Hohenheim, Univ., Diss., 2007.

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Made available in DSpace on 2016-12-08T16:44:48Z (GMT). No. of bitstreams: 1 PGPV14MA140.pdf: 2115107 bytes, checksum: 05e984eae1b8cfaa9796ba9aaff4592f (MD5) Previous issue date: 2014-08-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Santa Catarina highlands have been recognized for the production of fine wines with high quality. Downy mildew (Plamopara viticola) and bunch rot (Botrytis cinerea) are the most important diseases that occur in this winemaking region. The aim of this work was determinate the intensity of downy mildew in leaves and bunch rot in bunches under different training systems, as well the content of total polyphenols in skin of white varieties. Three experiments were done during 2012/2013 and 2013/2014 cycles, two of them in commercials vineyards with Cabernet Sauvignon, Sauvignon Blanc and Chardonnay in São Joaquim/SC subjected to Y-trellis and vertical shoot positioning trellis (VSP) and the third experiment in a experimental vineyard at Santa Catarina State University (CAV/UDESC) in Lages/SC with Merlot and Cabernet Sauvignon varieties, subjected to Simple Curtin, VSP, Geneva Double Curtin (GDC) and T-Trellis(TT) training systems. Based in the data obtained the temporal dynamic of downy mildew were quantified bi-weekly from the first symptoms appearance under natural conditions on leaves distributed in four medium-height branches on each five replications per treatment. The disease was compared by the beginning of symptoms appearance (BSA); time to reach the maximum disease incidence and severity (TRMDI and TRMDS); maximum value of disease intensity and severity (Imax e Smax) and area under the disease progress curve (AUDPC) were calculated. The data were analyzed by linear regression and adjusted for the models Logistic, Monomolecular and Gompertz. The intensity of B. cinerea were evaluate at the harvest time, in five replicants where 30 randomily clusters were evaluated per treatment. The Y-trellis training system provided higher severity of downy mildew and bunch rot at Cabernet Sauvignon variety. The GDC system induced a high intensity of downy mildew at Merlot. Both white varieties evaluated, showed higher intensity of B. cinerea in Y-trellis when it was compared to VSP. The high concentration of total polyphenols was observed in Chardonnay subjected to Y-trellis system. The Gompertz model showed the best data fit. In conclusion, Y-trellis training system favors the development of downy mildew and bunch rot diseases when right management conditions are not adopted. VSP system showed the best disease control in this conditions and it is recommended to growing grapes to produce fine wines in highlands of Santa Catarina State / Regiões de elevada altitude de Santa Catarina (SC) vem se destacando pela produção de vinhos finos de alta qualidade. O míldio (Plamospara viticola) e a podridão cinzenta (Botrytis cinerea) da videira são as principais doenças que afetam o cultivo de uvas viníferas (Vitis vinifera) na região. O objetivo do trabalho foi avaliar a intensidade de míldio em folha e podridão cinzenta no cacho sob diferentes sistemas de sustentação, bem como o teor de polifenóis totais nas cascas de variedades brancas. Foram realizados três experimentos durante os ciclos 2012/2013 e 2013/2014, sendo dois ensaios em vinhedos comerciais em São Joaquim/SC nas variedades Cabernet Sauvignon, Chardonnay e Sauvignon Blanc sob os sistemas de sustentação espaldeira e ypsilon (Y) e o terceiro ensaio em vinhedo experimental da Universidade do Estado de Santa Catarina CAV/UDESC em Lages/SC nas variedades C. Sauvignon e Merlot sob sistemas de sustentação latada descontínua, Geneva Double Curtin (GDC), espaldeira e cortina simples. A dinâmica temporal do míldio foi avaliada quinzenalmente após o início do aparecimento dos sintomas, sob condições de infecção natural, em folhas distribuídas em 4 ramos medianos marcados aleatoriamente com 5 repetições por tratamento. A epidemia foi comparada em relação ao início do aparecimento dos sintomas (IAS), tempo para atingir a máxima severidade e incidência da doença (TAMID e TAMSD), incidência máxima (Ymax), severidade máxima (Smax) e com os dados obtidos calculou-se as áreas abaixo da curva de progresso da incidência e severidade da doença (AACPID e AACPSD). Os dados foram analisados por regressão linear e ajustados para os modelos Logístico, Monomolecular e Gompertz. A intensidade de podridão cinzenta nos diferentes sistemas foi comparada no momento da colheita, em 