Ameliorating Effects of Exogenous Nitric Oxide on Ryegrass Seedlings under Cadmium Stress

The aim of the experiment was to study the ameliorating effects of exogenous nitric oxide on growth of ryegrass seedlings under cadmium stress.A hydroponic experiment was conducted to investigate the effects of different concentrations of sodium nitroprusside(SNP),a NO donor,on physiological characteristics of ryegrass under 100 μmol/L CdCl2 stress.The results showed that exogenous sodium nitroprusside(SNP) significantly alleviated the stress damage to ryegrass under 100 μmol/L CdCl2 stress,and increased the growth amount,the contents of chlorophyll and proline,the net photosynthetic rate(Pn),the transpiration rate(Tr),the stomata conductance(Gs),reduced H2O2 content,O2·-generation rate,intercellular CO2 concentration(Ci),significantly inhibit the transportation of Cd from root to shoot.When treated with 50 or 200 or 400 μmol/L of SNP,ameliorating effects on ryegrass were obviously decreased compared with 100 μmol/L of SNP treatment.It is proposed that exogenous NO as chemical activator could induce stress resistance,and alleviate damage degree of Cd stress to ryegrass seedlings.