Made available in DSpace on 2014-08-20T14:07:33Z (GMT). No. of bitstreams: 1 tese_paulo_ricardo_ebert_siqueira.pdf: 745146 bytes, checksum: e9aa866b96f415063e476a4469145bbb (MD5) Previous issue date: 2010-07-19 / The presence of Calepitrimerus vitis (Nalepa, 1905) in vineyards in the countryside of Rio Grande do Sul was verified from the 2004/2005 harvest associated with symptoms of tanning on the leaves. In Brazil there are no recommendations for monitoring of this mite, just as there is no acaricide recommended for management of the species in vineyards. To detect differences in infestation of C. vitis among cultivars was conducted the monitoring of population fluctuations of C. vitis vinifera cultivars Chardonnay and Merlot, in a commercial vineyard in Dom Pedrito, RS, during the years 2005/2006 and 2006/2007, in order to identify differences in infestation between cultivars of a crop year to another. It was observed that the cultivars Chardonnay and Merlot, the population peaks of C. vitis occurred between late February and early March and there is a high correlation between the number of C. vitis found on the underside of the leaves and the percentage of leaves with the species. In the greenhouse, during the years 2006/2007 and 2007/2008 was evaluated the efficiency of sticky traps to monitor C. vitis in cuttings for propagation, comparing catches in cuttings derived from nurseries and vineyards with different histories of infestation. We observed that the sticky traps to detect the presence in the cuttings of C. vitis. During the crop years 2007/2008 and 2008/2009 was conducted the monitoring of population dynamics of C. vitis in Cabernet Sauvignon, in a commercial vineyard located in the town of Candiota-RS, through the use of sticky traps and direct observation on the abaxial surface of leaves. As observed in the Dom Pedrito-RS, Candiota-RS was observed a significant and high correlation (r ² ≥ 0.95) between the number of C. vitis on the abaxial surface of leaves and percentage of leaves with the mites. The sticky traps used for monitoring were more efficient in detecting C. vitis during periods of high and low population levels. Was evaluated in a commercial vineyard, insecticides and acaricides in order to reduce the population of C. vitis in autumn and in spring 2008 and autumn 2009. The acaricides spirodiclofen and cyhexatin were the most promising in reducing the infestation during the autumn. The use of sulfur in a single autumn spray or two sprays, one in autumn and another in the spring, effectively controlled C. vitis in the spring. The use of acaricides abamectin and spirodiclofen a single spring spray or two sprays, one in autumn and another in the fall and spring, effectively controlled the population of C. vitis in the spring. The acaricides abamectin, azadirachtin, cyhexatin, sulfur and spirodiclofen evaluated for control of C. vitis were tested for selectivity to predatory mite Neoseiulus californicus (McGregor, 1954). It was found that 24 hours after application in vineyard acaricide cyhexatin was slightly harmful, and all other products tested as harmless. From the third day of application in the vineyards all products were harmless to N. californicus, to cause mortality under 30% / A presença de Calepitrimerus vitis (Nalepa, 1905) em vinhedos na Região da Campanha do Rio Grande do Sul foi verificada a partir da safra 2004/2005 associada a sintomas de bronzeamento nas folhas. No Brasil não existem recomendações para o monitoramento deste ácaro, assim como não se encontra nenhum acaricida recomendado para o manejo da espécie na cultura da videira. Visando detectar diferenças de infestação de C. vitis entre cultivares foi realizado o monitoramento da flutuação populacional de C. vitis nas cultivares viníferas Chardonnay e Merlot, em vinhedo comercial no município de Dom Pedrito-RS, durante os anos agrícolas 2005/2006 e 2006/2007, permitindo identificar diferenças de infestação entre as cultivares de uma safra agrícola para a outra. Foi observado que nas cultivares Chardonnay e Merlot, os picos populacionais de C. vitis ocorrem entre o final de fevereiro e o início de março e que há uma alta correlação entre o número de C. vitis presentes na face abaxial das folhas e o percentual de folhas com incidência da espécie. Em casa de vegetação, durante os anos agrícolas 2006/2007 e 2007/2008 foi avaliada a eficiência de armadilhas adesivas para monitorar C. vitis em estacas destinadas a propagação, comparando as capturas em estacas oriundas de viveiros e vinhedos com diferentes históricos de infestação. Foi observado que as armadilhas adesivas detectam a presença nas estacas de C. vitis. Durante os anos agrícolas 2007/2008 e 2008/2009 foi realizado o acompanhamento da dinâmica populacional de C. vitis na cultivar Cabernet Sauvignon, em vinhedo comercial localizado no município de Candiota-RS, através do emprego de armadilhas adesivas e da observação direta na face abaxial das folhas. Assim como verificado em Dom Pedrito-RS, em Candiota-RS foi observada uma correlação significativa e alta (r² ≥ 0,95) entre o número de C. vitis na face abaxial das folhas e o percentual de folhas com incidência do ácaro. As armadilhas adesivas utilizadas para o monitoramento foram mais eficientes na detecção de C. vitis tanto em períodos de alta como de baixos níveis populacionais. Avaliou-se