Résumé
High temperature (HT) accounts for large yield losses in crops worldwide. In the context of the climate change, understanding how plants cope with HT in their environment while maintaining good crop yield and quality is an important issue. Regarding viticulture, predictive models reported that temperature elevation should cause significant and permanent damage to the vine, affecting its phenology and yield. This results in desynchronizing sugar and organic acid metabolisms and increasing sugars and K+ accumulation during ripening. Indeed, HT modifies the fruit content at harvest and the quality of wines resulting in wines with a high alcoholic content, low acidity and ageing potential and poor organoleptic qualities. In this context, there is an urgent need to anticipate the effects of climate change on vineyards, including the consequences of extreme T°. In addition to wine-growing practices, exploiting the genetic diversity of the genus Vitis in order to select varieties better adapted to a warmer climate while maintaining the expected quality profiles remains a valid alternative. The ANR PARASOL aims at supporting this action by studying the functioning of relevant heat-modulated transcription factors (TFs) and their interaction with important physiological parameters driving plant response to HT and fruit quality: redox status and K+/acid balance. Taking advantage of the biological properties of the microvine, in association with molecular tools valuable for TF studies (CRES-T) or genome editing (CRISPR/Cas), PARASOL should allow to i) assess to what extent an altered genotype in one of the studied parameters (TFs, K+/acids, Redox) may be affected in thermotolerance and/or fruit quality, and ii) validate our hypothesis suggesting an interconnection between the identified heat-responsive TFs and key players of both K+/Acids and redox homeostasis in the context of HT response in grapevine. Some preliminary results will be presented here.