Dissertations / Theses on the topic 'Plant defenses'
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Prusak, Anne C. "Activated and constitutive chemical defenses in freshwater plants." Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131334/unrestricted/prusak%5Fanne%5Fc%5F200405%5Fms.pdf.
Full textHeckman, Melanie L. "A test of optimal defense theory vs. the growth-differentiation balance hypothesis as predictors of seaweed palatability and defenses." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42720.
Full textTsuji, Kaoru. "Sexual difference in plant defenses and herbivore adaptation." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/157819.
Full textFung, King-leung. "Purification of Brassica juncea chitinase BJCHI1 from transgenic tobacco." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22956347.
Full textWinger, Alison Marie. "Impact of 4-hydroxy-2-nonenal in Arabidopsis mitochondria /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0121.
Full textBrown, Rebecca L. "Regulation of jasmonate-dependent defence responses in arabidopsis /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16087.pdf.
Full textSá, Mário Moniz de. "Induction of phenylpropanoid metabolism in elicitor-treated hybrid poplar suspension-cultured cells." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30296.
Full textScience, Faculty of
Botany, Department of
Graduate
Shoemaker, Erica Felton Gary W. "Lepidopteran larval salivary secretions and their effect on tomato plant defenses." [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/PSUonlyIndex/ETD-4633/index.html.
Full textMahadevan, Geetha B. "Viral suppression of host defenses." Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0507104-110551.
Full textKatsir, Leron J. "Biochemical characterization of the COI1-JAZ receptor for jasmonate." Diss., Connect to online resource - MSU authorized users, 2008.
Find full textWest, Christopher. "The effect on phytophagous insects of variations in defence mechanisms within a plant." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670399.
Full textMohr, Peter G., and lswan@deakin edu au. "Abscisic acid regulation of plant defence responses during pathogen attack." Deakin University. School of Biological and Chemical Sciences, 2004. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20060927.120049.
Full textBecker, John van Wyk. "Plant defence genes expressed in tobacco and yeast." Thesis, Stellenbosch : University of Stellenbosch, 2002. http://hdl.handle.net/10019/2924.
Full textWinger, Alison Marie. "Impact of 4-hydroxy-2-nonenal in Arabidopsis mitochondria." University of Western Australia. Biochemistry and Molecular Biology Discipline Group, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0121.
Full textGodschalx, Adrienne Louise. "Symbiosis with Nitrogen-fixing Rhizobia Influences Plant Defense Strategy and Plant-predator Interactions." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3644.
Full text馮景良 and King-leung Fung. "Purification of Brassica juncea chitinase BJCHI1 from transgenic tobacco." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31224374.
Full textMeakem, Victoria. "Induced defenses in apple fruits: linking fruit chemistry, quality, and plant-insect-microbe interactions." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99100.
Full textMaster of Science
Plants may produce a diverse array of defensive phytochemical compounds in response to interactions with herbivores, pathogens, and the microorganisms that reside within plant tissues. These phytochemicals may simultaneously improve crop defenses and quality, representing a potential agricultural management strategy. However, plant chemical responses to different types and levels of biotic interactions are not well-understood, particularly in fruit tissues, and the feasibility of activating these defenses in fruits through the application of phytohormones that regulate defense pathways as a potential management strategy also requires further examination. Thus, apples were used to 1) examine the impact of distinct communities of biotic interactions among plants, insects, and microbes on fruit chemistry, focusing on phenolics, an important class of phytochemical compounds, and 2) examine the impact of the defense-activating phytohormones jasmonic acid (JA), salicylic acid (SA), and melatonin (M) on fruit phenolic chemistry and resistance against pests and pathogens. Ultimately, phenolic defenses were activated by fungal damage primarily in ripe pulp tissues, where there was also a positive relationship between fungal endophyte and phenolic diversity, supporting a broad hypothesis that chemical diversity may increase with biotic diversity. Additionally, two compounds were produced in response to fungal damage: chlorogenic acid and an unidentified benzoic acid. Phytohormone applications did not affect phenolic chemistry, but the application of the combined JA-SA analogues had some chemical or physical effect, as this treatment reduced emergence of the insect Rhagoletis pomonella. Overall, the phytochemical defenses activated by biotic interactions in fruits may occur primarily in certain tissue types, and may also vary due to environmental conditions, time of year, or plant species. These chapters examined the relationship between fruit chemistry and biotic interactions with the goal of improving understanding of plant-microbe-insect interactions and incorporating these interactions into more sustainable agricultural practices.