em vinhedo comercial, inseticidas e acaricidas visando a redução populacional de C. vitis no outono e na primavera de 2008 e no outono de 2009. Os acaricidas espirodiclofeno e cihexatina foram os mais promissores na redução da infestação durante o outono. O emprego de enxofre em uma única pulverização no outono ou em duas pulverizações, sendo uma no outono e outra na primavera, controlou eficientemente C. vitis na primavera. O emprego dos acaricidas abamectina e espirodiclofeno uma única pulverização na primavera ou em duas pulverizações, sendo uma no outono e outra na primavera, controlou eficientemente a população de C. vitis na primavera. Os acaricidas abamectina, azadiractina, cihexatina, enxofre e espirodiclofeno, avaliados para o controle de C. vitis, foram submetidos a testes de seletividade ao ácaro predador Neoseiulus californicus (McGregor, 1954). Foi verificado que 24 horas após a aplicação no vinhedo o acaricida cihexatina foi levemente nocivo, sendo todos os demais produtos testados considerados inócuos. A partir do terceiro dia de aplicação no vinhedo todos os produtos foram inócuos a N. californicus, por causarem mortalidade inferior a 30%.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Diabetes mellitus is a metabolic disease characterized by hyperglycemia due defective or deficient response to insulin secretion. Type 2 diabetes mellitus (Type 2 DM) is therefore associated with a general activation of the innate immune system, in which there is a chronic, cytokine-mediated state of low-grade inflammation. Dipeptidyl peptidase IV (DPP-IV) is a cell-surface protease that bind with Adenosine deaminase (ADA) and both enzymes act in the lymphocytes proliferation and citokyne production. Vitis vinifera is a plant that has been studied due its pharmacology effects including the hypoglycemic properties. Thus, the aim of this study is to evaluate some inflammatory biomarkers, the ADA and DPP-IV activities in type 2 DM and investigate the effects of aqueous grape seed extract from Vitis vinifera (cv. Merlot) (GSE) in the ADA and DPP-IV activities in lymphocytes submitted to different glucose concentrations, in vitro. In the manuscript I, in lymphocytes, we observed a decrease in CD26 expression, an increase in ADA and n-acetil-β-d-glucosaminidase (NAG) activities in type 2 DM patients when compared to controls, while the gamma-glutamyl tranferase (GGT) and DPP-IV activities did not show differences between the groups. Moreover, the NAG activity demonstrated a positive correlation with ADA activity and a negative, with CD26 expression. GGT activity was positively correlated with waist circumference and body mass index (BMI), in type 2 DM. In the manuscript II, we observed we observed an increase in ADA activity when lymphocytes were exposure to the high concentration (100mM) of glucose and GSE prevented this increase in ADA activity. In serum, in the manuscript I, we showed an increase in ADA activity and in C reactive protein (CRP) levels in type 2 DM. Furthermore, the levels of CRP in diabetics were positively correlated with waist circumference and BMI. The GGT and DPP-IV activities did not show alterations between the groups, but in type 2 DM the DPP-IV activity was positively correlated with glicated hemoglobin. We concluded that, glucose might stimulated the ADA activity in the same time that it cause decrease in CD26 expression, in lymphocytes. Moreover, GSE prevents the ADA activation in presence of glucose possible due its hypoglycemic properties. / O diabetes melito (DM) é uma desordem metabólica caracterizada por hiperglicemia em virtude de resposta defeituosa ou deficiente à secreção de insulina. O DM tipo 2 (DM 2) está associado com a ativação do sistema imune, no qual há uma inflamação de baixo grau mediada por citocinas. A dipeptidil peptidase IV (DPP-IV, CD26) é uma protease multifuncional e na superfície celular ela encontra-se ligada a adenosina deaminase (ADA). Ambas estão envolvidas na proliferação de linfócitos e na produção de citocinas inflamatórias. A Vitis vinifera é uma planta que tem sido estudada devido suas propriedades farmacológicas, dentre essas, por apresentar efeitos hipoglicêmiantes. Desta forma, o objetivo deste estudo foi avaliar biomarcadores inflamatórios, a atividade da ADA e da DPP-IV em pacientes com DM 2, e verificar o efeito do extrato aquoso de sementes de Vitis vinifera (cv. Merlot) sobre a atividade da ADA e da DPP-IV em linfócitos expostos a diferentes concentrações de glicose, in vitro. Em linfócitos, no manuscrito I observamos uma diminuição na expressão do CD26, um aumento na atividade da ADA e da n-acetil-β-d-glicosaminidase (NAG) em pacientes com DM 2 em relação aos controles, enquanto que a atividade da gamaglutamil transferase (GGT) e da DPP-IV não se alterou. Também, a atividade da NAG linfocitária em pacientes com DM 2 mostrou-se positivamente relacionada com a atividade da ADA e negativamente com a expressão do CD26 e a atividade da GGT mostrou-se positivamente relacionada à circunferência abdominal e ao IMC. Já no manuscrito II, observamos um aumento na atividade da ADA quando os linfócitos forma expostos a 100mM de glicose e este aumento foi atenuado quando, expostos a glicose e extrato aquoso de sementes de Vitis vinifera. Em soro, no manuscrito I, observamos um aumento na atividade da ADA e também nos níveis de proteína C reativa (PCR) em pacientes com DM 2. Além disso, os níveis de PCR em diabéticos mostraram-se positivamente correlacionados com a circunferência abdominal e o índice de massa corporal (IMC) desses pacientes. A atividade da GGT e da DPP-IV não mostraram diferenças entre os grupos. No entanto, a atividade da DPP-IV sérica mostrou-se correlacionada com os níveis de hemoglobina glicada nos pacientes com DM 2. Conclui-se que, a glicose possa estimular a atividade da ADA ao mesmo tempo em que provoca uma redução da expressão do CD26 em linfócitos. Além disso, o extrato aquoso de sementes de Vitis vinifera é capaz de impedir a ativação da atividade da ADA em presença de glicose possivelmente devido suas propriedades hipoglicemiantes.