Enhancing plant defense: carbon dots for efficient spray-induced gene silencing 

Polyphenols, namely anthocyanins and flavanols, are key compounds for wine color definition and taste perception (astringency and bitterness). During winemaking, several processes could influence the polyphenol composition and, therefore, the organoleptic parameters of wine.

Water scarcity is an increasing constraint for viticulture in Mediterranean regions, making the identification of molecular mechanisms underlying drought tolerance a key objective for grapevine breeding and management.

Valpolicella is a famous Italian wine-producing region. Wines produced in its different sub-regions are believed to be aromatically different, as confirmed by recent studies in our laboratory. Aging is a very common practice in Valpolicella and it is required by the appellation regulation for periods up to four years require wines. The aim of this study was to investigate the evolution, during aging, of volatile chemical composition of Valpolicella wines obtained from grapes harvested in different sub-regions during different vintages.

Oxidation in wine is mostly related to the Michael addition of nucleophiles on two quinones formed from the oxidation of ortho-diphenols. In wine this mechanism is responsible for the increase of the yellow hue and aroma loss. Glutathione exerts its antioxidant activity throughout its competitive addition onto quinones, but many other compounds can have the same behavior: sulfanyl
compounds, amino acids, etc. Addition of yeast derivates during the winemaking process can increase the level of those nucleophilic compounds and then confer to the wine a higher resistance

Until the 19th century, the wild form of cultivated grapevines (vitis vinifera l. subsp. sylvestris gmelin, v. sylvestris) was ubiquitous in many european and west asian regions. However, many factors like deforestation, the intensification of agriculture, or the introduction of several pests and pathogens decimated its presence in these growing sites, and natural populations are now mostly restricted to river-bank forests and creeks with specific soil and climate conditions. in fact, v. sylvestris is now considered an endangered subspecies that is protected by law in many european countries to prevent its loss.