采用盆栽试验,研究了外源NO对镉(Cd)胁迫下玉米幼苗膜脂过氧化、渗透调节物质、抗氧化酶活性及叶绿素含量等生理特性的影响.结果表明,与对照比较,100 mg/L的Cd处理降低了玉米幼苗脯氨酸(Pro)和叶绿素含量,减缓了可溶性蛋白和可溶性糖含量的积累,抗氧化酶活性下降,丙二醛(MDA)含量和超氧阴离子(O2-)产生速率增加、质膜透性增大；与100 mg/L Cd处理比较,添加100 μmol/L硝普钠(SNP)处理显著增加了Cd胁迫下玉米幼苗生物量,提高了超氧化物歧化酶(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、细胞质膜的透性以及O2-产生的速率.因此,外源NO对Cd胁迫下玉米生长有一定的缓解作用,可以增强玉米幼苗对Cd毒害的抗性.%The present study was conducted in pot to investigate the effects of exogenous nitric oxide (NO) on the membrane lipid permeability, osmotic adjustment substances, antioxidant enzyme activities and chlorophyll content of maize seedling under cadmium stress. The results showed that; compared with the CK, under 100 mg/L Cd2+ stress, proline and chlorophyll content were decreased, the accumulation of soluble protein and soluble sugar content were slowly accumulated, and the antioxidant enzymes activities were decreased, but MDA content, O2- generation rate and membrane permeability were increased. Compared with 100 mg/L Cd, 100 μmol/L SNP (sodium nitroprusside)significantly increased biomass amoun and improved the activity of super-oxide dismutase (SOD), peroxidase (POD) and catalase (CAT) , increased the content of chlorophyll and pro-line (Pro) , and promoted the accumulation of soluble sugar and soluble protein content, but reduced MDA content, the rate of accumulation of O2- and cell membrane permeability. The results indicated that exogenous nitric oxide had a significantly effect on the growth of seedlings under 100 mg/L Cd2+ stress, and enhanced the resistance of maize seedling to Cd toxicity.
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