Effect of salicylic acid on the antioxidant system in some grape varieties under cold stress

Aim and Recently, application of SO2 during cold storage is restricted since its residues are toxic and dangerous to human health. Salicylic acid (SA) is an alternative method to SO2 and can alleviate post harvest oxidative stress. Our research goal, in the present study, was to characterize the effects of salicylic acid (SA) on some antioxidative characteristics of grape (Vitis vinifera L. cv Bidaneh Sefid, Dastrchyn, Sahebi and Qizil üsum) fruits applied with or without SA under cold storage for two weeks. The selected clusters were randomly divided into two groups so that SA-treated group immersed for ten minutes in solutions of 1 mM SA and were air-dried at room temperature. Salicylic acid increased the relevant water content (RWC) of Sahebi and Qizil üsum in comparison to those of control at the end of the shelf life, whereas the effect of SA treatment on relative water content of the other cultivars was not significant during storage life. In Bidaneh Sefid, no difference in superoxide dismutase (SOD) activities between SA-pretreated and control fruit was observed, whereas SOD activity in SA-pretreated Dastrchyn was significantly higher than that in the controls during 15 days of postharvest life. In this work, SA considerably reduced the rise in malondialdehyde (MDA) content in cultivars Sahebi and Qizil üsum during storage, obviously because of an efficient scavenging following significant enhancement of SOD and catalase (CAT) activity. These results suggest that SA application can improve antioxidant defense system of Sahebi and Qizil üsum during storage, and it may be recommended for increasing storage life and maintaining their quality.