外源谷胱甘肽（GSH）对水鳖Zn2+毒害的缓解作用

AUeviatory Effect of Exogenous Glutathione （GSH） on Hydrocharis dubia Toxicated by Zn2+

摘要:

研究在10 mg L^-1Zn²⁺毒害下外施10-50mgL^-1梯度浓度的还原型谷胱甘肽（GSH）对水鳖（Hydrocharis dubia）的保护酶（SOD、CAT、POD）活性、GSH、可溶性蛋白质、叶绿素、H₂O₂含量以及O₂·-产生速率的影响。结果表明，相对单一的Zn²⁺毒害，施用外源GSH可明显减轻毒害症状，植物体内GSH含量增加了10.71％-35.71％，O₂·-的产生速率最低降至78.2％，H₂O₂含量最低降至62.7％。植物体内可溶性蛋白含量和CAT、SOD、POD的活性最大分别增加了74.2％、108.2％、61.4％、19.5％。随GSH浓度增大，缓解能力下降，在培养液中最佳缓解浓度为20-40 mg L^-1。

Abstract:

The effect of 10 mg L^-1 Zn²⁺ together with various concentrations of glutathione （GSH） on the changes in activity of protective enzymes （ SOD, CAT, POD）, generation rate of O₂·-, and the contents of GSH, soluble protein, chlorophyll and H₂O₂ in leaves of Hydrocharis dubia were determined. The results showed that the addition of endogenous GSH in treatments obviously increased the content of GSH in leaves by 10.71% to 35.71%, generation rate of O₂·- was lowered to 78.2% and H₂O₂ was scavenged to 62.7% as compared to the treatment with 10 mg L^-1 Zn²⁺ alone without GSH. The content of soluble protein increased at most by 74.2%, and the activities of CAT, SOD, POD increased at most by 108.2%, 61.4%, 19.5%, respectively. It is obvious that GSH relieve the toxic of Zn²⁺ to some extent. The most effective concentrations of GSH against Zn²⁺ stress are 20-40 mg L^-1 in culture solution.