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluated the UV-C irradiation in tissues of rachis with and without berries, and berries with stems of Vitis vinifera and Vitis labrusca. In berries of cv. Isabella, the volatile compounds were analyzed on days 2, 5 and 10 of storage at 20 ºC and the effect of UV-C irradiation on the 5th day of storage. The experiments were based on four treatments of UV-C radiation (0, 1, 2 and 3 kJ m-2) with four cv. (Niagara white, Trebbiano, Cabernet sauvignon and Isabella) and evaluation times (three in berries and four rachis). The rachis with and without berries and the berries with stems remained stored at 20 ºC to evaluate physiological parameters. Ethylene production rate, respiratory rate and total polyphenols were evaluated in all tissues. Only in the rachis was determined by weight loss on days 1, 3 and 5, reducing sugars, non-reducing sugars on the 5th day. Berries and the juice from the cv. Isabella the 5th day of storage at 20 °C the total soluble solids (TSS), titratable acidity (TA), anthocyanins, total phenols, sugars and the ratio (TSS/ TA) were measured. In berries of cv. Isabella on days 2, 5 and 10 storage and berries irradiated with UV-C in amounts of 0, 1, 2 and 3 kJ m-2, volatiles were extracted by solid phase microextration. After desorption, the volatile compounds were separated by gas chromatography, identified by mass spectrometry and quantified by flame ionization detector. For the sensory analysis of the juice discriminatory tests for paired comparison of difference and test ranking were used. The physiological response of UV-C irradiation depends on the cv. and the irradiated tissue. Only the rachis of grape Vitis labrusca ‗Niagara white behaves climateric during storage in post-harvest and may reduce the self life of table grapes. This study found a possible hormetic dose of 3 kJ m-2 only for the cv. Isabella berry. 84 volatile compounds were detected over the days of storage. After 5 days storage, berries irradiated with UV-C 66 volatiles were found. And the dose of 3 kJ m-2 increased the concentration of esters and aldehydes, and 43,8% increase in the total polyphenols in berry. In the paired comparison test of difference, the judges showed greater intensity in the aroma of the juice from grapes irradiated. In the ranking test, the judges were unable to discriminate between different doses of irradiation, though differing dose control (0 kJ m-2) of the irradiated treatments. The analytical test enabled by gas chromatography to determine statistical differences between the different doses detected volatiles, especially at a dose of 3 kJ m-2, in which panelists found no difference. / Este trabalho avaliou a irradiação UV-C em tecidos vegetais de ráquis com e sem bagas, e bagas com pedúnculo de Vitis vinifera e Vitis labrusca. Nas bagas da cv. Isabel, foram analisados os compostos voláteis nos dias 2, 5 e 10 de armazenamento a 20 ºC e sobre o efeito da irradiação UV-C no 5º dia de armazenamento. Os experimentos basearam-se em quatro tratamentos de irradiação UV-C (0, 1, 2 e 3 kJ m-2), com quatro cv. (Niágara branca, Trebbiano, Isabel e Cabernet sauvignon) e tempos de avaliação (três nas bagas e quatro nas ráquis). As ráquis com e sem bagas e as bagas com pedúnculo permaneceram armazenadas a 20 ºC para avaliar parâmetros fisiológicos. Em todos os tecidos foram avaliadas a taxa de produção de etileno, taxa respiratória e polifenóis totais. Apenas na ráquis foi determinado a perda de peso nos dias 1, 3 e 5, além de açúcares redutores e não redutores no 5º dia. Nas bagas e no suco da cv. Isabel do 5º dia de armazenamento a 20 ºC foram mensurados os sólidos solúveis totais (SST), acidez total titulável (ATT), antocianinas totais, polifenóis totais, açúcares totais e a relação (SST/ATT). Nas bagas da cv. Isabel dos dias 2, 5 e 10 de armazenamento e nas bagas irradiadas com UV-C nas doses de 0, 1, 2 e 3 kJ m-2, foram extraídos os compostos voláteis por microextração em fase sólida. Após a dessorção, os compostos voláteis foram separados em cromatógrafo a gás, identificados pelo espectrômetro de massas e quantificados por detector de ionização em chamas. Para a análise sensorial do suco, foram utilizados os testes discriminativos de comparação pareada de diferença e teste de ordenação. A resposta fisiológica da irradiação UV-C depende da cv. e do tecido irradiado. Apenas a ráquis da uva Vitis labrusca ‗Niágara branca se comporta de forma climatérica durante o armazenamento na pós-colheita, podendo reduzir a vida de prateleira da uva de mesa. Neste estudo foi encontrada uma possível dose hormética de 3 kJ m-2 