A Synchronized Increase of Stilbenes and Flavonoids in Metabolically Engineered cv. Gamay Red Cell Culture.

Stilbenes and flavonoids are two major health-promoting phenylpropanoid groups in grapes. Attempts to promote the accumulation of one group usually resulted in a decrease in the other. This study presents a unique strategy for simultaneously increasing metabolites in both groups in cv. Gamay Red grape cell culture, by overexpression of flavonol synthase () and increasing Phe availability. Increased Phe availability was achieved by transforming the cell culture with a second gene, the feedback-insensitive DAHP synthase (*), and feeding them with Phe. A combined metabolomic and transcriptomic analysis reveals that the increase in both phenylpropanoid groups is accompanied by an induction of many of the flavonoid biosynthetic genes and no change in the expression levels of stilbene synthase. Furthermore, overexpression with increased Phe availability resulted in higher anthocyanin levels, mainly those derived from delphinidin, due to the induction of . These insights may contribute to the development of grape berries with increased health benefits.