Accumulation of chromium and its effects on physiological and biochemical parameters of Alternanthera philoxeroides seedlings

Abstract

To assess the effects of different concentrations of chromium (25; 50; 100; 150 mg/l) in the plant, Alternanthera philoxeroides . Different concentrations of chromium (25; 50; 100; 150 mg/l) were applied for 12 days and assessed by measuring changes in the growth; photosynthetic pigments activities; and antioxidative enzymes: catalase (CAT); peroxidase (POD); ascorbate peroxidase (APX) and total soluble protein changes. Metabolic responses to chromium (Cr) exposure and metal uptake were also experimentated. It was found that chromium was accumulated in shoots and roots of A. philoxeroides . The shoots accumulated 111.27 mg Cr/g of their dry weight at 150 mg/l Cr concentration, while the roots accumulated 751.71 mg Cr/g. The photosynthetic pigment contents increased with the higher concentration of Cr. Both in shoots and roots Cr could induce rise of the activity of CAT; POD and APX. The total soluble protein contents also increased with the increased concentration of Cr. The results from the present experiments suggest that high concentrations of Cr cause oxidative damage as evidenced by increased antioxidative enzymes, photosynthetic pigments and changes in total soluble protein content. Induction of antioxidative enzymes could the reason for tolerating higher levels of metals by A. philoxeroides plants.