somente para a baga da cv. Isabel. Foram detectados 84 compostos voláteis ao longo dos dias de armazenamento. No 5º dia de armazenamento, das bagas irradiadas com UV-C, foram encontrados 66 compostos voláteis, sendo que a dose de 3 kJ m-2 aumentou a concentração de ésteres e aldeídos, além de elevar em 43,8% os polifenóis totais na baga. No teste de comparação pareada de diferença, os provadores indicaram maior intensidade no aroma do suco proveniente de uvas irradiadas. No teste de ordenação, os julgadores não conseguiram discriminar as diferentes doses de irradiação, mas diferenciaram a dose controle (0 kJ m-2) dos tratamentos irradiados. O teste analítico por cromatografia gasosa permitiu determinar diferença estatística entre as doses nos diferentes compostos voláteis detectados, principalmente na dose de 3 kJ m-2, na qual os julgadores não encontraram diferença.

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.

The grapevine is a fruit that has significant importance in the world economic sector and several factors may compromise its development and especially productivity, including pathogen attack. The disease known as downy mildew is caused by Plasmopara viticola and may cause serious damage to the crop if not controlled. Thus, the major way of controling the disease is associated with the use of fungicides, which causes risks to the environment and human health. The aim of this study was to evaluate the potential of biological agents and chitosan on controlling downy mildew throughthe induced resistance mechanism in grapevine cv. Cabernet Sauvignon. It was hypothesized that the biological agents Trichoderma spp. and Bacillus subtilis, as well as chitosan have the ability to affect directly the viability of P. viticola sporangia and to elicit defense responses in leaf cells of grapevine. Germination of sporangia was measured in vitro andexperiments in greenhouse were conducted, aimed at monitoring the progress of downy mildew on plants exposed to the products studied and, two days later, inoculated with P. viticola. In another experiment, in the absence of the pathogen, leaf tissue of grapevine plants exposed to the same products was collected for conducting biochemical and biological analysis, aiming to characterize the induction of resistance (IR) in plant cells. The activity of pathogenesis related proteins (PRPs) such as guaicol peroxidases, chitinases , β-1,3-glucanases , and polyphenoloxidases in leaves exposed to the products was determined, as well as the levels of total soluble phenols and lignin. Chitosan, but not the biological control agents, reduced the viability of sporangia of P. viticola. All products promoted protection, although not significant when compared to control plants. All studied products produced alterations in the production of PRPs and total phenols. Despite the sharp increase, but not significant, in the lignin content of leaves, small reduction in the area under the mildew progress curve was observed that can be attributed to mechanisms of resistance induction activated by the products studied through elicitor action. / A videira é uma frutífera que possui relevante importância no setor econômico mundial, sendo que vários fatores podem comprometer seu desenvolvimento e consequente rendimento, incluindo o ataque de patógenos. A doença conhecida como míldio da videira, causada pelo pseudofungo Plasmopara viticola, causa sérios danos à cultura quando não controlada. Dessa maneira, a principal forma de controle da doença está associada à utilização de químicos, os quais causam riscos ao ambiente e à saúde do homem. O objetivo deste trabalho foi avaliar o potencial de agentes biológicos e quitosana, na viabilidade de esporângios de míldio, o efeito no progresso da doença e os mecanismos de indução de resistência vegetal, em plantas de videira cv. Cabernet Sauvignon. Hipotetizou-se que os agentes biológicos Trichoderma spp. e Bacillus subtilis, bem como quitosana têm a capacidade de afetar diretamente a viabilidade de esporângios de P. viticola, assim como atrasar ou evitar o progresso de míldio e elicitar respostas de defesa em células foliares de videira. Para tanto, a viabilidade de esporângios de P. viticola foi analisada in vitro e experimentos em casa de vegetação foram conduzidos, afim de, acompanhar o progresso de míldio em plantas de videira expostas aos produtos estudados. Em outro experimento, na ausência do patógeno, tecido foliar de plantas de videira, submetidas aos mesmos produtos, foi coletado para realização de análises bioquímicas e metabólicas, visando à caracterização da indução de resistência (IR) celular vegetal. Foram determinadas atividades de proteínas relacionadas à patogênese (PRPs) como peroxidases de guaicol, quitinases, β-1,3-glucanases e polifenoloxidases em folhas expostas aos produtos, bem como os teores de fenóis solúveis totais e lignina. A quitosana, mas não os agentes biológicos, reduziram a viabilidade dos esporângios. Todos os produtos estudados geraram alterações na produção de PRPs e fenóis totais. Os teores de lignina embora não significativos em relação à testemunha demonstraram aumento, e isso pode estar associado com a porcentagem de proteção que os produtos conferiram às plantas de videira na área abaixo da curva de progresso da doença, induzindo a produção de compostos envolvidos na síntese de lignina.

