The developmental programs of maturing seed and fruit in pea (Pisum sativum L.) are tightly controlled by the interactions of several phytohormones, including gibberellins (GAs), auxins, and abscisic acid (ABA). To more fully understand these hormone networks and their roles in controlling development, transcription profiles of GA metabolism genes and metabolite profiles of key GAs, auxins, and ABA were determined in developing seeds, and histological studies were employed to correlate physiology and hormone metabolism. Data suggest that bioactive GA stimulates several aspects of seed growth, and ABA appears to promote bioactive GA1 synthesis in rapidly growing seed coats, and inhibit GA biosynthesis in the embryo axes of maturing embryos. Two putative auxin receptor genes were cloned, and their transcription profiles examined in developing seed and pericarp tissues. Pericarp PsAFB6A transcription was responsive to auxin and seed signals, indicating a potential role for the modulation of auxin sensitivity in fruit development.

Pterocarpan phytoalexins are antimicrobial compounds produced by legumes when challenged by biotic stresses. Most legumes produce pterocarpan phytoalexins with (-)-stereochemistry but pea (Pisum sativum L.) produces as its major phytoalexin (+)-pisatin. Pea also occasionally produces a minor amount of (-)-maackiain as a pterocarpan phytoalexin, and studies on the biosyntheses of (+)-pisatin and (-)-maackiain have shown that up to (-)-7,2'-dihydroxy-4',5'-methylenedioxyisoflavanone [(-)-sophorol] and 7,2'-dihydroxy-4',5'-methyl-enedioxyisoflavanol [(-)-DMDI]they have common intermediates with (-)-DMDI being where the two pathways diverge. The final step in (+)-pisatin biosynthesis is the methylation of (+)-6a-hydroxymaackiain [(+)-6a-HMK] by 6a-hydroxymaackiain methyltransferase (HMM2) but the steps from (-)-DMDI to (+)-6a-HMK are unknown.The shifting of the stereochemistry from (-)-DMDI to (+)-6a-HMK has been proposed to involve the achiral isoflavene, 7, 2'-dihydroxy-4', 5'-methylene-dioxyisoflav-3-ene (DMDIF). In this dissertation, I have shown that cis-(-)-DMDI is the enzymatic product of (-)-sophorol, and is the precursor of DMDIF which is produced by the dehydration activity of "isoflavene synthase" (IFVS). IFVS activity was not observed in elicited tissues of alfalfa, chickpea, beans, pepper, and broccoli, plants that do not produce (+) pterocarpans. Partial purification of IFVS demonstrated that it is either large in size or tightly complexed with other proteins. The SDS-PAGE of the 29-fold purified product revealed 12 major bands that aggregated into 3 bands in the non-denaturing PAGE. IFVS activity was in band 3 which co-migrated with marker proteins of>100 kDa in size. Proteins identified from LC-MS/MS peptide sequences of the proteins in band 3, when compared to three protein databases, did not identify any proteins with an enzymatic activity expected for IFVS. A disease resistance-response protein (a dirigent-like protein) and two protein-binding proteins were the most abundantly detected proteins in the pea transcriptome-translated database. Also, four of the known enzymes (isoflavone reductase, HMM1, HMM2, and sophorol reductase) involved in (+)-pisatin biosynthesis were among the proteins identified. It may be that IFVS is associated with these other proteins as a complex in vitro and in vivo. The lack of detection of IFVS in the databases could be because it has not yet been sequenced as it functions in a rare biosynthetic pathway.

No description available.

