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1
Ferreira, Gisela. "Reguladores vegetais na superação da dormência, balanço hormonal e degradação de reservas em sementes de Annona diversifolia SAFF. e A. purpurea Moc. & Sessé Ex Dunal (Annonaceae) /." Botucatu, 2011. http://hdl.handle.net/11449/106722.
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Memorial apresentado ao Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Filho", como parte dos requisitos para obtenção do título de Professor Livre-Docente na Dosciplina de Fisiologia VegetalResumo: As sementes de anonáceas são conhecidas por apresentarem mecanismos de dormência, o que dificulta a perpetuação das espécies e a formação de áreas produtivas para a exploração comercial. Deste modo, os objetivos deste trabalho foram estudar curva de aquisição de água; a germinação de sementes tratadas com GA3 e GA4+7 + Benziladenina; o balanço hormonal e a degradação de reservas em sementes de Annona diversifolia Saff e Annona purpurea Moc & Sessé ex Dunal tratadas com reguladores vegetais para a superação da dormência. Para tanto foram realizados três experimentos. Para a construção da curva de aquisição de água foram utilizadas 4 repetições de 25 sementes que foram mantidas em embebição e pesadas durante 480 horas. O segundo experimento foi constituído pela germinação das sementes tratadas com os reguladores vegetais; o delineamento experimental empregado foi o inteiramente casualizado com 4 repetições de 25 sementes por parcela em esquema fatorial 2 x 7 (reguladores x concentrações). Os tratamentos foram constituídos pelas combinações entre concentrações de GA3 e de GA4+7 + Benziladenina (GA4+7 + BA) x 0, 200, 400, 500, 600, 800 e 1000 mg L-1 i.a.. No terceiro experimento foram quantificados ABA (Ácido abscísico) e GA (Giberelinas), proteínas, açúcares... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Annonaceae seeds have been known by presenting dormancy mechanisms, which makes difficult the perpetuation of species and the formation of roductive areas for commercial exploration. Thus, the present work aimed to evaluate water uptake curve; germination of seeds treated with GA3 and GA4+7 + Benzyl adenine; hormone balance and reserve degradation in Annona diversifolia Saff and Annona purpurea Moc & Sessé ex Dunal seeds subjected to plant growth regulators for dormancy break. Three experiments were carried out. To obtain the water uptake curve, four replicates of 25 seeds were kept in imbibition and weighed for 480h. The second experiment evaluated the germination of seeds treated with plant growth regulators; experimental design was completely randomized, with four replicates of 25 seeds per plot in the 2x7 (plant growth regulators x concentrations) factorial arrangement. Treatments consisted of combinations between concentrations of GA3 and GA4+7 + Benzyl adenine (GA4+7 + BA) with 0, 200, 400, 500, 600, 800 and 1000 mg L-1 a.i.. In the third experiment, ABA (abscisic acid), GA (gibberellins), proteins, total soluble sugars and lipids were quantified in seeds soaked in water, without imbibition and soaked in GA4+7 + BA for 15 days (on the 0th, 2nd, 5th, 10th and 15th days). Based... (Complete abstract click electronic access below)
2
Tarr, Alun Rhys. "Genetically induced abscisic acid deficiencies." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335475.
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Saito, Shigeki. "Studies on (+)-abscisic acid 8'-hydroxylase, a key enzyme in the catabolism of abscisic acid." Kyoto University, 2005. http://hdl.handle.net/2433/144582.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第11801号
農博第1521号
新制||農||916(附属図書館)
学位論文||H17||N4075(農学部図書室)
23541
UT51-2005-F831
京都大学大学院農学研究科応用生命科学専攻
(主査)教授 坂田 完三, 教授 矢﨑 一史, 教授 宮川 恒
学位規則第4条第1項該当
4
Milborrow, Barry Vaughan Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Biosynthesis of abscisic acid in plants." Awarded by:University of New South Wales. Biotechnology & Biomolecular Sciences, 2007. http://handle.unsw.edu.au/1959.4/42883.
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Parry, Andrew David. "Abscisic acid biosynthesis in higher plants." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328480.
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Farias, Euménes Tavares de [UNESP]. "Expressão gênica no embrião e no endosperma micropilar de sementes de café (coffea arabica L.) durante a germinação." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/86394.
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A germinação de sementes de café (Coffea arabica L.) é lenta e irregular, controlada por eventos que ocorrem, simultaneamente, no embrião e no endosperma. Embora os referidos eventos estejam determinados, ainda são necessários estudos sobre a fisiologia molecular, para auxiliar na avaliação da qualidade fisiológica das sementes durante a germinação. O objetivo do trabalho foi realizar estudos fisiológicos e moleculares durante a germinação de sementes embebidas em água e em ácido abscísico (ABA) na concentração de 1000 μM. Durante o trabalho foi determinado o teor de água, a curva de embebição, a germinação, o crescimento do embrião e a expressão dos genes associados com o crescimento do embrião e com a degradação do endosperma micropilar. Para tanto, embriões e os endospermas micropilares foram isolados para a extração de RNA total e síntese de cDNA. “Primers” específicos foram desenhados para o estudo da expressão gênica em PCR em tempo real. Foi estudada a expressão dos genes actina, ciclina e α-expansina, associados ao crescimento do embrião, e α-galactosidase, β-manosidase e endo-β-mananase, associados à degradação do endosperma micropilar. A curva de embebição apresentou um padrão trifásico. A primeira semente de café germinou com cinco dias de embebição e 50% de germinação ocorreram no décimo dia de embebição. A expressão dos genes associados com o crescimento do embrião, tais como actina, α-expansina e quinase dependente de ciclina, aumentou durante a germinação em água e inibiu parcialmente a expressão destes genes quando tratados com ABA. A expressão de β-manosidase e endo-β-mananase aumentou durante a embebição em água e ABA inibiu completamente a expressão. No entanto, α-galactosidase parece ter a expressão mais constitutiva durante a germinação em água e é menos influenciada por ABA, em comparação com outras enzimas estudadas
Germination of coffee (Coffea arabica L.) seed is slow and uneven. The germination is a net result of events that occur simultaneously in the embryo and endosperm under the control of ABA. The aim of the study was to perform physiological and molecular studies during germination of seeds imbibed in water and 1000 μM abscisic acid (ABA). We studied the expression of the genes ciclin, α-expansin and cyclin-dependent of kinase in the embryo and α-galactosidase, β-mannosidase, endo-β-mannanase in the micropylar endosperm. The first coffee seed germinate at five days of imbibition and 50% germinate at tenth day of imbibition. Coffee embryo grew inside the seed pior radicle protrusion and ABA inhibited the embryo grow as well as radicle protrusion. The expression of the genes associated with the growth of the embryo such as ciclin, α-expansin and cyclin-dependent of kinase increased during germination and ABA partially inhibited the expression of these genes. The expression of β-mannosidase and endo-β-mannanase increased during imbibitions in water and ABA completely inhibited its expression. However, α-galactosidase seems to have a more constitutive expression during germination in water and it is less affected by ABA as compared with other enzymes studied
7
Farias, Euménes Tavares de 1986. "Expressão gênica no embrião e no endosperma micropilar de sementes de café (coffea arabica L.) durante a germinação /." Botucatu :, 2012. http://hdl.handle.net/11449/86394.
