Impact of drought stress and rootstock genotype on grape berry composition

Abstract

Grapes are one of the most important fruit crops in the world, especially for winemaking. The biochemical composition of grapevine berry is a major determinant of wine quality. This composition depends on complex interactions between the genotypes of the rootstock and the scion, vineyard management and environmental factors. Climate change affects the physiology of the vine, yield and fruit composition, and ultimately the quality and typicity of wines. In this context, a better understanding of the physiological mechanisms and the genetic background underlying the interactions between the grapevine plants and the environment is needed, and this will be helpful for the development of sustainable viticulture under changing environmental conditions.

Using field experiments, we study the effects of two water regimes (well-watered and moderate water stressed) on berry composition of Vitis vinifera L. cv. Pinot noir grafted on two different rootstocks (110R, drought-tolerant and 125AA, drought-sensitive). We integrate the analysis of primary and secondary metabolisms, as well as gene expression studies. Water limitation, especially at véraison, caused a substantial increase of anthocyanins, among which malvidin-3-0-glucoside was the most affected by water supply. Both the rootstock genotype and water limitation affected the amino acid composition of the berries. Proline and arginine were always the major amino acids in 2009 and 2010.  

Transcriptional and metabolic profiling will be integrated at four berry developmental stages (from still hard and green, through véraison to maturity) in three seasons (2009, 2010 and 2011). The results will allow understand better the impact of rootstock and drought on grape berry quality.