5 repetições e 30 cachos aleatórios avaliados por tratamento. O sistema em ypsilon (Y) proporcionou uma maior intensidade de míldio e de podridão cinzenta da videira em relação ao sistema espaldeira, nas formas de manejo adotadas no vinhedo da variedade C. Sauvignon. O sistema GDC apresentou maior intensidade de míldio para variedade Merlot. As variedades brancas apresentaram maior intensidade de B. cinerea no sistema em ypsilon (Y). O teor de polifenóis totais foi superior no sistema ypsilon (Y) para variedade Chardonnay. Dos modelos matemáticos testados o modelo Gompertz foi o modelo que permitiu melhor ajuste dos dados. O sistema em ypsilon (Y) favorece o desenvolvimento do míldio e da podridão cinzenta quando técnicas de manejo adequadas não são aplicadas. O sistema espaldeira mostrou maior controle fitossanitário nas condições adotadas, sendo recomendado para produção de uvas viníferas nas regiões de elevada altitude no Planalto Sul de Santa Catarina

Made available in DSpace on 2014-06-11T19:29:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-11Bitstream added on 2014-06-13T20:39:09Z : No. of bitstreams: 1 santana_aps_me_ilha.pdf: 405645 bytes, checksum: 9dc5a1f5256bb3d0046f8cd5cfb7ed9e (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A região noroeste de São Paulo é uma das principais produtoras de uvas de mesa do Estado. Entretanto, os altos custos de implantação e de condução dos vinhedos exigem altas produtividades, para tornar a atividade compensatória. A grande exigência de tratos culturais e fitossanitários tem estimulado os viticultores a buscarem alternativas para reduzir este custo, entre as quais, o uso de reguladores vegetais e programas de controle de doenças de baixo impacto ambiental. Contudo, a necessidade de restringir, cada vez mais, o uso de produtos sintéticos em sistemas sustentáveis de produção, como na produção orgânica e produção integrada, torna a quebra de dormência química e o controle fitossanitário fatores limitantes para a atividade no Brasil. Objetivou-se neste trabalho avaliar, em campo, a eficácia do extrato de alho (Bioalho®) e do fertilizante organomineral (Erger G®), na quebra de dormência de gemas de videiras; e, em laboratório, a eficácia dos produtos: óleo de nim e de tomilho, quitosana, biomassa cítrica, silicato de potássio, fosfito de potássio, acibenzolar-S-methyl, tebuconazol, metalaxil+mancozebe, azoxistrobina, extratos aquosos e hidroetanólicos de melão-de-são-caetano e pacari; no controle dos patógenos da cultura da videira P. viticula, P. euvitis e E. ampelina. No primeiro experimento, aos 35 dias após a aplicação dos produtos para quebra de dormência, observou-se que o produto Erger G® mais NK 7% diferiu estatisticamente de todos os outros produtos avaliados, com 86% no total de gemas brotadas; e, em porcentagem de brotação na 5a e 6a gemas, teve 100% de brotação, não diferindo estatisticamente do Erger G® mais NK 5%, com 77% de brotação; e do padrão positivo, com 61%. Em avaliação final, do segundo experimento aos 30 dias após a aplicação dos tratamentos com Bioalho® e Erger G®, verificou-se que todos... / The northwestern region of São Paulo is one of the main producers of table grapes in the state. However, the high cost of deployment and conduct of vineyards require high productivity, to make compensatory activity. The requirements of cultural practices and plant health has prompted growers to seek alternatives to reduce this cost, including the use of plant growth regulators and programs for disease control with low environmental impact. However, the need to restrict, increasingly, the use of synthetics in sustainable production systems, such as the organic and integrated production, makes the dormancy breaking chemical pest control and the factors limiting the activity in Brazil. The objective of this work to evaluate, in laboratory and field efficacy of Bioalho® and Erger G®, to break the dormancy of buds of grapevines, and the effectiveness of the following products: neem oil and thyme, chitosan, citric biomass, silicate potassium, potassium phosphite, acibenzolar-S-methyl, tebuconazole, metalaxyl + mancozeb, azoxystrobin, aqueous and hidroetanolic melon-to-be-caetano and pacari; control pathogens culture P. viticulture, P. euvitis and E. ampelina In the final evaluation, 30 days after treatment application with Bioalho® and Erger G®, it was found that all treatments were similar in the induction of sprouting and above the standard negative (water), which emphasizes the potential for these alternative products dormancy when compared to the standard positive hydrogen cyanamide. However, the development of branches with the garlic extract was highly uneven. For products to control pathogens, all products tested inhibited, but 60% germination of sporangiospores of P. viticola, highlighting the aqueous and hydro-pacari and melon-to-be-caetano and citric biomass whose percentage of inhibition of germination conidiósferos (SGA) ranged from 85% to 92%. In the germination... (Complete abstract click electronic access below)

