Effect of exogenous nitric oxide on seed germination and physiological characteristics of Brassica napus

The aim of this research was to investigate the effects of exogenous NO on seed germination, seedling growth, and other physiological characteristics of Brassica napus under PEG stresses. The results indicate that the damages to Brassica napus caused by the stress of 10% PEG were significantly alleviated in the presence of 25μM SNP: the seed germination rate increased by 35.3%; the plant height, main root length and the number of adventitious roots increased by 14.26%, 6.1% and 35.76%, respectively; the protective enzyme activities of CAT and APX increased by 69.25% and 53.95%; the level of MDA decreased by 31.87%; the chlorophyll content increased by 62.5%. When SNP was increased to 100μM, a diminishing stimulative effect was observed and the oxidative damage to leaves sustained. Based on the data reported, we conclude that to some extent SNP can alleviate inhibitory effect under PEG stresses effectively and stimulates Brassica napus seed germination and seedling growth. SNP can also regulate the activity of protective enzymes and relief oxidative damages.