are not well elucidated. Thus, the aim of this thesis was to study of restoring of atemoya (Annona cherimola Mill. x A.squamosa L. cv. 'Thompson') grafted onto atemoya (A. cherimola Mill. x Annona squamosa L. cv. 'Thompson'), araticum-mirim [A. emarginata (Schltdl.) H. Rainer 'variety mirim'], araticum-de-terra-fria [A. emarginata (Schltdl.) H. Rainer 'variety terra-fria'] and biribá [A. mucosa (Bail.) H. Rainer]. After grafting were evaluated gas exchange; plant growth; ionic concentration of mineral elements in the leaf and root tissues; determinations of the concentrations of phenolic compounds and peroxidase activity; UGP gene expression and enzymatic activity of UDP-glucose pyrophosphorylase (UGPase). Rootstocks modulate gas exchange by altering the carboxylation efficiency and transpiration, without, however showed favorable water economy. Changes in growth and concentrations of mineral elements in leaves and roots were also observed as a function of scion/rootstock combinations. In relation to the peroxidase activity, there was an increase in 'araticum-mirim' rootstock in relation to other species. Moreover, there were no differences in the concentrations of phenolic compounds in the grafted union, although these concentrations were higher than in rootstock. Grafting altered UGP gene expression, and the combination atemoya grafted onto 'araticum-de-terra-fria' (previously regarded as compatible combination) showed an increase in gene expression since the early stages after grafting. The results showed that there UGPase enzymatic activity, but there is no difference in this activity between different scion/ rootstock ...
FAPESP: 11/00853-8

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21

Baron, Daniel. "Estudo da compatibilidade de atemoia ((Annona cherimola Mill. X Annona squamosa L. CV. 'THOMOSON') enxertada em araticum-de-terra-fria [Annona emarginata (Schltdl.) H. Rainer "variedade terra-fria] e biribá [[Annona mucosa (Bai.) H. Rainer] /". Botucatu, 2014. http://hdl.handle.net/11449/123795.

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Orientador: Gisela Ferreira
Coorientador: Ivan de Godoy Maia
Banca: Magali Ribeiro da Silva
Banca: Carmen Silvia Fernandes Boaro
Banca: Ivan de la Cruz Chacón
Banca: Celso Luis Marino
Resumo: A enxertia é utilizada de maneira eficaz para o cultivo de espécies frutíferas comercias, uma vez que é necessário garantir as caraterísticas genéticas de espécies produtivas com o emprego de clones selecionados. Apesar da enxertia ser técnica comum e amplamente difundida, os mecanismos de compatibilidade em frutíferas lenhosas ainda não estão bem elucidados. Desta forma, o objetivo desta tese foi estudar a restabelecimento da atemoieira (Annona cherimola Mill. x A. squamosa L. cv. 'Thompson') enxertada em atemoieira (A. cherimola Mill. x A. squamosa L. cv. 'Thompson'), araticum-mirim [A. emarginata (Schltdl.) H. Rainer "variedade mirim", araticum-de-terra-fria [A. emarginata (Schltdl.) H. Rainer "variedade terra-fria" e biribá [A. mucosa (Bail.) H. Rainer]. Após a enxertia foram realizadas avaliações das trocas gasosas; de crescimento vegetal; análises da concentração iônica de elementos minerais no tecido foliar e radicular; determinações das concentrações de compostos fenólicos totais e atividade da peroxidase; expressão do gene UGP e atividade enzimática da UDP-glicose pirofosforilase. Os porta-enxertos modularam as trocas gasosas alterando a eficiência de carboxilação e a transpiração. Variações no crescimento e nas concentrações de elementos essenciais em folhas e raízes também foram observadas em função das combinações copa/porta-enxerto. Em relação a atividade da peroxidase, observou-se aumento no porta-enxerto araticum-mirim em relação às demais espécies. Por outro lado, não foram verificadas diferenças nas concentrações de compostos fenólicos nas regiões enxertadas, no entanto tais concentrações foram maiores do que nos péfrancos. A enxertia alterou a expressão do gene UGP, o que indica a possibilidade de maior formação de tecido de parede celular, sendo que a combinação atemoia enxertada ...
Abstract: Grafting is used efficiently for the commercial cultivation of fruit species, because it is necessary to ensure the genetic characteristics of productive species with the use of selected clones. Although grafting is common and widespread technique, mechanisms for compatibility in woody fruit are not well elucidated. Thus, the aim of this thesis was to study of restoring of atemoya (Annona cherimola Mill. x A.squamosa L. cv. 'Thompson') grafted onto atemoya (A. cherimola Mill. x Annona squamosa L. cv. 'Thompson'), araticum-mirim [A. emarginata (Schltdl.) H. Rainer 'variety mirim'], araticum-de-terra-fria [A. emarginata (Schltdl.) H. Rainer 'variety terra-fria'] and biribá [A. mucosa (Bail.) H. Rainer]. After grafting were evaluated gas exchange; plant growth; ionic concentration of mineral elements in the leaf and root tissues; determinations of the concentrations of phenolic compounds and peroxidase activity; UGP gene expression and enzymatic activity of UDP-glucose pyrophosphorylase (UGPase). Rootstocks modulate gas exchange by altering the carboxylation efficiency and transpiration, without, however showed favorable water economy. Changes in growth and concentrations of mineral elements in leaves and roots were also observed as a function of scion/rootstock combinations. In relation to the peroxidase activity, there was an increase in 'araticum-mirim' rootstock in relation to other species. Moreover, there were no differences in the concentrations of phenolic compounds in the grafted union, although these concentrations were higher than in rootstock. Grafting altered UGP gene expression, and the combination atemoya grafted onto 'araticum-de-terra-fria' (previously regarded as compatible combination) showed an increase in gene expression since the early stages after grafting. The results showed that there UGPase enzymatic activity, but there is no difference in this activity between different scion/ rootstock ...
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Castro, Sílvia Raquel Cardoso. "Reproductive biology conservation of the endemic Polygala vayredae". Doctoral thesis, Universidade de Aveiro, 2007. http://hdl.handle.net/10773/935.

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Doutoramento em Biologia
Existe um consenso generalizado de que o estudo da biologia reprodutiva de espécies endémicas, raras ou ameaçadas é essencial para compreender o seu estado actual e no desenvolvimento de estratégias adequadas de conservação in situ e ex situ. Polygala vayredae Costa (Polygalaceae) é uma espécie endémica da cadeia pré-Pirenaica oriental classificada como vulnerável de acordo com as categorias da IUCN. Os objectivos da presente Tese de Doutoramento consistiram em estudar a biologia reprodutiva de P. vayredae, avaliando de que forma pode afectar o ciclo de vida, em fornecer informação de base para futuros programas de conservação e em explorar em maior profundidade as interacções planta-animal e os processos de evolução de determinados traços florais. Para alcançar estes objectivos foram investigados os seguintes tópicos: biologia floral e sistema de reprodução (Capítulo 2), mecanismo de apresentação secundária de pólen (ASP, Capítulo3), ecologia da polinização (Capítulo 4) e mecanismos de dispersão (Capítulo 5). Os resultados revelaram que (1) P. vayredae depende estritamente de vectores de polinização para produzir sementes, (2) as suas características florais (corola fechada, accionada por comportamentos específicos do insecto) limitam o conjunto de polinizadores eficientes, (3) a sua longevidade floral favorece a transferência de pólen mas apresenta também custos reprodutivos sobre o êxito feminino, (4) a ASP acarreta custos reprodutivos sobre o êxito das componentes masculina e feminina, (5) as flores de P. vayredae são visitadas por um diversificado conjunto de insectos, dos quais apenas quatro espécies se comportam como polinizadores eficientes, (6) os polinizadores eficientes são, frequentemente, escassos e variáveis ao longo do tempo e do espaço, (7) os visitantes ineficientes exercem um efeito negativo sobre o comportamentos dos polinizadores eficientes e consequentemente sobre o êxito masculino (reduzindo o fluxo de pólen) e feminino (reduzindo a produção de frutos e sementes), (8) a dispersão dos frutos alados a longas distâncias encontra-se largamente reduzida, e finalmente, (9) a dispersão é maioritariamente efectuada por formigas que dispersam as sementes a distancias reduzidas, com o conjunto de espécies variando grandemente entre populações e anos. Perante estas observações podemos concluir que P. vayredae apresenta os seguintes problemas reprodutivos: limitação de pólen/polinizadores e curtas distâncias de dispersão. Os programas futuros de conservação que considerem estes pontos, conservando a fauna da área e protegendo as interacções planta-animal, promoverão a manutenção das populações e, consequentemente, a conservação desta espécie.
There is a consensus that studies on the reproductive biology of endangered, rare or threatened species are useful for understanding their current status and for evaluating in situ and ex situ management strategies. Polygala vayredae Costa (Polygalaceae) is a narrow endemic species from oriental pre-Pyrenees classified as vulnerable according with the IUCN categories. The aims of this PhD thesis were to study the reproductive biology of P. vayredae, to evaluate the implications of its reproductive features on its life cycle, to provide valuable background information for future management programs and deeply explore plant-animal interactions and the evolution of certain floral traits. To achieve the proposed objectives the following points were investigated: the floral biology and breeding system (Chapter 2), the singular secondary pollen presentation (SPP) mechanism (Chapter 3), the pollination ecology (Chapter 4) and the dispersal mechanisms (Chapter 5). The results revealed that (1) P. vayredae strictly depends on pollen vectors to produce seeds, (2) its floral features (closed corolla and the need to be trigged by specific behaviours of the insects) limit the spectrum of efficient pollinators, (3) its floral longevity favours the opportunity to pollen transfer but also have reproductive costs over female fitness, (4) SPP imposes several reproductive costs over male and female fitness, (5) a large spectrum of floral visitors were observed, but with only four species being efficient pollinators, (6) efficient pollinators were scarce and highly variable both along time and space, (7) inefficient visitors add a negative effect on the behaviour of efficient pollinators and on male (reducing pollen flow) and female components (reducing fruit set and seed ovule ratios), (8) long dispersal of the alate fruits is largely reduced, and finally, (9) dispersal is mainly performed by ants who are able to disperse seeds for short distances, with the spectrum of ant species being spatially and temporally variable. The general conclusions on the status of P. vayredae indicate that this species bears the following reproductive problems: pollen/pollinator limitation and short distance dispersal of the diaspores. Future management programs that account with this issues conserving the fauna of the area and protecting plant-animal interactions will facilitate the maintenance of the populations and thus its conservation.

