Phenols and stilbene polyphenols in the wood of esca-diseased grapevines

Trans-resveratrol and epsilon-viniferin, already described as stress metabolites produced by the leaves of Vitis vinifera in response to fungal infection, UV irradiation and incubation by chemicals, have been detected in the wood of healthy as well as in the brown-red wood of esca-diseased grapevines. Brown-red wood is considered an initial symptom of esca in grapevine. Resveratrol was the predominant component, although epsilon-viniferin was also accumulated in appreciable quantities. The biological significance of the production of resveratrol and epsilon-viniferin is discussed