外源一氧化氮对铅胁迫下玉米幼苗的缓解作用

Mitigative effects of exogenous nitric oxide on Pb^(2+) stress in maize seedlings

为探讨Pb胁迫下外源一氧化氮(NO)对玉米幼苗伤害的缓解作用,利用室内盆栽试验研究了外源NO供体硝普钠(SNP)对铅(Pb)处理下玉米(Zea mays)幼苗生长及生理特性的影响。结果表明:与对照相比,1.0mmol·L-1Pb处理明显抑制了玉米幼苗的生长,减缓了玉米幼苗可溶性蛋白和可溶性糖含量的积累,抗氧化酶活性下降,叶绿素含量减少,丙二醛(MDA)含量增加、质膜透性增大;添加0.1 mmol·L-1的SNP明显缓解了Pb胁迫对玉米幼苗生长的抑制作用,提高Pb胁迫下超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性,增加了幼苗叶绿素和脯氨酸含量,促进了可溶性糖和可溶性蛋白的积累,降低了MDA含量、细胞质膜的透性。外源NO对Pb胁迫下玉米生长有一定的缓解作用,可以增强玉米幼苗对Pb毒害的抗性。

The pot experiment was conducted to investigate the effects of exogenous nitric oxide（ NO） on the growth and physiological characteristics of maize（ Zea mays） seedlings under Pb2＋stress. The results demonstrated that,after treated with 1. 0 mmol·L-1Pb2＋,the growth of maize seedlings was inhibited,the accumulation of soluble protein and soluble sugar was slowed down,the activity of antioxidant enzymes and chlorophyll content were declined,while the MDA content and membrane permeability were increased. When 0. 1 mmol·L-1SNP was supplied,the inhibition effect of Pb2＋to the growth of seedlings was significantly relieved,the activity of superoxide dismutase（ SOD）,peroxidase（ POD） and catalase（ CAT） was increased,the content of chlorophyll and proline（ Pro） was increased,the accumulation of soluble sugar and soluble protein was promoted,and the MDA content and membrane permeability were declined.Therefore,exogenous NO has a significantly alleviatory effect on the growth of Pb2＋stressed maize seedlings,and may enhance the Pb2＋resistance of maize seedlings.