Comparative study on the effect of nitric oxide. c hromium and EDTA on oxidative stress responses in Agathi (Sesbania grandiflora L. pers)

Abstract

Heavy metal contaminations are a major cause of global environmental pollutions. The release of heavy metals into the environment has increased the threat of serious health issues for living organism. Among the known heavy metals, chromium is released into the environment by various anthropogenic activities causing various ill effects on the life forms. Hence in the present study which was carried out in Vellore Institute of Technology, Tamil Nadu, India and the phytoextraction of chromium enhanced with metal chelator ethylenediamine tetraacetic acid was studied in Sesbania grandiflora in VIT, India. To asses this, various treatments were prepared with combinations of chromium and chelator. The antioxidant enzyme activities such as Superoxide dismutase, Catalase, Ascorbate peroxidase and Glutathione reductase activity were determined in the presence of metal and chelator. The results showed an increase in all the antioxidant enzymes in the presence of metal and chelator due to the increased metal uptake. To reduce the stress levels created by the metal and chelator, sodium nitroprusside a nitric oxide donor was exogenously sprayed on to the plants and a comparative study was made in the presence and absence of sodium nitroprusside. The results indicated that the presence of sodium nitroprusside had a positive role in combating the stress created by the metal and chelator which was evident by the reduced antioxidant enzyme levels in spite of metal uptake. Hence sodium nitroprusside could be considered for its wider application against metal stress conditions to combat oxidative stress. The plant Sesbania grandiflora showed higher withstanding capacity to the heavy metal stress and was effective in extracting the metal out of the contaminated soil.