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Hu, Chien-an Andy. "Osmoregulation and proline biosynthesis in plants /". The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487843688956923.

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Huet, Trujillo Estefanía. "Nuevas metodologías para la producción de anticuerpos recombinantes en plantas". Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/90469.

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Genetic engineering has allowed the design and production of recombinant antibodies (rmAbs) in plants. Nowadays, rmAbs are used in the treatment of a wide range of pathologies such as infectious diseases, inflammatory diseases and cancer, making rmAbs an important group of biomolecules within the pharmaceutical and biotechnology industry. By the time this study was started, the immunoglobulin G (IgG) was the antibody isotype predominantly expressed in plants. In recent years Modular DNA cloning technology has facilitated antibody engineering, with the development and expression of new rmAbs formats. However, there is hardly any study where different antibody formats are produced and compared in terms of yield and neutralizing capacity. Therefore, the starting point of the first chapter of this thesis is a comparative study where five different formats of the same commercial rmAb (Infliximab) against the human cytokine Tumor Necrosis Factor (TNF-¿) were expressed and compared. The results obtained in Chapter 1 demonstrate that both the isotype and the structure of the chosen rmAb influence the yield and the neutralizing capacity of rmAb. The expression of new antibody formats not only refers to the antibody isotype or structure; the format also refers to the combination of antibody idiotypes, leading to the production of oligo or polyclonal antibodies. Therefore, the possibility of co-expressing different monoclonal antibodies simultaneously in plants (creating oligoclonal or polyclonal formats) was raised. In the second chapter of this thesis, the expression of three rmAbs against the Ebola virus glycoprotein was studied. The three rmAbs were transiently expressed in N. benthamiana individually, by establishing separated production lines; in parallel, all three rmAbs were also co-expressed simultaneously in the same production line. The results obtained in this chapter demonstrated that the individual expression of rmAbs is feasible. However, when all three rmAbs are co-expressed, a drastic decrease in the binding of the antibody to the antigen was observed due to chain shuffling, as each heavy chain (HC) can be bound to any light chain (LC) other than its cognate chain, giving rise to an antibody cocktail with lower activity. With the objective of developing a method that allows co-expression of several rmAb in a single production line, we next proposed to exploit the viral interference phenomenon (also known as superinfection exclusion, SE). The results shown in Chapter three demonstrate that the production of an oligoclonal cocktail composed of 36 rmAbs in plants was possible using a viral expression system showing SE. The data obtained in this chapter showed that the resulting oligoclonal cocktail was active and capable of neutralizing toxic activities of the venom of the snake Bothrops asper in vitro and in vivo, wich was used as a model for studying the efficacy of the oligoclonal antibodies produced. The results of this thesis confirm and support the use of plants as platforms for the expression of alternative formats of antibodies.
La ingeniería genética ha permitido el diseño y la producción de anticuerpos recombinantes (rmAbs) en plantas. Hoy en día, los rmAbs se utilizan en el tratamiento de un amplio rango de patologías como enfermedades infecciosas, enfermedades inflamatorias y cáncer, convirtiéndose en un importante grupo de biomoléculas dentro de la industria farmacéutica y biotecnológica. Hasta la fecha de este estudio, en plantas se ha producido mayoritariamente la inmunoglobulina del tipo G (IgG). Gracias al desarrollo de la ingeniería del ADN recombinante y de la ingeniería de anticuerpos, es posible diseñar y producir nuevos formatos de rmAbs. Sin embargo, apenas existen estudios comparativos donde se demuestre si el formato de anticuerpo elegido es el idóneo en términos de rendimiento y capacidad neutralizante. Por tanto, el punto de partida del primer Capítulo de esta tesis consistió en la realización de un estudio comparativo de la expresión en plantas de cinco formatos distintos de un mismo rmAb comercial (Infliximab) frente a la citoquina humana Tumor Necrosis Factor (TNF-¿). Los resultados obtenidos en el Capítulo 1 demuestran que tanto el isotipo como la estructura del rmAb elegido influye en los niveles de rendimiento y en la capacidad neutralizante del rmAb. La expresión de nuevos formatos de anticuerpos no solo afecta al isotipo o a la estructura de las regiones constantes, sino que también se puede incluir en este término la expresión conjunta de distintos idiotipos de anticuerpos recombinantes, dando lugar a anticuerpos policlonales u oligoclonales recombinantes. Por tanto en esta tesis se planteó la posibilidad de co-expresar simultáneamente distintos anticuerpos monoclonales en plantas formando un cóctel oligoclonal. En el segundo Capítulo de esta tesis se diseñaron tres rmAbs frente a la glicoproteína de la cubierta del virus del Ébola. Los tres rmAbs se expresaron transitoriamente en N. benthamiana de manera individual mediante el establecimiento de líneas paralelas de producción y también se co-expresaron los tres rmAbs simultáneamente en una misma línea de producción. Los resultados obtenidos en este Capítulo demostraron que la expresión de los rmAbs de manera individual es factible. Sin embargo, cuando se co-expresan los tres rmAbs se observa una drástica disminución en la unión del anticuerpo al antígeno debido al barajado de cadenas, fenómeno por el cual cada cadena pesada (HC) se puede unir con cualquier cadena ligera (LC) distinta de su acompañante, dando lugar a un anticuerpo con una baja actividad. Finalmente, con el objetivo de desarrollar un método que permita co-expresar en una misma línea de producción varios rmAbs de forma reproducible se propuso explotar el fenómeno de la exclusión viral, un característica propia de los virus de plantas. Los resultados mostrados en el Capítulo 3 demuestran que es posible la producción de un cóctel oligoclonal compuesto por 36 rmAbs en N. benthamiana aprovechando el fenómeno de la exclusión viral. Los datos obtenidos en este capítulo muestran que el cóctel oligoclonal producido de esta forma mantiene intactas las actividades de los anticuerpos individuales y es capaz de neutralizar las actividades tóxicas del veneno de la serpiente Bothrops asper en ensayos in vitro e in vivo. Los resultados de esta tesis confirman y avalan el uso de las plantas como plataformas de expresión de formatos alternativos de anticuerpos.
El desenvolupament de l'enginyeria genètica ha permès el disseny i la producció d'anticossos recombinants (rmAbs) en plantes. Hui en dia, els rmAbs s'utilitzen en el tractament d'un ampli rang de patologies com malalties infeccioses, malalties inflamatòries i càncer convertint-se en un important grup de biomolècules dins de les indústries farmacèutiques i biotecnològiques. Fins a la data, s'han expressat majoritàriament la immunoglobulina del tipus G. Gràcies al desenvolupament de l'enginyeria de l'ADN recombinant i l'enginyeria dels anticossos s'han desenvolupat i expressat formats alternatius de rmAbs. Tanmateix, hi ha molts pocs estudis comparatius on es demostra si el format de l'anticòs elegit influeix en el rendiment i en la capacitat neutralitzant. Per tant, el punt de partida del primer Capítol d'esta Tesi és la realització d'un estudi comparatiu on s'expressen cinc formats diferents d'un mateix anticòs comercial (Infliximab) front a la citocina humana Tumor Necrosis Factor (TNF-¿). Els resultats obtesos demostren que tant l'isotip com l'estructura del rmAb elegit influeix en el rendiment i en la capacitat neutralitzant del rmAb. L'expressió de nous formats d'anticossos no sols afecta a l'isotip o a l'estructura del rmAb sinó que també pot incloure's dins d'aquest concepte l'expressió individual i l'expressió conjunta de diferents rmAbs. Partint d'aquesta hipòtesi, es va plantejar la possibilitat de co-expressar diferents rmAbs (còctel oligoclonal) en plantes. En el segon Capítol d'esta tesi es dissenyaren tres rmAbs front a la glicoproteïna del virus de l'Ébola. Els tres rmAbs s'expressaren transitòriament en N. benthamiana de manera individual mitjançant l'establiment de línies paral·leles de producció i també es co-expressaren els tres rmAbs en la mateixa línia de producció. Els resultats obtesos en este Capítol demostraren que l'expressió dels rmAbs de manera individual és factible. Tanmateix, quan es co-expressaren els tres rmAbs s'observà una dràstica disminució en la unió de l'anticòs a l'antigen com a conseqüència del shuffling chain, pel qual la cadena pesada (HC) s'uneix amb qualsevol cadena lleugera (LC) diferent a la seua acompanyant, formant un anticòs amb una baixa capacitat d'unió a l'antigen. Amb l'objectiu de desenvolupar un mètode que permeta co-expressar, en una mateixa línia de producció, un còctel oligoclonal es proposà explotar el fenomen de l'exclusió viral. Els resultats obtesos en el Capítol 3 demostren que l'expressió d' un còctel oligoclonal format per 36 rmAbs en plantes és possible. Els resultats mostren que el nostre còctel oligoclonal es capaç de neutralitzar activitats tòxiques del verí de la serp Bothrops asper en assaigs in vitro i in vivo. Els resultat obtesos en aquesta Tesi confirmen i avalen l'ús de les plantes com plataformes d'expressió de formats alternatius d'anticossos.
Huet Trujillo, E. (2017). Nuevas metodologías para la producción de anticuerpos recombinantes en plantas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90469
TESIS

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25

Ramula, Satu. "Population viability analysis for plants : practical recommendations and applications". Doctoral thesis, Stockholm : Department of Botany, Stockholm University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-845.

