外源一氧化氮对干旱胁迫小麦幼苗生长和生理特性的影响

[目的]研究外源NO对干旱胁迫下小麦幼苗生长、叶片光合特性以及叶片氧化损伤的影响。[方法]以绵阳26号二叶一心期的小麦幼苗为试材,采用10%的聚乙二醇6000对幼苗根部进行轻度干旱胁迫处理8d,并添加不同浓度(0.01,0.05and0.1mm/mol)的一氧化氮(NO)供体硝普钠(SNP),研究外源NO处理对干旱胁迫下小麦幼苗生长和生理特性的影响[结果]0.05mm/molSNP能显著降低干旱胁迫下小麦幼苗丙二醛(MDA)含量和超氧自由基(O2-)产生速率,但能显著增加小麦幼苗叶绿素b、类胡萝卜素、叶绿素(a+b)含量及株高、根长、叶面积和干重,表明0.05mm/molSNP处理对干旱胁迫下小麦幼苗具有明显的保护作用,可以促进植株生长。[结论]外源低浓度NO供体可以明显缓解干旱胁迫所造成的小麦幼苗叶片膜脂过氧化,从而提高小麦抗旱能力。

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.