Badruzsaufari. "Molecular analysis of cross communication between signal transduction pathways during pathogen resistance response in Arabidopsis thaliana /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18619.pdf.
Full textMedina-Ortega, Karla Jacqueline. "Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch: Euphorbiacea) Resistance Mechanisms against the Silverleaf Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Biotype B." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306856939.
Full textMajorczyk, Alexis M. "Chemical Defense Mechanisms of Arabidopsis thaliana Against Insect Herbivory: The Role of Glucosinolate Hydrolysis Products." Bowling Green, Ohio : Bowling Green State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1249513273.
Full textMuchlinski, Andrew Joseph. "Identification, Characterization, and Functional Analysis of Terpenoid Specialized Metabolism in Switchgrass (Panicum virgatum) and Carrot (Daucus carota)." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/102778.
Full textDoctor of Philosophy
Chow, Hiu Tung. "Arabidopsis miR163 and its target are involved in defense against Pseudomonas syringae." HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/312.
Full textPoreddy, Spoorthi [Verfasser], Ian T. [Gutachter] Baldwin, Rolf G. [Gutachter] Beutel, and Philippe [Gutachter] Reymond. "Probing the herbivores responses to plant defenses using plant-mediated RNAi / Spoorthi Poreddy ; Gutachter: Ian Thomas Baldwin, Rolf G. Beutel, Philippe Reymond." Jena : Friedrich-Schiller-Universität Jena, 2016. http://d-nb.info/1177612267/34.
Full textBecker, John van Wyk 1975. "Evaluation of the role of PGIPs in plant defense responses." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/17476.
Full textENGLISH ABSTRACT: Plants have developed sophisticated means of combating plant diseases. The events that prepare the plant for, and follow plant-pathogenic interactions, are extremely complex and have been the topic of intensive investigation in recent years. These interactions involve a plethora of genes and proteins, and intricate regulation thereof; from the host and pathogen alike. Studying the contribution of single genes and their encoded proteins to the molecular dialogue between plant and pathogen has been a focus of plant molecular biologists. To this end, a gene encoding a polygalacturonase-inhibiting protein (PGIP) was recently cloned from Vitis vinifera. These proteins have the ability to inhibit fungal endopolygalacturonases (ePGs), enzymes which have been shown to be required for the full virulence of several fungi on their respective plant hosts. The activity of PGIP in inhibiting fungal macerating enzymes is particularly attractive for the improvement of disease tolerance of crop species. The VvPGIP-encoding gene was subsequently transferred to Nicotiana tabacum for high-level expression of VvPGIP. These transgenic plants were found to be less susceptible to infection by Botrytis cinerea in an initial detached leaf assay. Also, it was shown that ePG inhibition by protein extracts from these lines correlated to the observed decrease in susceptibility to B. cinerea. This study expands on previous findings by corroborating the antifungal nature of the introduced PGIP by whole-plant, timecourse infection assays. Six transgenic tobacco lines and an untransformed wildtype (WT) were infected and the lesions measured daily from day three to seven, and again at day 15. The transgenic lines exhibited smaller lesions sizes from three to seven days post-inoculation, although these differences only became statistically significant following seven days of incubation. At this point, four of the six lines exhibited significantly smaller lesions than the WT, with reductions in disease susceptibility ranging between 46 and 69% as compared to the WT. Two of the lines exhibited disease susceptibility comparable to the WT. In these resistant plant lines, a correlation could be drawn between Vvpgip1 expression, PGIP activity and ePG inhibition. These lines were therefore considered to be PGIP-specific resistant lines, and provided ideal resources to further study the possible in planta roles of PGIP in plant defense. The current hypothesis regarding the role(s) of PGIP in plant defense is twofold. Firstly, PGIPs have the ability to specifically and effectively inhibit fungal ePGs. This direct inhibition results in reduced fungal pathogenicity. Alternatively, unhindered action of these enzymes results in maceration of plant tissue and ultimately, tissue