Biochemical Changes under Chromium Stress on Germinating Seedlings of Vigna radiata

Hexavalant chromium is considered the most toxic form because of its high solubility in water. Cr is known to induce production of elevated concentration of reactive oxygen species (ROS) resulted in macromolecule damage. Plants are having unique mechanisms to overcome ROS induced damage by accumulation of proline, ascorbate and glutathione and increasing the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and ascorbate peroxidaes (APX), peroxidise (POX). In the present investigation effects of chromium on seed germination of Mung bean (Vigna radiata 'Gujarat Mung-4’) were studied. Seeds were treated with different Cr concentrations (50, 100, 150 and 200 4M) for seven days. On 7th day root and shoot length was measured and activities of antioxidant enzyme SOD, APX, POX, CAT and GR were checked along with protein, proline and lipid peroxidation. It was observed that there is gradual decrease in shoot and root length with respect to the increase in Cr concentration. Level of lipid peroxidation significantly increased along with proline and antioxidant enzyme activity at higher Cr concentration. Lipid peroxidation is an indication of membrane damage due to elevated production of reactive oxygen species (ROS). To combat oxidative damage by ROS antioxidant enzyme activity increased significantly, which indicates that antioxidant enzymes (SOD, CAT, APX and GR) play a crucial role during Cr stress during germination of V. radiata.