Dissertations / Theses on the topic 'Gametophyte development'
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1
Madrid, Eric. "Female gametophyte development and evolution in Piperales." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337127.
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McClelland, D. J. "Genetical studies of gametophyte development in the moss Physcomitrella patens." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233202.
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Ku, Chuan-Chih. "TCP6, a regulator in Arabidopsis gametophyte development and DNA damage response." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/17892.
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Plants have developed intricate mechanisms to control growth in response to a variety of environmental cues, to compensate its immobility and to survive in both normal and adverse conditions. The TCP proteins are a family of plant-specific, basic helix-loop-helix (bHLH) transcription factors that involve in different aspects in plant growth and developmental control. The Arabidopsis TCP20 has been shown to involve in coordinating cell growth and proliferation, and in growth arrest in response to DNA double-stranded breaks (DSB). In this thesis, the main interest is to examine the function of Arabidopsis TCP6, which shares the highest homology with TCP20, and like TCP20, contains a putative ATM phosphorylation motif that suggests potential involvement in the ATM/ATR-mediated DSB responses. Expressional analysis including transcript measurement and reporter gene tagging demonstrated that TCP6 is expressed in flowers, in particular in the first mitotic event of pollen and ovule/embryo sac development, indicating that TCP6 potentially involves in regulating the mitotic cell cycle during gametophyte development. Yet no gametophytic or fertility-affecting mutant phenotype was observed in the tcp6 single and tcp6/tcp20 double mutants, which may be due to high functional redundancy. The tcp6/tcp20 double mutant seedlings exhibited significantly higher growth performances in true leaf growth compared to wild type when treated with gamma radiation, implying that both functional TCP6 and TCP20 are involved in response to gamma radiation-generated DSBs. The work of this thesis provides the first expressional and functional characterizations of TCP6, with the results suggesting that TCP6 and other class I TCPs play a role in regulating growth under both normal and stress conditions.
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Srilunchang, Kanok-orn. "Molecular characterization and identification of genes involved in maize female gametophyte development." kostenfrei, 2009. http://www.opus-bayern.de/uni-regensburg/volltexte/2009/1366/.
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Kőszegi, Dávid. "RKD genes : a novel transcription factor family involved in the female gametophyte development of Arabidopsis and wheat." kostenfrei, 2008. http://nbn-resolving.de/urn:nbn:de:gbv:3:4-823.
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Siebers, Meike [Verfasser]. "The Role of Acyl-ACP Thioesterases and Glycerophosphodiester Phosphodiesterases for Gametophyte Development in Arabidopsis thaliana / Meike Siebers." Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/1165650665/34.
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Rizzo, Paride [Verfasser]. "Novel insights on female gametophyte development in the apomictic model species Boechera spp. and Hypericum spp. / Paride Rizzo." Halle, 2016. http://d-nb.info/1137509848/34.
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Kőszegi, Dávid [Verfasser], Gerd Akademischer Betreuer] Jürgens, Gunter [Akademischer Betreuer] Reuter, and Ulrich [Akademischer Betreuer] [Wobus. "RKD genes: a novel transcription factor family involved in the female gametophyte development of Arabidopsis and wheat / Dávid Kőszegi. Betreuer: Gerd Jürgens ; Gunter Reuter ; Ulrich Wobus." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2008. http://d-nb.info/1024874583/34.
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Šoljić, Lucija [Verfasser], Thomas [Akademischer Betreuer] Dresselhaus, and Stephan [Akademischer Betreuer] Schneuwly. "Microarray analysis of single isolated cells of the female gametophyte reveals potential regulators of female germline development in Arabidopsis thaliana / Lucija Soljic. Betreuer: Thomas Dresselhaus ; Stephan Schneuwly." Regensburg : Universitätsbibliothek Regensburg, 2012. http://d-nb.info/1030179379/34.
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Šoljić, Lucija Verfasser], Thomas [Akademischer Betreuer] [Dresselhaus, and Stephan [Akademischer Betreuer] Schneuwly. "Microarray analysis of single isolated cells of the female gametophyte reveals potential regulators of female germline development in Arabidopsis thaliana / Lucija Soljic. Betreuer: Thomas Dresselhaus ; Stephan Schneuwly." Regensburg : Universitätsbibliothek Regensburg, 2012. http://d-nb.info/1030179379/34.