Les récepteurs PRR (Pattern-recognition receptors) jouent un rôle clé dans l’immunité des plantes en assurant la reconnaissance d’éliciteurs, des motifs moléculaires associés aux microorganismes (MAMP) qui témoigne de leur présence microbienne. La perception de ces MAMPs constitue le premier système de détection d’agents potentiellement pathogène, et déclenche des mécanismes de défense qui ont pour but de bloquer leur développement.Cette étude met en lumière comment la vigne (Vitis vinifera) perçoit deux MAMPs : le peptide flg22 dérivé de la flagelline et la chitine, des motifs conservés existant dans la plupart des espèces bactériennes et fongiques, respectivement. Cette étude analyse les événements précoces de signalisation, l’expression de gènes de défense activés par ces MAMPs et l’efficacité de la résistance induite contre les agents de la pourriture grise et du mildiou de la vigne. Si nos résultats suggèrent que des systèmes de perception pour ces deux MAMPs existent chez la vigne, aucun récepteur PRR n’est actuellement connu pour cette plante cultivée.La disponibilité du génome de la vigne nous a permis d’identifier in silico des récepteurs putatifs (VvFLS2, VvCERK1-3 et VvCEBiP1-2) pouvant fonctionner comme PRR respectif de flg22 et de chitine. Leur analyse fonctionnelle a été réalisée d’une part par complémentation des mutants correspondants d’Arabidopsis et, d’autre part, par une stratégie d’extinction de gène chez la vigne.Nos résultats ont permis d’identifier VvFLS2, le récepteur de la vigne à la flagelline bactérienne. La fonction de VvFLS2 a été démontrée en restaurant la réponse à flg22 du mutant fls2 d’Arabidopsis. Ainsi, nos travaux sont les premiers à décrire un couple PRR-MAMP actif chez la vigne. Nous avons également comparé les capacités de perception de VvFLS2 et du récepteur d’Arabidopsis, AtFLS2, envers des épitopes flg22 provenant de bactéries endophytes ou pathogènes. Nos données montrent clairement que VvFLS2 reconnait différemment les peptides flg22 des différentes bactéries et suggèrent que la flagelline de la bactérie bénéfique Burkholderia phytofirmans a évolué pour échapper au système de reconnaissance immunitaire de la vigne. Nous avons également obtenu des données préliminaires concernant le système de perception de la chitine chez la vigne et montré que VvCERK3 pourrait être un orthologue fonctionnel d’AtCERK1 en restaurant partiellement le burst oxydatif induit par la chitine dans le mutant cerk1-2 d’Arabidopsis. / Pattern-recognition receptors (PRRs) play a key role in plant immunity by assuring recognition of microbe-associated molecular patterns (MAMPs), signature of microbial presence. MAMP perception constitutes the first layer of pathogen detection and activates defense mechanisms that aim to block the intruder. This study brings an insight into how grapevine (Vitis vinifera) perceives two MAMPs: the flagellin-derived flg22 peptide and chitin, which are conserved motifs occurring over the whole bacterial and fungal classes, respectively. This study analyzed MAMP-triggered early signaling events, defense gene expression and also the efficiency of elicited defense against gray mold and downy mildew diseases. These two MAMPs are active in grapevine suggesting that perception systems exist. So far, no PRR is known for this crop.Given the availability of grapevine genome, we could identify in silico putative grapevine receptors (VvFLS2, VvCERK1-3 and VvCEBiP1-2) that might function as PRRs for flg22 and chitin, respectively. Their functional characterization was firstly achieved by complementation assays in the corresponding A. thaliana mutants and, secondly, by a gene silencing strategy in grapevine.Our results permitted the identification of VvFLS2, the V. vinifera receptor for the bacterial flagellin. The function of VvFLS2 was demonstrated by restoring the flg22 responsiveness in the Arabidopsis fls2 null mutant. Thus, our work provides the first description of an active grapevine PRR-MAMP pair. We further compared VvFLS2 and the Arabidopsis receptor, AtFLS2, in their capability to perceive flagellin-derived flg22 epitopes from endophytic or pathogenic bacteria. Our data clearly show that VvFLS2 differentially recognizes flg22 from different bacteria and suggest that flagellin from the beneficial plant growth-promoting rhizobacteria (PGPR) Burkholderia phytofirmans has evolved to evade grapevine immune recognition system. We also obtained preliminary data on chitin sensing system in grapevine and show that VvCERK3 might be a functional ortholog of AtCERK1 by partly restoring the oxidative burst triggered by chitin in the Arabidopsis cerk1-2 mutant.

