Nitric oxide effect on proline, soluble sugars and activity of antioxidant enzymes in Pb stress terms in Brassica napus L.

Lead Stress is one of the most important environmental stresses that limit plant growth. Nitric oxide (NO) in signal transduction and biological and abiotic stress response is involved. In this study, the effect of nitric oxide of lead stress on proline, soluble sugars and activities of antioxidant enzymes in 401 Hyola canola plants in hydroponic culture using Hoagland solution was investigated in roots and shoots. Statistical analysis using SPSS and the comparisons were performed using Duncan. Three levels of lead by Pb(NO3)2 [0, 100 and 200 µM] and two levels of NO by sodium nitroprusside [0 and 100 µM] took place. Lead to mild stress, root proline increased significantly and NO increases the plant adaptation to the environment. Soluble sugars in roots and shoots were not significantly increased. Peroxidase enzyme activity was significantly reduced in all treatments, roots and shoots. CAT activity in shoots under stress conditions lead to significantly reduced but Root catalase activity did not change significantly. Peroxidase and catalase enzyme activity loss can be caused by the activity of NO as an antioxidant.