Zinc toxicity on antioxidative response in (Zea mays L.) at two different pH

Zn is the second most abundant transition metal after iron (Fe). Excess Zn can have negative effects on plants. The effect of Zn at two different pH on lipid peroxidation (MDA), membrane permeability (EC), hydrogen peroxide (H2O2),non-protein thiols (NPT) and the activities of major antioxidant enzymes Zea mays were investigated under controlled growth conditions. Zn-excess conditions increased the EC, MDA, H2O2 content and non-protein thiols and also activities of antioxidant enzymes were increased. Also zinc toxicity was higher in 4.5 pH than 7.5 pH.