外源一氧化氮对铬胁迫下小麦幼苗根系生长和抗氧化能力的影响

Effects of exogenous nitric oxide on the growth and antioxidant ability of wheat seedling roots under Cr^(6+) stress

研究了在40mg/L Cr6+胁迫下,0.1～1.0mmol/L外源NO供体硝普钠(SNP)处理对小麦幼苗根系生长、氧化损伤、保护酶活性及可溶性糖含量的影响.结果表明,0.2mmol/L SNP处理缓解Cr6+胁迫伤害的效果最好,显著提高了小麦幼苗根系生长,保护酶SOD、POD、CAT活性和可溶性糖含量;显著降低了MDA含量.表明外源NO通过促进Cr6+胁迫下保护酶活性和渗透调节物质的提高,降低MDA水平,缓解Cr6+胁迫对小麦幼苗根系生长的抑制作用,增强植株的耐重金属能力.

Under 40 mg/L Cr6＋ stress, the effects of sodium nitropprusside （SNP, an exogenous nitric oxide donor） at the concentrations of 0.1-~1.0 mmol/L on the growth, oxidative damage, protective enzymatic activities and soluable sugar content in wheat seedling roots were investigated. The results showed that the best effect on the alleviation of Cr6＋ stress damage was observed in the treatment of 0.9 mmol/L SNP. At this concentration, the growth, activities of protective enzymes （including SOD, POD and CAT） and soluble sugar content of seedling roots were significantly increased, while malondialdehyde （MDA） content in roots was significantly decreased. The results suggest that NO enhances the tolerant ability of wheat seedlings to Cr6＋ stress via increasing the activities of protective enzymes and the contents of osmotic adjustment substances.