Le mildiou est une maladie de la vigne affectant les feuilles et les baies et pouvant entraîner des diminutions importantes de la quantité et de la qualité de la vendange. L'agent responsable, Plasmopara viticola, un oomycète biotrophe obligatoire, provoque différentes altérations physiologiques au niveau de la feuille infectée. D'une part, il y a des accumulations anormales d'amidon au niveau des taches d'huile, symptômes caractéristiques de la maladie. D'autre part, l'infection induit une dérégulation des mouvements stomatiques. Les stomates, ouvertures naturelles permettant les échanges gazeux entre la plante et l'atmosphère, restent anormalement ouverts de nuit et ne se ferment plus en réponse à un stress hydrique ou à un traitement à l'ABA. Les deux parties de cette thèse avaient pour objectif de i) expliquer l'origine et le mécanisme de l'accumulation d'amidon et ii) isoler et identifier le facteur responsable de la dérégulation stomatique. Les modifications du métabolisme de l'amidon au niveau des feuilles infectées ont d'abord été étudiées à l'aide d'une analyse transcriptomique afin d'identifier les gènes codant pour des enzymes impliquées dans ce métabolisme dont l'expression était affectée. Après validation de deux gènes de référence, une étude par qRT-PCR a permis de vérifier les changements d'expression de certains de ces gènes au cours de la cinétique de l'infection, puis les activités des enzymes correspondantes ont été déterminées. Ces approches, complétées par des dosages de l'amidon et des sucres solubles ainsi que la mesure de l'activité photosynthétique, ont permis de corréler différents événements avec l'infection. D'après nos résultats, l'accumulation de l'amidon dans les taches d'huile pourrait résulter d'une augmentation de sa synthèse liée à l'augmentation de l'activité AGPase, combinée à une diminution de sa dégradation par modification de l'activité des amylases. Une diminution de la photosynthèse et une augmentation de l'activité invertase traduisent une transition source-puits au niveau des taches d'huile. La deuxième partie de la thèse a porté sur la recherche d'une molécule soluble d'origine végétale ou pathogène, secrétée dans l'apoplasme au cours de l'infection et responsable du dysfonctionnement stomatique. Sur « épidermes isolés », les fluides apoplastiques extraits de feuilles infectées induisent une ouverture stomatique à l'obscurité et contrecarrent la fermeture induite par l'ABA à la lumière, mimant ainsi la dérégulation observée sur feuille entière. Le composé actif serait une protéine assez stable, de taille >50 kDa et modifiée post-traductionellement par une glycosylation essentielle à son activité sur l'ouverture stomatique. Après séparation par chromatographie d'exclusion des fluides apoplastiques de feuilles infectées, deux fractions ont été retenues : une présentant une forte activité sur l'ouverture stomatique, et une seconde sans activité. Neuf protéines de vigne ont été identi fiées spécifiquement dans la fraction active après une analyse comparative de ces deux échantillons par spectrométrie de masse. Des expérimentations supplémentaires seront nécessaires pour purifier et identifier la protéine recherchée. / The grapevine downy mildew affects leaves and young berries and can affect the harvest quality and quantity. The causal agent is the obligate biotroph oomycete Plasmopara viticola that induces severe physiological alterations in infected leaves. One is the abnormal accumulation of starch in oil spots, the characteristic symptoms of the disease. Another is a deregulation of stomatal movements. Stomata, natural openings on the leaf surface allowing gas exchanges between the plant and the atmosphere, stay abnormally open during the night and do no longer close upon water stress or ABA treatment in infected leaves. This thesis is divided into two chapters that aim to i) explain the origin and mechanism of the abnormal starch accumulation and ii) isolate and identify the compound responsible for the stomatal deregulation. The modifications of starch metabolism in