necrosis. Subsequently, it could be shown that, in vitro, the inhibition of ePGs prolongs the existence of oligogalacturonides, molecules with the ability to activate plant defense responses. Thus, PGIPs limit tissue damage by inhibition of ePG; this inhibition results in activation of plant defense responses aimed at limiting pathogen ingress. Several publications reported reduced susceptibility to Botrytis in transgenic plant lines overexpressing PGIP-encoding genes. However, none of these publications could expand on the current hypotheses regarding the possible in planta roles of PGIP in plant defense. In this study we used transgenic tobacco lines overexpressing Vvpgip1 as resources to study the in planta roles for PGIP. Transcriptomic and hormonal analyses were performed on these lines and a WT line, both before and following inoculation with Botrytis cinerea. Transcriptomic analysis was performed on uninfected as well as infected tobacco leaf material utilizing a Solanum tuberosum microarray. From the analysis with healthy, uninfected plant material, it became clear that genes involved in cell wall metabolism were differentially expressed between the transgenic lines and the WT. Under these conditions, it could be shown and confirmed that the gene encoding tobacco xyloglucan endotransglycosylase (XET/XTH) was downregulated in the transgenic lines. Additionally, genes involved in the lignin biosynthetic pathway were affected in the individual transgenic lines. Biochemical evidence corroborated the indication of increased lignin deposition in their cell walls. Additionally, phytohormone profiling revealed an increased indole-acetic acid content in the transgenic lines. These results show that constitutive levels of PGIP may affect cell wall metabolism in the Vvpgip1-transgenic lines which may have a positive impact on the observed reduced susceptibilities of these plants. An additional role for PGIP in the contribution to plant defenses is therefore proposed. PGIP may directly influence defense responses in the plant leading to the strengthening of cell walls. This might occur by virtue of its structural features or its integration in the cell wall. These reinforced cell walls are thus “primed” before pathogen ingress and contribute to the decrease in disease susceptibility observed in lines accumulating high levels of PGIP. Transcriptional and hormonal analyses, at the localized response, were performed on Botrytis-infected leaf tissue of the transgenic lines and a WT line. Several Botrytis responsive genes were found to be upregulated in both the WT and the transgenic lines. Although limited differential expression was observed between the two genotypes, the analyses identified a gene which was upregulated two-fold in the transgenic lines, as compared to WT. This was confirmed by quantitative Real-Time PCR. This gene is involved in the lipoxygenase pathway, specifically the 9-LOX branch, leading to the synthesis of the divinyl ether oxylipins colneleic and colnelenic acid, which show inhibitory effects on Botrytis spore germination. Phytohormone profiling revealed that the transgenic lines accumulated more of the defense-related hormone pool of jasmonates. These are formed via the 13-LOX pathway and have been shown to be important for the restriction of Botrytis growth at the site of infection. Collectively, the results from the infection analyses indicate that in these transgenic lines, both branches of the lipoxygenase pathway are differentially induced at the level of the localized response to Botrytis infection. Similarly, an increased induction of the synthesis of the defense-related hormone salicylic acid could be observed, although this hormone did not accumulate to significantly higher levels. These results are the first report of differential induction of a defense-related pathway in pgip-overexpressing lines and substantiate the proposal that following ePG inhibition by PGIP, signaling which activates plant defense responses, takes place. Taken together, these results significantly contribute to our understanding of the in planta role of PGIP in plant defense responses.
