Influence of Salicylic Acid(SA) on Cold Resistance of Wheat Seedling

[Objective] The study aimed to explore the influence and mechanism of salicylic acid(SA) on cold resistance of wheat seedling.[Method] With a wheat variety Zhengmai 9023 as tested material,0.1 mmol/L SA was sprayed on wheat leaves with water as CK.When the first leaf of wheat was open,each half seedlings of each group was cultured under normal temperature(20 ℃) and low temperature(4 ℃) resp.After 5 days,the physical indexes of cold resistance were measured on wheat seedlings.[Result] The activity of SOD enzyme of wheat seedling under low temperature stress was significantly increased by the treatment with 0.1mmol/L SA.Compared with CK wheat seedlings treated with low temperature,the activity of SOD enzyme and content of praline in the wheat seedlings treated with 0.1mmol/L SA under low temperature stress was increased by 10.95% and 42.80% resp,while content of MDA and membrane permeability was decreased by 5.0% and 6.0% resp.[Conclusion] SA could significantly increase the activity of SOD enzyme and the content of praline,decrease the content of MDA,reduce the cell damage caused by low temperature and enhance cold resistance of wheat seedling.