infected leaves were first studied by transcriptomic analysis allowing to identify transcriptional modifications of genes involved in starch metabolism. After the validation of two reference genes, a qRT-PCR analysis was performed in order to verify the expression alterations of some of these genes and the corresponding enzymatic activities were measured. The quantification of soluble sugars and starch, and the measurement of photosynthetic activity were included in the analysis and their alterations could be correlated with the infection. Altogether, the obtained results hint towards an increase of starch synthesis via an increase in AGPase activity, that, combined with a decrease of its degradation by modification of amylase activities, could be responsible for the observed starch accumulation in oil spots. Concurrently, a source-sink transition is apparent in infected leaves by decrease of photosynthetic activity and increase of a cell wall invertase activity. The second part of this thesis dealt with a soluble molecule of plant or pathogen origin that is secreted into the apoplast during infection and could be responsible for the stomatal deregulation. The apoplastic wash fluids from infected leaves increase tha stomatal aperture in the dark in grapevine epidermal peels and counteract the ABA-induced stomatal closure, thus mimicking the deregulation observed on whole leaves. The active compound seems to be a stable protein of > 50kDa with a glycosylation that is essentiel for its activity. After separation of the fluids by size exclusion chromatography, two fractions were compared : one active on stomatal aperture and an inactive one. 9 grapevine proteins could be identified in the active sample by mass spectrometry analysis, but further analyses are needed to purify and identify the one responsible for the stomatal deregulation.

Entre as doenças de maior impacto nos vinhedos paulistas, encontram-se o míldio (Plasmopara viticola) e a ferrugem (Phakopsora euvitis). Os objetivos deste trabalho foram: i. caracterizar a estrutura genética populacional e identificar espécies crípticas de P. viticola; ii. avaliar o progresso temporal de míldio da videira, o efeito da doença na produção das plantas e verificar a contribuição da reprodução sexuada e assexuada de P. viticola na epidemia da doença e; iii. avaliar o progresso temporal de ferrugem da videira. Foram coletados 516 isolados de P. viticola em 11 municípios de São Paulo. Os isolados foram genotipados com 7 marcadores microssatélites. Para a identificação de espécies crípticas de P. viticola, uma subamostra de 130 isolados foi analisada pela técnica CAPS (Cleaved Amplified Polymorphic Sequence), e 94 isolados foram sequenciados para a região ITS1. O progresso temporal do míldio e da ferrugem da videira foram avaliados em 3 ciclos de produção (2014/15, 2015/16 e 2016/17) nos sistemas de condução em espaldeira (ESP), Y descoberto (YD) e Y sob cobertura plástica (YC). A área experimental, localizada em Piracicaba-SP, foi constituída por plantas da variedade Niágara Rosada. As variáveis analisadas foram fenologia, número de folhas por ramo, incidência e severidade das doenças. Para verificar o efeito do míldio na produção das plantas, avaliaram-se a massa média do cacho, a produção por planta, o teor de sólidos solúveis totais (SST) e a acidez titulável (AT) dos frutos. A área abaixo da curva (AAC) foi calculada para o número de folhas por ramo, a incidência e a severidade de míldio e de ferrugem. Os valores de massa do fruto, produção por planta, SST e AT, e os resultados da AAC para as variáveis analisadas, foram submetidos a análise de variância e as médias comparadas pelo teste de Tukey (P<0,05). Na safra 2015/16, 166 isolados de P. viticola foram coletados em três diferentes momentos da epidemia, os quais foram genotipados com os 7 microssatélites mencionados anteriormente. P. viticola clado aestivalis foi a única espécie críptica identificada no Estado de São Paulo. Dentre os 516 isolados analisados, 55 genótipos multilocos (MLG) foram identificados. Quatro MLGs dominantes representaram 65,7% dos genótipos observados. Para o míldio da videira, em 2 das 3 safras avaliadas observou-se desfolha precoce das plantas doentes. A severidade média máxima de míldio observada foi de 14,3% na ESP e 30,9% no YD. Para esses valores de severidade, a doença causou a redução na produção por planta (0,7 a 0,9 kg por planta) e na massa do cacho (67 a 78 g). Em nenhuma das safras houve efeito da doença no teor de SST e na AT. Maiores valores de AAC da severidade de míldio