Effect of abiotic stress and grape variety on amino acid and polyamine composition of red grape berries
Vines are exposed to environmental conditions that cause abiotic stress on the plants (drought, nutrient and mineral deficits, salinity, etc.). Polyamines are growth regulators involved in various physiological processes, as in abiotic plant stress responses. Stressful conditions can modify grape’s composition, and in this work, we have focused on studying the effect of abiotic stress on the composition of polyamines and amino acids in grapes. In addition, the effect of grape variety on these compounds has been studied. Forty-two grape samples from different vineyards of Pago de Carraovejas Winery, were harvested at the optimum ripening. Polyamines and amino acids of these musts were analyzed by reverse-phase high performance liquid chromatography with a diode-array detection system. Enological parameters were also determined according to official analysis methods. Multifactor analysis (MFA) was performed using the RStudio program, considering stress as qualitative variable.
MFA allowed differentiating the samples by stress and grape variety. Grapes from more stressed vineyards had the highest content of arginine, alanine, glutamine, methionine, lysine and serine. In contrast, Cabernet Sauvignon and Merlot grapes showed higher content of proline, glycine, putrescine and spermidine, and lower content of most amino acids (tryptophan, glutamic acid, aspartic acid, arginine, alanine, glutamine and methionine) than Tempranillo grapes.
These results indicate influence of grape variety and stress factor on polyamine and amino acid content of grape berries. Polyamine concentration seems to be more associated to grape variety than to stress. Further studies are needed to assess the evolution of these compounds during ripening and fermentation since amino acids are an important source of nitrogen for yeast growth and they are volatile compound precursors.
Acknowledgements: This study was supported by the project 2022/474 from “Rural Development Program (PDR) of Castilla y León 2014-2020” and financed with FEADER funds.
Issue: ICGWS 2023
1 Instituto Tecnológico Agrario de Castilla y León, Ctra. Burgos Km 119, 47071 Valladolid, Spain.
2 Pago de Carraovejas, Camino de Carraovejas, s/n. 47300 Peñafiel, Valladolid, Spain.