Thermotolerance Related To Antioxidation Induced By Jasmonic Acid, Salicylic Acid And Heat Acclimation In Young Grape Plants

One-year-old grape plants(Vitis vinifera L.cv.Cabernet Sauvignon )were used as experiment materials.The effect of high temperature on the content of solube protein ,electrolyte leakage of membrane,the activites of antioxidant enzymes,and the content of antioxidants in young grape plants were studied .the measures of pretreatment with heat acclimation (38℃)and concentration of 50μmol·L-1 jasmonic acid(JA) ,100μmol·L-1saliylic acid(SA) for six hours were taken to induce the thermotolerance of young grape plants under (different time) high temperature in this study.The physiology and biochemical mechanism of heat stress on grape with heat acclimation,jasmonic acid, saliylic acid on grape under heat stress were discussed.All results given above provide the base evidences for cultivation and breeding of grape plants.The result showed that JA ,SA and HA can enhance more superoxide dismutase(SOD),catalase(CAT),perocidase(POD),ascorbic peroxidase(APX)and Glutathione reductase (GR) activity and the content of soluble protein, ascorbic acid and glutathione than the control under normal temprture, after pretreating the young grape plants with 50μmol·L-1 JA solution,100μmol·L-1SAand HA. At the same time, electrolyte leakage and H2O2 content were lower than those in the concrol. Secondly, the electrolytic leakage of membrane was amplified, H2O2 content was accumulated in grape plant under high temperature stress.The activities of superoxide dismutase(SOD), catalase(CAT), perocidase(POD), ascorbic peroxidase(APX)and Glutathione reductase (GR) were incited by first period of high temperature and then decreased with long time stress in grape plant under heat stress. Ascorbic acid (ASA) content decreased during all stress period, Glutathione content were increased at first stress time then decreased as the stress time lengthened. JA , SA and HA pretreated inhibited the lecomposition soluble protein, decreased the electrolytic leakage of cellular membrane under heat stress.The same time, the activities of antioxidant enzymes and the antioxidants were higher than the control.in contrast, the H2O2 content in different pretreatment grape plant was lower than those in the control under heat stress. The grape plant pretreated by JA , SA and HA else can prolong leathal time compared with these untreated under heat stress. It was suggested that JA , SA and HA enhances thermoprotection in similar mechanisms.