AFRIKAANSE OPSOMMING: Plante het deur evolusie gesofistikeerde meganismes teen die aanslag van plantsiektes ontwikkel. Die gebeure wat die plant voorberei, asook dié wat op plant-patogeen interaksies volg, is uiters kompleks en vorm die kern van verskeie navorsingstemas die afgelope paar jaar. Etlike plant- én patogeengene en proteïene is by hierdie interaksies betrokke en aan komplekse reguleringsprosesse onderworpe. Die bestudering van die bydrae van enkelgene en hul gekodeerde proteïene tot die molekulêre interaksie tussen ‘n plant en patogeen is ‘n sterk fokus van plant-molekulêre bioloë. Met hierdie doel as fokus, is ‘n geen wat vir ‘n poligalakturonaseinhiberende proteïen (PGIP) kodeer, van Vitis vinifera gekloneer. Hierdie proteïene beskik oor die vermoë om fungiese endopoligalakturonases (ePG's), ensieme wat benodig word vir die virulensie van verskeie fungi op hul gasheerplante, te inhibeer. Die inhibisie van ePG's deur PGIP en die gepaardgaande verminderde weefseldegradasie is ‘n baie belowende strategie vir die verbetering van verboude gewasse se patogeentoleransie. Die VvPGIPenkoderende geen is gevolglik na Nicotiana tabacum oorgedra vir hoëvlakuitdrukking van VvPGIP. Daar is gevind dat hierdie transgeniese plante minder vatbaar vir Botrytis cinerea-infeksies was in ‘n inisiële antifungiese toets wat gebruik gemaak het van blaarweefsel wat van die moederplant verwyder is. Daar is ook ‘n korrelasie gevind tussen B. cinerea-siekteweerstand en ePG-inhibisie deur proteïenekstrakte van die transgeniese populasie. Die huidige studie bou voort op en bevestig vorige bevindinge betreffende die antfungiese aard van die heteroloë PGIP in die heelplant en oor tyd. Ses transgeniese tabaklyne en 'n ongetransformeerde wilde-tipe (WT) is geïnfekteer en die lesies is vanaf dag drie tot sewe, en weer op dag 15, gemeet. Die transgeniese lyne het in die tydperk van drie tot sewe dae ná-inokulasie kleiner lesies as die WT getoon, alhoewel hierdie verskille slegs statisties beduidend geword het na sewe dae van inkubasie. Op daardie tydstip het vier van die ses lyne aansienlik kleiner lesies as die WT getoon, en verlagings in siektevatbaarheid het, in vergelyking met die WT, van 46% tot 69% gewissel. Twee van die lyne het siektevatbaarheid getoon wat vergelykbaar was met dié van die WT. In die siekteweerstandbiedende plantlyne was daar 'n verband tussen Vvpgip1-ekspressie, PGIP-aktiwiteit en ePG-inhibisie. Hierdie plantlyne is dus as PGIP-spesifieke siekteweerstandslyne beskou en dien dus as ideale eksperimentele bronne vir die ontleding van die moontlike in plantafunksies van PGIP in plantsiekteweerstandbiedendheid. Die huidige hipotese betreffende die funksie(s) van PGIP in plantsiekteweerstand is tweeledig. Eerstens het PGIP die vermoë om fungusePG's spesifiek en doeltreffend te inhibeer. Hierdie direkte inhibisie veroorsaak ‘n vermindering in patogenisiteit van die fungus op die gasheer. Indien ePG's egter hulle ensimatiese aksie onverstoord voortsit, sal weefseldegradasie en uiteindelik weefselnekrose die gevolg wees. Daar kon ook bewys word dat die in vitroinhibisie van ePG's deur PGIP die leeftyd van oligogalakturoniede, molekules wat die vermoë het om die plantweerstandsrespons aan te skakel, kan verleng. PGIP het dus nie net die vermoë om ePG's, en dus weefseldegradasie, te inhibeer nie; maar hierdie inhibisie lei ook daartoe dat plantweerstandsresponse aangeskakel word met die oog op die vermindering van patogeenindringing. Verskeie publikasies het reeds gerapporteer oor verminderde Botrytisvatbaarheid in PGIP transgeniese plantlyne. Geeneen van hierdie publikasies kon egter uitbrei op die huidige hipotese aangaande die moontlike in planta-funksie van PGIP in plantsiekteweerstand nie. In hierdie studie is transgeniese tabaklyne wat PGIP ooruitgedruk gebruik om hierdie moontlike in planta-funksies vir PGIP uit te klaar. Transkriptoom- en hormonale analises is op hierdie plantlyne en ‘n WT voor en ná inokulasie met die nekrotroof Botrytis cinerea uitgevoer,. Transkriptoomanalises is uitgevoer op ongeïnfekteerde, sowel as geïnfekteerde tabakblaarmateriaal deur gebruik te maak van ‘n Solanum tuberosum-mikroraster. Die analises met gesonde, ongeïnfekteerde plantmateriaal het daarop gewys dat gene betrokke by selwandmetabolisme tussen die transgeniese lyne en die WT verskillend uitgedruk was. Dit kon bewys word dat, sonder infeksiedruk, die geen wat xiloglukaan-endotransglikosilase (XET) kodeer, in die transgeniese lyne afgereguleer was. Gene wat betrokke is in die lignien-biosintetiese pad was ook in die individuele transgeniese lyne beïnvloed. Biochemiese toetse het ook die aanduiding van verhoogde ligniendeposisie in die transgeniese lyne se selwande bevestig. Addisionele fitohormoonprofiele het getoon dat hierdie lyne ook beskik oor verhoogde vlakke van indoolasynsuur (IAA). Hierdie resultate wys daarop dat konstitutiewe vlakke van PGIP