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26

Wu, Wenping. "Endophytic fungi from leaves of evergreen woody plants : taxonomy, biology and ecology". Thesis, Royal Holloway, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263684.

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Abstract (sommario):

Taxonomic diversity, biology and ecology of leaf endophytes were studied from some evergreen plants including Arbutus unedo, Buxus sempervirens, flex aquifolium, Laurus nobilis, Ligustrum vulgare, Prunus lusitanica, Rhododendron ponticum, Rhododendron sp., and Skimmia sp. from England, and some others from China. It was found: 1. A great number of fungal species, including several new species and new British records, have been isolated. Distribution patterns of endophyte assemblages and their variations between plant species and geographical locations are described. 2. Comparisons of leaf endophytes and saprobes of R. ponlicum at the same locality showed they belonged to two different ecological groups. This was further confirmed by study on endophytes and saprobes from a number of plant species growing in the same locality. 3. Host specificity of endophytic fungi at the species level was rare and this was supported by comparisons of endophyte assemblages from both taxonomically related (same family) and unrelated (different families) plant species. Molecular characterisations of Phyllosticta species confirmed this. 4. Infection and colonisation studies during a two year period showed that leaf endophytes of R. ponlicum were horizontally transmitted. Internal bud material was sterile and became infected by aerial spores. The infection and colonisation level of endophytes were strongly affected by environmental conditions. 5. Phylogenetic studies of Phyllosticta based on ITS 1-5.8s rDNA-ITS2 sequences concluded there was no evidence to show that the evolution of host plants of Phyllosticta species and ITS were related. Most Phyllosticta species from the same locality were found to have a broad host range and occurred on many taxonomically unrelated plants in the same locality. P. concentrica was separated into 4 species including P. concentrica on Hedera, P. arxii on Ilex, P. maxima on Rhododendron and P. taxi on Taxus.

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27

Doroodian, Paymon. "Overexpression of Differentiation and Greening-Like Alters Stress Response of Arabidopsis thaliana". Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1596227767908937.

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28

Figueroa-Castro, Dulce M. "Mating systems in Nicotiana longiflora and N. plumbaginifolia the effect of interspecific interactions /". Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5587.

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Thesis (Ph. D.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on June 4, 2009) Vita. Includes bibliographical references.

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29

Francis, Anthony P. "Biodiversity of plants: Broad-scale patterns and mechanisms". Thesis, University of Ottawa (Canada), 2003. http://hdl.handle.net/10393/28984.

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One of the most obvious patterns in ecology is the geographic variation in species richness over broad spatial scales. However, despite observations of these patterns of richness for two centuries, mechanisms for the patterns remain controversial. This thesis is a study of the broad-scale biodiversity patterns of plants and the potential mechanisms behind those patterns. Richness-climate relationships often account for >80% of the spatial variance in richness. However, it has been suggested that richness-climate relationships differ significantly among geographic regions, and that there is no globally consistent relationship. Since there is little point in arguing about mechanisms before the patterns they predict have been documented, I investigated the global patterns of species and family richness of angiosperms in relation to climate. One hypothesized mechanism that predicts strong and consistent richness-climate patterns is the Physiological Tolerances hypothesis. This hypothesis predicts that the number of species found in a given location is a function of the number that can tolerate the climatic conditions in that place. Using global angiosperm family richness distributions and climatic data to estimate the climatic tolerances of plant families, I examined the relationships of potential family richness patterns to both climatic gradients and observed patterns of family richness. Observed family richness was not strongly related to potential family richness. However, both richness and potential richness were related to climate, but in different ways. Potential family richness necessarily sets an upper limit on observed richness levels, but observed richness did not generally reach that limit. In other words, there are generally many more species that can tolerate the climate in a particular area than actually occur there. A second hypothetical mechanism predicting strong consistent richness-climate patterns, the Energy-Diversity or Species-Energy hypothesis, suggests that for a species to persist in an area, there must be sufficient energy available in that area to support enough individuals of that species to maintain a viable population. Thus species richness will depend upon the number of individuals, which in turn depends upon energy availability. Using tree counts from 15 forest sites along a latitudinal gradient running from James Bay, Canada to Costa Rica, I tested whether a series of direct correlative links existed from climate to tree density to tree species richness. Despite a positive (but not statistically significant) correlation between AET and richness, the tree density per site was negatively correlated with energy. (Abstract shortened by UMI.)

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Gibson, Michelle Rene. "Invasive Australian acacias : reproductive biology and effects on native plant-pollinator communities in Cape fynbos". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20399.