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Orientador: Edvaldo Aparecido Amaral da SilvaBanca: Claudio Cavariani
Banca: Juliana Pereira Bravo
Resumo: A germinação de sementes de café (Coffea arabica L.) é lenta e irregular, controlada por eventos que ocorrem, simultaneamente, no embrião e no endosperma. Embora os referidos eventos estejam determinados, ainda são necessários estudos sobre a fisiologia molecular, para auxiliar na avaliação da qualidade fisiológica das sementes durante a germinação. O objetivo do trabalho foi realizar estudos fisiológicos e moleculares durante a germinação de sementes embebidas em água e em ácido abscísico (ABA) na concentração de 1000 μM. Durante o trabalho foi determinado o teor de água, a curva de embebição, a germinação, o crescimento do embrião e a expressão dos genes associados com o crescimento do embrião e com a degradação do endosperma micropilar. Para tanto, embriões e os endospermas micropilares foram isolados para a extração de RNA total e síntese de cDNA. "Primers" específicos foram desenhados para o estudo da expressão gênica em PCR em tempo real. Foi estudada a expressão dos genes actina, ciclina e α-expansina, associados ao crescimento do embrião, e α-galactosidase, β-manosidase e endo-β-mananase, associados à degradação do endosperma micropilar. A curva de embebição apresentou um padrão trifásico. A primeira semente de café germinou com cinco dias de embebição e 50% de germinação ocorreram no décimo dia de embebição. A expressão dos genes associados com o crescimento do embrião, tais como actina, α-expansina e quinase dependente de ciclina, aumentou durante a germinação em água e inibiu parcialmente a expressão destes genes quando tratados com ABA. A expressão de β-manosidase e endo-β-mananase aumentou durante a embebição em água e ABA inibiu completamente a expressão. No entanto, α-galactosidase parece ter a expressão mais constitutiva durante a germinação em água e é menos influenciada por ABA, em comparação com outras enzimas estudadas
Abstract: Germination of coffee (Coffea arabica L.) seed is slow and uneven. The germination is a net result of events that occur simultaneously in the embryo and endosperm under the control of ABA. The aim of the study was to perform physiological and molecular studies during germination of seeds imbibed in water and 1000 μM abscisic acid (ABA). We studied the expression of the genes ciclin, α-expansin and cyclin-dependent of kinase in the embryo and α-galactosidase, β-mannosidase, endo-β-mannanase in the micropylar endosperm. The first coffee seed germinate at five days of imbibition and 50% germinate at tenth day of imbibition. Coffee embryo grew inside the seed pior radicle protrusion and ABA inhibited the embryo grow as well as radicle protrusion. The expression of the genes associated with the growth of the embryo such as ciclin, α-expansin and cyclin-dependent of kinase increased during germination and ABA partially inhibited the expression of these genes. The expression of β-mannosidase and endo-β-mannanase increased during imbibitions in water and ABA completely inhibited its expression. However, α-galactosidase seems to have a more constitutive expression during germination in water and it is less affected by ABA as compared with other enzymes studied
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8
Shinde, Suhas, Shivakumar Devaiah, and Aruna Kilaru. "Profiling Abscisic Acid-Induced Changes in Fatty Acid Composition in Mosses." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/4745.
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In plants, change in lipid composition is a common response to various abiotic stresses. Lipid constituents of bryophytes are of particular interest as they differ from that of flowering plants. Unlike higher plants, mosses have high content of very long-chain polyunsaturated fatty acids. Such lipids are considered to be important for survival of nonvascular plants. Here, using abscisic acid (ABA )-induced changes in lipid composition in Physcomitrella patens as an example, a protocol for total lipid extraction and quantification by gas chromatography (GC) coupled with flame ionization detector (FID) is described.
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Peng, Xiaobing Carleton University Dissertation Biology. "The role of abscisic acid and abscisic acid-analogs in inducing desiccation tolerance in microspore-derived embryos of Brassica Napus." Ottawa, 1994.
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Smith, Timothy Robert. "Enantioselective Synthesis and Chemical Genomics of Abscisic Acid." Thesis, University of Warwick, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491505.
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Abscisic acid is an important phytohonnone implicated in many aspects of plant growth and development. The search for the biological targets of this ubiquitous honnone has produced many sophisticated strategies for the preparation of analogues and conjugates for use in affinity-based methods. In this study, biologically active . enantiomerically pure abscisic acid conjugates were synthesised and screened against a phage display library of Arabidopsis thaliana cDNA products in order to identify receptor proteins. A short and high-yielding synthesis of enantiomerically pure S-(+)- and R-(-)abscisic acid are described. The syntheses proceed through key intennediates that preferentially recrystallise as single diastereoisomers for each enantiomer. This versatile route to abscisic acid was adapted for generation of novel side-chain analogues suitable for conjugation and immobilisation. S-(+)-Abscisic acid conjugated to biotin via an acyl hydrazone linkage was assessed for in vivo stability using bioassays twinned with LCMS2 analysis on deuterated samples. Cleavage ofthe otherwise stable acyl hydrazone linkage was observed. Phage display biopanning on immobilised conjugates selected two protein fragments that had high affinity for the immobilised abscisic acid. The corresponding proteins, CBL-interacting protein kinase 6 and Vernalization Independence 5 are likely candidates as abscisic acid binding proteins. Biopanning on a Magic-Tag® immobilised analogue similarly selected for three putative abscisic acid binding proteins: EFS, peptidyl-prolyl cis-trans isomerase and CAXX amino protease.
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Ross, Gavin Stuart. "Abscisic acid and the control of seed development." Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356970.
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Jones, Matthew O. "Abscisic acid biosynthesis in tomato and tobacco roots." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479001.
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Duckham, Stephen Craig. "The biochemical basis of abscisic acid deficient mutants." Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303129.
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Priest, David M. "Investigation of a glucosyltransferase that recognises abscisic acid." Thesis, University of York, 2005. http://etheses.whiterose.ac.uk/14075/.
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Todoroki, Yasushi. "STUDIES ON HIGHLY POTENT ANALOGUES OF ABSCISIC ACID." Kyoto University, 1996. http://hdl.handle.net/2433/160864.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第6474号
農博第887号
新制||農||720(附属図書館)
学位論文||H8||N2918(農学部図書室)
UT51-96-F353
京都大学大学院農学研究科食品工学専攻
(主査)教授 大東 肇, 教授 安本 教傳, 教授 岩村 俶
学位規則第4条第1項該当
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Griffiths, Allen. "Abscisic acid and the water relations of tomato roots." Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306779.
