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

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.