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Thesis (MSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: My master’s research combines aspects of pollination biology and invasion biology to explore the invasive predictors and impacts of a globally invasive group of plants – Australian acacias. Specifically, I investigate the role of reproductive biology in their invasion success (Chapter 2), the impacts of a specific species, Acacia saligna, on native plant-pollinator communities in South Africa (Chapter 3), and if the impact of A. saligna on native plant species can be predicted, based on floral trait similarity (Chapter 4). Australian acacias possess many floral traits implicated in plant invasion success, including extensive, dense floral displays, prolific seed production, long-lived seed banks, and propensity for vegetative reproduction. In Chapter 2 of my thesis, co-authors and I investigate if such reproductive traits influence whether or not a species becomes invasive once it is introduced by qualitatively and quantitatively analyzing literature and data collected from published and unpublished data. We found that invasive species reach reproductive maturity earlier and are more commonly able to resprout. Our findings have important implications for management of existing Acacia invasions as well as the assessment and prevention of further introductions of Acacia species leading to invasion. Impacts of invasive plant species on native plant visitation and consequent reproduction are often negative and have important implications for future ecosystem health. Acacia saligna is a problematic woody invasive shrub in many Mediterranean regions, and in South Africa, it invades fynbos vegetation, which boasts one of the highest plant diversities per area in the world as well as many specialized pollination mutualisms. It blooms during the flowering peak of most native species and forms dense, showy floral displays, thus the possibility of pollinator-mediated interactions with co-flowering native species is high. In Chapter 3, I assess the impact of flowering A. saligna on insect visitation to co-flowering native species by conducting flower observations at both an invaded and uninvaded (control) site. One of the native species most-visited by native honeybees, Roepera fulva, had high flower visitor overlap with A. saligna and suffered significantly lower visitation from all insects and from bees when A. saligna was present than at the control site. The native honeybee appears to be the most important visitor to A. saligna as it was the most frequent and mobile. Due to its foraging efficiency and dominance in pollinator communities, Apis mellifera subsp. capensis could be an important mediator of the negative effect of A. saligna on co-flowering natives, especially those frequently visited by honeybees. The use of floral traits as predictors of a species’ effect on co-flowering plants via pollination is commonly used in pollination biology. In the fourth chapter of my thesis, I apply the predictive principle of floral traits on flower visitation to see if floral traits can predict the impact of an invasive plant species on co-flowering native species, and if so, which floral traits are the most important. Following the same flower observation protocol as Chapter 3, I assess two measures of invasion impact on native flowers – change in visitation rate to native plant species between invaded and uninvaded sites and flower visitor overlap between A. saligna and native species – and test for a correlation with floral trait similarity of native species to and A. saligna. Similarity of categorical traits and all traits combined (categorical and continuous) were significantly positively correlated with flower visitor overlap, indicating that native species with categorical traits similar to A. saligna were more likely to share flower visitors with A. saligna. Floral symmetry and shape similarity were the most important categorical traits in driving flower visitor overlap. Findings suggest an important link between categorical floral traits and ability to predict invasive plant impact on native flower-insect interactions; however, more comprehensive studies are required for conclusive results.
AFRIKAANSE OPSOMMING: My Meestersgraad se navorsing kombineer aspekte van bestuiwingsbiologie en indringerbiologie om ondersoek in te stel na die indringing-voorspelbaarheid en die impak van Australiese Akasias, 'n wêreldwye indringende groep van plante. Ek het spesifiek gekyk na die rol van voortplantingsbiologie in hul indringing sukses (Hoofstuk 2), die impak van 'n spesifieke spesie, Acacia saligna, op die inheemse plant-bestuiwer gemeenskappe in Suid-Afrika (Hoofstuk 3), en of die impak van Acacia saligna op inheemse plantspesies voorspel kan word, gebaseer is op die ooreenkomste in blomeienskappe (Hoofstuk 4). Australiese Akasias het baie voortplantingseienskappe wat geassisioeer word met plantindringing sukses, insluitend ‘n uitgebreide, digte blommedrag, uitermatige hoë saadproduksie, langlewende saadbank, en die geneigdheid vir vegetatiewe voortplanting. In hoofstuk 2 van my tesis, ondersoek ek en my medeskrywers of sulke voortplantingseienskappe beïnvloed of 'n spesie ‘n indringer raak, deur 'n ontleding van die literatuur en data wat versamel is uit gepubliseerde en ongepubliseerde data. Ons het gevind dat indringerspesies geslagsrypheid vroeër bereik en meer algemeen in staat is om weer uit te loop. Ons bevindinge het belangrike implikasies vir die bestuur van die bestaande Akasiastande sowel as die evaluering en die voorkoming van verdere vestiging van Akasia spesies wat lei tot indringers. Impakte van uitheemse plantspesies op inheemse plant-besoeke deur bestuiwers, en gevolglike voortplanting is dikwels negatief en het belangrike implikasies vir die toekomstige ekosisteem gesondheid. Acacia saligna is 'n problematiese houtagtige indringende struik in baie Mediterreense streke, en in Suid-Afrika. Dit dring in die Fynbos in, wat spog met een van die wêreld se hoogste plant diversiteit per oppervlak, sowel as baie gespesialiseerde bestuiwing-mutualismes. Dit blom gedurende die bloeiseisoen van die meeste inheemse spesies en vorm digte, pronkerige blomuitstallings, dus is die moontlikheid hoog vir bestuiwer-gemedieerde interaksies met inheemse spesies wat saam blom. In Hoofstuk 3, het ek die impak van Acacia saligna, op insek besoeke aan saamblommende inheemse spesies bepaal, deur waarnemings op beide ingedringde en natuurlike studie gebiede. Een van die inheemse spesies, Roepera fulva, wat die meeste besoek is deur inheemse heuningbye, het 'n hoë blom besoeker oorvleueling met Acacia saligna en het aansienlik minder besoeke van alle insekte en van bye gekry toe Acacia saligna teenwoordig was as by die natuurlike studie gebied. Die inheemse heuningby, Apis mellifera subsp. capensis, blyk die mees belangrikste besoeker aan Acacia saligna te wees aangesien dit die mees gereeldste en beweeglikste was. As gevolg van sy oorheersing in bestuiwer gemeenskappe, is die by 'n belangrike faktor van die negatiewe uitwerking van Acacia saligna op die inheemse plante wat dieselfde tyd blom, veral dié wat gereeld besoek word deur heuningbye. Die gebruik van blomeienskappe as voorspellers van 'n spesie se effek op saamblommende plante deur middel van bestuiwing, word algemeen gebruik in bestuiwingsbiologie. In die vierde hoofstuk van my tesis, het ek die voorspellende beginsel van die blomeienskappe op blombesoeking toegepas, om te sien of blomeienskappe die impak van 'n uitheemse plantspesie kan voorspel op saamblommende inheemse spesies, en indien wel, watter blomeienskappe die belangrikste is. Deur dieselfde blom waarneming protokol as in Hoofstuk 3 te gebruik, het ek twee maatstawwe van indringings impakte op inheemse blomme vergelyk - verandering in besoek gereeldheid aan inheemse plante tussen ingedringde en natuurlike studie gebiede en blom besoeker oorvleueling tussen die Acacia saligna en inheemse spesies – en die toets vir 'n korrelasie van blomeienskap ooreenkomste in inheemse spesies en Acacia saligna. Soortgelykheid van kategoriese eienskappe en al die eienskappe gekombineer (kategoriese en deurlopende) is beduidend positief gekorreleerd met blombesoeker oorvleueling, wat aandui dat inheemse spesies met kategoriese eienskappe soortgelyk aan Acacia saligna meer geneig was om blom besoekers te deel met Acacia saligna. Blom simmetrie en vorm ooreenkoms was die belangrikste kategoriese eienskappe wat ly tot blombesoeker oorvleueling. Bevindinge dui op 'n belangrike skakel tussen die die kategoriese blomeienskappe en die vermoë om indringerplant impakte op inheemse blom-insek interaksies te voorspel, alhoewel, meer omvattende studies nog nodig is.
DST-NRF Centre of Excellence for Invasion Biology and the Department of Botany and Zoology at Stellenbosch University for research funding

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31

Bustamante, Montoya Mariana. "Genomic analyses of the cup-shaped cotyledoni 1 network". Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/461296.

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El desarrollo de la flor ha sido un importante campo de investigación por muchos años y el análisis extensivo de interacciones genéticas resultó en un marco de referencia que permitió entender cómo se produce la especificación de los órganos florales. Recientemente, la introducción de tecnologías de nivel genómico permitió confrimar y expandir los modelos existentes sobre el establecimiento de la identidad de los órganos florales y otros eventos importantes que ocurren durante la formación de la flor. A pesar de esto, hay otros aspectos del desarrollo floral para los cuales no existen modelos generales, como el caso de la formación de los límites entre los órganos de la flor. El gen CUP-SHAPED COTYLEDON1 (CUC1) Arabidopsis thaliana es un factor de transcripción clave involucrado en la regulación del desarrollo floral mediante el control de la formación de estos límites o fronteras. En las plantas, la separación correcta entre distintos tejidos es fundamental para el mantenimiento de los meristemos y para coordinar la formación de nuevos órganos. Esto ocurre a través de todo el desarrollo de la planta, desde la separación temprana de cotiledones en las dicotiledóneas, hasta la fromación de límites entre óvulos durante la fase reproductiva. CUC1 reprime el crecimiento en la zona de los límites que contribuye a establecer y se propuso que lo hace afectando la división celular. A pesar de este rol crucial de CUC1, los mecanismos moleculares a través de los cuales controla la formación de límites no están descriptos de manera extensiva. Aquí, la red regulatoria de CUC1 es caracterizada a nivel genómico, usando tecnologías de última generación. En este trabajo, varios aspectos de la función de CUC1 fueron analizados por primera vez mediante la combinación de enfoques complementarios que incluyen la transcriptómica, el perfil de unión al DNA del factor de transcripción y el análisis de interacción entre proteínas. Los resultados obtenidos por estas técnicas permitieron dilucidar un set de dianas transcripcionales, vías moleculares e interactores proteicos de CUC1 que ayudan a delinear los mecanismos por los cuales este factor de transcipción del tipo NAC contribuye al establecimiento de los límites entre órganos florales. Estos resultados representan un avance sustancial para la comprensión de los eventos moleculares controlados por CUC1 en esta etapa fundamental del desarrollo de una planta. En este sentido, esta Tesis provee un cuerpo de trabajo fundacional que puede utilizarse para explorar la red regulatoria de CUC1 más profundamente.
Flower development has been an active field of research for many years and the thorough analysis of genetic interactions provided a general framework to understand how floral organs are specified. More recently, the introduction of genome-wide technologies helped confirm and expand the existing models about organ identity establishment and other important events during flower formation. Still, there are other aspects of flower development for which general models are lacking, such as the formation of floral organ boundaries. The Arabidopsis thaliana CUP-SHAPED COTYLEDON1 (CUC1) gene is a key transcription factor involved in the regulation of flower development by controlling boundary formation. In plants, proper boundaries are fundamental for meristem maintenance and to coordinate organogenesis. This occurs throughout plant development, from the early separation of cotyledons in dicots to the formation of boundaries between ovules during the reproductive phase. CUC1 suppresses growth in the boundary regions that it helps to delimit, and it has been proposed that it does so by affecting cell division. Despite the crucial role of CUC1, the molecular mechanisms by which it controls boundary formation are still poorly understood. Here, CUC1 regulatory network is characterized at the genome-wide level, using state-of-the-art genomic technologies. In this work, several aspects of CUC1 function were analyzed for the first time through the combination of complementary genome-wide approaches including transcriptomics, transcription factor binding profiles and protein interactome analyses. The results obtained from such techniques allowed to elucidate a set of transcriptional targets, molecular pathways and CUC1 interactors that help delineate the mechanisms by which this NAC transcription factor contributes to the establishment of floral organ boundaries. These results represent a substantial advance in the understanding of the molecular events that are controlled by CUC1 in this key developmental stage of plant development. In this regard, this Thesis provides a foundational body of work that can be used to further explore CUC1's regulatory network.

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Maher, Keri Renee. "A geographically constrained molecular phylogeny of Panamanian Aechmea species (Bromeliaceae, subfamily bromelioideae)". CSUSB ScholarWorks, 2007. https://scholarworks.lib.csusb.edu/etd-project/3280.

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This study lends strong support to the idea that members of Bromeliaceae have undergone a recent adaptive radiation, and therefore show that, at least in part, diversity in the tropics is due to a fast speciation rate and that the tropics can be a "cradle" for new diversification and exploitation of varying ecological niches through the diversification of ecophysiological traits within a lineage.