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Rodrigo-Peiris, Thushani. "Unraveling the Functions of Plant Ran GTPase-Activating Protein (RanGAP) by T-DNA Mutant Analysis and Investigation of Molecular Interactions of Tandem Zinc Finger 1 (TZF1) in Arabidopsis thaliana." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343796551.
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Töller, Armin [Verfasser], Paul [Akademischer Betreuer] Schulze-Lefert, and Martin [Akademischer Betreuer] Hülskamp. "Studies of plant innate immunity provide new functional insights on class IIa WRKY transcription factors and reveals a role for two Glucan Synthase-Like genes in gametophyte development / Armin Töller. Gutachter: Paul Schulze-Lefert ; Martin Hülskamp." Köln : Universitäts- und Stadtbibliothek Köln, 2011. http://d-nb.info/1038064929/34.
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Lindsay, Stuart. "Field experiments on the development of fern gametophytes." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/15219.
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This thesis describes (1) a simple and effective method for growing large numbers of fern gametophytes under field conditions and (2) the application of this method to investigate the sequence and timing of events in the fern life-cycle following spore dispersal or soil disturbance at different times of the year. Long-term field experiments involving Athyrium filix-femina, Blechnum spicant, Polystichum setiferum and Phyllitis scolopendrium were initiated at 2 sites near Edinburgh in January and October 1988. During these experiments (which continued till January 1990) both sites experienced a series of exceptionally mild Winters. The results for the 4 species were strikingly similar. Spores sown in January germinated in the Spring and gametophytes became sexual in the following year between mid-Spring and mid-Summer. Germination was synchronous although many spores did not produce gametophytes. Gametophytes quickly became 2-dimensional; no protonemata were observed. Sex organs developed and matured rapidly and their production was continuous. Most populations consisted of male, female and bisexual gametophytes. In general, female gametophytes were larger than bisexual gametophytes and all archegoniate gametophytes were larger than male gametophytes. All archegoniate gametophytes were meristic; all male gametophytes were ameristic. Most populations were predominantly male. Female gametophytes were always more abundant than bisexual gametophytes. All bisexual gametophytes were protandrous. Fertilization was often rapid, often occurred at high frequency and was not seasonal. Polyembryony was rare. All gametophytes from the January sowing survived the Winter of 1988/'89 but male and fertilized archegoniate gametophytes began to die in the Spring or Summer of 1989. No sporelings died. All gametophytes and sporelings from the October sowing survived throughout the experiment. A third (short) field experiment involving A.filix-femina, B.spicant, P.setiferum, P.scolopendrium, Dryopteris affinis subsp. borreri, Dryopteris dilatata, Dryopteris filix-mas and Pteridium aquilinum was initiated in August 1989. Spores of all 8 species germinated more or less immediately but only gametophytes of P.aquilinum became sexual before Winter. In one population fertilization occurred before the end of the year.
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Wakeley, Philip Robert. "A study of maize male gametophytic gene expression." Thesis, Royal Holloway, University of London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261723.
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Horst, Nelly [Verfasser], and Ralf [Akademischer Betreuer] Reski. "The homeobox gene BELL1 is the master regulator for the developmental switch from gametophyte to sporophyte in Physcomitrella patens." Freiburg : Universität, 2016. http://d-nb.info/111989946X/34.
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Coury, Daniel Adam. "Exceptional segregation of Kanamycin resistance in Arabidopsis gametophytic factor 1 (gfa1) mutants: A genetic, developmental, and molecular analysis." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/266592.
