Effects of Zn stress on antioxidant enzyme activity in Lemna polyrrhiza L.

Abstract

The effect of deleterious concentration of zinc provided individually was investigated in order to assess the effect of metal interaction in Lemna polyrrhiza L. The present study also emphasizes on the response of catalase and guaiacol peroxidase enzymes under zinc stress. Both antioxidant enzymes exhibited an increasing trend under different treatment conditions but it was reverse at highly toxic metal concentration. The antioxidant activities of enzymes, i.e of catalase, ascorbate peroxidase, guaiacol peroxidase and their activity proportions were examined. Catalase activities were substantially increased in a stress environment as compared to guaiacol peroxidase. Further, catalase and showed increased activities in a combined stress environment. Physiological role of these enzymes in stress tolerance mechanism is discussed. The response of Lemna polyrrhiza L to toxic concentrations of Zn appears to induce oxidative damage as observed by the increase antioxidant metabolism.

Keywords

• Antioxidant
• ascorbate peroxidase
• catalase
• enzyme activity
• glutathione reductase
• guaiacol peroxidase