Effect of Exogenous Nitric Oxide on Seedling Growth and Physiological Characteristics of Wheat under Drought Stress

[Objective] The propose was to study the effect of exogenous nitric oxide(NO) on seedling growth,leaf photosynthetic characteristics and leaf oxidative damage of wheat under drought stress.[Method] With the seedlings of Mianyang 26 with two fully expanded leaves as tested materials,their roots were treated with 10% PEG 6000 solution in combination of adding the exogenous NO donor sodium nitroprusside(SNP) with different concn.(0.01,0.05 and 0.1 mm/mol) for 8 days to study the effect of the exogenous NO on seedling growth and physiological characteristics of wheat under drought stress.[Result] Under drought stress 0.05 mm/mol SNP could reduced the MDA content and the producing rate of superoxide radical(O2-) in wheat seedling obviously and increase the content of chlorophyll b,carotenoids,chlorophyll(a+b) and plant height,root length,leaf area and dry weight in wheat significantly,suggesting that the treatment with 0.05 mm/mol SNP had obvious protective function on the wheat seedling and promote the seedling growth under drought stress.[Conclusion] The exogenous NO donor could relieve the membrane lipid peroxidation of wheat leaf caused by drought stress,thus increasing the ability of drought resistance in wheat.