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The molecular mechanisms underlying plant reproductive development are poorly understood. Segregation distortion has recently been employed as a screening criterion to identify genes required for the development and function of the gametophyte generation. This dissertation presents analyses of the genetic, developmental, and molecular basis of the segregation distortion used to identify one such Arabidopsis thaliana mutant, gametophytic factor 1 (gfa1). The genetic basis of segregation distortion was examined by quantifying transmission of two gfa1 alleles in reciprocal crossed to wildtype. Both alleles displayed a complete lack of transmission of the gfa1 allele through the female parent, and a significant reduction of transmission through the male parent. In addition, self-pollinated siliques had a reduced seed set phenotype characteristic of a female gametophytic mutation. Both alleles co-segregated with the seed set phenotype, indicating that mutations in the GFA1 gene were responsible for the seed set phenotype. The developmental basis of gfa1 segregation distortion was identified by first examining gfa1-1 male (MG) and female (FG) gametophytes using confocal microscopy. Approximately half of the FGs scored in gfa1-1/+ siliques showed abnormalities in the number and position of the nuclei within the FG, as well as defects in cellularization. Although there were no obvious abnormalities in gfa1-1 pollen grains, analysis of the position of kanamycin-resistant seeds in gfa1-1/+ siliques showed that fewer gfa1-1 pollen fertilized ovules at the basal (receptacle) end of the silique. Taken together, these results suggest that gfa1 mutations affect primarily FG development and MG function. The GFA1 gene was cloned and found to belong to the U5-116 kD small nuclear ribonucleoprotein family of RNA splicing factors first identified in mammals and yeast. In addition, a second gene-family member, GFA1-like (GFL), was found in the Arabidopsis genome. GFA1 expression was found throughout plant development, and evidence of GFL expression was also found. The paternal GFA1 allele did not appear to be silenced during early seed development. Therefore, we conclude that a mutation in an essential splicing factor is responsible for the reduced transmission and seed set phenotypes observed in gfa1 mutants.
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Santa-Rosa, Sandra. "Desenvolvimento floral e do óvulo e aspectos da reprodução em Aechmea sp. e Vriesea sp. (Bromeliaceae)." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/64/64133/tde-14062016-110325/.
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A utilização de Bromélias tem sido crescente no mercado de plantas onamentais, por outro lado, muitas espécies encontram-se ameaçadas, grande parte pelos impactos humanos no ambiente. Aechmea correia-araujoi E. Pereira & Moutinho, Aechmea gamossepala Wittm, Vriesea ensiformis (Vell.) Beer e Vriesea saundersii (Carrière) E. Morren ex Mez, espécies nativas da Mata Atlântica brasileira, têm sido alvo de extrativismo. Informações básicas sobre a espécie são essenciais para subsidiar a condução de programas de conservação e melhoramento genético, que aliados a ferramentas biotecnológicas permitem a incorporação de estratégias inovadoras aos métodos de melhoramento. Neste sentido, o objetivo do presente trabalho foi descrever essas espécies, quanto à micromorfologia floral, aspectos reprodutivos envolvidos no processo de polinização, desenvolvimento floral e deesenvolvimento gametofítico, como mecanismo de preservação e produção comercial. A caracterização morfológica e anatômica das flores das espécies de Aechmea e Vriesea contribuiu para a compreensão do processo reprodutivo. As espécies apresentam grãos de pólen com alta capacidade reprodutiva, viabilidade polínica superior a 93%, germinação in vitro maior que 80% e o estigma apresenta-se receptivo da antese ao final do dia. A ontogênese floral de A. correia-araujoi é centrípeta, os primórdios desenvolvem-se na ordem, sépala, pétala, androceu e gineceu. O apêndice petalar é formado na fase final do desenvolvimento. O primórdio de óvulo tem origem placentária e caráter trizonal, o óvulo é anátropo, bitegumentado e crassinucelado. O meristema floral de A. gamosepala se desenvolve de forma centrípeta, de forma unidirecional reversa. O estigma diferencia-se na fase inicial do desenvolvimento e os apêndices petalares, na fase final. O óvulo é anátropo, crassinucelado, bitegumentado, tétrade linear, megásporo calazal funcional, desenvolvimento tipo monospórico e Polygonum. As anteras são bitecas, tetraesporangiadas, com tapete secretor. Botões florais de 8,7 - 13,0 mm são indicados no estudo de embriogênese a partir de micrósporo. As alterações celulares e o padrão de distribuição de pectinas e AGPs foram caracterizadas por análise citoquímica com azul de toluidina, KI e DAPI e imunocitoquímica por imunofluorescência com os anticorpos para RNA, pectinas esterificadas (JIM7), não esterificadas (JIM5) e AGPs (LM2, LM6, MAC207, JIM13, JIM14) e analisadas por microscopia de fluorescência. Foram caracterizados padrões de distribuição espaço-temporal de pectinas e AGP que podem ser utilizados como marcadores de desenvolvimento gametofítico masculino. As observações feitas nesse trabalho