Comment concilier productivité et réduction de l'usage des pesticides ? Le développement de l'oïdium, maladie majeure en viticulture, peut être limité (service de régulation de l'oïdium) par un faible niveau de développement végétatif de la vigne associé à une forte porosité du couvert. Or, de telles caractéristiques limitent également la quantité de rayonnement intercepté par la vigne, et donc la production de biomasse par photosynthèse, et finalement le rendement (service d'approvisionnement). Peut-on augmenter la régulation de l'oïdium sans diminuer le rendement de la vigne ? Autrement dit, existe-t-il une relation de compromis entre ces deux services ? Pour répondre à cette question, deux expérimentations ont été mobilisées : une expérimentation au champ réalisée près de Montpellier de 2010 à 2012 (Syrah), et un réseau de témoins non traités suivis par l'IFV dans la région de Bordeaux de 2007 à 2013. L'analyse des données issues de ces expérimentations a permis de montrer (i) que l'effet des stress hydrique et azoté sur la formation des inflorescences dans les bourgeons latents à la floraison de l'année n-1 détermine 65 à 70 \% du rendement de la vigne lors de l'année n ; (ii) que l'effet du développement végétatif de la vigne sur le développement de l'oïdium n'est significatif que dans le cas d'épidémies de précocité moyenne, dont les premiers symptômes ont été détectés sur feuilles entre la floraison et la fermeture de la grappe. Le développement végétatif de la vigne à la floraison est donc un indicateur pertinent du service de régulation de l'oïdium. Ces résultats ont ensuite permis de confirmer expérimentalement l'hypothèse de l'existence d'un compromis entre rendement de la vigne et régulation de l'oïdium et d'identifier le stress hydrique à la floraison comme un déterminant partagé de ces deux services. Ce dernier point a alors été transcrit dans un modèle simple dans lequel le rendement de la vigne de l'année n dépend principalement de l'année n-1, et le développement végétatif dépend seulement de l'année n. L'analyse des propriétés mathématiques de ce modèle a permis de montrer que la réalisation de compromis favorables entre ces deux services (i.e. un fort niveau des deux services) est possible mais déterminée par l'occurrence de séquences climatiques particulières (une année humide suivie d'une année sèche). Ainsi, les compromis favorables ne peuvent être atteints deux années consécutives et ne sont donc pas stables dans le temps. Les règles de décisions d'application des traitements phytosanitaires pourraient ainsi être adaptées en fonction de la variabilité climatique inter-annuelle et de ses conséquences sur les compromis entre le rendement de la vigne et la régulation des maladies cryptogamiques. / How to combine crop productivity and reduction in pesticide use ? A reduction in plant growth and an increase in crop canopy porosity has been shown to limit the development of the grapevine powdery mildew (powdery mildew regulation service), which is a major disease in viticulture. However, this could also limit grapevine yield through a reduction in light interception and biomass production through photosynthesis. Can regulation of powdery mildew be increased without grapevine yield impairment ? In other words, do these two services trade off ? To address this question, two experiments were used. A field experiment was conducted in Montpellier from 2010 to 2012 on Shiraz, and a network of non-sprayed vineyard plots was monitored by the French Institute of Vine and wine in the Bordeaux region from 2007 to 2013. Data analyses showed that: (i) 65 to 70 \% of grapevine yield in year n were determined by the effect of water and nitrogen stresses on inflorescence formation in the latent buds at flowering in year n-1; (ii) the effect of grapevine vegetative development on powdery mildew depended on epidemic earliness and was significant only when first symptoms were detected on leaves between flowering and bunch closure. Grapevine vegetative development at flowering was therefore a relevant indicator of the powdery mildew regulation service. Based on these results, the hypothesis of a trade-off between grapevine yield and powdery mildew regulation was experimentally confirmed and water stress at flowering was identified as a shared driver of these two services. Then, a simple model was built that accounted for the effect of water stress at flowering on the two services, where grapevine yield depended mostly on year n-1 and grapevine vegetative development depended only on year n conditions. Analysis of the model's mathematical properties showed that "win-win" scenarios (high level of both services) did exist and were reached when specific climatic sequences occured (a wet year followed by a dry year). The "win-win" scenarios could not be reached two consecutive years and were therefore temporally unstable. Decision rules for pesticides application may be adapted in function of the inter-annual climatic variability and its effect on the trade-off between grapevine yield and regulation powdery mildew.

