Heat-stress responses regulated via a MYB24-MYC2 complex

Grapevines (Vitis vinifera L.) are plants of great economic importance, with over 80% of grape production dedicated to wine production, yielding more than 258 million hectoliters annually [1].

Dans les études des terroirs, il est souvent délicat d’établir des zonages et de mesurer les effets de l’environnement sur les vins. Avec plus d’un million d’hectares dans l’aire d’appellation délimitée, le terroir du célèbre vignoble de Cognac est bien connu pour ces eaux-de-vie et ainsi divisé en 6 crus.

Phenolic compounds are released from the wood into the wine spirit (WS) during the ageing process, and are of utmost importance to the colour, flavour, taste and the overall quality acquired by this spirit drink.1 Their concentrations in the WS and the related effects mainly depend on the kind of wood (oaks vs chestnut), toasting level and ageing technology (traditional using wooden barrels vs alternative).1,2,3

Aim: To define the uniqueness of Australian Cabernet Sauvignon wines by evaluation of the chemical composition (volatile aroma and non-volatile constituents) that may drive regional typicity, and to correlate this with comprehensive sensory analysis data to identify the most important compounds driving relevant sensory attributes.

Anthocyanin potential of grape berries is an important quality factor in wine production. Anthocyanin concentration and profile differ among varieties but it also depends on the environmental conditions, which are expected to be greatly modified by climate change in the future. These modifications may significantly modify the biochemical composition of berries at harvest, and thus wine typicity. Among the diverse approaches proposed to reduce the potential negative effects that climate change may have on grape quality, genetic diversity among clones can represent a source of potential candidates to select better adapted plant material for future climatic conditions. The effects of individual and combined factors associated to climate change (increase of temperature, rise of air CO2 concentration and water deficit) on the anthocyanin profile of different clones of Tempranillo that differ in the length of their reproductive cycle were studied. The aim was to highlight those clones more adapted to maintain specific Tempranillo typicity in the future. Fruit-bearing cuttings were grown in controlled conditions under two temperatures (ambient temperature versus ambient temperature + 4ºC), two CO2 levels (400 ppm versus 700 ppm) and two water regimes (well-watered versus water deficit), both in combination or independently, in order to simulate future climate change scenarios. Elevated temperature increased anthocyanin acylation, whereas elevated CO2 and water deficit favoured the accumulation of malvidin derivatives, as well as the acylation and tri-hydroxylation level of anthocyanins. Although the changes in anthocyanin profile observed followed a common pattern among clones, such impact of environmental conditions was especially noticeable in one of the most widely distributed Tempranillo clones, the accession RJ43.