fornecem dados sobre aspectos reprodutivos das espécies que podem ser utilizados em programas de melhoramento genético, conservação e desenvolvimento de haploidesThe use of bromeliads has grown in the ornamental market, however many native species are threatened, mostly due to human impacts. Basic information about the species is essential to support breeding and conservation programs, which combined with biotechnological tools allow for the innovative approaches to breeding methods. The objective of this study was to characterize the floral development and reproductive aspects of the ornamental species Aechmea correia-araujoi, Aechmea gamosepala, Vriesea ensiformis and Vriesea saundersii, with detais on floral morphology and anatomy, reproductive aspects involved in pollination. For the Aechmea species the gametophytic development was characterized, as well as the cellular changes that occur during the development of the male gametophyte, characterizing the distribution pattern of pectin and arabinogalactan proteins (AGPs), for biotechnological applications. The plants were characterized by observations of the material in the greenhouse and floral organs were described using microscopic techniques. The flowers are actinomorphic, trimerous, dichlamydeous, heterochlamydeous, with double petal appendages, six stamens, gamocarpelar, tricarpellate ovary, with septal nectaries and a large number of ovules. Aspects of the floral biology involved in reproduction were assessed by stigma receptivity, pollen morphology, viability and in vitro pollen grain germination. The species produce large amounts of pollen grains with high reproductive capacity, pollen viability higher than 93%, in vitro germination higher than 80% and stigma is receptive throughout the day. The floral ontogeny of A. correia-araujoi is centripetal, the primordia develop sepals, petals, stamens and pistil. The petal appendages are formed in the final stages of floral development. The cellular changes, and the distribution pattern of pectins and AGPs were characterized by cytochemical analysis with IKI and DAPI, and immunocytochemistry and immunofluorescence with antibodies for RNA, esterified pectins (JIM7) de-esterified (JIM5) and AGPs (LM2 , LM6, MAC207, JIM13, JIM14) and analyzed by confocal microscopy. Various spatio-temporal distribution patterns of pectins and AGPs were characterized and may be used as male gametophyte development markers. The observations made in this work provide data on reproductive aspects of the species studied, and can be further used in breeding and conservation programs, and haploid production
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Kerim, Tursun. "Proteome analysis of male gametophyte development in rice anthers." Phd thesis, 2003. http://hdl.handle.net/1885/9219.
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In this thesis, two-dimensional electrophoresis (2-DE)-based comparative
proteomics were applied to monitor the global changes in protein expression during the
male gametophyte development in anthers of the Australian rice cultivar Doongara,
with the aim of providing a protein-level insight into the molecular mechanism
underlying this important reproductive developmental process. At the same time, this
thesis also evaluates the potential application of 2-DE based proteomics to other
aspects of plant developmental biology.
In order to collect sufficient amount of homogenous anther populations which
represent a number of discrete cellular events encompassing the process of
microsporegenesis, the cytological examination of developing anthers was done to
establish the allometric relationships between a number of growth parameters and
anther developmental stages. This provided a base for the quick and nondestructive
assessment of microspore developmental stages. From this study, a strategy for the
collection of rice anthers for six developmental stages was established using a
combination of anther length, auricle distance and days before heading. The findings
of the cytological analysis opened up the possibility of establishing rice plants as a new
model system for male gametophyte research of plants.
Anther proteome maps were established for six microspore developmental stages
within the pH ranges of 4 to 7 and 6 to 11. Over 3,500 protein spots were reproducibly
resolved in the combined pH range of 4 to 11. Comparison of proteome maps of six
developmental stages resulted in the detection of 150 differentially displayed protein
spots at various stages. Putative identities were predicted for 49 out of 155 protein
spots which were subjected to peptide mass fingerprinting (PMF) analysis. Eight low
molecular weight protein spots were matched to putative translation products of rice
expressed sequence tags (EST) by N-terminal terminal sequencing followed by
homology searches. This verified the translation of these small open reading frames
(ORF) and revealed the presence of some post translational modifications of these
proteins. By integrating the information about the functions of identified proteins and
their temporal regulation patterns, three developmentally regulated metabolic pathways
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were identified and the significance of these pathways in relation to male gametophyte
development was discussed.