selwandmetabolisme in die Vvpgip1-transgeniese lyne moontlik kan beïnvloed, wat plantsiekteweerstand in dié lyne positief kan beïnvloed. Dit wil dus voorkom asof PGIP 'n bykomende funksie in plantsiekteweerstand het. Plantweerstandsreponse kan direk deur PGIP beïnvloed word, wat tot die versterking van plantselwande kan lei; dit kan geskied by wyse van die strukturele eienskappe van die proteïen of die integrasie daarvan in die selwand. Hierdie selwande is dus “voorberei” alvorens patogeenindringing plaasvind en kon bydra tot die verminderde siektevatbaarheid wat waargeneem is in lyne wat hoë vlakke van PGIP akkumuleer. Transkriptoom- en hormonale analises is ook uitgevoer op Botrytisgeïnfekteerde blaarmateriaal van beide die transgeniese lyne en ‘n WT. Verskeie Botrytis-responsgene is in beide die transgeniese lyne en die WT opgereguleer. Differensïele geenekspressie tussen die twee genotipes was taamlik beperk, maar in die analises kon ‘n geen geïdentifiseer word wat tweevoudig in die transgeniese lyne opgereguleer was in vergelyking met die WT. Hierdie resultaat is ook bevestig met behulp van die “Real-Time” Polimerasekettingreaksie (PKR). Hierdie geen is betrokke in die lipoksigenase (LOX) -pad (spesifiek die 9-LOXarm), wat tot die sintese van die diviniel-eter oksilipiene “colneleic-” en “colnelenic”-suur lei. Daar is al bewys dat hierdie twee verbindings Botrytisspoorontkieming kan inhibeer. Fitohormoonprofiele van die geïnfekteerde plante het gewys dat die transgeniese lyne verhoogde vlakke van die poel van jasmonate wat plantsiekteweerstands-hormone is, ná inokulasie akkumuleer. Hierdie hormone word in die 13-LOX-arm van die lipoksigenase pad gevorm en is belangrik vir die beperking van Botrytis by die infeksiesetel. Die resultate van die analises wat op Botrytis-infeksie volg, dui daarop dat beide arms van die lipoksigenasepad in die transgeniese lyne verskillend by die lokale respons geïnduseer word. ‘n Verhoogde induksie van ‘n ander plantsiekteweerstandshormoon, salisielsuur, kon ook opgemerk word, alhoewel die totaal geakkumuleerde vlakke nie beduidend hoër was as dié van die WT nie. Hierdie resultate is die eerste wat onderskeidende induksie van ‘n siekteweerstandspad in enige van die pgip-ooruitgedrukte plantlyne rapporteer. Daarmee ondersteun dit ook die hipotese dat, seintransduksie wat plantweerstandsresponse aanskakel, ná inhibisie van ePG deur PGIP plaasvind. Die resultate wat met hierdie studie verkry is, dra dus beduidend by tot die huidige kennis van die in planta-funksie van PGIP in plantsiekteweerstandsresponse.
Puentes, Adriana. "Plant-Herbivore Interactions and Evolutionary Potential of Natural Arabidopsis lyrata Populations." Doctoral thesis, Uppsala universitet, Växtekologi och evolution, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-183433.
Full textBezerra, Cézar da Silva 1990. "Estudo do potencial inseticida de um inibidor de proteinase de sementes de Inga vera sobre o desenvolvimento de Anagasta kuehniella (Lepidoptera: Pyralidae) : aspectos fisiológicos e bioquímicos." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314533.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-25T23:17:16Z (GMT). No. of bitstreams: 1 Bezerra_CezardaSilva_M.pdf: 16272882 bytes, checksum: c9bdf2bf628fb555d1bc1ccc47c972c5 (MD5) Previous issue date: 2014
Resumo: Os inibidores de proteases de plantas têm sido amplamente estudados como uma alternativa para o controle de insetos-praga devido à capacidade de inibir enzimas envolvidas na digestão. Assim sendo, o objetivo deste trabalho foi estudar a atividade biológica do inibidor de tripsina de sementes de Inga vera (IVTI) sobre o desenvolvimento, fisiologia nutricional e atividade enzimática de Anagasta kuehniellla. Larvas neonatas (n=40) foram mantidas em dieta artificial sem inibidor (controle) ou contendo 1% de IVTI (p/p) até atingirem o quarto e quinto instares. As análises realizadas determinaram o efeito sobre o desenvolvimento destas, desde período larval até emergência dos adultos. Através de outras aferições elaboramos uma tabela de parâmetros nutricionais. A atividade proteolítica do homogenato intestinal e fecal foi analisada através de zimograma e ensaios enzimáticos in vitro, utilizando BApNA e Suc-AAPF-pNA como substratos para tripsina e quimotripsina, respectivamente. IVTI foi incubado com o homogenato intestinal larval para verificar a degradação do mesmo. O consumo de IVTI pelas larvas provocou uma redução de cerca de 50% no peso médio larval e uma redução significativa taxa de sobrevivência