以郑单958玉米（ Zea mays ）为试验对象，采用盆栽试验方法，分别用0．01、0．05、0．1、0．5 mmol·L－1和1．0 mmol·L－1的外源一氧化氮（NO）供体硝普钠（Sodium nitroprusside ，SNP）对干旱胁迫下玉米幼苗进行浇灌处理，研究外源NO对干旱胁迫下玉米幼苗膜脂过氧化的影响。结果表明，适当浓度（0．05 mmol·L－1）的外源NO可缓解干旱胁迫对玉米幼苗造成的损伤，与单独干旱胁迫相比，显著提高超氧化物歧化酶（SOD ）和过氧化氢酶（CAT ）等保护酶活性，分别增加了23．89％和87．78％；脯氨酸、可溶性糖、可溶性蛋白和叶绿素的含量分别增加23．89％、87．78％、43．44％、39．84％、41．33％和21．45％；MDA含量和质膜透性分别下降11．76％和51．17％。说明适当浓度的外源NO可以缓解干旱胁迫对玉米幼苗生长的抑制效应。%In order to explore the influences of oxidative damage by nitric oxide (NO ) on maize seedlings under drought stress ,a pot experiment to investigate the effects of exogenous nitric oxide donors (sodium nitroprusside ,SNP) at concentrations of 0 .01 ,0 .05 ,0 .1 ,0 .5 mmol·L-1 and 1 .0 mmol·L-1 on membrane lipid peroxidation was carried out using Zhengdan 958 as experimental material .The results showed that appropriate concentration (0 .05 mmol·L-1 ) of exogenous NO could relieve the damage from drought stress , significantly improving the activity of protective enzymes SOD and CAT .Compared with those under drought stress ,the SOD and CAT activities were increased by 23 .89% and 87 .78% ,respectively . Proline , soluble sugar , soluble protein and chlorophyll content were increased by 23 .89% , 87 .78% ,43 .44% ,39 .84% ,41 .33% and 21 .45% ,respectively .However ,MDA content and membrane permeabil-ity were significantly reduced by 11 .76% and 51 .17% ,respectively .There were dosage effects of exogenous nitric oxide donor (SNP) on alleviation of drought stress in maize seedlings ,which significantly enhanced the drought tolerance of maize seedlings .
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