Effect of exogenous nitric oxide on seedling growth and physiological characteristics of maize seedlings under cadmium stress

The present study was conducted in pot to investigate the effects of exogenous nitric oxide(NO) on the membrane lipid permeability,osmotic adjustment substances,antioxidant enzyme activities and chlorophyll content of maize seedling under cadmium stress.The results showed that: compared with the CK,under 100 mg/L Cd2+ stress,proline and chlorophyll content were decreased,the accumulation of soluble protein and soluble sugar content were slowly accumulated,and the antioxidant enzymes activities were decreased,but MDA content,O2-·generation rate and membrane permeability were increased.Compared with 100 mg/L Cd,100 μmol/L SNP(sodium nitroprusside)significantly increased biomass amoun and improved the activity of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT),increased the content of chlorophyll and proline(Pro),and promoted the accumulation of soluble sugar and soluble protein content,but reduced MDA content,the rate of accumulation of O2-·and cell membrane permeability.The results indicated that exogenous nitric oxide had a significantly effect on the growth of seedlings under 100 mg/L Cd2+ stress,and enhanced the resistance of maize seedling to Cd toxicity.