de 15%, bem como o prolongamento do período larval em 8 dias. A análise dos índices nutricionais revelou uma redução na eficiência de conversão do alimento ingerido e digerido e um aumento no custo metabólico, sugerindo que IVTI apresenta efeito antinutricional para esta espécie. IVTI alterou a atividade proteolítica intestinal das larvas com a redução atividade tríptica e o aumento da atividade quimotríptica. Na análise fecal, os níveis da atividade tríptica foram semelhantes tanto nas fezes das larvas alimentadas em dieta controle quanto contendo inibidor, entretanto foi observado um aumento no nível da atividade quimotríptica nas larvas alimentadas com inibidor. IVTI não foi degradado pelas enzimas intestinais, sendo excretado nas fezes e permanecendo com sua atividade inibitória ativa. O zimograma não revelou nenhuma forma variante de enzima nas larvas alimentadas com inibidor, mas foi possível observar quais sofreram influências pelo mesmo. Com base nesses resultados, IVTI apresentou uma atividade tóxica e antinutricional contra A. kuehniella
Abstract: Plant protease inhibitors have been extensively studied as an alternative for the control of insect pests because of their ability to inhibit enzymes digestive enzymes. In this work, the biological activity of trypsin inhibitor of Inga vera seed (IVTI) on the development, nutritional physiology and enzyme activity of Anagasta kuehniellla was evaluated. Neonate larvae (n=40) were maintained on artificial diet without inhibitor (control) or containing 1% IVTI (w / w) until fourth and fifth instar. This bioassay determined the effect on the development from the larval period to adult emergence. Through other measurements prepared a table of nutritional parameters. The proteolytic activity of intestinal and fecal homogenate was analyzed by zymography and enzymatic assays, in vitro, using BApNA and Suc-AAPF-pNA as substrates for trypsin and chymotrypsin, respectively. IVTI was incubated with the larval gut and check the degradation of the inhibitor. IVTI consumption by the larvae resulted in a reduction of about 50% of larval weight and a significant larval survival rate of 15%, as well as the extension of the larval period to 8 days. Nutritional analyses showed a reduction of efficiency of conversion of food eaten and digested and an increase in metabolic cost, suggesting that IVTI produces an anti-nutritional effect for this specie. IVTI changed the proteolytic activity in the gut of the larvae with decrease of trypsin activity and increase of chymotrypsin activity. Fecal analyses, the levels of trypsin activity were similar in the feces of larvae fed on control diet as containing inhibitor, however there was an increase in the level of chymotrypsin activity in larvae fed with inhibitor. IVTI was not degraded by intestinal enzymes, but it excreted in the feces and their inhibitory activity remained active. Zymogram revealed no variant form of the enzyme in the larvae fed inhibitor, but was observed which were influenced by it. Based on these results, IVTI presented an anti-nutritional and toxic activity against A. kuehniella
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
Goodman, Keri M. "Freshwater red algae use activated chemical defenses against herbivores." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41208.
Full textPastor, Fuentes María Victoria. "Redox homeostasis, callose and hormonal responses in primed defenses." Doctoral thesis, Universitat Jaume I, 2012. http://hdl.handle.net/10803/565663.
Full textRidenour, Wendy L. "No simple tradeoffs Centaurea plants from America are better competitors and defenders than plants from the native range /." CONNECT TO THIS TITLE ONLINE, 2006. http://etd.lib.umt.edu/theses/available/etd-03292007-102153/.
Full textCrampton, Bridget Genevieve. "Elucidation of defence response mechanisms in pearl millet." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-10132008-143627.
Full textRooke, Tuulikki. "Defences and responses : woody species and large herbivores in African savannas /." Umeå : Dept. of Animal Ecology, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/s276.pdf.
Full textShowalter, David N. "The Nature and Role of Host Defenses in Forest Pest Invasions: A Case Study Using Emerald Ash Borer (Agrilus planipennis)." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1481727081503819.
Full textMorrison, Wendy Elizabeth. "Aquatic plant-herbivore interactions across multiple spatial scales." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34734.
