Reducing Arsenic Toxicity Stress in Soybean (Glycine max L.) by Using of Sodium Nitroprusside

Arsenic contamination is one of the most important compounds all over the world. Arsenic in different ways, including the formation of reactive oxygen species and membrane lipid peroxidation impairs growth of plants. In this study, the effect of arsenic and sodium nitroprusside (SNP) were evaluated on soybean. Soybean at four leaf stage was treated with different concentrations of arsenic (0, 150 and 300 mM) and SNP (0 and 100 mM), and then concentrations of hydrogen peroxide, proline, malondialdehyde and activity of antioxidant enzymes in its shoot were measured. The results showed that increasing concentration of arsenic in Hoagland solution reduced total chlorophyll content in the shoot and increased the activity of catalase and peroxidase significantly. It was also observed that treating plants with arsenic increased hydrogen peroxid accumulation which resulted in peroxidation of membrane lipids. Higher malondialdehyde content confirmed this result. Using SNP in the medium containing arsenic increased total chlorophyll content, activities of guaiacol peroxidase enzyme and ascorbate peroxidase, significantly. However, the catalase activity in this case decreased. Thus it can be concluded that using SNP, would reduce effectively the damage of oxidation.