水杨酸对镉胁迫下葡萄根系质膜ATPase和自由基的影响

【目的】研究水杨酸对镉胁迫下葡萄根系特性的影响,探讨缓解葡萄镉伤害的途径。【方法】以‘泽香’葡萄扦插苗为试材,在水培条件下,研究水杨酸预处理对氯化镉胁迫下葡萄根系活力、质膜H+-ATPase和Ca2+-ATPase活性以及活性氧和一氧化氮(NO)生成的影响。【结果】0.10mmol·L-1氯化镉能够提高根系活力和质膜Ca2+-ATPase活性;1.0mmol·L-1氯化镉明显促进根系超氧阴离子()、H2O2和NO的生成,显著抑制根系活力及质膜H+-ATPase和Ca2+-ATPase活性。50μmol·L-1水杨酸显著降低1.0mmol·L-1氯化镉处理下根系、H2O2和NO的生成,阻止根系活力及质膜H+-ATPase和Ca2+-ATPase活性下降,而随着浓度升高至200μmol·L-1,水杨酸的这种作用减弱。【结论】水杨酸缓解葡萄根系镉伤害的适宜浓度为50μmol·L-1;在该浓度下,水杨酸通过降低镉胁迫下自由基的产生而减轻镉对葡萄根系活力和质膜ATPase的损伤。

Effects of Salicylic Acid on Plasma Membrane ATPase and Free Radical of Grape Root Under Cadmium Stress

Objective] To explore the effect of salicylic acid (SA) on cadmium stress and the pathway of alleviating cadmium damage to grapes roots. Method] The experiment was carded out with the cutting seedlings of Zexiang grape pretreated by salicylic acid under CdCl_2 stress via hydroponics. The .activity of root, the activity of H~+-ATPase and Ca~(2+)-ATPase in plasma membrane (PM), and the formation of reactive oxygen species and nitric oxide (NO) were determine. Result] The 0.01 mmol·L~(-1)CdCl~2 increased the activity of root and PM Ca~(2+)-ATPase. 1.0 mmol·L~(-1) CdCl_2 promoted the formation of O_2~(-·), H_2O_2 and NO, and inhibited significantly root activity and the activity of H~+-ATPase and Ca~(2+)-ATPase in PM. Pretreatment of SA at 50 μmol·L~(-1) greatlydecreased the formation of O_2~(-·), H_2O_2 and NO, which retarded the declining of root activity and the activity of H~+-ATPase and Ca~(2+)-ATPase in PM under 1.0 mmol·L~(-1) CdCl_2 treatment. This effect of SA on roots decreased when SA concentration was raised to 200 μmol·L~(-1). Conclusion] It was found that SA at 50 μmol·L~(-1) is the optimal concentration for Alleviation of the damage of cadmium on grape roots, and at this concentration, SA mitigated the injurious effects of cadmium on root activity and PM ATPase in roots of grape by inhibiting the formation of free radicals.