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Bass, Peter R. "Purification of an enzyme involved in abscisic acid biosynthesis." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385939.
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Guri, Amir Joseph. "Abscisic acid ameliorates glucose tolerance and obesity-induced inflammation." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29433.
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Obesity is a disease characterized by chronic inflammation and the progressive loss in systemic insulin sensitivity. One of the more effective medications in the treatment of insulin resistance have been the thiazolidinediones (TZDs), which act through the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma ). Due to the many side-effects of TZDs, our laboratory sought out a natural phytochemical, abscisic acid (ABA), with chemical similarities to TZDs. Our first study demonstrated that ABA activates PPARgamma in vitro and significantly ameliorates white adipose tissue (WAT) inflammation and glucose tolerance in db/db mice. We next further examined the effect of ABA on the phenotype of adipose tissue macrophages (ATMs). In doing so, we discovered two separate ATM populations which differed in their expression of the macrophage surface glycoprotein and maturation marker F4/80 (F4/80hi vs F4/80lo). Dietary ABA-supplementation significantly reduced F4/80hiCCR2+ ATMs and had no effect on the F4/80lo population. Utilizing a tissue-specific knockout generated through Cre-lox recombination, we were able to determine that this effect was dependent on PPARgamma in immune cells. To further characterize the differences between the ATM subsets that were affected by ABA, we performed a multi-organ assessment (i.e., WAT, skeletal muscle and liver) of the effect of diet-induced obesity on the phenotype of infiltrating macrophages and T cells into metabolic organs. Based on our new data, we formulated a model by which F4/80hiCCR2hi ATMs infiltrate WAT and ultimately induce a CD11c+ pro-inflammatory phenotype in the resident F4/80loCCR2lo subset. Ultimately, our findings provide evidence that ABA has potential as an alternative preventive intervention, expound the role of PPARgamma in immune cells and, in general, expand our knowledge concerning the immunopathogenesis of obesity-induced insulin resistance.Ph. D.
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Cowan, Ashton Keith. "The metabolism of abscisic acid in higher plant tissues." Thesis, Rhodes University, 1989. http://hdl.handle.net/10962/d1002024.
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The biosynthesis of ABA from R-[2-¹⁴C]-MVA was demonstrated in Persea americana cv. Fuerte mesocarp and in mature seeds of Hordeum vulgare cv. Dyan and cv. Himalaya. Radioactivity from R-[2-¹⁴-C]-MVA was also incorporated into the 1',4'-trans ABA diol in Persea americana mesocarp and a possible role for this metabolite as a precursor of ABA in plants is discussed. The biosynthesis of ABA from MVA could not be demonstrated in either turgid and waterstressed Hordeum vulgare cv. Dyan, Pisum sativum cv. Black-eyed Susan and Phaseolus vulgaris cv. Top-crop or in immature seeds of Pisum sativum and Phaseolus vulgaris. (R,S,)-[2-¹⁴C]-ABA was catabolised to PA, DPA and aqueous conjugates in leaves and mature seeds of Hordeum vulgare cv. Dyan, seedlings and immature seeds of Pisum sativum and Phaseolus vulgaris and in mesocarp from ripening fruits of Persea americana. PA and DPA were identified by either microchemical methods and/or capillary GC-MS. 7'-Hydroxy ABA was characterised as a novel ABA catabolite in light-grown and etiolated leaves of Hordeum vulgare by capillary GC-MS. Circular dichroism analysis revealed that it was derived predominantly from the (R)-enantiomer of ABA. This catabolite was absent in similar studies using the dicotyledons Pisum sativum and Phaseolus vulgaris. Refeeding studies with [¹⁴C]-PA, [C]-DPA and [¹⁴C]-7'-hydroxy ABA were used to confirm the metabolic interrelationship between ABA and its catabolites in both vegetative and non-vegetative tissues from monocotyledonous and dicotyledonous species. The methyl ester of (R,S,)-ABA was hydrolysed efficiently by light-grown leaves of Hordeum vulgare. Older, vegetative tissues catabolised (R,S,)-ABA more efficiently than their younger counterparts. In contrast, small, immature seeds of Pisum sativum catabolised (R,S,)-ABA more effectively than larger, immature seeds of this species. Light did not appear to influence ABA biosynthesis but markedly enhanced ABA catabolism. Light stimulated the overall rate of ABA catabolism in both vegetative and non-vegetative tissue. Water stress reduced ABA catabolism in Hordeum vulgare leaves but had little effect on this process in Phaseolus vulgaris seedlings. Pretreatment of tissues with (R,S,)-ABA retarded the catabolism of (R,S,)-[2-¹⁴C]-ABA, negating ABA-induced conversion to PA. Cycloheximide inhibited ABA biosynthesis and catabolism but did not affect ABA conjugation. Chloramphenicol and lincomycin had little or no effect on ABA metabolism suggesting that the enzymes involved were labile and cytoplasmic in origin. Ancymidol and cycocel inhibited ABA biosynthesis while AM01618 stimulated this process. The cytokinins, benzyladenine, kinetin, isopentenyl adenine and zeatin also inhibited ABA biosynthesis. These results are discussed in relation to the possible involvement of carotenoids in ABA biosynthesis. AM01618, ancymidol andcycocel did not significantly influence the conversion of ABA to PA and DPA while cytokinins appeared to enhance this process only in vegetative tissue. The information derived from these studies was then used in attempts to develop a cell-free system from higher plants capable of metabolising ABA. A cell-free system prepared from imbibed Hordeum vulgare cv. Dyan embryos biosynthesized and catabolised ABA. This is the first demonstration of a cell-free system from non-vegetative tissue capable of metabolising ABA and could prove useful for elucidating its biosynthetic route. This cell-free system generated the terpenyl pyrophosphates IPP, FPP and GGPP from MVA. ABA was produced from both MVA and IPP in the presence of 0₂ and NADPH. The biosynthesis of ABA was stimulated by the addition of the squalene 2,3-oxide cyclase and kaurene synthetase inhibitor, AM01618 and a "cold-pool trap" of (R,S,)-ABA. Ancymidol, cycocel and cytokinins reduced incorporation of label from MVA into ABA. Similar cell-free preparations, in the absence of AM01618, converted (R,S,)-[2-¹⁴-C]-ABA into PA, 7'-hydroxy ABA and water-soluble conjugates. Although the methyl ester of (R,S,)-ABA was efficiently hydrolysed in this cell-free system no DPA was generated. The possible involvement of mixed function oxidase activity and soluble oxidases is discussed in relation to ABA metabolism. While cell-free preparations from Persea americana cv. Fuerte mesocarp and immature seeds of Pisum sativum and Phaseolus vulgaris were unable to synthesize ABA from MVA, these tissue homogenates converted ABA into more polar acidic products. PA and DPA were identified as products of ABA catabolism in extracts from immature seeds of Phaseolus vulgaris and the l',4'-cis diol of ABA in extracts from Pisum sativum immature seeds
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Vasanthi, G. "Hormones and Cuscuta Development Abscisic Acid And Its Conjugates-Endogenous Levels And Metabolism During Growth And Haustoria Formation." Thesis, Indian Institute of Science, 1994. http://hdl.handle.net/2005/102.
