水杨酸对小麦幼苗抗寒性的影响

目的]探讨水杨酸(SA)对小麦幼苗抗寒性的影响及其机理。方法]以小麦品种郑麦9023为试材,用0.1 mmol/LSA作叶面喷施处理,清水作对照,当小麦幼苗第1片叶展开时,将各组各1/2幼苗分别置于常温(20℃)和低温(4℃)下培养,5 d后对小麦幼苗进行耐寒生理指标测定。结果]0.1 mmol/LSA显著提高了低温胁迫下小麦幼苗细胞内SOD酶的活性。与低温对照处理的小麦幼苗相比,低温胁迫下0.1 mmol/L SA处理的小麦幼苗的SOD酶活力提高了10.95%,脯氨酸含量增加了42.80%;MDA含量减少了5.00%,膜透性降低了6.00%。结论]SA显著提高小麦幼苗细胞内SOD酶的活性,增加脯氨酸含量,降低MDA含量,减少了低温对细胞的伤害,增强了小麦幼苗的抗寒性。

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.