foram verificados no YD em comparação à espaldeira, sugerindo que o sistema em YD favorece o progresso da doença. No YC, a redução da incidência de míldio foi de até 93,7% em relação aos sistemas descobertos, indicando que o sistema em Y associado ao cultivo protegido foi uma ferramenta eficiente no controle da doença. O monitoramento de genótipos de P. viticola na safra 2015/16 revelou que a epidemia foi resultante, predominantemente, de infecções clonais múltiplas causadas por um único genótipo. Queda prematura de folhas em decorrência da epidemia de ferrugem foi observada para os sistemas em YC e YD com valores de severidade inferiores a 5,6%. Em função da desfolha, verificaram-se alterações na fenologia das plantas nos estádios fenológicos finais de desenvolvimento. O progresso da incidência de ferrugem foi mais rápido nos sistemas em YC e YD em relação a ESP. Diferentemente das epidemias de míldio da videira, o uso da cobertura plástica não foi suficiente para o controle satisfatório da ferrugem. / Downy mildew (Plasmopara viticola) and rust (Phakopsora euvitis) are important diseases on vineyards located in São Paulo State. The aims of this study were: i. characterize the population genetic structure and identify cryptic species of P. viticola; ii. evaluate the temporal progress of grapevine downy mildew, the disease effect on yield, and verify the contribution of sexual and asexual reproduction of P. viticola on disease epidemic and; iii. evaluate the temporal progress of grapevine rust. A total of 516 isolates of P. viticola were collected from 11 locations of São Paulo State. The isolates were genotyped with 7 microsatellite markers. To identify cryptic species of P. viticola, a subsample of 130 isolates were analized by Cleaved Amplified Polymorphic Sequence (CAPS), and 94 isolates were sequenced for ITS1 region. Temporal progress of downy mildew and rust were evaluated in 3 growing seasons (2014/15, 2015/16 and 2015/16) on vertical trellis (VT), Y-trellis without plastic cover (YWP), and Y-trellis with plastic cover (YPC). The experimental area, located in Piracicaba-SP, was composed by plants of the variety Niagara Rosada. The variables analyzed were phenology, number of leaves per shoot, disease incidence and disease severity. To verify the effect of downy mildew on yield were evaluated bunch weight, yield per plant, total soluble solids content (TSS) and titratable acidity (TA) of the fruits. Area under the curve (AUC) was calculated for number of leaves per shoot, downy mildew and rust incidence and downy mildew and rust severity. The values of bunch weight, yield per plant, TSS and TA, and AUC results for the analyzed variables, were submitted to variance analysis and the mean values were compared by Tukey test (P<0.05). In the growing season of 2015/16, 166 isolates of P. viticola were collected at three different moments of downy mildew epidemic. The isolates were genotyped with the 7 microsatellites previously mentioned. P. viticola clado aestivalis was the only cryptic species identified in São Paulo State. Among the 516 isolates analyzed, 55 multilocus genotypes (MLG) were identified. Four dominant MLGs represented 65.7% of the observed genotypes. For downy mildew, 2 of the 3 growing seasons evaluated were observed early defoliation of the diseased plants. The maximum average values of disease severity observed were 14.3% in ESP and 30.9% in YD. For these disease severity values, the disease reduced yield per plant (0.7 to 0.9 kg per plant) and bunch weight (67 to 78 g). No effect of downy mildew was verified on TSS and TA in none of the growing seasons. Higher AUC values for downy mildew severity were observed in YWP compared to the VT, suggesting that YWP favors the disease progress. On the YPC, incidence of downy mildew was reduced by up to 93.7% compared to the uncovered systems, indicating that Y-trellis associated with plastic cover was an efficient tool to control the disease. The monitoring of genotypes of P. viticola in the 2015/16 growing season revealed that disease epidemic was drived predominantly by multiple clonal infections caused by a single genotype. Early defoliation due to grape rust epidemic was observed on YWP and YPC with disease severity lower than 5.6%. Due to defoliation caused by rust modification on plant phenology were verified in the final stages of plant development. The progress of rust incidence was faster in YWP and YPC than in VT. Unlikely grape downy mildew epidemics, the use of plastic cover was not sufficient to effectivly control grape rust.