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Cuscuta or dodder is one of the best known higher plant parasite with around 158 species over 5 continents parasitising a wide variety of host plants (Yuncker,1932) Dodders are characterised by their interesting parasitic behaviour and extraordinary appearance among the obligate parasitic flowering plants (Kuijt, 1969)
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Mohr, 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.
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The plant hormone, abscisic acid (ABA), has previously been shown to have an impact on the resistance or susceptibility of plants to pathogens. In this thesis, it was shown that ABA had a regulatory effect on an extensive array of plant defence responses in three different plant and pathogen interaction combinations as well as following the application of an abiotic elicitor. In unique studies using ABA deficient mutants of Arabidopsis, exogenous ABA addition or ABA biosynthesis inhibitor application and simulated drought stress, ABA was shown to have a profound effect on the outcome of interactions between plants and pathogens of differing lifestyles and from different kingdoms. The systems used included a model plant and an important agricultural species: Arabidopsis thaliana (Arabidopsis) and Peronospora parasitica (a biotrophic Oomycete pathogen), Arabidopsis and Pseudomonas syringae pathovar tomato (a biotrophic bacterial pathogen) and an unrelated plant species, soybean (Glycine max) and Phytophthora sojae (a hemibiotrophic Oomycete pathogen), Generally, a higher than basal endogenous ABA concentration within plant tissues at the time of avirulent pathogen inoculation, caused an interaction shift towards what phenotypically resembled susceptibility. Conversely, a lower than basal endogenous ABA concentration in plants inoculated with a virulent pathogen caused a shift towards resistance. An extensive suppressive effect of ABA on defence responses was revealed by a range of techniques that included histochemical, biochemical and molecular approaches. A universal effect of ABA on suppression or induction of the phenylpropanoid pathway via regulation of the key entry point gene, phenylalanine ammonia-lyase (PAL), when stimulated by biotic or abiotic elicitors was shown. ABA also influenced a wide variety of other defence-related components such as: the development of a hypersensitive response (HR), the accumulation of the reactive oxyden species, hydrogen peroxide and the cell wall strengthening compounds lignin and callose, accumulation of SA and the phytoalexin, glyceollin and the transcription of the SA-dependent pathogenesis- related gene (PR-1). The near genome-wide microarray gene expression analysis of an ABA induced susceptible interaction also revealed an yet unprecedented insight into the great diversity of defence responses that were influenced by ABA that included: disease resistance like proteins, antimicrobial proteins as well as phenylpropanoid and tryptophan pathway enzymes. Subtle differences were found in the number and type of defence responses that were regulated by ABA in each type of plant and pathogen interaction that was studied. This thesis has clearly identified in plant/pathogen interactions previously unknown and important roles for ABA in the regulation of many defence responses.
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Linforth, R. "A genetic approach to the study of abscisic acid biosynthesis." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378491.
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Zhang, Yi. "Improving Freezing Tolerance of Wine Grapes with Exogenous Abscisic Acid." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354643490.
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Inomata, Masahiro. "Studies on the biosynthetic pathway of abscisic acid in fungi." Kyoto University, 2005. http://hdl.handle.net/2433/145008.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第11606号
農博第1462号
新制||農||904(附属図書館)
学位論文||H17||N3999(農学部図書室)
23249
UT51-2005-D355
京都大学大学院農学研究科食品生物科学専攻
(主査)教授 大東 肇, 教授 村田 幸作, 教授 坂田 完三
学位規則第4条第1項該当
25
Augustyn-Gradkowska, E. "Stereocontrolled synthesis of plant growth regulators, abscisic acid and xanthoxin." Thesis, London Metropolitan University, 1985. http://repository.londonmet.ac.uk/3314/.
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The project is concerned with the total synthesis of plant growth regulators related to abscisic acid (ABA). The biological activity of these plant growth regulators, ABA and Xanthoxin, and their derivatives is influenced by the stereochemistry of the double bond system in the side chain, the 2Z,4E-isomers being most potent.
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Jiang, Mingyi. "Role and mechanism of abscisic acid in the induction of antioxidant defense in maize leaves." HKBU Institutional Repository, 2002. http://repository.hkbu.edu.hk/etd_ra/415.
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Tang, Yulin. "Analysis of auxin and abscisic acid signal transduction in Arabidopsis thaliana." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=970018517.
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Liang, Jiansheng. "Xylem-carried abscisic acid (ABA) in plant responses to soil-drying." HKBU Institutional Repository, 1997. http://repository.hkbu.edu.hk/etd_ra/167.
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Fan, Rong. "The roles of 1-aminocyclopropane-1-carboxylate synthase isogenes in the flower and fruit development in tomatoes." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40203906.
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Jokhan, Anjeela Devi. "Root-to-shoot communication in Ricinus communis L. plants subjected to drying a part of the root system." Thesis, University of Bristol, 1997. http://hdl.handle.net/1983/4a9159a4-0a32-457c-bf08-61e6745f8a75.
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This thesis examines the role of root-sourced abscisic acid in the regulation of stomatal closure and leaf expansion in response to drying approximately half of the roots of Ricinus communis L. plants. Drying part of the root system of Ricinus communis promoted stomatal closure and slowed leaf expansion in the absence of any disturbances in shoot water relations, implying the involvement of chemical rather than hydraulic signalling. Initially root-sourced ABA was believed to be responsible for these responses. Delivery rates (concentration x flow rate) of ABA out of the drying roots were calculated which took into account the effect of dilution on solutes in the well-watered and droughted plants due to different transpiration rates in these plants. The delivery term was further modified to account for the differences in sizes of their roots and shoots. ABA delivery out of the roots of plants with drying upper roots increased within the first 12 h and was maintained over the next 3 days. However, significant decline in stomatal apertures and leaf elongation occurred only 2 - 3 days after root drying began. During the early stages of drying upper roots (2-3 d) xylem sap pH, and delivery rate of nitrate and l-aminocyclopropane-l-carboxylic acid were little changed, while hydraulic conductivity of the root system as a whole was reduced approximately 25%, and ABA accumulation (synthesis?) in roots increased. Increased ABA levels in phloem sap was not found, suggesting no enhanced re-cycling of ABA between shoots and roots was taking place in the plants during this time. Antitranspirant activity in xylem sap of droughted plants that was not ABA was sought as a possible cause of stomatal closure. However, convincing evidence of such activity was not found. Examination of ABA output by roots into shoot compared to that entering lamina of the 5th leaf in the canopy showed the attenuation of the signal as transpiration fluid moved up the plant. These obs~f\ations indicate that ABA from roots is unlikely to be a highly active signal eliciting shoot responses to mild drought in Ricinus communis.
