The effect of nitric oxide on seed germination and activities of some antioxidant enzymes in sesame under salt stress

The present experiment was aimed to investigate the effect of nitric oxide derived from sodium nitroprusside on sesame germination and some antioxidant enzymes activity under salinity stress in factorial manner and completely randomized design with three replications in seed research laboratory of Research Station in Eastern Iran (Kashmar). Treatments included seed pretreatment with sodium nitroprusside in six levels (zero, distilled water, 50, 100, 150 and 200 mM) and salinity stress at three levels (0, 50 and 100 mM l). The results showed that salt stress decreased germination rate, shoot and root length and dry weight and also were increase the activity of antioxidant enzymes superoxide dismutase, ascorbate peroxidase and glutathione reductase in sesame. Pretreatment seeds with SNP were increased seed germination, root and shoot length and weight. The enzyme activity of superoxide dismutase, glutathione reductase and ascorbate peroxidase treated with nitric oxide were increased, while catalase activity and the content of malondialdehyde as the index fell membrane degradation were decreased. In general, suitable and efficient concentration to reduce the effects of salinity on plant seeds in this experiment was 150 mM, because in this concentration was found the highest germination rate and dry weight of shoot and root. It also seems to concentrations above 150 mM sodium nitroprusside, toxic effects on the cells induce nitric oxide.