The aim of this study is to determine the content of selected metals (As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Se, Sn, Sr, Pb, V, Zn) in samples of leaves and grapes produced by ecologic agriculture and compare to results with leaves and grapes produced by integrated agriculture. The measured results used to assess the impact of agricultural technology on the quality of vines and grapes. The amount of elements was analysed using inductively coupled plasma mass spectrometry after previous digestion of sapmles using microwaves. Concentrations of elements in leaves and grapes from organic and integrated farming did not differ significantly only in the case of copper concentrations were measured higher concentrations in samples from organic farming. This difference is probably caused by different doses of authorized protective equipment based on copper in the organic and integrated farming.

Thesis (PhD(Agric))--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Water scarcity is a key limiting factor for viticulture in dry regions. Traditionally drought sensitive varieties have the potential to grow in dry areas, however in most situations, through the use of rootstocks. Drought-tolerant rootstocks are expected to improve grapevine response to water deficit by improving the water uptake and transport and by reducing the water loss in leaves by root-to-shoot signalling. The mechanisms of rootstocks’ tolerance to drought are not yet fully understood. The main aim of this study was to improve the understanding of the rootstock/scion-cultivar interaction in the regulation of grapevine water use and leaf stomatal behaviour. Irrigated field vines without any water constraint were compared to rain-fed grapevines subjected to moderate water constraint. To better manage vine water status, reduce variability, and compare more rootstocks, greenhouse trials were also conducted where plants were well watered or subjected to severe water constraints. Pinotage grapevines (Vitis vinifera L.) grafted onto 110 Richter, 140 Ruggeri and 1103 Paulsen rootstocks were used for field experiments whereas Pinotage grapevines grafted onto 99 Richter, 110 Richter, 140 Ruggeri, 1103 Paulsen and Ramsey were used for greenhouse experiments. Our study suggested the influence of rootstocks on scion-cultivar water status and leaf stomatal size and density and gas exchange of the scion, implying an influence on water uptake and transport and a tight regulation of the stomatal conductance. Our data supported the hypothesis that the influence of rootstock in response to drought seemed to be higher under increasing water deficit up to a point where the plant water status is the main driver of the stomatal conductance and therefore photosynthesis regulation, considering the plant water status thresholds. In addition, the results suggested that stomatal development is affected by light, drought and possibly by rootstocks. Nevertheless, it is still not clear how the rootstock affects stomatal development and the link with scion-cultivar water use. It seems that the transpiration rate of leaves is more related to stomatal size than density. Thus one possible mechanism of Pinotage leaf adaptation to water constraints was structural during leaf growth, with a reduction in pore size to reduce plant water loss. The results showed that the rootstock is regulating the cultivar's stomatal size (anatomical changes during leaf growth) and functioning (stomatal regulation) through a complex signalling process. The effect of light on stomatal development is interesting in the context of canopy microclimate and canopy manipulation (choice of the vine architecture vs canopy size, in the context of climate change versus the possible increase in drought and water scarcity). The use of rootstocks is a long term investment which aims to provide resistance to soil pests and pathogens and to confer to the scion-cultivar drought and salt tolerance. The use of drought tolerant rootstocks is actually one of the most relevant practical solutions in dry terroir – units and in situations where water availability is limited. The understanding of the physiological and genetic mechanisms which govern scion-cultivar drought tolerance/behaviour induced by rootstocks is critical in terms of rootstocks choice in interaction with the scion-cultivar and is critical to assist breeding programs to create/select drought tolerant rootstocks.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The global wine industry has shifted to a more adopted ‘consumer-preference’ production. Modern wine consumers are more knowledgeable and cultivated in their understanding of wine quality, value and style. The quality of red wines mainly depends on grape composition, the wine making process and the ability of tasters to recognise sensory attributes. The harvest date/stage has an influence on the grape composition, thus making the decision on when to harvest an important factor in the production of quality wines or different wine styles. The traditional indicators used in the wine industry to determine time of harvest are more related to the perception of taste and mouthfeel and give little indication of the style of wine in terms of aromatic profile. A new physiological indicator using berry sugar accumulation for the purpose of sequential harvest is proposed to assist the winemaker in producing wines with possible different sensory profiles. This indicator can be used in association with the classical indicators of ripening to affect