Full textSinclair, Steven J. "QPRTase : a wound-induced defence gene in Nicotiana." Monash University, School of Biological Sciences, 2003. http://arrow.monash.edu.au/hdl/1959.1/6571.
Full textParker, John D. "Plant-herbivore interactions : consequences for the structure of freshwater communities and exotic plant invasions." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/9460.
Full textMuilenburg, Vanessa L. "Biochemistry, physiology, and ecology of paper birch defenses to bronze birch borer and their responses to anthropogenic greenhouse gases." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1291140593.
Full textMay, Bronwen. "Investigations into insect-induced plant responses of water hyacinth (Eichhornia crassipes (Mart.) Solms-Laub.) (Pontederiaceae)." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018906.
Full textDiner, Brandee. "Plant-herbivore interactions between North American porcupines (Erethizon dorsatum) and trembling aspens (Populus tremuloides)." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84024.
Full textHoyos, Rendón Mary Elizabeth. "From signal to gene induction : molecular aspects of bacterial HR /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924888.
Full textOrosa, Puente Beatriz. "Participación del gen AtCPK1 en la defensa de Arabidopsis thaliana frente a patógenos." Doctoral thesis, Universitat de Barcelona, 2011. http://hdl.handle.net/10803/670834.
Full textBerasategui, Aileen [Verfasser], Jonathan [Gutachter] Gershenzon, Erika [Gutachter] Kothe, and Luis [Gutachter] Sampedro. "Conserved gut microbiota in a herbivorous beetle mediates the degradation of host plant defenses / Aileen Berasategui ; Gutachter: Jonathan Gershenzon, Erika Kothe, Luis Sampedro." Jena : Friedrich-Schiller-Universität Jena, 2018. http://d-nb.info/1170396801/34.
Full textPerkovich, Cynthia L. "Responses of oaks to mammal and insect herbivory." Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1619098714170774.
Full textSoriano, Imelda Rizalina. "Novel inducible phytochemical defences against plant parasitic nematodes /." Title page, table of contents and summary only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phs7141.pdf.
Full textShirano, Yumiko. "A Novel Plant Defense Mechanism that Involves A Chloroplastic Lipoxygenase in Rice Plants." Kyoto University, 1998. http://hdl.handle.net/2433/182412.
Full textNguyen, Thi Ngoc nga. "Functional expression of Plant Defensins type 1 for zinc tolerance in plants." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20032/document.
Full textPlant Defensin type 1 (PDF1s) are mainly recognized for their response to pathogen attack via ethylene (Et)/jasmonate (JA) signaling activation pathway. However, PDF1s originating from Arabidopsis genus also showed their capacity to induce cellular zinc tolerance up on expression in yeast. In planta, a group of observation highlighted the correlation of AhPDF1 high transcript accumulation for their contribution to zinc tolerance. Here, transcriptomic analysis (qRT-PCR) revealed that in both A. thaliana and A. halleri species, PDF1 paralogues were barely or not at all responsive to zinc. Nevertheless, there is a species specialization of PDF1s in response to activation of JA-signaling in Arabidopsis genus. In addition, in A. thaliana, the functional contribution of PDF1 members in zinc tolerance was investigated through genetic approach. Examining combination of T-DNA insertion knockout mutant and artificial miRNA, these studies were first direct demonstration of the functional involvement of AtPDF1s in zinc tolerance. These also highlighted the functional diversity among AtPDF1s because not all of them could play a role in zinc tolerance. Indeed, a diversity of PDF1 molecular determinants for zinc tolerance in plants was underlined. Remarkably, PDF1 high transcript is not the only important parameter for zinc tolerance and PDF1 tissue specificity could be an important factor to consider. Moreover, post-transcriptional and post-translational regulation might occur. Studies on these modifications are now the further questions in order to understand the contribution of the different PDF1s to zinc tolerance
Winterer, Juliette. "The ecology and evolution of plant defense, herbivore tolerance, and disease virulence /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/5241.
Full textAït-Salem, Elhosseyn. "Etude de la signalisation contrôlant l’accommodation intracellulaire au cours de la symbiose Medicago/Sinorhizobium The Multiple Faces of the Medicago-Sinorhizobium Symbiosis Control of the ethylene signaling pathway prevents plant defenses during intracellular accommodation of the rhizobia." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS096.
