Novel approaches and promising perspectives for enhancing grapevine editing and regeneration

Grapevine downy mildew is a disease of foliage caused by Oomycete Plasmopara viticola an endoparasite that develops inside grapevine organs and can infect virtually every green organ. Downy mildew is one of the most destructive diseases in wine-growing regions, drastically reducing yield and fruit quality. Traditional manual disease detection relies on farm experts. Human field scouting has been widely used for monitoring the disease progress, however, is costly, laborious, subjective, and often imprecise.

Canopy-management practices are applied in viticulture to improve berries composition and quality, having a great impact on primary and secondary grape metabolism. Among these techniques, cluster zone leaf removal (defoliation) is widely used to manage air circulation, temperature and light radiation of grape bunches and close environment. Since volatiles are quantitatively and qualitatively influenced by the degree of fruit ripeness, the level of solar exposure, and the thermal environment in which grapes ripen, leaf removal has been shown to affect volatile composition of grape berries [1].

Champagne is a well-known wine region in Northern France with distinct terroirs and three main grape varieties. As for any vineyard, wine quality is highly linked to the microbiological characteristics of the raw materials. However, Champagne grape microbiota, especially its fungal component, has yet to be fully characterized. Our study focused on describing this mycobiota, from vine to small scale model wine, for the two main Champagne grape varieties, Pinot Noir and Meunier, using complementary cultural and omics approaches.

The French viticultural appellation areas are the result of an empirical, historical and evolutionary selection which, generally, has consecrated a match between natural factors, grape varieties and viti-vinicultural practices. The notion of terroir is the main basis of the Appellation d’Origine Contrôlée in viticulture. It is based on the one hand on privileged natural factors and on the other hand on the know-how of the winegrowers; the whole allowing the production of a wine endowed with an authenticity and a sensory typicity. Wine-growing practices evolve according to progress in viticulture and oenology, while the natural factors of the terroir are much more stable, with the exception of the vintage. They therefore represent a fundamental pillar of the identity of an appellation vineyard.

Due to the global demand for terroir wines, the winemaking industry has focused attention on exploiting the local yeast microflora of each wine growing region to express the regional character and enhance the sensory profile of wines such as varietal typicity and aroma complexity. The objective of the present study was to isolate and compare the indigenous strains of Saccharomyces cerevisiae present in different vineyards in the Mesogeia – Attiki wine region (Greece), evaluate their impact on chemical composition and sensory profile of Savatiano wines and select the most suitable ones for winemaking process.