Le mildiou de la vigne est causé par l’oomycète Plasmopara viticola, qui s’attaque aux parties aériennes non-lignifiées affectant la production viticole. Une alternative à l’utilisation de pesticides est l’utilisation de variétés de vigne à la résistance durable, et un programme pour leur création par croisement entre espèces résistantes et la vigne cultivée, Vitis vinifera, est en cours. Ce programme nécessite l’identification de nouveaux gènes de résistance, ce que le projet vise à faire par (1) le criblage de vignes résistantes avec des effecteurs conservés chez P. viticola, (2) l’étude fonctionnelle d’effecteurs candidats. Le criblage de plantes résistantes n’a conduit à l’identification d’aucun nouveau facteur de résistance majeur. L’étude fonctionnelle d’effecteurs a permis la mise en évidence d’une nouvelle famille d’effecteurs chez P. viticola et a conduit à l’identification de deux effecteurs Pv33, nucléaire, et Pv47, associé au réticulum endoplasmique, qui induisent des défenses végétales. / Grapevine downy mildew is caused by the oomycete Plasmopara viticola, which attacks the aerial non-lignified tissues affecting wine production. An alternative to the use of pesticides is the use of vine varieties with sustainable resistances. A programme aiming to create such varieties by crossing resistant species with the cultivated grapevine, Vitis vinifera, is ongoing. Within this program requiring the indentification of new resistance genes, which the project aims to do by (1) screening resistant vines with effectors stored in P. viticola, (2) performing a functional study of candidate effectors. The screening of resistant plants did not lead to the identification of any new major resistance factors. The functional study of effectors revealed a new family of effectors in P. viticola and led to the identification of two effectors Pv33, nuclear, and Pv47, associated with the endoplasmic reticulum, which induce plant defences.

Les stilbènes sont les métabolites de défense majeurs de la vigne, qui sont également connus pour leurs nombreuses propriétés pharmacologiques. Tirant parti du récent séquençage du génome de la vigne, l’objectif de ce travail est de caractériser les familles de gènes impliqués dans la biosynthèse des stilbènes chez la vigne, et de préciser leur rôle dans les défenses contre le mildiou (Plasmopara viticola). La première étape de la biosynthèse des stilbènes est catalysée par la stilbène synthase (STS), pour former le resvératrol. L’analyse détaillée du génome de la vigne a permis d’identifier 48 gènes STS, dont 32 gènes potentiellement fonctionnels. La caractérisation fonctionnelle d’une sélection de gènes représentatifs de la diversité de la famille suggère que l’ensemble des 32 gènes STS code pour des protéines ayant réellement une activité stilbène synthase. L’analyse évolutive des gènes STS montre que la famille est très contrainte, sans trace de néo-fonctionnalisation. La famille des STS de la vigne représente donc un exemple unique d’une famille de plus de 30 gènes codant pour des protéines de fonction identique, et la signification biologique de cette expansion est discutée. Une seconde enzyme importante du métabolisme des stilbènes est la resvératrol O-méthyltransférase (ROMT). La ROMT est impliquée dans la méthylation du resvératrol pour former le ptérostilbène, un composé hautement fongitoxique qui pourrait jouer un rôle important dans les mécanismes de défenses de la vigne. Notre analyse de la famille ROMT montre qu’elle est constituée de 17 gènes, dont deux seulement (VvROMT1 et VvROMT2) semblent impliqués dans la synthèse de ptérostilbène. L’expression de ces deux gènes est induite suite à une infection par P. viticola au niveau des feuilles de vigne. Deux autres gènes de la famille, VvROMT12 et VvROMT13, sont exprimés constitutivement au niveau des racines, et ne semblent pas répondre au stress. Des analyses métabolomiques sur des plants de Nicotiana benthamiana transgéniques exprimant ces deux ROMT ainsi que des tests enzymatiques in vitro ont été réalisés afin de déterminer la fonction des gènes ROMT12 et 13. L’ensemble de ces résultats fait apparaître une amplification remarquable des gènes impliqués dans la synthèse des stilbènes chez la vigne et ouvrent la voie à l’étude détaillée de la régulation de cette voie importante du métabolisme de défense de la vigne. / Stilbenes are major defense metabolites in grapevine (Vitis vinifera), which are known for their many pharmacological properties. Taking advantage of the recent sequencing of the grapevine genome, the aim of this work is to characterize genes families involved in stilbene biosynthesis, in order to clarify the role of these defense compounds in the interaction with downy mildew (Plasmopara viticola). The first step of stilbene biosynthesis is catalyzed by stilbene synthase (STS), to yield resveratrol. Our annotation of the STS gene family identified 48 STS genes, including at least 32 potentially functional ones. This unusual expansion of the STS family is original, since it is not found in other stilbene-producing plants. Functional characterization of a selection of STS proteins indicates that all STS genes are likely to encode enzymes with STS activity. Evolutionary analysis of the STS gene family revealed that STS evolution is dominated by purifying selection, with no evidence for neofunctionalization. STS family then represents a unique example a family of more than 30 genes encoding proteins with identical function, and the biological significance of this amplification is discussed. A second important enzyme in stilbene metabolism is resveratrol O-methyltransferase (ROMT), involved in the methylation of resveratrol to yield pterostilbene. This highly fungitoxic compound is believed to play an important role in grapevine defense metabolism. Our analysis of the ROMT family identified 17 genes, two of them only (VvROMT1 and VvROMT2) being involved in pterostilbene biosynthesis. qPCR analyses have shown an induction of the expression of these two genes after an inoculation of P. viticola on grapevine leaves. Two others genes, VvROMT12 and VvROMT13, are constitutively expressed in grapevine roots, and do not seem to respond to stress. Metabolomic analysis on transgenic Nicotiana benthamiana plants expressing these two ROMT genes, together with in vitro enzymatic assays, have been performed in order to determine the function of ROMT12 and ROMT 13. All together, these results show a remarkable amplification of genes involved in stilbene biosynthesis in grapevine. This work paves the way for detailed analyses of the regulation of this important pathway of grapevine defense metabolism.

Un déploiement optimal de variétés résistantes nécessite une excellente connaissance des relations entre la vigne et P. viticola. Ces connaissances fondamentales pourront ensuite alimenter les stratégies pour le développement de variétés durablement résistantes au vignoble. Bianca est une variété de vigne résistante au mildiou qui possède le gène résistance Rpv3. Cette variété est résistante à la plupart des souches de P. viticola. Cependant, une souche virulente capable de l’infecter a été isolée. Dans ce projet, un pathosystème original, fondé sur la variété Bianca confrontée à une souche avirulente et à une souche virulente de P. viticola, a été utilisé pour obtenir une image complète de l'impact sur la vigne de l'infection par P. viticola en situation compatible et incompatible, en combinant des études de physiopathologie avec des analyses métabolomiques par spectrométrie de masse à haute résolution et par résonance magnétique nucléaire. Parallèlement, l'identification de métabolites et de séquences géniques spécifiques de P. viticola a permis le développement de méthodes de suivi dynamique de l'infection, grâce à la PCR quantitative et à la quantification de lipides caractéristiques de l'agent pathogène. / Optimal deployment of resistant varieties requires an excellent knowledge of the relationship between grapevine and P. viticola. This fundamental knowledge can then feed the strategies for the development of grapevine varieties with sustainable resistance. Bianca is a downy mildew-resistant grapevine variety, due its Rpv3 resistance gene. This variety is resistant to most strains of P. viticola. However, a virulent strain capable of infecting Bianca has recently been isolated. In this project, we use this original pathosystem to obtain a complete picture of the impact P. viticola infection on grapevine, by combining physiopathological studies with metabolomic analyses. In addition, the identification of specific metabolites and gene sequences from P. viticola has allowed the development of original methods for dynamic monitoring of the infection process, through quantitative PCR and quantification of specific lipids.