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Michler, Charles H. "Effects of light quality on morphology and endogenous abscisic acid during somatic embryogenesis of carrot /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487265143147375.
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Richardson, Gaynor Rose-Marie. "Cell-free biosynthesis of abscisic acid (ABA) in extracts of flavedo from Citrus sinensis (L.) osbeck." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1003790.
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The biosynthetic origin of the plant growth regulator abscisic acid remains equivocal and almost nothing is known about the enzymes involved in this process. The present research programme describes the development of a cell-free system, capable of synthesizing abscisic acid and attempts to provide further information about the biochemistry and enzymology of this important biosynthetic pathway. Cell-free extracts were prepared either directly from the flavedo (crude) or from an acetone powder derived from flavedo, of mature coloured fruits of Citrus sinensis L. cv. Midknight and incubated with mevalonic acid, isopentenyl pyrophosphate, famesylpyrophosphate, geranylgeranyl pyrophosphate, ß-carotene and 1',4'-trans-abscisic acid diol. The neutral and acidic products formed were purified by thin-layer chromatography and high performance liquid chromatography, and quantified by high performance liquid chromatography, gas chromatography-electron capture and unequivocally identified by combined gas chromatography-mass spectrometry. Abscisic acid, 1',4'-trans-abscisic acid diol and phaseic acid were unequivocally identified as the major acidic products formed in this cell-free system. The acid fraction also contained xanthoxin acid. Labelled and unlabelled ß-carotene was converted into the neutral compounds xanthoxin and xanthoxin alcohol. In addition. high performance liquid chromatography-photodiode array analYSis of the oxy-carotenoid fraction revealed the complete spectrum of ß, ß-carotenoids induding zeaxanthin, antheraxanthin and violaxanthin with accumulation of an oxygenated carotenoid tentatively identified as 9- cis-violaxanthin. Identification of putative C₁₅ intermediates was achieved by either UV spectrophotometry and combined capillary gas chromatography-mass spectrometry or microchemical analYSis and co-chromatography. Refeeding studies using (±)-[2-¹⁴C]_ abscisic acid diol as substrate revealed that abscisic acid was not metabolized to abscisic acid diol, suggesting that it was/is produced as an intermediate rather than as a catabolite of ABA in this system. Stigmasterol, and to a lesser extent cholesterol reduced conversion of ß-carotene to abscisic acid but did not influence transformation of 1',4'-trans-abscisic acid diol to abscisic acid. AM01618 stimulated fonnation of abscisic acid and appeared to exert its effect at the level of conversion of 1' ,4'-trans-abscisic acid diol. Zeatin and the cytokinin analogue, ancymidol inhibited the biosynthesis of abscisic acid whereas dithiothreitol increased incorporation of label from ß-carotene into abscisic acid suggesting involvement of a cytochrome P450-type mixed function oxidase in this reaction sequence. Sodium dodecylsulphate polyacrylamide gel electrophoresis of the enzyme extract derived from Citrus flavedo revealed the presence of a 53 kD protein with peroxidase activity characteristic of a cytochrome P-450. Abscisic acid biosynthesizing activity was always greater in extracts from acetone powder and abscisic acid biosynthesis was enhanced in the presence of AMO 1618, NAD+, NADH, NADPH, MgCI₂ and Molybdate but was inhibited by FAD. Activity was further enhanced by the addition of (R,S)-abscisic acid as a cold-pool trap and by induding 0.1% w/v of either Tween 20 or Triton X 100 in the extraction buffer. When cis-ß-carotene was used as substrate, no abscisic acid was produced. Conversely when either all-trans-ß-carotene or a mixture of the two isomers was used, incorporation into abscisic acid occurred. Upoxygenase activity in cell-free extracts of Citrus flavedo increased with increasing protein concentration. As the ability of lipoxygenase to make xanthoxin from violaxanthin, had been reported, increased activity in the cell-free system implied that carotenoid deavage was being brought about by a non-haem oxygenase with lipoxygenase-like properties. Reports had implicated phoshorylation in the activation of many catalytic enzymes (Hanks et aI., 1985). Phosphorylation of the enzymes in this cell-free system proved unsuccessful. Further, it had been reported that in vitro phosphorylation of several membrane polypeptides and soluble polypeptides from com, had been promoted by the addition of Ca²₊ In this cell-free system Ca + did not have a stimulatory effect on protein phosphorylation. Dioxygenases generally occur as soluble enzymes, where they catalyse many oxygenation reactions in metabolic pathways. The addition of 2-oxo-glutarate, a requirement of most soluble oxidases, did not affect the activity of the cell-free system.
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Cho, In-jeong. "Function of abscisic acid in maintenance of maize primary root growth under water deficit." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4459.
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Thesis (Ph.D.)--University of Missouri-Columbia, 2006.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 plus two media files. Title from title screen of research.pdf file (viewed on May 1, 2009) Vita. Includes bibliographical references.
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Sun, Xin. "Characterization of an auxin- and abscisic acid-inducible reporter gene : Dc3-GUS in reported auxin mutants, and mutant screening based on auxin responsive Dc3-GUS expression /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202003%20SUN.
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Yang, Zhen. "AtERF4 and AtERF7 are involved in the abscisic acid response in arabidopsis." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4170.
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Thesis (M.S.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains ix, 80 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 65-80).
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Cook, Ritchard Matthew. "Changes in gene expression in response to abscisic acid and environmental stress." Thesis, University of the West of England, Bristol, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293362.
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Grundy, Jack. "Control of environmental stress responses by the circadian clock and abscisic acid." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/90280/.
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Plants are exposed to a variety of abiotic stresses, including salinity and drought. These environmental stresses cause major losses in crop yield. High salinity stress alone impairs crop production on at least 20% of irrigated land worldwide. Thus, the development of stress-tolerant crops is of major importance for food security. Many physiological responses to ensure acclimation to adverse environmental conditions require the synthesis and perception of the plant hormone abscisic acid (ABA). Recent studies have shown that the function of the circadian clock is altered under some abiotic stress conditions such as drought, and osmotic stress. The first part of this thesis investigates the role of the stress response hormone abscisic acid in changing the function of the clock under osmotic stress. It was found that multiple core clock genes are responsive to ABA application, with sharp transient induction of morning associated genes in particular. In comparison, osmotic stress caused a damping of the amplitude of gene expression. It was then shown that the disruptive effect of osmotic stress on circadian leaf movement rhythms required the biosynthesis of ABA. This is important as it demonstrates that ABA is a key factor in mediating osmotic stress responses to the clock. The second half of this thesis then focuses on how altered function of the clock might impact plant performance under drought or osmotic stress. It was found that the morning associated LATE ELONGATED HYPOCOTYL (LHY) transcription factor, which functions as a key component of the circadian clock, regulates many of the components of the ABA signalling pathway. Evidence was provided that, while overexpression of LHY results in reduced ABA levels, ABA responsive gene expression is significantly increased upon ABA treatment. Finally, through phenotypic analysis it was determined that increased LHY expression leads to increased performance in drought and osmotic stress conditions. This is important as it suggests that manipulation of circadian clock function may be useful as a novel approach in the future engineering of stress tolerant crop lines.
