Membrane lipid peroxidation, free radical scavangers and ethylene evolution in Amaranthus as affected by lead and cadmium

Membrane lipid peroxidation, activity of free radical scavangers and ethylene evolution of Amaranthus lividus seedlings were used to determine the lead and cadmium (1, 10, 100 and 1000 µM) induced phytotoxicity. Malondialdehyde (MDA) accumulation and higher lipoxygenase activity (LOX) was found in the 7-d-old treated seedlings. The activities of free radical scavangers like peroxidase, catalase and superoxide dismutase declined considerably with the concomitant rise in hydrogen peroxide level. Heavy metal treatment also caused decline in ethylene evolution in germinating seedlings.