the diversity of wine styles from a single vineyard or a group of vineyards. The wines could thus have different potential aroma profiles, depending on when the grapes were harvested. The main aim of this study was to assess the effect of performing sequential harvest using a physiological indicator on red wine’s sensory composition. This was done to study the possible relation between harvest time (e.g. fruit composition evolution) and the wine styles/sensory attributes across the different harvest times, thereby possibly increasing the diversity of wine styles. A theoretical berry sugar loading concept was compiled and displays a phase of rapid sugar loading starting at véraison followed by a plateau phase. Depending on whether grapes were harvested in the beginning, mid or end of the plateau phase of fruit sugar accumulation the wines could have different potential aroma profiles. Three main stages: fresh fruit (FF), neutral (N) or pre ripe and mature fruit (MF) has been previously proposed using the sugar loading concept and in terms of harvesting dates. Cabernet Sauvignon and Merlot grapes form Eikendal Vineyards, Stellenbosch were used to make wines according to sequential harvest. Four harvest stages were considered, pre fresh fruit (Pre FF), fresh fruit (FF), mature fruit (MF) and over ripe (OR). The wines were tasted and analysed using two different sensory techniques. In both Merlot and Cabernet Sauvignon wines, the PreFF and OR stages could be more easily discriminated than the two harvest stages in-between, FF and MF. The results suggested that the wines made from the FF and MF stages could not be distinguished from each other in general when the attribute citation frequency method or sorting tasks were performed. However, a trend could be observed for both Cabernet Sauvignon and Merlot wines in terms of aroma attributes with attributes changing from green to ripe fruit during ripening using expert tasters. Relevant research should be engaged to refine sequential harvest in order to obtain more diverse wine styles from a single site or a group of vineyards. / AFRIKAANSE OPSOMMING: Die wêreldwye wynbedryf het ’n verskuiwing ondergaan na ’n verbruikersvoorkeurbenadering in produksie. Wynverbruikers is deesdae beter ingelig en meer ontwikkeld ten opsigte van hulle kennis van wyngehalte, wynstyl, asook die waarde van wyn. Die gehalte van rooiwyn hang hoofsaaklik af van die druifsamestelling, die wynmaakproses en die vermoë van proewers om sensoriese eienskappe te herken. Aangesien die oesdatum/-fase ’n invloed het op druifsamestelling, is die besluit oor wanneer daar geoes moet word ’n belangrike faktor in die vervaardiging van gehaltewyne of verskillende wynstyle. Die tradisionele aanwysers wat in die wynbedryf gebruik word om oestyd te bepaal, hou verband met die waarneming van smaak en mondgevoel en gee weinig aanduiding van die wynstyl op grond van die aromatiese profiel. ’n Nuwe fisiologiese aanwyser wat gebruik maak van suikerakkumulasie in die druiwekorrel in opeenvolgende oeste, het ten doel om die wynmaker te help om wyne met verskeie moontlike sensoriese profiele te vervaardig. Hierdie aanwyser kan saam met die klassieke aanwysers van rypwording gebruik word om ’n verskeidenheid wynstyle uit een wingerd of wingerdgroep te vervaardig. Die wyne kan dus potensieel oor verskillende aromatiese profiele beskik, afhangend van wanneer die druiwe geoes is. Die hoofdoel van die studie was om die invloed van opeenvolgende oes te toets deur ’n fisiologiese aanwyser op rooiwyn se sensoriese samestelling toe te pas. Dit word gedoen deur die moontlike verhouding tussen die oestyd (bv. ontwikkeling van vrugsamestelling) en die wynstyle of wyn se sensoriese kenmerke op verskillende oestye te bestudeer ten einde die verskeidenheid wynstyle potensieel te vermeerder. ’n Teoretiese konsep van druifsuikeropname is saamgestel wat dui op ’n fase van vinnige suikeropname wat by véraison begin, gevolg deur ’n plato-fase. Wyn kan oor verskillende moontlike aromatiese profiele beskik, afhangend daarvan of die druiwe aan die begin, middel of einde van die plato-fase van suikeropname geoes is. Drie hooffases is al voorheen voorgestel deur gebruik te maak van die konsep van suikeropname volgens oesdatum, te wete vars vrugte (VV) (“fresh fruit”, FF), neutraal (N) (“neutral”, N) of voor ryp (“pre ripe”), en ryp vrugte (RF) (“mature fruit”, MF). Cabernet Sauvignon- en Merlot-druiwe van Eikendal, Stellenbosch, se wingerde is gebruik om wyn volgens opeenvolgende oes te maak. Vier oesfases is oorweeg, te wete voor vars vrugte (VVV) (“pre fresh fruit”, Pre FF), vars vrugte (VV) (“fresh fruit”, FF), ryp vrugte (RV) (“mature fruit”, MF), en oorryp (OR) (“over ripe”, OR). Die wyn is geproe en geanaliseer deur gebruik te maak van twee verskille sensoriese tegnieke. In die geval van beide die Merlot- en Cabernet Sauvignon-wyn kon die VVV- en OR-fases makliker onderskei word as die twee tussenin-fases, VV en RV. Resultate dui daarop dat wyn wat van die VV- en RV-fases gemaak is, oor die algemeen nie van mekaar onderskei kan word wanneer die frekwensie van kenmerkaanhaling-metode en sorteringstaak uitgevoer word nie. ’n Tendens kon egter waargeneem word vir Cabernet Sauvignon- én Merlot-wyn ten opsigte van aromatiese kenmerke, deurdat kenmerke gedurende rypwording van groen na ryp vrugte verander het indien ekspertproewers gebruik is. Verdere navorsing moet gedoen word om opeenvolgende oes te verfyn ten einde ’n wyer verskeidenheid wynstyle van ’n enkele area of wingerdgroep te verkry.