Resveratrol and Stilbene Synthase mRNA Production in Grapevine Leaves Treated with Biotic and Abiotic Phytoalexin Elicitors

Abstract

Vitis rupestris and Vitis vinifera cvs. Pinot noir and Chardonnay plants grown in vitro were treated with defense elicitors in order to study the expression of stilbene synthase (StSy) genes. Changes in StSy mRNA production were monitored 0 to 24 hr after treatment with UV light. A constant level of expression was observed for V. rupestris (a species tolerant to gray mold), whereas there were two peaks in expression for the V. vinifera varieties Pinot noir and Chardonnay (both susceptible to gray mold). Similar profiles were observed for resveratrol accumulation, showing that stilbene synthesis is correlated to StSy mRNA production. Three elicitors of grapevine defense mechanisms—UV irradiation, aluminum chloride, and Botrytis cinerea—did not induce the same StSy mRNA production in V. rupestris. UV irradiation induced a high, constant level of StSy mRNA production correlated to resveratrol accumulation, while the other two elicitors induced irregular responses.