The involvement of nitric oxide in exogenous glutathione regulates antioxidant defense capacity against salt stress in tomato seedlings
WEN Ze-Lin;LIU Hui-Ying;ZHOU Yan;CHEN Xian-Jun;FENG Yu-Long;Department of Horticulture, College of Agronomy, Shihezi University;Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Crops;
A hydroponic experiment was performed to investigate the effects of exogenous glutathione(GSH) on nitric oxide(NO) levels, the activities of key enzymes related to NO synthesis, the lipid peroxidation level, production of reactive oxygen species(ROS), and the ROS scavenging capacity in leaves of tomato(Lycopersicon esculentum) seedlings under NaCl and NaCl+Hb(NO scavenger) treatments. Our results showed that the application of Hb increased the oxidative damage and decreased the NO level, but had no significant effect on GSH contents in the leaves of salt-stressed tomato seedlings. Exogenous GSH application significantly increased the contents of GSH and NO and the activities of nitrate reductase(NR), monodehydroascorbate reductase(MDHAR), superoxide dismutase(SOD)(except 72 h), and catalase(CAT)(except 48 h) during the whole sampling period, as well as the activities of glutathione reductase(GR), ascorbate peroxidase(APX) and dehydroascorbate reductase(DHAR) at 48 and 72 h after treatments, and decreased the electrolyte permeability, the contents of thiobarbituric acid reactive substance(TBARS) and hydrogen peroxide(H_2O_2) during the whole sampling period and superoxide anion(O_2ˉ·) at 48 and 72 h in leaves of salt-stressed tomato seedlings. The application of GSH also significantly increased the levels of GSH, ascorbic acid(AsA) and NO, the activities of CAT and APX at all three sampling dates, and the activities of NR at 24 and 48 h and nitric oxide synthase(NOS) at 48 and 72 h, and decreased the electrolyte permeability and the contents of TBARS and H_2O_2 in leaves of tomato seedlings under NaCl+Hb treatment. These results indicate that exogenous GSH could alleviate the oxidative damage induced by NaCl or NaCl+Hb treatments by up-regulating the levels of GSH and NO, and increasing the activities of antioxidant enzymes and the ROS scavenging capacity. In conclusion, NO is involved in the regulation of antioxidant defense capacity against salt stress in tomato seedlings by exogenous GSH.
【Fund】： 国家自然科学基金(31360478);; 兵团国际合作项目(2014BC002)~~
【CateGory Index】： S641.2
【CateGory Index】： S641.2