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Badrakh, Turmandakh. "Effects of Abscisic Acid (ABA) on Germination Rate of Three Rangeland Species." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/5881.
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Seeds sown in the fall to restore sagebrush (Artemisia spp.) steppe plant communities could experience high mortality when they germinate and seedlings freeze during the winter. Delaying germination until the risk of frost is past could increase seedling survival. We evaluated the use of abscisic acid (ABA) to delay germination of Elymus elymoides, Pseudoroegneria spicata, and Linum perenne. The following treatments were applied: uncoated seed, seed coated with ABA at 2.2, 4.4, 8.8, 13.2, and 17.6 g of active ingredient kg-1 of seed, and seed coated with no ABA. The influence of seed treatments on germination were tested at five different incubation temperatures (5-25°C). The lowest application rate of ABA had no significant influence on germination percentage but higher application rates showed a decline. All concentrations of ABA tested delayed germination, especially at low incubation temperatures. For example, the time required for 50% of the seeds to germinate at 5°C was increased with the use of the lowest ABA application rate by 56, 61, and 14 days, for E. elymoides, P. spicata, and L. perenne, respectively. Quadratic thermal accumulation regression models were developed for each species and treatment to predict progress toward germination. For the two grasses, models had sufficient accuracy (R2 = 0.61- 0.97) to predict germination timing using field seedbed temperatures. Equations for L. perenne were less accurate (R2 = 0.03-0.70). Use of these models will allow testing whether ABA will delay germination sufficiently to avoid winter frost periods and provide the basis for future field tests.
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Tonini, Patricia Pinho. "Conexão entre os processos de degradação das resservas de proteinas e carboidratos e o edfeito dos hormonios e açucares em sementes de Sesbania virgata (Cav.) Pers." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317725.
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Orientador: Marcos Silveira BuckeridgeTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-12T17:19:07Z (GMT). No. of bitstreams: 1 Tonini_PatriciaPinho_D.pdf: 2946398 bytes, checksum: 0c45bddc87c835268cd2cfd05f89d364 (MD5) Previous issue date: 2008
Resumo: Sementes de Sesbania virgata (Cav.) Pers. acumulam suas reservas de carbono no endosperma na forma de um polissacarídeo de parede celular, o galactomanano. A mobilização deste ocorre após a germinação e envolve três enzimas hidrolíticas, dentre elas a a-galactosidase. Além da reserva de carbono, há uma grande quantidade de corpos protéicos, no citoplasma das células endospérmicas, que constituem a principal reserva de nitrogênio nestas sementes. Para que ocorra a correta distribuição dos produtos de degradação das reservas deve haver sincronização entre os processos de degradação das reservas de carbono e nitrogênio, porém para compreender tais mecanismos, é necessário estudar aspectos do controle da produção e ação das enzimas responsáveis pela hidrólise das reservas. Buscando determinar em que ponto do metabolismo a semente de S. virgata se encontra em relação à produção destas enzimas hidrolíticas, durante e após a germinação, e supostamente os tecidos envolvidos nesta produção, sementes desta espécie foram embebidas em actinomicina-D (inibidor de transcrição) e cicloheximida (inibidor de tradução) e os efeitos destes inibidores verificados através da atividade e detecção da a-galactosidase no tegumento e endosperma destas sementes. Além disso, buscando verificar e relacionar o efeito do ácido abscísico, do etileno e dos açúcares na degradação das reservas após a germinação de S. virgata, sementes desta espécie foram embebidas em ABA, etileno, glucose e sacarose, e os efeitos destes foram verificados através dos teores protéicos, da atividade da a-galactosidase e da produção endógena de ABA e etileno nestas sementes. Como a presença de actinomicina-D e cicloheximida não inibiram a produção e a atividade da a-galactosidase no endosperma durante e após a germinação, sugere-se que a produção desta enzima ocorra principalmente durante a maturação da semente. Aparentemente, a partir do período pós-germinativo, a enzima pré-formada seria processada e ativada, para conseqüente degradação dos galactomananos, através de um processo proteolítico. Em contrapartida, como a presença deactinomicina-D e cicloheximida inibiram a degradação das proteínas de reserva no tegumento e endosperma e, inclusive, induziram a atividade da a-galactosidase nestes tecidos no final do processo de degradação dos galactomananos, sugerese a síntese de novo de proteases durante e após a germinação e a relação íntima destas enzimas com a degradação das proteínas de reserva e da a-galactosidase no final do processo de degradação dos galactomananos. Quanto aos hormônios, a presença de ABA exógeno retardou o início da degradação das proteínas de reserva no endosperma, assim como diminuiu a atividade da a-galactosidase no mesmo tecido no final do processo de degradação do galactomanano, sugerindo um efeito modulador deste hormônio durante a degradação das reservas, reprimindo a ação das enzimas hidrolíticas. A presença de etileno exógeno, entretanto, aumentou a atividade da a-galactosidase no endosperma e, inclusive, no tegumento no final do processo de degradação do galactomanano, sugerindo um efeito indutor deste hormônio na ativação e ação das enzimas hidrolíticas. De fato, analisando a produção endógena de ABA e etileno, observou-se um aumento brusco dos hormônios no período de mobilização das reservas, que pode estar relacionado à influência destes hormônios na atividade das enzimas hidrolíticas em sementes de S. virgata. Ainda, como ocorreram mudanças na produção de ABA e etileno endógeno na presença de glucose e sacarose, sugere-se uma relação íntima entre a via de sinalização destes hormônios e a dos açúcares, a fim de controlar o processo de degradação das reservas. Desta forma, estas evidências sugerem que o ABA e o etileno controlariam antagonicamente a mobilização de reservas em sementes de S. virgata, juntamente com os açúcares, através da ativação e ação das enzimas hidrolíticas, a fim de controlar o processo de degradação das proteínas e dos galactomananos, evitando a produção dos açúcares redutores e de sacarose em excesso durante o período pós-germinativo e garantindo o afluxo eficiente de carbono e nitrogênio para o desenvolvimento da plântula.