Based on the N-terminal sequencing data, three isoforms of rice homologues of
grass group II pollen allergens (Ory s 2) were identified and further characterized using
bioinformatics and immunochemical techniques. Polyclonal antibodies were produced
against Ory s 2 isoforms using gel-separated proteins as the antigen. Immunoblot
analysis revealed that Ory s 2 proteins are pollen specific and accumulated to high
abundance at mature pollen, indicating their possible involvement in fertilization
process. Immunochemical analysis also showed that rice group II allergens do not
possess cross-reactivity with group II allergens of other grasses.
This study produced valuable molecular data to provide some insight into the
global changes of protein expression accompanying pollen development, and identified
some developmentally regulated protein markers which have potential practical
application to other research projects. From the promising results of this proteomic
study it can be expected that our understanding of complex biological processes in
plant development will be enhanced with the availability of a fully annotated rice
genome and the application of integrated systems biology research approaches.
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REŇÁK, David. "Role of transcription factors in early male gametophyte development of Arabidopsis." Doctoral thesis, 2011. http://www.nusl.cz/ntk/nusl-55691.
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In the presented work the relationship between transcription factors and male gametophyte development was studied. The Ph.D. Thesis covers selection of candidate genes, wide-scale screening of T-DNA mutant lines and detailed analysis of a selected transcription factor on pollen development.
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Hsu, Wei-Han, and 許巍瀚. "Functional analysis of genes regulating cell division and gametophyte development in Arabidopsis." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/tuje6h.
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博士國立中興大學
生物科技學研究所
100
How to suppress the cell division in the differentiated cells but not the meristematic cells is largely unknown in plants. The family of Yippee-like (YPEL) genes has been found in various eukaryote species. However, no study on YPEL genes has been reported in plant species. In this study, an Arabidopsis YPEL gene AtYIP1 was characterized. The promoter::GUS assay indicated that AtYIP1 mRNA was constitutively expressed in all tissues except meristematic cells and the AtYIP1 proteins were degraded constantly in cells without further division. Hastened growth and increased size and cell number of leaf were observed in 35S::AtYIP1 RNAi plants. By contrast, growth in the 35S::AtYIP1 plants ectopically expressing AtYIP1 was significantly inhibited. The anatomical analysis revealed that the severe 35S::AtYIP1 mutant phenotype is primarily due to the lack of the cell division in both shoot and root apical meristem. These results revealed a repressor role for AtYIP1 in preventing cell division in Arabidopsis. This assumption was further supported by the suppression of the cells growth for tobacco cell line BY-2 and human embryonic kidney cell line HEK 293T after transfection with flag-tagged AtYIP1. Furthermore, AtYIP1 proteins were found to be able to suppress the abnormal cell division for differentiated cells by entering nucleus and bind to DNA. Our data represents a novel finding that a plant gene is able to suppress cell division and growth in both plant and animal system. (Chapter 1) Arabidopsis AGL13 is the gene classified as AGL6 lineage of MIKC type MADS-box gene family. Our previous study indicated that AGL13 expression was specifically detected from the initiation to maturation of both pollen and ovules. Ectopic expression of AGL13 RNAi construct was found to cause sterility by inducing the production of flowers with defective pollen and ovules in transgenic Arabidopsis plants. In this study, two types of pollen in equal numbers were found in 35S::AGL13 RNAi/qrt1-2 tetrads. The first type resembles wild-type whereas the second type is reduced in size with a flat or collapsed shape, suggesting that the development of the pollen grains that carried the 35S::AGL13 RNAi was arrested during meiosis. The viability of the wild-type like pollen in AGL13 RNAi plants was tested by adhesion assay and pollination assay. These data indicated that AGL13 not only regulates pollen development but also controls the tapetum function for exine formation. The enhancement of the alteration of pollen development, the sterility of the plants and the flower organ formation in AGL13:SRDX (containing a suppression motif) transgenic plants suggested that AGL13 acts as a repressor. Furthermore, similar defects in floral organs was observed in AGL13:SRDX and SEP2:SRDX plants which was caused by the suppression of the expression for A, B and C function MADS-box genes. AGL13 could interact with B, C function MADS-box protein and form complex to regulated downstream genes expression, including the pollen developing and tapetum formation genes. (Chapter 2) Finally, series systems of binary vectors have been generated for plant molecular cloning and functional study. All vectors share the same restriction enzyme cloning sites, and contain different combinations of promoters, fusion tags and selection markers. These vectors can be applied to the experimental assays of ectopic expression, RNA silencing, fluorescent tags fusion, heat inducible expression, monocot transformation, dominant negative repression, dominant positive activation, trans-expression. New vectors provided the additional construction procedures for the lab and the experiment assay could be designed with systematically work through standard operating procedure (SOP). (Chapter 3)
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Anderson, Cindy Louise. "Gametophyte development in Cheilanthes Viridis Var. Glauca (adiantaceae) with special reference to Apogamy." Thesis, 1992. http://hdl.handle.net/10539/22179.
