Particularities of Syrah wines from different growing regions of Southern Brazil: grapevine phenology and bioactive compounds.

The aim of this study was to monitor the phenological parameters of grapevine (Vitis vinifera) of Syrah variety recently introduced in the region of Marari, Água Doce, Campos Novos and São Joaquim, Santa Catarina State (SC), Brazil, and to characterize the phenolic composition and antioxidant activity of wines produced from this variety of the vintages 2010 and 2011. The adaptation of the grapevine to climate conditions of these grape growing regions of Southern Brazil for this variety has also been assessed. The climate variations occurring between the phenological cycles of grapevine of Syrah for each growing region influenced the phenological extension and heat accumulation of the grapevine. The wines showed significant levels of phenolic compounds and high antioxidant activity, while catechin, a potent antioxidant, was the main phenolic compound quantified in wines. Positive correlations between the phenolic compounds and antioxidant activity were observed. The principal component analysis confirmed the influence of the growing region and vintages on the phenolic composition of wines, indicating the importance of climate conditions. This study identified possible phenolic markers indicative of climatic influence.

Proteome of Plasmopara viticola-infected Vitis vinifera provides insights into grapevine Rpv1/Rpv3 pyramided resistance to downy mildew.

Grapevine is one of the major fruit crops worldwide and requires phytochemical use due to susceptibility to numerous pests, including downy mildew. The pyramiding of previous identified QTL resistance regions allows selection of genotypes with combined resistance loci in order to build up sustainable resistance. This study investigates resistance response of pyramided plants containing Rpv1 and Rpv3 loci to Plasmopara viticola infection process. Phenotypic characterization showed complete resistance and lack of necrotic hypersensitive response spots. Principal Component Analysis revealed infected 96hpi (hours post-inoculation) samples with the most distant proteomes of the entire dataset, followed by the proteome of infected 48hpi samples. Quantitative and qualitative protein differences observed using 2-DE gels coupled to nanoHPLC-ESI-MS/MS analysis showed a lack of transient breakdown in defense responses (biphasic modulation) accompanying the onset of disease. Forty-one proteins were identified, which were mainly included into functional categories of redox and energy metabolism. l-ascorbate degradation pathway was the major altered pathway and suggests up-regulation of anti-oxidant metabolism in response to apoplastic oxidative burst after infection. Overall, these data provide new insights into molecular basis of this incompatible interaction and suggests several targets that could potentially be exploited to develop new protection strategies against this pathogen. BIOLOGICAL SIGNIFICANCE: This study provide new insights into the molecular basis of incompatible interaction between Plasmopara viticola and pyramided Rpv1/Rpv3 grapevine and suggests several targets that could potentially be exploited to develop new protection strategies against this pathogen. This is the first proteomic characterization of resistant grapevine available in the literature and it presents contrasting proteomic profiles of that of susceptible plants. The resistance against downy mildew in grapevine has been a long sought and the availability of resistance loci is of major importance. This is the first molecular characterization of resistance provided by Rpv1 and Rpv3 genes.