Abstract
Trans‐resveratrol is a metabolite involved in resistance of plants during biotic and abiotic stress. Here we report the optimization of a rapid solvent extraction protocol and its application to different parts of grapevines. We also demonstrate the influence of sample pretreatment with liquid nitrogen on trans‐resveratrol stability, which results as the key step in avoiding oxygen degradation during solvent extraction. Up to 94% of trans‐resveratrol was recovered using this procedure. Berries and leaves from healthy and symptomatic, esca proper–affected vines collected at two different phenological growth stages were analyzed. Trans‐resveratrol was determined in berry and leaf samples; symptomatic vines always showed a significantly higher amount with respect to healthy vines. The mean concentration of trans‐resveratrol in berries was 0.93 µg/gdm and 1.92 µg/gdm at veraison and 1.49 µg/gdm and 2.72 µg/gdm at harvest from healthy and symptomatic vines, respectively.
Acknowledgments
Study commissioned by ARSIA‐Toscana (Regional Agency for Development and Innovation in Agriculture and Forest) by fourteen administrative Regions and one autonomous Province, and financed with funds provided by the Ministero per le Politiche Agricole e Forestali (Ministry for Agriculture and Forestry Policy) to implement the Interregional Project “Grapevine esca: research and experiment in the nursery and in the field for prevention and cure”.