Made available in DSpace on 2014-06-11T19:30:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-16Bitstream added on 2014-06-13T18:40:30Z : No. of bitstreams: 1 machado_cg_dr_botfca.pdf: 685636 bytes, checksum: 7c0e6ecdc3b569488fe111188298b1c3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A qualidade da semente na produção agrícola é um dos principais fatores a ser considerado na implantação da cultura, havendo consenso sobre a importância da germinação, do vigor das sementes e da necessidade de avaliá-los. O trabalho teve como objetivo estabelecer metodologias para os testes de germinação e vigor com ênfase no teste de condutividade elétrica para a avaliação da qualidade fisiológica de sementes de ervilha forrageira (Pisum sativum subsp. arvense). Para estabelecer a metodologia do teste de germinação utilizou-se quatro lotes sendo dois da cultivar IAPAR 83 e dois da BRS Forrageira. Foram testadas cinco temperaturas (15ºC, 20ºC, 25ºC, 20-30ºC e 15-25ºC) e dois substratos (areia e papel). Para a metodologia para o teste de condutividade elétrica foram utilizados dez lotes da cultivar IAPAR 83. Foram realizados os testes de germinação, primeira contagem de germinação, emergência de plântulas em casa de vegetação para caracterização dos lotes e estudos específicos para os testes de condutividade elétrica (temperaturas de 20ºC e 25ºC, volumes de 75mL e 250mL de água, 50 sementes, e períodos de 8, 16, 20, 24 e 28 horas). Concluiu-se que o teste de germinação para ervilha forrageira deve ser conduzido a 20ºC em rolo de papel com primeira contagem e contagem final ao 4º e 7º dia, respectivamente. O teste de condutividade elétrica utilizando 50 sementes embebidas em 250 mL de água, na temperatura de 25ºC por 24 horas mostrou-se promissor para a diferenciação de lotes de sementes de ervilha forrageira / Seed quality is an important role in the establishment of crops. It is consensual that seed germination and vigor are important tools for the production process and must be evaluated. The present research had as objective to establish methodologies for the germination and electrical conductivity tests to evaluate physiological quality of forage pea seeds (Pisum sativum subsp. arvense). Two lots of the cultivar „IAPAR 83‟ and two lots of the cultivar „BRS Forrageira‟ were used to establish the methods for the germination test. Five temperatures (15ºC, 20ºC, 25ºC, 20-30ºC and 15-25ºC) and two substrates (between sand and rolled paper towel) were tested. Ten lots of the cultivar „IAPAR 83‟ were studied to establish the methodology for the electrical conductivity test. Germination, first count of germination and seedling emergence in greenhouse were studied. For the electrical conductivity test, different temperatures (20ºC and 25ºC), water volumes (75 mL and 250 mL) and imbibition periods (8, 16, 20, 24 and 28 hours) were evaluated. It was concluded that the germination test for forage pea seeds must be carried out under 20ºC and in rolled paper towels with first counting and final counting to the 4 and 10 days after sowing, respectively. The electrical conductivity test is sensitive to differentiate seedlots of forage pea whenever conducted with 50 seeds imbibed in 250 mL of water under 25ºC for 24 hours

The aim of this thesis is the study of the genetic substance of the important domestication sign pod dehiscence. Two types of pea were analyzed, with indehiscence pods JI92 (Pisum sativum subsp. sativum) and wild field pea with dehiscent pods JI64. (Pisum sativum subsp. elatius). By reciprocal crossbreeding of these two lines, were created recombinant inbred lines (RILs), of a total of 134 RILs lines were selected with 9 contrast lines. We utilized the massive parallel sequencing of the 3'ends of the cDNA, obtained by reverse transcription of mRNA isolated from the seam. Thanks to this method, 3 candidate genes were generated. Subsequently, we determined the expression of these three candidate genes for the using quantitative Real-Time PCR (RT-qPCR). Amplification curves and Ct values generated from the RT-qPCR were subsequently used to generate graphs to show the degree of expression of the candidate genes. The most suitable candidate was the Ps15 gene, which is present in LGIII in the Dpo1 region, and therefore could be responsible for pod dehiscence.