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A dissertation submitted to the faculty of science
university of the Witwatersrand, Johannesburg
for the Degree of Master of Science
Johannesburg
1992The gametophyte generation of the fern life cycle is initiated with the formation of spores. The spores of C. viridis (Fonsic) Swarts var. glaeca (Sim) schelp Anthony are trilete and have a cristate spore wall ornamentation. Under favourable conditions the spores of C. viridis var. glauca show polar germination [Abbreviated Abstract. Open document to view full version]
GR2017
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Tai, Shih-Hsin, and 戴世昕. "Aquaculture Development of different generation of Thalloid Sporophyte and Gametophyte of Grateloupia taiwanensis." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/85119990204169529472.
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碩士國立臺灣大學
漁業科學研究所
101
Grateloupia is a commercial macroalgal which belonging to the phyla of Rhodophyta under the order of Halymeniales. Field collection from the intertidal zone of Taiwan North-eastern coast, Grateloupia has been widely consumed as a delicacy by the local people. Wild Grateloupia was hand-picked by snorkelers in an inefficient way. Thus, the production of Grateloupia was limited and unable to meet the demand from the market. Despite this fact, very few researches on the cultivation of Grateloupia were done on the production of Grateloupia at commercial scale. In this study, the propagation of Grateloupia taiwanensis nodulous filament for germ stock and seedling development was investigated. The nodulous filaments were prepared from germinating carporspores and tetraspores separately. Discoid crust from germinating spores were detached from the substrat, and maintained in enriched medium. Subsequently, various conditions to scale-up the production of nodulus filament cultures were determined. The nodulus filaments were blended into small fragments which were capable in forming new discoid crusts under appropriate conditions. At 20℃, under high illumination of light (7000 lux), young shoots formed from the crusts. The young shoots were transferred to outdoor environment for further growth under appropriate conditions. It was also observed that diploid nodulus filaments germinated from carpospores grew better at higher temperature compared to the haploid nodulous filaments, which were germinated from tetraspores. Most of the discoid crusts formed from diploid nodulous filaments and carpospores were smaller in size, and were easily detached from substrate. Therefore, we suggest that nodulus filaments from detached diploid discoid crusts is an ideal source of seedlings which can be cultivated in suspension. During its growing season, the length of thalli developed from the diploid nodulus filaments reached about 10-20 cm. However, the morphology of the thallus is significantly different from those collected from the field. We suggest that the indoor cultivation of seedling sources to be improved at larger scale. The life cycle of Grateloupia may also can be determined artificially using this technique.
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[Verfasser], Kanok-orn Srilunchang. "Molecular characterization and identification of genes involved in maize female gametophyte development / vorgelegt von Kanok-orn Srilunchang." 2009. http://d-nb.info/997895004/34.
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Daigle, Caroline. "Expansion d'une nouvelle famille de protéines kinases (MAPKKKs) impliquée dans le développement reproductif chez les Solanacées." Thèse, 2016. http://hdl.handle.net/1866/18509.
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Les cascades de Mitogen-Activated Protein Kinases (MAPKs) sont présentes chez tous les eucaryotes et permettent la transduction des signaux de l’extérieur vers l’intérieur de la cellule. Chez les végétaux, elles sont très abondantes et actives dans une multitude de processus, autant lors de la réponse aux stress que lors du développement. Elles fonctionnent comme un système de phosphorelais, se transférant un groupement phosphate d’une protéine à l’autre, de la MAPKKK à la MAPKK (MKK), puis de la MKK à la MAPK (MPK) et finalement, de la MPK vers des facteurs de transcription ou toute autre protéine qui permettra un changement au niveau de la réponse cellulaire.