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33

Carvalho, Saul Jorge Pinto de. "Características biológicas e suscetibilidade a herbicidas de cinco espécies de plantas daninhas do gênero Amaranthus". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-07032007-141229/.

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As espécies de plantas classificadas no gênero Amaranthus são frequentemente encontradas infestando áreas agrícolas brasileiras, contudo existem poucos trabalhos que avaliaram as características biológicas e o controle destas espécies. Assim sendo, este trabalho foi conduzido com o objetivo de analisar a germinação, o crescimento e o desenvolvimento, estimar a área foliar, a competitividade e a susceptibilidade a herbicidas de cinco espécies de plantas daninhas do gênero Amaranthus As espécies de Amaranthus estudadas foram: A. deflexus (caruru-rasteiro), A. hybridus (carururoxo), A. retroflexus (caruru-gigante), A. spinosus (caruru-de-espinho) e A. viridis (caruru-de-mancha). O experimento que avaliou a germinação foi conduzido no Laboratório de Análise de Sementes e os demais em casa-de-vegetação do Departamento de Produção Vegetal da ESALQ/USP, Piracicaba - SP, no período compreendido entre março e dezembro de 2005. Com relação à germinação, constatou-se que variações na disponibilidade de luz e temperatura interferem em todas as espécies de Amaranthus, em que as maiores taxas de germinação foram obtidas em condição de fotoperíodo com alternância de temperatura (8h-luz-30°C / 16h-escuro-20°C). Em condições menos favoráveis, A. viridis e A. hybridus obtiveram maiores taxas de germinação que as demais espécies. Em geral, A. deflexus e A. spinosus foram as espécies de plantas daninhas que apresentaram os menores índices de velocidade de germinação. Sobre o crescimento e desenvolvimento, constatou-se que A. deflexus foi a espécie com ciclo vegetativo mais curto, menor acúmulo de massa seca e área foliar; por outro lado, A. retroflexus e A. hybridus foram aquelas que alcançaram os maiores valores para estas variáveis. A estimativa de área foliar demonstrou que a equação linear passando pela origem (Ar=a.(C.L)) foi adequada para ajustar a relação entre as medidas lineares do limbo e a área foliar real de todas as espécies. Com relação à competição, concluiu-se que a cultura do feijoeiro é melhor competidora que todas as espécies de plantas daninhas do gênero Aramanthus que foram utilizadas neste trabalho, quando cultivadas em igualdade de proporções. A. deflexus e A. viridis foram as espécies com a fenologia menos afetada pela competição com o feijoeiro; a competição intraespecífica foi a mais prejudicial à cultura do feijoeiro, o que sugere que os danos causados pelas plantas daninhas estão mais relacionados com as altas densidades em que estas ocorrem do que com a habilidade competitiva intrínseca das espécies. O controle químico obtido para as espécies de Aramanthus avaliadas neste trabalho demonstrou diferenças de susceptibilidade aos herbicidas aplicados em pósemergência, principalmente ao trifloxysulfuron-sodium e ao chlorimuron-ethyl, em que A. deflexus foi a espécie menos suscetível, seguido por A. spinosus, A. viridis, A. hybridus e A. retroflexus.
Plant species classified in the Aramanthus genus are frequently found infesting brazilian agricultural areas, although there are few researches that evaluated the biological characteristics and the control of these species. Therefore, this work was conducted with the objective of analyzing the germination, the growth and the development, estimating the leaf area, the competitiveness and the susceptibility to herbicides of five weed species of the Aramanthus genus. The species of Aramanthus studied were: A. deflexus, A. hybridus, A. retroflexus, A. spinosus and A viridis. The experiment that evaluated the germination was conducted in the Laboratory of Seed Analyses and the others in the greenhouse of the Crop Science Department of ESALQ/USP, Piracicaba - SP, in the period comprehended between March to December 2005. About the germination, it was established that variation in the availability of light and temperature interferes in all the species of Aramanthus and the highest levels of germination were obtained in condition of photoperiod with alternating temperature (8h-light-30°C / 16h-dark-20°C). In less favorable conditions, A. viridis and A. hybridus obtained higher germination levels than all the other species. In general, A. deflexus and A. spinosus were the weed species that presented the lowest rates of germination speed. About the growth and development, it was observed that A. deflexus was the species with shortest vegetative cycle, the lowest dry mass and leaf area accumulation; however, A. retroflexus and A. hybridus were the species which reached the highest values for these variables. The leaf area estimation showed that the linear equation crossing the origin (Ar=a.(C.L)) was adequate to adjust the correlation between the linear blade dimensions and the real leaf area for all the species. About competition, it was concluded that the crop of common bean is more competitive than all the weed species of the Aramanthus genus that were studied in this work, when grown in equivalent proportion; A. deflexus and A. viridis were the species which phenology was less affected by the competition with common bean; the intraspecific competition was the most damaging to the crop of common bean, what suggests that the damages caused by the weeds are more connected with its high density of infestation than the intrinsic competitive ability of the species. The control obtained for the Aramanthus species evaluated in this research presented differences of susceptibility to post-emergence applied herbicides, mainly to trifloxysulfuron-sodium and chlorimuron-ethyl, which A. deflexus was the least susceptible species, followed by A. spinosus, A. viridis, A. hybridus and A. retroflexus.

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34

Kilaru, Aruna. "Endocannabinoid System in Plants?" Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/4781.

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35

Paulus, Carsten. "Asimetrías en la oclusión bajo el enfoque de la distribución del peso plantar". Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/461948.

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ANTECEDENTES: la asimetría en la oclusión es una condición que se caracteriza por la falta de una oclusión idéntica en ambos lados, de tal manera que se produce una desviación de la línea media y una asimetría en el encaje entre las mandíbulas superior e inferior. Aunque se han propuesto varias hipótesis acerca del origen de esta condición, los estudios morfométricos intentan establecer un vínculo entre la simetría de la cara, la falta de ajuste en la oclusión mandibular y la presión plantar como posible factor etiológico implicado en el origen de esta condición. El objetivo de este estudio es analizar la relación existente entre la presión plantar, la asimetría facial y la maloclusión. MÉTODOS: se diseñó un estudio descriptivo, transversal, comparativo con dos grupos: grupo con asimetría en la oclusión (n = 16) y grupo sin asimetría (n = 27). Los participantes fueron seleccionados en la ciudad de Colonia (Alemania), con una edad media de 11,7 años (DT = 3,0 años). Se realizó una evaluación de la oclusión dental, de la simetría facial y de la presión plantar. RESULTADOS: las pruebas aplicadas no indican un vínculo entre la asimetría en la oclusión, la simetría facial y la presión plantar. CONCLUSIÓN: la asimetría en la oclusión no parece tener como factor etiológico las diferencias de presión plantar, lo que implica la búsqueda de nuevos factores que puedan explicar el origen de la maloclusión.
BACKGROUND: Asymmetric occlusion is a condition characterized by lack of symmetric occlusion of the teeth, so that a midline shift is created between the upper and lower jaws and a different occlusion on one compared to the other side. Although several hypotheses have been proposed regarding the origin of this condition, the morphometric studies try to establish a link between the symmetry of the face, the lack of fit in the occlusion and the implanted pressure as a possible etiological factor involved in the origin of this condition. The aim of this study is to analyze the relationship between plantar pressure, facial asymmetry and malocclusion. METHODS: A descriptive, transversal, comparative study was designed with two groups: group with asymmetry in occlusion (n = 16) and group without asymmetry (n = 27). Participants were selected in the city of Cologne (Germany), with a mean age of 11.7 years (SD = 3.0 years). An evaluation of dental occlusion, facial symmetry and plantar pressure was performed. RESULTS: Applied tests do not indicate a link between asymmetry in occlusion, facial symmetry and plantar pressure. CONCLUSION: Asymmetry in occlusion does not seem to have as etiologic factor differences in plantar pressure, which implies the search for new factors that allow to explain the origin of malocclusion.

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36

Schechtmann, Dalila Figueiredo. "O controle do desenvolvimento de gemas laterais em linum usitatissimum L". [s.n.], 1988. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315550.

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Orientador : Rosely Rocha Sharif
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Plantas de Limum usitatissimum (linho) apresentam o eixo principal alongado e diferente padrões de crescimento de gemas axilres: no nó cotiledonar, as gemas dos cotilédones e das folhas 1 e 2 (gemas axilares basais), se desenvolvem em ramos; acima dessa região da folha 3 até a folha 12, as gemas estão sob forte inibição, mais acima, depois da folha 12, a inibição é mais fraca e mesmo em plantas intactas, essa gemas aparecem, porém apresentam pouco crescimento. No hipocólito das plantas de linho, pode haver a diferenciação de gemas adventícias que geralmente não se desenvolvem. Em vários estudos realizados sobre dominância apical, ou seja, a inibição de crescimento de gemas axilares exercida pela gema apical, é relativo o envolvimento de auxina e citocinina no processo correlativo. Este trabalho estudou o controle do desenvolvimento de gemas e ramos auxiliaes e hipocotiledonares de linho, através de experimentos envolvendo a remoção de órgãos e tratamento com auxina, Tiba e citocinina. Nos primeiros estádios de seu desenvolvimento, as axilares basais sofrem influencias inibitórias da auxina apical. Mais tarde esses ramos apresentam crescimento vigoroso e não são afetados pela presença do ápice ou por sua substituição por auxina. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: Not informed.
Mestrado
Mestre em Ciências Biológicas

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37

DeMars, Brent Gordon. "Nutrient dynamics and resorption in four understory woodland plants and notes on the mycorrhizal status of some typically nonmycorrhizal plants /". The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487863429091484.