Made available in DSpace on 2014-08-20T13:59:08Z (GMT). No. of bitstreams: 1 dissertacao_marcio_espinosa_de_farias.pdf: 3645960 bytes, checksum: 2a09be33a4c426dea1aef53c4073f253 (MD5) Previous issue date: 2014-02-17 / Photosynthesis plays a fundamental role in the processes of growth and development of plants. It occurs in the chloroplasts of leaf mesophyll cells and consists of two steps, a photochemical phase that converts light energy into chemical energy, and other biochemical phase, which uses the energy of the first step for fixing CO2. The study aimed to evaluate, in detached leaves of pea (Pisum sativum L.), the behavior of the electron transport chain in the presence of inhibitors of specific points. The plants were grown in a greenhouse. Two to four weeks after sowing, when the leaves had become fully expanded, they were detached and the petioles were immersed in solutions containing 0, 25, 50, 100, 250, and 500 μM of DCMU, atrazine, DBMIB and methyl viologen. To DCMU, atrazine and methyl viologen the leaves remained for 2 h in contact with the solutions, to DBMIB was 5h. Measurements of transient fluorescence of chlorophyll, delayed fluorescence and modulated reflection at 820nm were made using M-PEA fluorometer. The leaves were dark adapted for 30 minutes, before a saturating pulse emission, and the fluorescence intensities were measured for 60 seconds. Pea leaves treated with 500 μM concentration of DCMU and atrazine showed to be sensitive to this dose of inhibitors, in analyzing the results of transient fluorescence, delayed fluorescence and modulated reflection at 820 nm. The leaves treated with 500 μM of methyl viologen showed differences in parameters related to the mechanism of action of the inhibitor.The same concentration used to DBMIB, had no significant difference in many results compared to the control, only in those involved in the reduction of end acceptors of photosystem I. Therefore, a detailed analysis of the transient fluorescence, delayed fluorescence and modulated reflection at 820nm, allows us to collect and correlate a series of information about the whole electron transport chain. / A fotossíntese exerce um papel fundamental para os processos de crescimento e desenvolvimento das plantas. Ela ocorre nos cloroplastos das células do mesofilo foliar e consiste de duas etapas, uma fase fotoquímica, que converte energia luminosa em energia química e outra fase bioquímica, que utiliza a energia da primeira etapa pra a fixação do CO2. O trabalho teve como objetivo avaliar, em folhas destacadas de ervilha (Pisum sativum L.), o comportamento da cadeia de transporte de elétrons na presença de inibidores de pontos específicos. As plantas foram cultivadas em casa de vegetação. Duas a quatro semanas após semeadura, quando as folhas apresentavam-se completamente expandidas, elas foram destacadas e os pecíolos foram imersos em soluções contendo 0, 25, 50, 100, 250 e 500 μM de DCMU, atrazina, DBMIB e metil viologênio. Para DCMU, atrazina e metil viologênio as folhas permaneceram por 2h em contato com as soluções, para o DBMIB foi de 5h. As medidas da fluorescência transiente da clorofila, da decaída de fluorescência e da reflexão modulada à 820nm, foram feitas utilizando fluorômetro M-PEA. As folhas foram adaptadas ao escuro por 30 minutos, antes da emissão de um pulso saturante, e as intensidades de fluorescência foram medidas por 60 segundos. As folhas de ervilha tratadas com a concentração de 500 μM de DCMU e atrazina demonstraram ser sensíveis a essa dose dos inibidores, ao analisar os resultados da fluorescência transiente, decaída de fluorescência e da reflexão modulada a 820 nm. As folhas tratadas com 500 μM de metil viologênio apresentaram diferenças nos parâmetros relacionados com o mecanismo de ação do inibidor. A mesma concentração utilizada para DBMIB, não teve diferença em muitos resultados em relação ao controle, apenas naqueles envolvidos com a redução dos aceptores finais do fotossistema I. Dessa maneira, uma análise detalhada da fluorescência transiente, da decaída da fluorescência e da reflexão modulada a 820 nm, permite coletar e correlacionar uma série de informações sobre toda a cadeia de transporte de elétrons.

La connaissance des effets et modes d’action des QTL (Quantitative Trait Loci) de résistance des plantes aux maladies est un enjeu majeur pour l’exploitation durable des résistances génétiques en agriculture. Dans le pathosystème pois/Aphanomyces euteiches, présentant une importance économique majeure, l’objectif de la thèse a consisté à valider les effets de QTL de résistance, seuls ou en combinaison, et à connaitre leurs modes d’action sur les étapes du cycle de l’agent pathogène. Un total de 157 NILs (Near Isogenic Lines) de pois issues d’un programme de Back-cross Assisté par Marqueurs, porteuses d’aucun, un, deux ou trois des sept principaux QTL de résistance préalablement identifiés, a été génotypé à l’aide d’une puce 15K SNPs et évalué pour la résistance. Les NILs porteuses de QTL à effets majeurs, seuls ou en combinaison avec des QTL à effets mineurs,ont présenté des niveaux accrus de résistance partielle en conditions contrôlées et au champ par rapport aux NILs dépourvues de QTL, dans différents fonds génétiques. Certaines NILs comportant des QTL individuels ou combinés à effets mineurs ont également montré un niveau réduit de sévérité de la maladie dans l’une ou les deux conditions de test. La plupart des QTL a présenté des effets significatifs sur le ralentissement de l’infection et/ou de la quantité d’ADN pathogène ayant colonisé la racine pendant sept jours après inoculation. Cette thèse fournit des outils et éléments de choix de QTL à combiner en sélection pour augmenter l’efficacité de la résistance partielle à A. euteiches dans les futures variétés de pois / Knowledge of the effects and action modes of resistance QTL to plant diseases is a major challenge for the durable use of genetic resistances in agriculture. In the pea/Aphanomyces euteiches pathosystem, which has a major economic importance, the aim of this study was to validate the single or combined effects of main resistance QTL, and study their action modes on steps of the pathogen life cycle. A total of 157 pea NILs (Near Isogenic Lines) created by Marker-Assisted Back-crossing and carrying no, one, two or three of the seven main resistance QTL previously identified, was genotyped using a 15K SNPs array and evaluated for resistance. The NILs carrying major-effect QTL, individually or in combination with minor-effect QTL, had increased levels of partial resistance in controlledconditions and in the field compared to NILs without QTL, in different genetic backgrounds. Several NILs carrying single or multiple minor-effect QTL also showed reduced levels of disease severity in one or the two test conditions. Most of the QTL had significant effects on slowing down infection and/or pathogen DNA quantity which had colonized the root for seven days after inoculation. This study gives tools and information for the choice of resistance QTL to use in pyramiding breeding strategies for increasing partial levels of resistance to A. euteiches in future pea varieties.

