Interactive effects of Cr and Fe treatments on plants growth, nutrition and oxidative status in Zea mays L.

The effects of Cr and Fe, singly and in combination were investigated on nutrients uptake (Cu, Zn and Mn), lipid peroxidation, antioxidant enzymes, chlorophyll content and growth parameters in Zea mays L. var. Ruchi (SRHM 445). Roots of the Cr treated plants were stunted and root hair formation was greatly impaired. The leaves were bearing wilted appearance. Cr was primarily accumulated in the roots with a low translocation rate to the leaves. Cu absorption decreased with increase in Cr concentrations only in roots. In leaves there is no correlation. Iron induced lipid peroxidation was higher in the leaves at both the concentrations (3 and 9 μg ml−1) after 7 d, and decreased significantly by the addition of Cr. Concentrations of most leaves antioxidants were lower in mixed metal treatment compared to single treatments, indicating an interaction between metals leading to reduced cellular effects as indicated by lower lipid peroxidation levels. Changes in APX and GPX activities observed in the leaves of contaminated-plants suggest their involvement in heavy-metal stress tolerance. The plant seems to be tolerant as the translocation of Cr was recorded less, which decreased in the presence of Fe.