Resumo: A região noroeste de São Paulo é uma das principais produtoras de uvas de mesa do Estado. Entretanto, os altos custos de implantação e de condução dos vinhedos exigem altas produtividades, para tornar a atividade compensatória. A grande exigência de tratos culturais e fitossanitários tem estimulado os viticultores a buscarem alternativas para reduzir este custo, entre as quais, o uso de reguladores vegetais e programas de controle de doenças de baixo impacto ambiental. Contudo, a necessidade de restringir, cada vez mais, o uso de produtos sintéticos em sistemas sustentáveis de produção, como na produção orgânica e produção integrada, torna a quebra de dormência química e o controle fitossanitário fatores limitantes para a atividade no Brasil. Objetivou-se neste trabalho avaliar, em campo, a eficácia do extrato de alho (Bioalho®) e do fertilizante organomineral (Erger G®), na quebra de dormência de gemas de videiras; e, em laboratório, a eficácia dos produtos: óleo de nim e de tomilho, quitosana, biomassa cítrica, silicato de potássio, fosfito de potássio, acibenzolar-S-methyl, tebuconazol, metalaxil+mancozebe, azoxistrobina, extratos aquosos e hidroetanólicos de melão-de-são-caetano e pacari; no controle dos patógenos da cultura da videira P. viticula, P. euvitis e E. ampelina. No primeiro experimento, aos 35 dias após a aplicação dos produtos para quebra de dormência, observou-se que o produto Erger G® mais NK 7% diferiu estatisticamente de todos os outros produtos avaliados, com 86% no total de gemas brotadas; e, em porcentagem de brotação na 5a e 6a gemas, teve 100% de brotação, não diferindo estatisticamente do Erger G® mais NK 5%, com 77% de brotação; e do padrão positivo, com 61%. Em avaliação final, do segundo experimento aos 30 dias após a aplicação dos tratamentos com Bioalho® e Erger G®, verificou-se que todos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The northwestern region of São Paulo is one of the main producers of table grapes in the state. However, the high cost of deployment and conduct of vineyards require high productivity, to make compensatory activity. The requirements of cultural practices and plant health has prompted growers to seek alternatives to reduce this cost, including the use of plant growth regulators and programs for disease control with low environmental impact. However, the need to restrict, increasingly, the use of synthetics in sustainable production systems, such as the organic and integrated production, makes the dormancy breaking chemical pest control and the factors limiting the activity in Brazil. The objective of this work to evaluate, in laboratory and field efficacy of Bioalho® and Erger G®, to break the dormancy of buds of grapevines, and the effectiveness of the following products: neem oil and thyme, chitosan, citric biomass, silicate potassium, potassium phosphite, acibenzolar-S-methyl, tebuconazole, metalaxyl + mancozeb, azoxystrobin, aqueous and hidroetanolic melon-to-be-caetano and pacari; control pathogens culture P. viticulture, P. euvitis and E. ampelina In the final evaluation, 30 days after treatment application with Bioalho® and Erger G®, it was found that all treatments were similar in the induction of sprouting and above the standard negative (water), which emphasizes the potential for these alternative products dormancy when compared to the standard positive hydrogen cyanamide. However, the development of branches with the garlic extract was highly uneven. For products to control pathogens, all products tested inhibited, but 60% germination of sporangiospores of P. viticola, highlighting the aqueous and hydro-pacari and melon-to-be-caetano and citric biomass whose percentage of inhibition of germination conidiósferos (SGA) ranged from 85% to 92%. In the germination... (Complete abstract click electronic access below) / Orientador: Aparecida Conceição Boliani / Coorientador: Luiz Correa de Souza / Banca: Marli de Fátima Stradioto Papa / Banca: Rosemeire de Lellis Naves / Mestre