Biochimie et physiologie : accès libre

Abstrait

Effect of Metal Stress due to Strontium and The Mechanisms of Tolerating it by Amaranthus caudatus L.

Ramasubramanian Venkatachalam

Heavy metals are major environmental pollutants when present in high concentration in soil and have toxic effects on growth and development of plants. Experiment were carried out to find out the effect of different levels of strontium element commonly used in the fireworks – cottage industries of this area and the predominant pollutant on growth, biochemical and enzymatic characteristics of Amaranthus caudatus L. widely cultivated in this area. This study is aimed at assessing the stress tolerant ability of Amaranthus caudatus L. The seedlings of Amanranthus caudatus L. were treated with various concentration of strontium (2 mM, 4 mM, 6 mM, 8 mM, 10 mM) for ten days and its effect on the morphometric, biochemical and enzymatic characters were analyzed. After ten days of treatment, the growth parameters such as leaf area, fresh weight, dry weight, shoot and root length were found decreased than in the control. Biochemical characteristics such as the content of chlorophyll, carotenoid, soluble sugar and protein also decreased with the increase in the concentration of strontium. In contrary, the content of free amino acid, proline, leaf nitrate and the activities of anti-oxidative enzymes such as catalase and peroxidase were found increased with the increase in the concentration of strontium while the activity of nitrate reductase was found decreased. The result suggest that Amaranthus caudatus L. has been affected adversely by metal stress due to strontium but at the same time the plant adopts mechanisms such as accumulation of anthocyanin and enhanced activities of antioxidant enzymes to overcome the ill effects of the metal ions.