Ameliorating Effects of Exogenous Nitric Oxide on Festuca arundinacea under Cadmium Stress

In order to discuss the regulatory mechanism of nitric oxide(NO) on Festuca arundinacea physiological response under Cd stress,a hydroponic experiment was conducted to investigate the effects of different concentrations of sodium nitroprusside(SNP,NO donor) on the physiological performance of F.arundinacea under 100μmol·L~(-1) CdCl_2 stress.These physiological performances included the growth,photosynthetic characteristics and mineral element contents of F.arundinacea.The results showed that exogenous SNP not only significantly increased the NO contents of leaves,plant dry weight,root growth rate and root activity of F.arundinacea under Cd stress;but also increased leaf chlorophylls and carotenoids contents,net photosynthetic rate(P_n,PS Ⅱ maximum photochemical efficiency(F_vF_m).In addition,SNP significantly enhanced the calcium(Ca),magnesium(Mg),iron(Fe),zinc(Zn) contents of shoots and roots,inhibited the transportation of Cd from root to shoot.These results showed that adding exogenous nitric oxide could increase the resistance of F.arundinacea under Cd stress.Comprehensive view of the indicators indicated that 100μmol·L~(-1) SNP had the best effect on improving photosynthetic activity and maintaining the mineral nutrition balance,then the inhibition of photosynthesis caused by Cd stress was alleviated and the tolerance of F.arundinacea increased.