Depuis quelques années, plusieurs membres de la grande famille des MAPKs ont été étudiés pour leur rôle dans la reproduction sexuée des végétaux. Des mutants ont été caractérisés, mais jusqu’à maintenant, peu de voies complètes ont été décelées. Des précédents travaux dans le laboratoire ont démontré que deux MAPKKKs, de la sous-famille des MEKKs, ScFRK1 et ScFRK2, sont importantes pour le développement normal de l’ovule et du pollen chez Solanum chacoense, une espèce de pomme de terre sauvage diploïde. Sachant que les mutants des gènes les plus orthologues chez Arabidopsis thaliana ne possèdent pas les mêmes phénotypes, nous avons émis l’hypothèse que les Solanacées, du moins S. chacoense, possèdent une famille de MAPKKKs différente, qui n’est pas présente chez A. thaliana.
Nous avons donc analysé les génomes/transcriptomes/protéomes de 15 espèces issues de différents clades du règne végétal afin d’étudier les relations phylogénétiques à l’intérieur de la sous-famille des MEKKs. Cela nous a permis d’observer que ScFRK1 et ScFRK2 ne sont pas seuls, mais sont inclus dans un groupe monophylétique que nous avons nommé la classe des FRKs (FRK pour Fertilization-Related Kinase). De plus, nous avons observé une expansion considérable de cette classe chez les Solanacées, comparativement à d’autres dicotylédones comme le peuplier, la vigne ou le coton. La classe des FRKs est absente chez les monocotylédones étudiées (riz et maïs) et ne possède qu’un seul membre (une FRK primitive) chez l’angiosperme basal Amborella trichopoda. Cette analyse phylogénétique des MEKKs nous a poussés à nous poser des questions sur l’origine de la classe des FRKs ainsi que sur son rôle au sein des Solanacées.
Dans un deuxième temps, nous avons fait la caractérisation fonctionnelle de ScFRK3, un troisième membre de la classe des FRKs chez S. chacoense, aussi impliqué dans le développement des gamétophytes mâle et femelle. Du patron d’expression jusqu’à l’établissement d’une voie de signalisation potentielle, en passant par la caractérisation phénotypique des mutants, plusieurs expériences ont été réalisées dans le but de comprendre le rôle de ScFRK3 au niveau de la reproduction chez S. chacoense. Dans un contexte plus global, il est important de se questionner sur les rôles semblables, mais forcément différents, des trois membres de la famille FRKs qui ont été caractérisés jusqu’à présent.Mitogen-Activated Protein Kinases (MAPKs) signaling cascades are found in all Eucaryotes and allow signal transduction from the outside of the cell to the inside. In plants, they are particularly numerous and play roles in several signaling processes, including stress responses and response to developmental cues. Their system involves a phosphorelay: they interact with each other to transfer a phosphate group. It starts with an activated MAPKKK, which transfers the phosphate group to a MAPKK (MKK), then this MKK transfers the signal to a MAPK (MPK), which ends this relay by phosphorylating transcription factors or any other proteins that will, in a way or an other, change the cell response according to the signal. During the last few years, many MAPKs members have been studied for their role in plants sexual reproduction. Some mutants were characterized, but until now, our knowledge of complete signaling cascades is very limited. Previous studies in our lab have shown that two MAPKKKs from the MEKK subfamily, ScFRK1 and ScFRK2, are important for male and female gametophytes development in Solanum chacoense, a wild diploid potato species. Genes that are the most orthologous to ScFRK1 and ScFRK2 in Arabidopsis thaliana, AtMAPKKK19, 20 and 21, do not seem to play the same roles in reproduction, which led us to make the hypothesis that in solanaceous species, at least in S. chacoense, there is one MAPKKK family that is different and not present in A. thaliana. At first, we did analyze the genomes/transcriptomes/proteomes of 15 species from different clads of the plant kingdom to find all the members of the MEKK subfamily of MAPKKKs in order to study their phylogenetic relationship. We then observed that ScFRK1 and ScFRK2 are included in a large monophyletic group which was called the FRK class (Fertilization Related Kinase). Moreover, we also observed that this class has considerably expanded within the solanaceous species, compared to other species like A. thaliana, poplar, cotton or grape vine. The FRK class is totally absent in the monocot species studied (rice and maize) and only one member is found in the basal angiosperm Amborella trichopoda. This phylogenetic analysis led us to ask questions about the origins of the FRK class and its role inside the Solanaceae family. Secondly, we characterized ScFRK3, a third member of the FRK class in S. chacoense, which is also involved, as its two FRK sisters, in male and female gametophytes development. From its expression pattern to the establishment of a potential signaling cascade, analysis and phenotyping of ScFRK3 mutant lines, many experiments were realized in order to understand the role of ScFRK3 in S. chacoense sexual reproduction. Overall, the appearance of this new and expanded class of MEKKs questions its specific role in comparison to other species that have much lesser members, mainly when compared to the model plant A. thaliana, which harbor only a fifth of the FRKs found in solanaceous species.
