外源NO对Cu^(2+)胁迫下小桐子幼苗抗氧化能力的影响

Effects of Exogenous NO on Antioxidant Ability of Jatropha curcas L.under Cu^(2+) Stress

为探讨外源一氧化氮(NO)供体硝普钠(SNP)对铜(Cu2+)胁迫的缓解效应,该试验以小桐子幼苗为材料,先通过小桐子幼苗根茎生长指标的变化筛选出后续实验适宜的SNP(0.2mmol/L)和Cu2+浓度(90mmol/L),再进一步考察SNP预处理对Cu2+胁迫下幼苗脯氨酸(Pro)和丙二醛(MDA)的含量及抗氧化酶活性的影响。结果显示:(1)Cu2+处理能诱导小桐子幼苗叶片中Pro和MDA含量显著升高,且过氧化氢酶(CAT)、超氧物歧化酶(SOD)、愈创木酚过氧化物酶(POD)及抗坏血酸专一性过氧化物酶(APX)的活性增强。(2)用SNP预处理能显著提高Cu2+胁迫下幼苗叶片Pro的含量,进一步增强叶片中CAT、SOD、POD和APX活性,降低MDA的含量。研究表明,0.2mmol/L的SNP能够通过提高小桐子幼苗的抗氧化酶活性和游离脯氨酸含量来增强其抗氧化胁迫能力,从而显著缓解Cu2+胁迫对幼苗造成的氧化伤害,维持其正常生长发育。

In order to investigate the relief effect of exogenous nitric oxide donor sodium nitroprusside on plants under copper stress,Jatropha curcas was chosen.The effects of different concentrations of SNP and CuCl2 on the growth of J.curcas seedlings were investigated and the appropriate concentrations of SNP （0.2 mmol/L） and 2＋ （90 mmol/L） were selected.Then the effects of SNP on the contents of proline,malondialdehyde and antioxidant enzyme activities under 2＋ stress were studied.The results showed that：（1）2＋ treatments increased the contents of proline and MDA,the activities of catalase （CAT）,superoxide dismutase （SOD）,guaiacol peroxidase （POD） and ascorbic acid specificity peroxidase （APX）.（2）The pretreatment with SNP could further enhance the content of proline（Pro）,the activities of CAT,SOD,POD and APX,decrease the MDA content under 2＋ stress in seedling leaves.In general,0.2 mmol/L SNP can markedly relieve the oxidative stress by increasing the antioxidative enzymes’ activities and the free proline content,enhancing antioxidative ability of J.curcas seedlings under 2＋ stress.