ABA Initiates Anthocyanin Production in Grape Cell Cultures

Abscisic acid (ABA) has a well-known positive impact on grape ripening, especially color development, but its role in the initiation of anthocyanin synthesis remains unclear. To elucidate this point, ABA treatment was applied to a simple Vitis vinifera model, consisting of Cabernet Sauvignon cell suspensions that do not spontaneously produce anthocyanins under laboratory conditions. Endogenous ABA levels, the expression of some genes in the upstream part of the anthocyanin pathway, and anthocyanin content were determined. Exogenous ABA treatment sharply increased cell ABA content and induced both structural and regulatory genes involved in anthocyanin production. These changes were promptly detected, as early as 6 h after ABA treatment, whereas anthocyanin production was observed only after 4 days in culture. These results demonstrate that ABA promotes anthocyanin synthesis in grape cell culture.