Changes in Malondialdehyde, Anthocyanin, and Hydroxycinnamic Acid Contents in Shoots and Buds of Prunus L. Representatives Induced by Cold Stress

Abstract

This study is devoted to the assessment of cold tolerance in selected cultivars of the genus Prunus L., including P. persica, P. cerasifera, and P. domestica, during winter dormancy based on biochemical markers associated with oxidative stress and antioxidant defense. The contents of anthocyanins, hydroxycinnamic acids, and malondialdehyde (MDA) were determined in shoots and buds of eleven cultivars, and an integrated Cold Tolerance Index (CTI) was calculated using Max-normalized biochemical parameters. The results demonstrated that buds generally accumulated higher levels of anthocyanins and hydroxycinnamic acids than shoots across all studied Prunus species, indicating enhanced antioxidant activity in generative organs. The highest anthocyanin contents were recorded in P. persica cv. Antotsianovyi, P. domestica cv. Oda and Stanley, while elevated hydroxycinnamic acid levels were characteristic of P. domestica (cv. Oda and Stanley), P. cerasifera cv. Kubanska Kometa, and P. persica cv. Antotsianovyi. In contrast, MDA content varied considerably among cultivars and species and reflected the intensity of lipid peroxidation under low-temperature stress, with generally higher values observed in P. persica compared to P. cerasifera and P. domestica. Cultivars of P. domestica, particularly Oda and Stanley, combined relatively low MDA accumulation with high CTI values, suggesting an efficient and stabilized adaptation strategy. The CTI values ranged from 42 to 72%, revealing substantial interspecific and intraspecific differentiation in cold tolerance. The highest cold tolerance was observed in P. domestica cultivars, whereas several P. persica cultiars, including Suputnyk, Lisostepovyi, and Osinnii Siurpryz, showed increased sensitivity to cold stress. Cluster analysis (UPGMA, Euclidean distance) identified distinct groups of genotypes differing in adaptive strategies across species. A significant inverse correlation between MDA content and CTI (R² = 0.6499) confirmed the key role of oxidative membrane damage in determining cold tolerance in Prunus species. Overall, the study demonstrates that cold tolerance in Prunus is strongly species-dependent, with P. domestica showing the highest adaptive potential, P. cerasifera intermediate responses, and P. persica the greatest variability, highlighting the importance of species-level differentiation in biochemical adaptation to low-temperature stress.