Effects of Drought Stress and Rootstock Genotype on Grape Berry Quality

Grape berry components are important because they determine the quality of the grape and are the most important parameter for the quality of wine. These components depend on a complex interaction between two genotypes (rootstock and scion) and other environmental factors. Climate change affects the physiology of the vine, yield and fruit composition, and ultimately the quality and authenticity of wines. In this context, we need to better understand the physiological mechanism and the genetic background underlying the interaction between viticulture and the environment, as this will be helpful for the development of sustainable concepts under changing conditions. We studied the interactions of two grapevine rootstocks (110R drought-tolerant and 125AA drought-sensitive) and two water regimes (well-watered and moderate water stressed) on grape berry composition of Pinot noir. These interactions are studied by integrating analysis of secondary metabolites, enzymes involved in primary and secondary metabolism, and gene expression. The transcriptional and metabolic profiling complemented with biochemical data of four developmental stages from berries still hard and green, through veraison to mature berries (EL 33, EL 35, EL 36, EL 38) and in three seasons (2009, 2010 and 2011) will be compared. The results will provide new information of the response of grape berry quality to rootstock and to drought.