Defining gene regulation and co-regulation at single cell resolution in grapevine

In recent years, the ageing bouquet of red Bordeaux wines has been partially unveiled by a chemical and sensory point of view1–3. Minty and fresh notes were found to play a key role in the definition of this complex concept, moreover the freshness dimension in fine aged red wines plays an important role in typicity judgement by wine professionals

La qualité des vins dépend de différents facteurs et procédés, notamment de la nature des terrains viticoles. Dans ce travail, nous avons cherché à établir les liens entre descripteurs pédologiques des parcelles et descripteurs sensoriels des vins. Sur la base de Classifications Ascendantes Hiérarchiques (CAH) et d’Analyses en Composante Principale (ACP), il a été possible d’établir des liens entre la nature des parcelles (sableuse, argileuse, sablo-graveuleuse) et certains descripteurs sensoriels des vins (chaleur, astringence, fruit noir) et plus globalement avec le type de vins élaborés.

The composition of grape berry cell walls was studied on two grape varieties, two years and two maturation levels at the same time as the extraction of anthocyanins and tannins. The chemical composition of skins, seeds, and pulps, focused on polyphenols and polysaccharides, was compared to the chemical composition in polyphenols after extraction from the skins in model solutions or after wine making of the berries. Polyphenols were mainly characterized by UPLC-MS and HPLC-SEC. Polysaccharides were characterized by analysis of the neutral sugar compositions, and also by the CoMPP (comprehensive micropolymer profiling) analysis, a new method which targets the functional groups of cell wall polysaccharides.

To characterize a wine, the most frequently used criteria describe its color, its origin, the grape varieties from which they come, or even for white wines its residual sugar content (dry, semi-dry, sweet). In france, the system of appellations of origin set up in 1919 was initially based solely on the notoriety and origin of the wines. But given the unfavorable consequences that this lack of details generated, the public authorities quickly integrated in 1927 into the “capus” law criteria for access to designations of origin, relating to the specific characteristics of the soils of the vineyards and the grape varieties used, in particular exclusion of interspecific hybrid varieties. In 1935 the creation of the aoc system confirmed the interest in precisely defining all the production conditions that must be implemented to be able to claim the benefit of an aoc, and grape varieties were an essential condition for acquisition.

Le marché international du vin est désormais tourné vers la qualité et les vignobles de vin de masse se transforment pour construire la qualité et la réputation de leurs produits. Cette construction s’appuie notamment sur la valorisation de ressources territoriales de nature physique (terroir, pacage, écosystème) et humaine (savoir-faire, culture, patrimoine…). Les « Routes des Vins » sont des exemples concrets de ces processus de «territorialisation», combinant ces ressources territoriales pour communiquer sur l’ancrage géographique et la spécificité des vins. Les «Routes des Vins» émergentes, observées dans les régions vitivinicoles en transition vers la qualité, en Languedoc Roussillon, à Mendoza (Argentine) et au Western Cape (Afrique du Sud), participent souvent à la valorisation des terroirs, en organisant un itinéraire sur le territoire associé, en faisant découvrir les vins «de qualité», les paysages, les pratiques et le savoir-faire associés à leur élaboration.