Full textWhen grown under limited nitrogen resources, legumes establish a symbiotic relationship with soil bacteria called rhizobia. This interaction leads to the formation of a new root organ, the nodules. Within nodules, rhizobia differentiate into bacteroids and fix atmospheric nitrogen for the plant. The massive and chronic colonization of nodule symbiotic cells by the rhizobia does not trigger any visible defense reactions. In the laboratory, we previously isolated two symbiotic mutants developing defense reactions in Medicago truncatula nodules, indicating a strict control of the nodule immunity. The thesis project aimed first to understand the relationship between symbiotic genes and immunity mediated by defense hormones and second to find new tools to help to better understand nodules defense mechanisms. For this, molecular, pharmacological and genetic approaches were used. The results obtained in this thesis suggest that the defense mechanisms adopted by M. truncatula vary depending on the plant ecotypes. The A17 ecotype uses two resistance pathways; senescence and defense reactions. While, the R108 ecotype uses defense reactions pathway to fight against rhizobia. This work also suggests that in M. truncatula A17, the SymCRK protein represses jasmonic acid signalling. This work also suggests that in M. truncatula A17, the SymCRK protein represses the jasmonic acid signaling pathway involved in senescence triggering. In contrast, the DNF2 protein mainly represses the salicylic acid signaling pathway involved in defense reactions and also represses the JA pathway. In M. truncatula R108, the two proteins SymCRK and DNF2 control salicylic acid and ethylene signaling pathways involved in triggering defense reactions. DNF2 controls the salicylic acid pathway more than the ethylene signaling pathway, while, SymCRK controls more the ethylene pathway than the salicylic acid signaling pathway in nodules. This thesis also suggests the involvement of R proteins in the control of intracellular accommodation of rhizobia. The intracellular receptor CNL-5 appears to be involved in controlling the infection of symbiotic cells and the receptors CNL-4 and TNL-2 genes appear to be involved in controlling the infection efficacy of the symbiotic cells. Finally, this thesis allowed the identification of a new bacterial strain E. adhaerens, capable of behaving as a symbiont or as a pathogen for several Medicago species. This can be used as a tool to study the nodules defense induction and to understand the rhizobia intracellular accommodation in symbiotic cells
Vallad, Gary Edward. "Potentiation of plant defenses with organic soil amendments /." 2003. http://www.library.wisc.edu/databases/connect/dissertations.html.
Full textMadala, Ntakadzeni Edwin. "Metabolomic studies of biotransformation-related changes in plant metabolism in response to isonitrosoacetophenone treatment." Thesis, 2013. http://hdl.handle.net/10210/8535.
Full textThis thesis concerns a study of the effect of isonitrosoacetophenone on plant metabolism. Three different systems were investigated; cultured tobacco and sorghum cells as well as Arabidopsis thaliana plants, and a metabolomic approach was followed. Unlike most scientific studies, metabolomics is a discipline which is not driven by a specific hypothesis, but rather by the obtained data to add scientific insights to the topic under investigation. As such, the current study lacks a definite overarching hypothesis, but specific objectives were outlined and answered in each experimental chapter. This thesis is therefore presented as a compilation of nine chapters in which experimental/research work is described in Chapter 3- 8. It is important to note that each chapter is presented in accordance with the guidelines for the respective journal in which the corresponding manuscript was published or submitted to.
"Identification of lipopolysaccharide-interacting plasma membrane proteins in Arabidopsis thaliana." Thesis, 2015. http://hdl.handle.net/10210/15087.
Full textDuring microbial invasion, a variety of defense responses are induced in host plants. In order for host plants to combat potential diseases induced by microbes, they must be equipped with pattern recognition receptors (PRRs) localized at the cell surface, since such receptors enable the perception of conserved microbial epitopes termed microbe/pathogen-associated molecular patterns (M/PAMPs), thereby resulting in the activation of plant innate immunity via M/PAMP-triggered immunity (P/MTI). Lipopolysaccharide (LPS) is the major component of the outer leaflet of the external membrane of Gram-negative bacteria. This thermo-stable lipoglycan is exposed towards the external environment and plays an important role in bacterial adaptation to external surroundings. LPS is recognized as a major M/PAMP in plants, and thus potentiates or elicits defense-related responses such as the production of antimicrobial compounds and the expression of immune response genes. One of the most widely investigated effects of LPS on plants is its ability to prevent and/or suppress the hypersensitive response (HR) induced by an array of bacteria. The HR is a programmed cell death response which ends in a local necrosis of plant tissue, thereby resulting in a reduced number of viable bacteria that can further promote disease progression in the host.