Characterization of a multifunctional caffeoyl-CoA O-methyltransferase activated in grape berries upon drought stress

Drought stress affects anthocyanin accumulation and modification in vegetative and reproductive plant tissues. Anthocyanins are the most abundant flavonoids in grape (Vitis vinifera L) coloured berry genotypes and are essential markers of grape winemaking quality. They are mostly mono- and di-methylated, such modifications increase their stability and improve berry quality for winemaking. Anthocyanin methylation in grape berries is induced by drought stress. A few caffeoyl-CoA O-methyl-transferases (CCoAOMT5) active on anthocyanins have been described in grape. However, no drought activated O-methyltransferases have been described in grape berries yet.