Differential response of the biosynthesis of resveratrols and flavonoids to UV-C irradiation in grape leaves

Abstract

Resveratrols and flavonoids have important beneficial roles in plants and to humans. The grape family (Vitaceae) is one of several families that can biosynthesise both resveratrols and flavonoids. Previous research has shown that UV-C may induce the biosynthesis of resveratrols in the fruit of grape. But little is known about the UV-C-induced biosynthesis of resveratrols and flavonoids in grape leaves. This study demonstrated that the biosynthesis of resveratrol in grape leaves strongly increased in response to UV-C irradiation. The largest contribution to total resveratrols was trans-resveratrol. The expression of related genes, including PAL, C4H, 4CL and STS, increased and peaked 6-12 h after treatment, earlier than the peak of total resveratrol. In contrast, total flavonoid content and the expression of the key gene CHS was not affected by UV-C radiation, staying at a low level after UV-C irradiation. In summary, there is a differential response to UV-C radiation for the biosynthesis of stilbenes and flavonoids in grape leaves.