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38

Murphy, Kenneth P. "Mineral nutrition of micropropagated plants". Thesis, University of Central Lancashire, 1997. http://clok.uclan.ac.uk/20235/.

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Aspects of the mineral nutrition of plants in in vitro cultures were studied in Delphinium 'Princess Caroline' and Hosta 'Fladspen Blue', two species with contrasting growth habits. Initially methods for accurately measuring mineral concentrations within gelled culture media using atomic absorption spectrophotometry were developed and verified. The effects of light, EDTA, phosphate and agar concentration on mineral availability were studied. Substantial quantities of mineral impurities are introduced by the inclusion of agar and sucrose in culture media and significant precipitation was shown to occur within culture media and to be mediated by the absolute phosphate concentration of the medium. The chelating agent EDTA was most beneficial to growth when used in an equimolar ratio with iron. Rates of mineral diffusion in agar-gelled media were measured for a range of gel strengths. It was shown that the diffusion of phosphate was inhibited more than that of other minerals and also that the restriction of diffusion was dependant on the concentration of agar used. The common antagonistic interaction between potassium and magnesium was found not to occur in Murashige and Skoog medium, possibly because of the different structure of an agar-gelled medium compared with that of a typical soil. Plant growth and the associated depletion of medium mineral reserves were studied over extended culture periods and showed a rapid depletion of phosphate from the culture medium, a low rate of iron uptake in both species and low tissue phosphate concentrations. Medium pH was significantly affected by the plants and a possible link between medium pH and the relative uptake of nitrate and ammonium was investigated. The rapid initial pH changes in Delphinium cultures were shown not to be the result of differential nitrate and ammonium uptake rates though pH shifts in the culture medium were reflective of the relative supply and uptake of ammonium and nitrate in Hosta cultures. The growth of Delphinium plants was affected by the nitrogen source in the culture medium though Hosta plant growth was unaffected. The role of the gaseous environment within the culture vessels was investigated with a view to determine the effect of the high humidity in culture vessels. Using culture vessels with filter-paper covered apertures the gaseous composition and humidity, along with plant growth and mineral uptake, were measured. Gas exchange was significantly increased by the use of the aperture vessels, however humidity was not strongly affected. Plant growth and mineral uptake were largely unaffected by increased gas exchange though ex vitro survival was improved. An investigation of the kinetics of phosphate uptake showed that uptake was strongly linked to the medium concentration though 28day old Delphinium plants did exhibit high affinity phosphate uptake. In addition 7day old plants of both species exhibited more rapid uptake of phosphate than either older or younger plants. This was thought to be because of higher stress at the start and end of subculture periods reducing uptake in 2 and 28day old plants. The possibility of phosphate and iron as growth limiting factors is discussed in the context of a model detailing the major factors involved in the mineral nutrition of plants in vitro.

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39

Costa, Maria da. "Plantas medicinais no ensino de biologia do Timor-Leste". Universidade Federal de Goiás, 2010. http://repositorio.bc.ufg.br/tede/handle/tede/4287.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This dissertation aims to present a project to improve the teaching of biology using medicinal plants as teaching material. This paper contains an overview of history and culture of East Timor and education in various periods, a comparison of some official documents of Brazil and Timor-Leste, a description of visits made to schools and communities who use medicinal plants for the teaching of biology in Brazil, the project to be submitted to the Ministry of Education of Timor-Leste titled: Use of medicinal plants in the teaching of biology of Timor-Leste. We present, finally, the concluding remarks and an appendix with medicinal plants to be used in the project with Secondary School teachers in Timor-Leste.
A presente dissertação tem como objetivo, apresentar um projeto de melhoria do ensino de biologia, utilizando as plantas medicinais como material didático. Este trabalho contém uma visão histórica do Timor-Leste e da educação naquele país nos diversos períodos de sua existência, uma comparação de alguns documentos oficiais do Brasil e Timor-Leste, uma descrição das visitas feitas a escolas e comunidades que fazem uso de plantas medicinais para o ensino de Biologia no Brasil e finalmente o projeto a ser apresentado às autoridades do Timor-Leste, intitulado: Utilização de plantas medicinais no Ensino de Biologia do Timor-Leste.

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40

Ives, David. "Assessing the Impact of Genetically Modified Canola Cultivars on the Biology of Soil". Thesis, Griffith University, 2017. http://hdl.handle.net/10072/370734.

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Biotechnological development of transgenic crops and widespread international adoption has stimulated comprehensive research into their effects on the soil environment. Insects (both target and non-target), weeds, aquatic environments, and soils have all been extensively researched. Since the first commercial GM crop in 1995, the debate surrounding controversial aspects of their biology has polarised issues concerning insects, weeds, and the concentration of technology within a few multinational biotechnology corporations. The effect of transgenic crops on the biology of soils seemed to attract less attention. This thesis examines the interactions between transgenic canola plants through their root exudates and residues with the surrounding soil, its microbes, and their biology. The discovery of the commensal relationship of root exudates and their microbial partners has revolutionised the research into soil microbiology. From this knowledge of soil science, scientists now understand the critical importance of a healthy and abundant soil biome. This thesis focuses on the microbiology of soil. The effects of genotype on soil bacterial and fungal physiology of genetically modified (GM) canola are compared statistically with other cultivars which are genetically modified through conventional plant breeding rather than through genomic engineering, and with the canola cultivar from which the GM variety was developed. The research differentiates the effects of four canola genotypes on microbial DNA and enzymology in a greenhouse trial format. Specifically, the objective of the research is to focus on changes in microbial enzymatic activity of key functional enzymes in protein metabolism, and carbon (C), phosphorus (P), and sulphur (S) mineralisation. The effects on DNA concentration are also studied. The main results of this research generally suggest the effects of cultivar genetic differences with respect to their interactions through root exudates and residues on microbial enzymatic activity are generally not significantly different. Moreover, there are no significant differences in the effect of root exudates on DNA concentrations. This generally accords with the majority of refereed publications and therefore provides confidence to the growing of transgenic canola and to transgenic plants and technology generally. The review and analysis conducted also indicates an emerging trend to broaden the research efforts onto the study of farms and the systems of agriculture under which crops are grown. The findings of this thesis are based on an experimental method and data gathering using phosphorescence to measure changes in enzyme activity and DNA concentration. The statistical analysis employed ANOVA with randomised complete blocking for repeated measures using multiple sampling during the course of the plant‘s lifespan. Further statistical analysis using one-way ANOVA and sequential linear modelling were also employed to study the nature of effects in more detail where the initial analysis suggested significant differences. Furthermore, panel regression analysis examined time-series effects to gain an understanding of how sampling date and therefore stage of the plant‘s growth affected outcomes. The panel analysis indicated that Beta-gluconase enzyme activity significantly influenced soil DNA concentrations. There were limited numbers of occasions when statistical differences between genotypes were found. Overall the experimental results favour the argument that the transgenic canola crops do not damage the soil environment in any significant manner. Therefore it seems that the crops may safely continue to play a major role in meeting the future challenges of world food security. The qualitative data gathered via visits to contributing canola growers during the study enabled comparisons to be made between real world practices with experimental results, as well as results from the literature. Together such a process allowed the author to gain significant insights into the complex decisions the farmers must make in the choice of their employed technologies, including seed genetics. In summary, the major findings are:  minimal impact on protein and amino acid metabolism;  little or no effect on P mineralisation;  carbohydrate metabolism through breakdown of C residues unaffected;  minimal changes in S metabolism;  insignificant differences in DNA concentrations between genotypes;  some insights gained into the nutrient needs of microorganisms;  measurement by phosphorescence is both practical and inexpensive;  there were a number of environmental advantages emerging from the use of GM technology, including improved accumulations of soil carbon through organic matter increase and improvement in soil structure and fertility, as well as changes to less toxic and persistent herbicides;  productivity improvement created by GM technology is comparable with results from conventional plant breeding There are some limitations to the study that should be noted, as follows:  The impact of herbicides on microbial physiology was not explored due to aspects beyond the scope of this study;  The study on the whole was a greenhouse situation and did not directly involve farms;  The study was limited to one soil type (Vertisol) as a second soil type (Chromosol) inhibited germination and growth of the canola seedlings. An attempt to explore the types and Orders of microbes and how they changed during the development of the various plant genotypes was unsuccessful technically. The following areas are suggested as being relevant for further investigation:  Phospho Lipid Fatty Acid extractions and genomic techniques remain desirable technologies if resources and experience are available to implement them. These complex technologies can quantify individual microorganisms, including pathogens, giving deeper understanding;  Additional information about the effect of herbicides on the criteria being measured would be helpful in differentiating their impact alone on microbial function. This would require special analytical chemistry procedures for herbicide residue extraction and chromatography, a larger study, and greater financial resources;  Translating the experiment to a field study over several years in differing soil types would produce additional information such as yields, production penalties, respective costs, and practical outcomes, as well as soil microbial effects and thus provide a complete picture for the issues involved. Hence a clearer choice of the systems under which different cultivars are grown can be related to environmental outcomes.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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41

Pereira, Roman. "Expression of HPV-16 L2 in plants". Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/4317.