Les plantes cultivées peuvent modifier la disponibilité en ressources et les perturbations perçues par les communautés d’organismes présentes dans les agroécosystèmes et en conséquence, influencer les fonctions écosystémiques utiles à la production agricole telles que la minéralisation de N et de S ou la compétition culture-adventices. Notre objectif était d’évaluer l’effet du pois (Pisum sativum L.), introduit dans une succession de cultures, sur les communautés d’adventices et les communautés microbiennes impliquées dans la minéralisation de N et S. Pour ce faire, nous avons mené des expérimentations en conditions contrôlées et utilisé les données d’une expérimentation au champ conduite pendant 5 ans. En conditions contrôlées, nous avons montré que le pois influence via ses traits racinaires certaines activités enzymatiques liées à la minéralisation de N. En revanche au champ, les variables climatiques influencent principalement le fonctionnement des communautés microbiennes impliquées dans la minéralisation de N et S. Par ailleurs, nous avons observé que le pois sélectionnait des communautés d’adventices fonctionnellement différentes de celles d’autres cultures, comme le colza, mais cet effet du pois ne persistait pas sous la culture suivante. En conclusion, les effets du pois sur les communautés microbiennes impliquées dans la minéralisation de N et S sont faibles comparés à ceux d’autres facteurs comme les conditions climatiques. En revanche l’effet du pois sur les communautés d’adventices est fort mais limité dans le temps. Ces résultats montrent la nécessité de mener les expérimentations au champ sur plusieurs années afin de prendre en compte la variabilité climatique. / Crops species modify resources availability and perturbation regimes perceived by the communities of organisms residing in the agroecosystems and, as a consequence, can lead to alteration of ecosystem functions useful to crop production, such as nitrogen and sulfur mineralization or crop-weeds competition, realized by weeds or microorganisms. Our objective was to study the effect of a legume, pea, when introduced in a crop succession, on weed communities and microbial communities involved in protein decomposition and sulfate ester mineralization, which are the main forms of N and S, respectively, in agricultural soils. To do so, we performed experiments in controlled conditions used data from a 5-years field experiment. In controlled conditions, we showed that pea during its development modify through its root functional traits several enzymatic activities involved in N decomposition/mineralization. However, in the field experiment, climatic factors were the main drivers of the microbial communities involved in N and S decomposition/mineralization. Moreover, pea selected weed communities that were functionally different from weed communities growing in other crops such as oilseed rape. However, this effect did not persist under the following crop. As a conclusion, our results suggest that pea modifications of microbial communities are weak compared to other factors such as climatic factors. However, pea effects on weed communities are strong but short lived. Those results highlight the complementarity of microcosm and field experiments, and the necessity of long term field experiments to take into account climate variability.

