Proteomic profiling of grape berry presenting early loss of mesocarp cell vitality

Grapevine faces multiple biotic and/or abiotic stresses, which are interrelated. Depending on their incidence, they can have a negative impact on the development and production of the plant, but also on its longevity, leading to vine dieback. One of the consequences of vine dieback on production is the increased replacement rate of dead or missing vines within a parcel.

Wine quality is strongly linked to climate. Quality scores are often driven by climate variation across different winegrowing regions and years, but also influenced by other aspects of terroir, including variety. While recent work has looked at the relationship between quality scores and climate across many European regions, less work has examined New World winegrowing regions. Here we used scores from three major rating systems (Wine Advocate, Wine Enthusiast and Wine Spectator) combined with daily climate and phenology data to understand what drives variation across wine quality scores in major regions of the Western US, including regions in California, Oregon and Washington. We examined effects of variety, region, and in what phenological period climate was most predictive of quality. As in other studies, we found climate, based mainly on growing degree day (GDD) models, was generally associated with quality—with higher GDD associated with higher scores—but variety and region also had strong effects. Effects of region were generally stronger than variety. Certain varieties received the highest scores in only some areas, while other varieties (e.g., Merlot) generally scored lower across regions. Across phenological stages, GDD during budbreak was often most strongly associated with quality. Our results support other studies that warmer periods generally drive high quality wines, but highlight how much region and variety drive variation in scores outside of climate.

Soil and climate of 3 vineyards have been characterised in order to determine their influence on grape quality. These vineyards are located in Conca de Barberà (Catalonia, NE Spain) and belong to Cabernet sauvignon and Grenache noir cultivars. All 3 plots are very close, so only interannual climatic data of the nearest meteorological station have been considered.

Various molecular compounds are responsible for the complex mixture of fragrances that give wine its aroma. In particular, the ‘cooked fruit’ aroma found in red wines from hot and/or dry vintages or from the vinification of late harvested grapes has been intensively investigated in recent years. Lactones and especially γ-nonalactone were found to be responsible for the ‘cooked fruit’

Quercetin-3-glucoside, a grape flavonol defence metabolite, is extracted during winemaking and may undergo subsequent degradation in wines. Hydrolysation reactions lead to the formation of the aglycone quercetin, which presents limited solubility in the wine matrix and can induce visible precipitations.