NITRIC OXIDE REGULATED IMPROVEMENT IN GROWTH AND YIELD OF RICE PLANTS GROWN UNDER SALINITY STRESS: ANTIOXIDANT DEFENSE SYSTEM

The current work assessed the effects of exogenously applied sodium nitroprusside (SNP) on rice growth and yield under salt stress. Salt stress induced a significant reduction in biomass and grain yield while increased the plant proline, ascorbic acid, H2O2 and MDA contents in all studied cultivars. SOD, POD and CAT activities also significantly increased in salt stressed plants; however, the total phenolics content decreased. Application of SNP as seed priming reduced the adverse effects of salinity on plant biomass production and grain yield, while the accumulation of MDA and H2O2 decreased. Of different SNP levels, 0.1 mM regime was more effective in reducing the negative effects of salinity. Among fine rice cultivars, Shaheen basmati performed better, while among coarse rice cultivars the performance of IRRI-6 was better to exogenously applied 0.1 mM SNP. We concluded that exogenous application of SNP up-regulated the antioxidative defense mechanism in salt stressed rice plants which resulted in better yield.