Abstract: Seeds of Sesbania virgata (Cav.) Pers. have an endosperm which accumulates galactomannan as a storage polysaccharide in the cell walls that is hydrolysed after germination by three enzymes (a-galactosidase, endo-ß-mannanase and exo-ß-mannosidase). Besides the storage of carbon, there is a great amount of protein bodies in the cytoplasm of endospermic cells, which play the major role as a nitrogen reserve in this seed. It is likely that a synchronization between the process of galactomannan and protein degradation occurs for a more efficient distribution and use of the storage degradation products. However, to understand these mechanisms, it is necessary to study aspects of the production and action control of the hydrolytic enzymes responsible for the mobilisation of these reserves. Aiming to determine in which point of the metabolism the seed of S. virgata is in relation to the production of the hydrolytic enzymes, during and after germination, and the supposed tissues involved in this production, seeds of this specie were imbibed in actinomycin-D (transcription inhibitor) and cycloheximide (translation inhibitor), and the effects of these inhibitors verified thought the a-galactosidase activity and detection in the testa and endosperm of these seeds. Besides of this, for to verify and relate the effects of abscisic acid, ethylene and sugars on the reserves degradation after germination of the S. virgata, seeds of this specie were imbibed in ABA, ethylene, glucose and sucrose, and the effects of these were verified through the protein content, a-galactosidase activity and endogenous production of ABA and ethylene in this seeds. In the presence of actinomycin-D and cycloheximide, the production and activity of the a- galactosidase were not inhibited during and after germination, suggesting that the production of this enzyme occurs principally during the maturation of the seed. Apparently, after the germination, this enzyme is processed by proteolysis, so that it becomes activated to perform galactomannan degradation. On the other hand, the presence of actinomycin-D and cycloheximide inhibited the protein degradation in the testa and endosperm and at the same time induced the a-galactosidaseactivity in the same tissues at the final steps of the galactomannan degradation process. This suggests the existence of synthesis de novo of the proteases during and after germination and a possible relationship between the storage protein and galactomannan mobilisation. Regarding the hormones, the presence of exogenous ABA retarded the beginning of the storage protein degradation in the endosperm and also decreased a-galactosidase activity in the same tissue at the end of galactomannan degradation. This suggests that there is a regulator effect of this hormone during the storage degradation, repressing the enzymes action. In the presence of exogenous ethylene an increase in the a-galactosidase activity in the endosperm and in the testa were observed at the end of galactomannan degradation, suggesting an inducing effect of this hormone on the hydrolytic enzymes. The finding of endogenous ABA and ethylene production, observed during the period of the storage mobilisation, give support to the above raised hypothesis that the two hormones participate in the control of the hydrolytic enzyme activities in seeds of S. virgata. Furthermore, the changes observed in the endogenous ABA and ethylene production in the presence of glucose and sucrose, suggested a relation between the signaling pathway of these hormones and the sugars signaling, controlling the process of storage degradation. Thus, our results add evidence to suggest that ABA and ethylene antagonistically control the storage mobilisation in seeds of S. virgata, together with the sugars, through the hydrolytic enzymes activation, controlling the process of storage protein and galactomannan degradation, in other to avoiding the excess production of reductor sugars and sucrose during the post-germinative period and assuring the efficient afflux of the carbon and nitrogen to the seedling development.
Doutorado
Biologia Celular
Doutor em Biologia Celular e Estrutural
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Williams, Bruce. "Isolation and characterization of abscisic acid-responsive, embryo specific genes from Zea mays." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41786.
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Embryogenesis in plants, as in animals, requires the regulated expression of sets of genes involved in developmental processes. To gain insight into the processes regulating gene expression during embryogenesis differential screening was used to identify embryo-specific sequences in a cDNA library constructed from Zea mays embryo RNA. Four embryo-specific sequences and one constitutive sequence were characterized further by RNA blot hybridization and DNA sequence determination. The constitutive sequence and two of the embryo-specific sequences were found to encode parts of the previously-reported chloroplast 23S rRNA, Oleosin KD-18, and RAB-17 genes. Two sequences, named Emb5 and Emb564, were found to encode novel maize homologs of a gene expressed during late embryogenesis in a wide range of seed plants. These 5 genes exhibited differential temporal and spatial accumulation during development. Moreover, analysis of RNA from cultured embryos suggested that 4 of these genes were regulated by abscisic acid. The ABA-responsive genes could be divided into 3 classes, based on their developmental expression, tissue-specificity, and sensitivity to ABA. Antibodies raised against a $ beta$-galactosidase:EMB564 fusion protein were used to analyze the accumulation of the EMB564 and/or EMB5 proteins. These polyclonal antibodies detected one or several polypeptides with a molecular weight less than 14 kD which exhibited patterns of developmental accumulation and regulation similar to Emb5 and Emb564 transcripts.
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Longland, Jane Mary. "The molecular mode of action of abscisic acid in the induction of dormancy." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/12463.
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Cotter, Matthew Q. "Interactions of N-Acylethanolamine Metabolism and Abscisic Acid Signaling in Arabidopsis Thaliana Seedlings." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc31532/.
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N-Acylethanolamines (NAEs) are endogenous plant lipids hydrolyzed by fatty acid amide hydrolase (FAAH). When wildtype Arabidopsis thaliana seeds were germinated and grown in exogenous NAE 12:0 (35 µM and above), growth was severely reduced in a concentration dependent manner. Wildtype A. thaliana seeds sown on exogenous abscisic acid (ABA) exhibited similar growth reduction to that seen with NAE treatment. AtFAAH knockouts grew and developed similarly to WT, but AtFAAH overexpressor lines show markedly enhanced sensitivity to ABA. When low levels of NAE and ABA, which have very little effect on growth alone, were combined, there was a dramatic reduction in seedling growth in all three genotypes, indicating a synergistic interaction between ABA and NAE. Notably, this synergistic arrest of seedling growth was partially reversed in the ABA insensitive (abi) mutant abi3-1, indicating that a functional ABA signaling pathway is required for the full synergistic effect. This synergistic growth arrest results in an increased accumulation of NAEs, but no concomitant increase in ABA levels. The combined NAE and ABA treatment induced a dose-dependent increase in ABI3 transcript levels, which was inversely related to growth. The ABA responsive genes AtHVA22B and RD29B also had increased expression in both NAE and ABA treatment. The abi3-1 mutant showed no expression of ABI3 and AtHVA22B, but RD29B expression remained similar to wildtype seedlings, suggesting an alternate mechanism for NAE and ABA interaction. Taken together, these data suggest that NAE metabolism acts through ABI3-dependent and independent pathways in the negative regulation of seedling development.
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Fan, Rong, and 樊榮. "The roles of 1-aminocyclopropane-1-carboxylate synthase isogenes in the flower and fruit development in tomatoes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40203906.
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Thorne, Eleanor Tanene. "The influence of accumulated ABA on shoot growth of water-stressed tomato /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074448.