Made available in DSpace on 2014-08-20T13:44:37Z (GMT). No. of bitstreams: 1 tese_caroline_costa.pdf: 410037 bytes, checksum: 70221bc02297589fd9d80d107be7a2aa (MD5) Previous issue date: 2007-02-22 / The present work had the objective of to study biochemical and physiological alterations in function of pea seed pre hydration with e phasis in the electrolyte leakage and in the expression of different isoenzymatic systems,trying to contribute for the i provement of the pre hydration methods of seeds to be submitted to tests for evaluation of its physiological potential.Seeds lots of cvs.Axé and Maria, characterized for the water content,germination,first ger mination counting,accelerated aging,electrical conductivity and seedling emergence in the field,were used.The seeds of each lot were pre hydrated in saturated atmosphere and hum idified substratu until they reach 10,12 and 14%of water content.After the pre hydration,the seeds were submitted to the tests of electrical conductivity,accelerated aging and leakage of calcium ,potassium and magnesium and characterized for the expression pattern of the isoenzymatic systems Malate Dehydrogenase,Acid Phosphatase,Glutamate Dehydrogenase and Glutamate Oxalacetate Transaminase.The pre hydration of the seeds using saturated atmosphere or humidified substratum see s to affect the process of restructuring the seed cellular e branes system differently,being reflected in alterations in the pattern of electrolyte leakage and Acid Phosphatase isoenzymatic expression.Discrepancies take place a ong results obtained by the test of electrical conductivity for evaluation of the physiological potential of pea seeds,depending on the proceeding adopted to pre hydrate the seeds. / O presente trabalho teve o objetivo de estudar alterações bioquímicas e fisiológicas decorrentes da pré hidratação de sementes de ervilha,com ênfase na lixiviação de eletrólitos e na expressão de diferentes sistemas isoenzim áticos,procurando contribuir para o aperfeiçoamento dos métodos de pré hidratação de sementes a serem submetidas a testes para avaliação do seu potencial fisiológico.Foram utilizados lotes de sementes de ervilha das cultivares Axé e Maria,caracterizados quanto ao teor de água,germinação, primeira contagem de germinação,envelhecimento acelerado,condutividade elétrica e emergência de plântulas e campo.As sementes de cada lote fora pré hidratadas e pregando atmosfera saturada e substrato umedecido,até atingirem teores de água de 10, 12 e 14%.Após a pré hidratação,as sementes foram avaliadas pelos testes de condutividade elétrica,envelhecimento acelerado,lixiviação de cálcio,potássio e magnésio e caracterizadas quanto ao padrão de expressão dos sistemas isoenzimáticos Malato Desidrogenase,Fosfatase Ácida,Glutamato Desidrogenase e Glutamato Oxalacetato Transaminase.A pré hidratação de sementes de ervilha e pregando atmosfera saturada ou substrato umedecido afeta diferentemente o processo de reestruturação do sistema de e branas celulares das sem entes,refletindo se e alterações no padrão de lixiviação de eletrólitos e na expressão do sistema isoezimático Fosfatase Ácida.Ocorre discrepâncias entre resultados obtidos pelo teste de condutividade elétrica para avaliação do potencial fisiológico de sementes de ervilha,dependendo do procedim ento adotado para a pré hidratação das sementes.

Dans un contexte d’agriculture durable, la création de variétés combinant des facteurs génétiques de résistance et d’architecture de la plante présente un intérêt majeur pour limiter le développement des maladies. La thèse a visé à analyser l’interdépendance des déterminants génétiques de l’architecture racinaire et de la résistance à A. euteiches, agent pathogène tellurique majeur du pois. Une analyse de génétique d’association conduite sur tout le génome, à partir d’une collection de 266 lignées de pois, a permis d’identifier 150 locus de résistance et d’architecture et de les comparer aux QTL précédemment étudiés. Une région commune à effet majeur a été associée à la résistance et à un caractère de développement racinaire intrinsèque. Plusieurs régions ont été détectées à la fois pour la résistance et des caractères de vigueur racinaire en réponse à l’infection.La combinaison de la résistance et de caractères d’architecture dans une sélection de lignées a été associée à une réduction des pertes de rendement au champ. Les résultats ont permis d’apporter des connaissances originales sur la génétique comparative de la résistance aux maladies et de l’architecture des plantes au niveau racinaire. Ils fournissent des outils, géniteurs et éléments de choix de QTL de résistance et d’architecture racinaire à combiner pour la sélection de futures variétés de pois résistantes à A. euteiches. / In a sustainable agriculture context, breeding for varieties combining genetic resistance and plant architecture is of major interest to limit diseases impacts in crops. The aim of this thesis was to analyze the interpendance of the genetic determinants of root architecture and resistance to Aphanomyces euteiches, a major soil born pathogen of peas. A genome wide association analysis among a 266-pea-line collection enabled us to pinpoint a total of 150 loci associated with resistance and plant architecture, and to compare them with QTL detected in previous studies. A common major locus was associated with resistance and an intrinsic root architecture trait.Several loci were detected for both resistance and disease-induced architecture. The combination of resistance and some architecture traits in selected pea lines was associated with reduced yield losses in infested fields. Results provide original knowledge on comparative genetics of disease resistance and plant architecture for root rot diseases. They provide tools (SNPs and marker haplotypes), parental lines and information for the choice of resistance and architecture QTL to combine in breeding strategies to improve resistance to A. euteiches in future pea varieties.