Water stress and abscisic acid exogenous supply produce differential enhancements in the concentration of selected phenolic compounds in Cabernet Sauvignon

Abstract

The production of grapevine secondary metabolites can be magnified by abiotic stresses or exogenous abscisic acid. Selected phenolic compounds were determined in grape and wine by gas chromatography/mass spectrometry with the aim to asses the physiological responses of plants submitted to water stress and hormonal treatments. Exogenous abscisic acids as well as postveraison water stress produce differential enhancements on phenolic accumulation on Cabernet Sauvignon grapes and such effects were reflected in wine. Resveratrol and malvidin were enhanced by both abscisic acid and water stress and the improvement produced by such factors was additive. On the other hand, the synthesis of gallic acid, (+) catechin, quercetin and caffeic acid was not stimulated by water deficit. Combined hormonal-water stress treatments produced three positive effects on wine quality; a) increments of blue compounds, b) increments of flavonols and flavan 3-oles that favor copigmentation of wines, c) higher antioxidant compounds concentration with the consequent health benefits.