MAIZE (Zea mays L.) PLANT RESPONSES TO EXCESS COPPER, CADMIUM, COBALT, LEAD AND CHROMIUM

Abstract

The effect of heavy metals (Cu, Cd, Co, Pb, and Cr) on Zea mays L. plant was investigated with pot trial under glasshouse conditions. Heavy metals were applied at two concentrations, and treatments consisted of Cu at 250 and 500; Cd at 25 and 50; Co at 100 and 200; Pb at 250 and 500; Cr at 50 and 100 (as mu M); and a control with nutrient solution. Although the treatment with heavy metals significantly decreased fresh and dry weights of shoot and root, and it also increased soluble protein and antioxidative enzyme activities when compared to control plants. The concentrations of Cu (500 mu M), Co (200 mu M), and Cu (250 mu M) largely increased proline content, EC%, and total chlorophyll content of leaves, respectively. Heavy metals treatment resulted in an increase in heavy metal contents in leaf and root tissues Furthermore, it also increased macronutrient contents in the leaves (except K+) and roots (except Ca2+ and K+).