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Klodová, Božena. "Studie tvorby dimerů komplexu asociovaného s nascentním polypeptidem a jeho efektorů v huseníčku rolním." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-405573.
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The development of plant flowers represents a complex process controlled by numerous mechanisms. The creation of double homozygous mutant of both β subunits (sometimes also referred to as basic transcription factor 3) of nascent polypeptide associated complex in Arabidopsis thaliana (further referred to as nacβ1 nacβ2) caused quite a strong defective phenotype including abnormal number of flower organs, shorter siliques with a reduced seed set, and inferior pollen germination rate together with a lower ovule targeting efficiency. Previously, NAC complex was described to be formed as a heterodimer composed of an α- and β-subunit, which binds ribosome and acts as a chaperone in Saccharomyces cerevisiae. In plants, NACβ is connected to stress tolerance and to plant development as a transcription regulator. However, little is known of NAC heterodimer function in plants. In this thesis, yeast two hybrid system (Y2H) and bimolecular fluorescence complementation (BiFC) assays were used to verify the NAC heterodimer formation in A. thaliana and to establish any potential interaction preferences between both NACβ paralogues and five NACα paralogues. To deepen the understanding about molecular mechanisms behind the nacβ1 nacβ2 phenotype, flower bud transcriptome of the nacβ1 nacβ2 double homozygous mutants...
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Loubert-Hudon, Audrey. "Implication du peptide ScRALF3 dans le développement du gamétophyte femelle chez Solanum chacoense." Thèse, 2012. http://hdl.handle.net/1866/8972.
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La coordination du développement par les communications intercellulaires est essentielle pour assurer la reproduction chez les plantes. Plusieurs études démontrent qu’une communication entre le sac embryonnaire et le tissu maternel, le sporophyte, est essentielle au bon développement des gamètes. Les molécules, peptides ou autres protagonistes impliqués dans ces voies de signalisation ainsi que leur mode d’action restent toutefois nébuleux. Les gènes de type RALF codent pour des petits peptides sécrétés retrouvés de manière spécifique ou ubiquitaire dans la plante. Leur structure en font de parfaits candidats pour permettre ces communications cellule-cellule entre les différents tissus. Treize gènes de type RALF ont été isolés actuellement chez la pomme de terre sauvage Solanum chacoense. Maintenant, nous montrons qu’un de ceux-ci, ScRALF3, est impliqué dans la polarisation du sac embryonnaire et dans la synchronicité des divisions mitotiques assurant la formation d’un gamétophyte femelle mature fonctionnel. Étant exprimé de manière spécifique au niveau des téguments de l’ovule, ScRALF3 est un candidat idéal pour réguler les communications cellule-cellule entre le sporophyte et le sac embryonnaire.Development coordination through intercellular communication is essential for plant reproduction. Several studies show that communication between embryo sac and maternal tissue, the sporophyte, is essential to the development of gametes. These molecules, peptides or other actors involved in these signaling pathways and their mode of action remains unclear. Genes encoding small secreted RALF peptides specifically or ubiquitously expressed throughout the plant are good candidates to allow these cell-cell communications. Thirteen RALF-like genes have been isolated at present from the wild potato Solanum chacoense. Now, we show that one of these, ScRALF3, is involved in the polarization of the embryo sac and the synchronicity of mitotic divisions to ensure the formation of a functional mature female gametophyte. Since it is specifically expressed in the integument of the ovule, ScRALF3 is an ideal candidate to regulate cell-cell communication between the sporophyte and the gametophyte, e.g., the embryo sac.
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Barke, Birthe Hilkka. "The Evolutionary Establishment of Apomixis in Hybrids of the Ranunculus auricomus Complex: Developmental and Cytogenetic Studies." Thesis, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0005-13DD-D.
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