水杨酸对Zn^(2+)胁迫下小麦幼苗生理特性的影响

Effect of the Salicylic Acid on the Physiological Characteristics of Wheat Seedling under Zn^(2+) Stress

[目的]为预防小麦早期遭受Zn2+毒害探索新的途径。[方法]以小麦为试验材料,采用水培方法,研究不同浓度(10-6、10-5、10-4mol/L)水杨酸(SA)对Zn2+(5 mmol/L)胁迫小麦幼苗生理特性的影响,每处理3次重复。[结果]SA使Zn2+胁迫下小麦幼苗叶片和根中超氧化物歧化酶(SOD)、过氧化物酶(POD)活性显著增强,丙二醛(MDA)含量降低,叶片过氧化氢酶(CAT)活性提高。说明SA可诱导小麦幼苗抗Zn2+胁迫能力提高,缓解Zn2+胁迫所造成的伤害;且在5 mmol/L Zn2+胁迫条件下,以10-4mol/L SA处理效果最明显。[结论]Zn2+胁迫小麦初期对抗氧化酶具有激活效应,后期转为抑制效应;SA能提高小麦幼苗对Zn2+胁迫的抗性,缓解Zn2+胁迫对小麦的伤害。

[Objective] The new way of the prevention of early wheat seedling being poisoned by Zn^2＋ stress was explored.[Method] The effect of the salicylic acid（SA） with the different concentrations（10^-6,10^-5 and 10^-4 mol/L） on the physiological characteristics of the wheat seedling as testing material was studied with the method of the water culture containing Zn^2＋ of 5 mmol/L stress and each treatment with three replications.[Results] The activity of superoxide dismutase（SOD） and peroxidase（POD） in leaf and root of wheat seedling was significantly increased but the content of malondialdehyde（MDA） and the activity of catalase（CAT） in its leaf was increased through the treatment of salicylic acid under Zn^2＋ stress,which indicated that the SA could induce the resistance of wheat seedling to Zn^2＋ stress and relief its injury caused by Zn^2＋ stress.In the treatment of Zn^2＋ of 5 mmol/L,the effect of the SA of 10-4 mol/L was most obvious.[Conclusion] In the initial period of wheat seedling growth,its activation effect on the antioxidant enzyme under Zn^2＋stress of it could be arisen and in the latter,it was converted into inhibitory effect.The SA could improve the resistance of wheat seedling to Zn^2＋ stress and relief its injury caused by Zn^2＋ stress.