The Production of Resveratrol (3,5,4'-trihydroxystilbene) by Grape Berries in Different Developmental Stages

Abstract

Resveratrol (trans-3,5,4'-trihydroxystilbene), a grapevine phytoalexin related to grey mold resistance, is produced by grape berries of Vitis vinifera L. and Vitis labrusca L. in response to UV-irradiation; its production decreases during fruit ripening. In vinifera varieties, the resveratrol content of whole berries steadily declined between the green stage and complete maturity, nearing zero in ripe fruit, while a pronounced decrease was observed in the berries of V. labrusca after veraison. On the other hand, resveratrol synthesis was found to be located in the skin, thus showing that the principal resistance of grapes to fungal attacks takes place at this level. Finally, the decrease of resveratrol production during maturation was also confirmed by the fact that there is a clear negative correlation between the resveratrol content of grape skin and the developmental stage of berries measured by the sugar concentration of juice.