Abiotic Stress Effects on Phenolic Metabolism in Vitis vinifera: Implications for Grape Quality

Abstract Abiotic stresses represent major constraints in grapevine cultivation and directly influence fruit composition and product quality. Phenolic metabolism in Vitis vinifera plays a central role in stress adaptation. It affects both the plant’s performance and is closely related to the fundamental quality characteristics of grapes. This review synthesizes current studies on how abiotic stress factors, which are intensifying under climate change, influence the composition and accumulation of phenolic compounds in grapes. Emphasis is placed on phenolic groups, particularly anthocyanins, stilbenes, flavonols, and tannins, which are related to grape and wine quality. Data obtained under controlled conditions or in the field show that the duration and intensity of stress are very important determinants of the effect on phenolics. While phenolic compound content increases in moderately intense stresses, the phenolic balance of the plant can be disrupted in severe and prolonged stresses, and quality characteristics can be negatively affected to a great extent. Our study also examines the extent to which stress-induced changes in phenolic metabolism interact with viticultural experiments such as shading, irrigation programs, and light manipulation. This synthesis links stress responses with quality parameters and proposes adaptive viticultural strategies for climate-resilient production.