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Gómez-Porras, Judith Lucia. "In silico identification of genes regulated by abscisic acid in Arabidopsis thaliana (L.) Heynh." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980562899.
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Baron, Kevin. "GRAM genes and abscisic acid (ABA) metabolism in the reproductive development of Arabidopsis thaliana." Elsevier, 2012. http://hdl.handle.net/1993/18865.
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Abscisic acid (ABA) is a key plant hormone regulating agronomically important processes including seed maturation and dormancy, stomatal opening and closure, along with the transcriptional and physiological response of plants to abiotic and biotic stresses. The current study sought to functionally characterize members of an ABA-responsive gene family encoding GRAM (Glucosyltransferases, Rab-like GTPase activators and Myotubularins) domain proteins in Arabidopsis thaliana. Utilizing reverse genetics loss- and gain-of-function lines associated with GEM-RELATED 5 (GER5) were obtained, which displayed several defects in reproductive development. Gene expression profiling, RNA in situ hybridization and immunohistochemical techniques were utilized to evaluate GER5 and two closely related GRAM genes, GEM-RELATED 1 (GER1) and GLABRA2 EXPRESSION MODULATOR (GEM) in reproductive structures. Microarray profiling of seeds from ger5-2 mutants and wild-type plants revealed transcriptional changes in carbohydrate metabolism, hormone signaling and catabolic processes accompanied seed development defects of ger5-2 mutants. Seed germination assays further revealed ger5-2 mutants exhibited reduced sensitivity to ABA.
In assessing GER5, GER1 and GEM as putative ABA-response genes, a second study evaluated the expression of GRAM, AuTophaGy-related (ATG), and ABA-response genes in source and sink organs exposed to abiotic stress or within mutant backgrounds deficient in sugar signaling. Monodansylcadaverine (MDC) staining was also utilized to localize autophagosomes or autophagic bodies within vegetative or reproductive organs during plant development, or in response to carbon starvation or abiotic stress.
In a third study transcriptional differences in ABA metabolism, transport and homeostasis were examined within reproductive organs (cauline leaves, inflorescence meristem, developing siliques) exposed to cold and heat stress. This study revealed reproductive organs are characterized by unique patterns of ABA metabolism which differ from tissues typically associated with classical ABA responses. Together, these studies indicate GER5, an uncharacterized ABA-responsive GRAM domain gene, plays a novel role in the reproductive development of plants and that ABA metabolism and signaling are uniquely regulated in reproductive organs.
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Chandler, Jake Owen. "Chemical genetics of seed germination : modulation of a key step in abscisic acid biosynthesis." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/79569/.
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Cold conditions during imbibition can result in slow or no germination in some maize seed, leading to sub-optimal crop density and uniformity and loss of yield. A novel seed treatment is required that restores germination in seed batches that perform poorly under cold conditions. Germination of seed batches from different varieties was characterised following imbibition under cold conditions which permit no or slow germination. Hydroxamic acid inhibitors of 9-cis-epoxycarotenoid dioxygenase (NCED) stimulate germination through ABA biosynthesis inhibition in other species and had a small significant effect in increasing the proportion of normal seedlings after cold imbibition. This indicated that normal germination of maize may be inhibited by dormancy-related mechanisms during or after imbibition in cold conditions. The maize NCED (ZmNCED) family was characterised. D2 and D4 inhibit other enzymes in the carotenoid cleavage dioxygenase family and exhibit relatively weak inhibition of NCED. ZmNCEDs were cloned for in vitro enzyme inhibition studies to aid identification of NCED-specific inhibitors. An RT-qPCR assay for measuring ZmNCED expression was developed. Seed ZmNCED expression and ABA concentration was elevated under cold conditions, compared to optimal germination conditions. An assay was developed to screen for germination stimulating compounds. 965 of a diverse library of 5074 compounds were identified as potential germination stimulators. Germination stimulating activity was replicated in 171 of these compounds, with some more efficacious than D4. Germination stimulating activity of 88 compounds related to the current lead compound, D4, was assessed at concentrations of 10 ppb to 10 ppm. Compounds were identified that, at less than 10 ppm stimulated germination more than D4 at 312 ppm. The mode-of-action of these compounds will need to be determined and may yield novel targets for germination stimulation. Thus novel seed treatments for improving germination of low vigour maize seed lots under cold conditions could be based on NCED inhibition or the action of the newly identified compounds.
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Xiong, Liming. "A genetic study on environmental stress and abscisic acid signal transduction in Arabidopsis thaliana." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/284334.
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Many plant genes that are not expressed under normal growth conditions are activated in response to low temperature, drought, or salt stress. Plants must sense the stress they are under, then transmit the signal to the cellular machinery and activate stress-regulated genes. To help understand the signal events involved in the process, we used the firefly luciferase reporter gene driven by the stress-responsive RD29A promoter to screen for Arabidopsis mutants defective in stress signaling. In this study, the identification of several genetic loci is reported. Mutations in the FIERY1 locus resulted in increased gene expression under low temperature, drought, salt, and abscisic acid (ABA) treatments. FIERY1 thus underlies a connecting point of these diverse signaling pathways. FIERY1 encodes an inositol polyphosphate 1-phosphatase and is proposed to mediate the degradation of the second messenger inositol 1,4,5-trisphosphate. On the other hand, mutation in the SAD1 (s̲upersensitive to A̲BA and d̲rought 1) locus rendered the mutant plants more sensitive in gene expression, seed germination and seedling growth to ABA and salt/drought stress, but the response to cold was not changed. sad1 is also defective in drought-induced ABA biosynthesis and is impaired at the last step of ABA biosynthesis, i.e. the conversion of ABA aldehyde to ABA. SAD1 encodes an Sm-like U6 snRNP and is predicted to participate in mRNA processing. Two other loci defined in this study were found to encode enzymes in the ABA biosynthetic pathways. LOS5 encodes a molybdenum cofactor sulfurase and LOS6 encodes a zeaxanthin epoxidase. Mutations in these loci diminished osmotic stress-induced gene expression, suggesting that osmotic stress signaling does require ABA. Through studies with SAD1, LOS5 and LOS6 loci, a feedback regulatory loop was also identified. In this regulatory loop, ABA stimulates the expression of ABA biosynthetic genes, and this self-regulation may confer a rapid response to osmotic stress by speeding up ABA biosynthesis. These genetic, molecular, and biochemical studies provide many new insights into the signal transduction mechanisms in response to environmental stresses, and present successful examples of a molecular genetic approach to understand complex processes such as stress signal transduction.
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Hey, Sandra Janet. "Guard cell gene expression in Pisum sativum L." Thesis, University of the West of England, Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319258.
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Biddulph, Thomas Benjamin. "Mechanisms of dormancy, preharvest sprouting tolerance and how they are influenced by the environment during grain filling and maturation in wheat (Triticum aestivum L.) /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0168.
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