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Includes bibliographical references (leaves 77-84).
This study demonstrates high level expression of L2, 25 mg.kg⁻¹of leaf material, is achievable. Interestingly, expression was best when coded for by a mammalian codon-optimized form of the L2 gene as opposed to the wildtype or plant codon-optimized (plantized) genes. Moreover, real time PCR revealed limited levels of transcript when coded for by the plantized gene in comparison to the other genes. A set of vectors which target the protein to the cytoplasm, the endoplasmic reticulum (ER), chloroplast or apoplastic space were Expression of HPV -16 L2 in Plants used and it was found that targeting of the protein had no effect on its expression levels.

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42

Rutter, Brian D. "Contents and Functions of Extracellular Vesicles Isolated from Plants". Thesis, Indiana University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=13808326.

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Extracellular vesicles (EVs) are small, lipid compartments that function in the long-distance transport of proteins, nucleic acids and other metabolites. In mammals, EVs are important vehicles of intercellular communication and play a crucial role in modulating immune responses. Plant cells also secrete EVs, particularly in response to infection, but the contents of these vesicles have not been analyzed and their function is unknown. To better understand plant EVs and their roles in defense and signaling, I first pioneered methods for isolating and purifying EVs from the intercellular wash of Arabidopsis leaves. Secondly, I examined the protein and RNA contents of purified EVs. Proteomic analyses revealed that Arabidopsis EVs are enriched for defense- and stress-related proteins. Consistent with this finding, EV secretion was enhanced in response to biotic stress. Furthermore, a collaboration with Blake Meyer’s laboratory at the Donald Danforth Plant Science Center identified several species of small RNA in purified EV samples, as well as a surprising enrichment for tiny RNAs (tyRNAs) 10 to 17 nt long. Finally, by examining the interactions between Arabidopsis EVs and the plant pathogenic fungus Colletotrichum higginsianum, I discovered that plant EVs associate with fungal structures and affect developing fungal morphology. Combined, my research represents a significant advancement in the field of plant EV research. It provides strong evidence for the involvement of plant EVs in the immune response and suggests they are capable of trafficking proteins and RNAs into invading pathogens.

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43

Holmes, Jennifer K. "A Phylogentic Analysis of PLATZ Transcription Factors in Plants". University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo149339721432989.

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44

Carneiro, Andrea Almeida. "Analyses of curcurbit P-protein promoters in transgenic plants". Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/298810.

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P-proteins are structurally distinct proteins present in the sieve element-companion cell complexes of phloem tissue. Genomic clones encoding the two major P-proteins, the phloem filament protein (PP1) and the phloem lectin (PP2), were isolated and characterized. To understand mechanisms that control phloem-specific expression of these two genes, approximately 1 kb of the 5' flanking region from PP1 and PP2 genomic clones were fused with the GUS reporter gene and introduced into tobacco plants using Agrobacterium tumefaciens-mediated gene transfer. For both promoters, histochemical staining detected GUS activity specifically in the phloem tissue that was most easily detected in stems followed by midrib, secondary veins, roots, and leaf lamina of transgenic tobacco plants. GUS activity directed by the PP2 promoter was approximately 23 times greater than GUS activity directed by the PPI promoter. A nested set of 5' deletions between nucleotides -1014 and +32 were constructed to localize cis-elements that specify the patterns of PP2 gene expression in the phloem. Deletions within this region revealed that nucleotides -228 to +32 relative to the transcription initiation site contained sufficient information to direct phloem-specific gene expression, while positive regulators of promoter activity appeared to be located upstream of nucleotide -621. Mutation of a conserved 13-bp sequence, TTAAAAGAAGATA, found in the minimal PP2 promoter did not affect reporter gene expression. Sucrose responsive elements were identified in the PP2 promoter that could contribute to increased promoter activity in response to sugar. Finally we initiated studies to construct a phloem-specific promoter that could be induced by wound released compounds such as ethylene. Although not conclusive, our results suggest that it is possible to enhance phloem-specific expression in response to ethylene.

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45

Campbell, Lesley Geills. "Rapid evolution in a crop-weed complex (Raphanus spp.)". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1166549627.

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46

Bazile, Vincent. "Diversité des stratégies de nutrition chez les plantes à urnes du genre Nepenthes : le rôle du fluide digestif, de ses propriétés physicochimiques et biotiques". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS290.

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Le genre Nepenthes regroupe environ 160 espèces de lianes carnivores, principalement situées en Asie du Sud-Est, sur des sols pauvres en nutriments assimilables. L’apex de leurs feuilles est modifié en une vrille portant une urne qui leur permet de capturer des proies et d’acquérir des nutriments, principalement de l’azote. Réputées toutes insectivores, avec des urnes équipées de cire glissante sur la paroi interne et un liquide enzymatique à rôle digestif, ces plantes ont en fait un régime alimentaire plus diversifié. Des espèces sont coprophages, détritivores ou encore spécialisées sur une guilde particulière d’insectes. Elles poussent dans des milieux variés, plus ou moins ouverts, sur sols sableux ou tourbeux. Les traits fonctionnels des pièges de Nepenthes varient selon les espèces, avec présence ou non d’une collerette attractive, d’une zone cireuse glissante, et un liquide, viscoélastique ou non, hébergeant une faune spécifique (inquilines). Ces traits peuvent représenter autant d’adaptations attestant d’une diversité de stratégies de séquestration de l’azote. Beaucoup d’études se sont intéressées au rôle des parois glissantes dans la capture des insectes, peu aux propriétés du fluide digestif. La quantité d’azote disponible du milieu et la forme sous laquelle il se présente influencent-elles la concentration en azote des feuilles de la plante, l’origine de ses ressources azotées et son degré de carnivorie ? Quel est le rôle du fluide dans la capture et la digestion des proies, dans la stratégie de séquestration de l’azote de la plante ? Quid des différences d’acidité, de viscoélasticité ou de pool enzymatique entre espèces ? Des différences d’abondance et de composition de la faune inquiline ? Quelles sont les conséquences de toutes ces différences en termes de recyclage d’azote pour la plante ?Cette thèse explore la contribution du fluide digestif, de ses propriétés physico-chimiques et biotiques à la capture et la digestion des proies de 7 espèces de Nepenthes du Brunei (Bornéo).Dans un premier volet, nous montrons que les espèces sont adaptées à des milieux de richesse variée en azote édaphique et biotique grâce à différentes stratégies d’acquisition de l’azote. Le contenu des urnes montre une variation du degré d’insectivorie. La diversité de leurs traits fonctionnels expliquerait les différences dans la nature des proies et l’efficacité de capture. Nectar extrafloral, fluide digestif acide et cire épicuticulaire glissante sont associés à la capture de fourmis, trichomes glandulaires, fourmi symbiotique et urnes cylindriques à la capture de termites et enfin, fluide acide et viscoélastique, mais surtout urne en entonnoir, à grande ouverture et production d’odeur florale expliquent l’abondance d’insectes volants. Les espèces varient aussi fortement dans leurs sécrétions enzymatiques et dans leurs cortèges d’inquilines. Dans un second volet, nous montrons in situ que les propriétés physicochimiques et biotiques du fluide expliquent en partie les différences de stratégies d’acquisition de l’azote chez les Nepenthes. Le pH et la viscoélasticité du fluide influencent la quantité et la nature des proies capturées. Ses propriétés physicochimiques conditionnent également la richesse de l’écosystème aquatique associé au fluide, avec une macrofaune aquatique plus abondante et diverse dans les urnes au liquide peu acide et au diamètre d’ouverture large. Cette macrofaune inquiline joue un rôle important dans la dégradation des proies, et la présence d’un top-prédateur s’avère essentielle dans le recyclage de l’azote. Nous discutons enfin du rôle majeur du fluide dans le régime alimentaire de la plante et dans la probable radiation adaptative du genre Nepenthes et concluons par une réflexion sur les différentes formes de carnivorie observées chez ces plantes et leurs systèmes de digestion, allant d’une stratégie agressive autonome à une stratégie mutualiste, redéfinissant par-là le concept de carnivorie dans le monde végétal
The Nepenthes carnivorous plants genus encompasses about 160 species growing mostly in Southeast Asia in habitats characterised by their scarcity in absorbable nutrients. The leaf apex is modified into a tendril bearing a pitcher trap which allows the plant catching its prey and taking up the nutrients indispensable for its growth, mainly nitrogen. Reputed to be insectivorous, bearing traps equipped with a slippery wax covering the inner pitcher wall and with an enzymatic liquid involved in the digestion, Nepenthes species actually have a more diverse diet. Coprophagous, detritivorous, and insect-guild specialised species have been reported. These plants grow in more or less open environments, on sandy or peaty soils. Nepenthes traps show an inter-specific diversity of functional traits, bearing or not an attractive collar, a slippery waxy zone, and a viscoelastic liquid, which shelters a species-specific living infauna. Such different traits may reflect as many adaptations attesting to a diversity of nitrogen-sequestration. Many studies have focused on the role of slippery walls in insect capture but few of them have investigated the importance of the digestive fluid in both capture and digestion. Do the quantity of nitrogen available in the environment and the form of its availability influence the nitrogen foliar concentration of these plants, the source of their nitrogen supply and their carnivorous habit? How does the fluid influence prey capture and digestion? Can it contribute to the nitrogen-sequestration strategy of the plant? Do the fluids differ in their acidity, viscoelasticity, enzymatic pool, and in the abundance and species diversity of their infauna? What are the consequences of all these differences in terms of nitrogen recycling for the host plant?This PhD thesis explores the contribution of the digestive fluid and its physico-chemical and biotic properties on prey capture and digestion in 7 Nepenthes species in Brunei (Borneo).The first part shows that Nepenthes species have adapted to habitat differing in edaphic and biotic nitrogen available through distinct strategies of nitrogen acquisition. Pitcher contents’ analyses show that plants vary for their degree of insectivory. The variety of functional traits could explain the differences in their capture efficiency and prey diversity. While extrafloral nectar, slippery epicuticular wax and acidic fluid pH are associated with ants’ capture, cylinder-shaped traps, glandular trichomes and ant-association increase termites’ capture. Yellow colour, acidic pH and fluid viscoelasticity but above all, pitcher conicity, wide aperture diameter and magnitude of floral odour account for the abundance of flying insects. These Nepenthes species also strongly vary in their enzymatic secretions and inquilines spectra.In a second part, we show in situ how such differences in physico-chemical and biotic properties of the fluid partly account for the differences in nitrogen-sequestration strategy in these plants. Fluid pH and viscoelasticity influence the quantity and the nature of prey. Those physico-chemical properties also condition the richness of the aquatic ecosystem associated to the fluid, with an aquatic macrofauna more abundant and diverse in pitchers with lowly-acidic liquids and wide pitcher-openings. This inquiline macrofauna plays an essential role in prey degradation, and the presence of a top-predator is crucial for the nitrogen recycling to the plant.We finally discuss the major contribution of the fluid in the plant’s diet and its role in the probable adaptive radiation of the Nepenthes genus and conclude by a survey of the various forms of carnivory in these plants and their digestive systems, which range from an autonomous aggressive strategy to a mutualistic strategy, thus redefining the concept of carnivory in the plant’s world

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47

Haq, Md I., e Aruna Kilaru. "FATTY ACID AMIDE HYDROLASE IN NAE METABOLIC PATHWAY IN PHYSCOMITRELLA PATENS". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/199.

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In plants, saturated and unsaturated N-acylethanolamines (NAEs) with acyl chains 12C to 20C are reported for their differential levels in various tissues and species. While NAEs were shown to play a vital role in mammalian neurological and physiological functions, their metabolism and functional implications in plants however, remain incomplete. Fatty acid amide hydrolase (FAAH) is one of the metabolic enzymes that breaks the amide bond in NAEs to release free fatty acid and ethanolamine. FAAH orthologs, putative PpFAAHs (Physcomitrella patens FAAH) were identified based on the sequence blast of ratFAAH, and named as PpFAAH1 to PpFAAH10. Based on the highest mRNA expression of the PpFAAH homologs upon NAE treatment, PpFAAH1 was selected for further in vitro characterization, which shares 31% sequence identity with ratFAAH. PpFAAH1 was heterologously expressed in E. coli and purified for characterization. Highest amidohydrolysis activity of PpFAAH1 was observed in vitro at pH 8.0 and temperature 37°C. Methoxy arachidonyl fluorophosphonate (MAFP), an inhibitor showed highest inhibition with 10mM concentration, however, one of the principal classes of FAAH inhibitor O-aryl carbamates (URB597) exhibited only 22% inhibition with the same concentration. Both in vivo and in vitro studies showed that unsaturated NAE substrate (NAE 20:4) is hydrolyzed faster than the saturated NAE (NAE16:0); more than 50- and 10-fold higher in vitro and in vivo assays, respectively. Amidohydrolase activity in vivo was mostly associated with microsomes compared with cytoplasmic fractions. Additionally, microsomal fraction of mature gametophytes showed higher amidohydrolase activity than of the protonemal or early gametophyte stages; however, PpFAAH expression was not significantly different between the developmental stages. Further functional characterization of NAE metabolic pathway is ongoing by generation of PpFAAH knock out (KO) and overexpressor (OE) to understand the biological implications of FAAH in growth and development of early land plants.

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48

Patel, Cheril, e Gerardo Arceo-Gomez. "Understanding Variation in The Effects of Heterospecific Pollen Receipt: The Effect of Pollen and Recipient Traits". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/158.

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Co-flowering plants within communities typically share pollinators which can lead to the deposition of pollen grains from varying species onto stigmas; or heterospecific pollen transfer (HPT). It has been shown that HPT can have varying effects on plant reproductive success. These effects can range from an 80% reduction on seed production to no effect. However, to date, there are no studies that have evaluated the causes underlying variability of these effects. We investigated this variability through a greenhouse experiment. Hand-pollinations were conducted with a mix of conspecific and heterospecific pollen and a control (conspecific pollen only). We used six pollen recipient and four species as donors for the heterospecific pollen (5 treatments total) We conducted hand-pollinations on a minimum of 10 plants per species (584 total pollinations). After pollination seed set data was recorded for each treatment and the amount of conspecific and heterospecific pollen on stigmas was recorded. We evaluated if the effects of HPT can be explained by the recipient species, the donor species or the interaction between donor and recipient. The results show high variability in the magnitude of HPT(2-93) but this variability is not a result of donor characteristics or even recipient characteristics but a result of the interactions between donors and recipients (df=20, α=.05, p=0.015). We will further investigate if the interaction can be explained by stigma/pollen size ratio, degree of co-flowering, or phylogenetic distance between donor and recipient species. This study will contribute to advance our understanding of how co-flowering plant communities interact amongst themselves after pollination.

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49

Willett, Deanna Allyn. "Temperature-regulated proteins in plants". Thesis, The University of Arizona, 1999. http://hdl.handle.net/10150/291647.

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Studies in this thesis concern expression of one class of small HSPs (sHSPs) in field grown desert plant species and the isolation of a new HSP gene encoding an sHSP targeted to plant mitochondria. Expression of class I, cytosolic sHSPs was assessed in three desert species: Screwbean Mesquite, Baja Fairyduster, and Sweet Acacia. Total leaf protein, and if available, flower and pod protein, was extracted from samples and analyzed by SDS-PAGE and Western blotting. Sweet Acacia showed strong sHSP expression in leaves with an apparent diurnal pattern of increased expression in the hotter PM. Screwbean Mesquite pods showed significant sHSP expression, which was not correlated to temperature. The isolation and sequence analysis of a gene encoding a mitochondrion-localized sHSP from Arabidopsis was completed. Comparisons to other plant sHSPs verified it was most similar to other mitochondrial-localized sHSPs from plants.

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50

Choe, Sunghwa. "Genetics and biology of Arabidopsis brassinosteroid dwarf mutants". Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/298758.

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Brassinosteroids (BRs) have long been known to be effective in plant growth promotion. However, definitive evidence of BR's role in growth stimulation has remained unclear. Recently, genetic approaches using BR-deficient dwarf(dwf) mutants have begun to unravel the role of BRs in plant growth and development. BR dwarf mutants are characterized by multiple growth alterations: robust stem, reduced fertility, prolonged life cycle, dark-green appearance, round and curled leaves, and when grown in the dark, short hypocotyls and expanded cotyledons. Genetic analysis of the dwf mutants defined eight independent genetic loci defective in BR biosynthesis or perception. Allelism tests with previously reported genes revealed that d̲i̲m̲inuto 1 (dim1) was an allele of dwf1, and dwf2, dwf3, and dwf6 are allelic to b̲r̲assinosteroid i̲nsensitive (bri), c̲onstitutive p̲hotomorphogenesis and d̲warfism (cpd), and d̲e̲-e̲t̲iolated2 (det2), respectively. dwf4, dwf5, dwf7, and dwf8 were found to be novel and are the focus of this research. Anatomical analysis demonstrates that a reduction in cell length causes dwarf phenotype. Dwarfism was rescued by exogenous application of BRs. Feeding studies utilizing BR biosynthetic intermediates were employed to identify defective steps of BR biosynthesis in each of these dwarf mutants. dwf4 mutants were rescued only by 22α hydroxylated BRs, suggesting that the 22α hydroxylation reactions, putative rate-determining steps, are blocked. In fact, DWF4 has been cloned and shown to encode a cytochrome P450 steroid hydroxylase. Feeding studies also showed that dwf8 plants are rescued only by intermediates after 3 dehydrogenation reactions, indicating that the 3-dehydrogenase is defective in dwf8 plants. Gas Chromatography-Selective Ion Monitoring (GC-SIM) analysis of endogenous BRs in dwf5 plants showed that the level of 24-methylene cholesterol is greatly diminished as compared to wild type, suggesting that the biochemical defect occurs before 24-methylene cholesterol. Similar to dwf5, the biosynthetic defect in dwf7 is also shown to be in a step before 24-methylene cholesterol. The pleiotropic phenotypes in these dwf mutants due to biochemical defects in BR biosynthesis suggests that BRs are essential for proper growth and development of plants.

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Tesi sul tema "Plant's biology"

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