外源NO对NaCl胁迫下紫花苜蓿种子萌发及幼苗氧化损伤的影响  

Effects of exogenous nitric oxide on seed germination and seedling oxidative damage in Medicago sativa under NaCl stress

作　　者：徐严[1,2] 魏小红[1] 李兵兵[1] 曹丽[1] 唐志敏 

机构地区：[1]甘肃农业大学生命科学技术学院,甘肃兰州730070 [2]郴州市农业科学研究所,湖南郴州423042

出　　处：《草业学报》2013年第5期145-153,共9页Acta Prataculturae Sinica

基　　金：澳大利亚援助局资助项目(072-036007)资助

摘　　要：1)利用浓度分别为0.1和1.0mmol/L的外源NO供体硝普钠(sodium nitroprusside,SNP)浸泡紫花苜蓿种子48h。在(25±1)℃下将每批50粒种子置于培养皿进行恒温光照培养,重复3次,连续10d在培养皿中加入6mL 0.15%NaCl处理液并统计日发芽率,以探讨NO对NaCl胁迫下紫花苜蓿种子萌发的影响。2)利用0.1和1.0mmol/L浓度的外源NO供体SNP处理0.15%NaCl胁迫下的紫花苜蓿幼苗。试验设计了4个处理,分别为T1:对照组(CK)为蒸馏水;T2:0.15%NaCl;T3:0.1mmol/L SNP+0.15%NaCl;T4:1.0mmol/L SNP+0.15%NaCl。每个处理重复3次。分别于0(胁迫前),2,4,6和8d后采集生长状况一致的幼苗叶片测定游离脯氨酸含量、丙二醛(malondialdehyde,MDA)含量、过氧化氢(H2O2)含量、O2-产生速率、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)、超氧化物歧化酶(superoxide dismutase,SOD)、叶绿素含量、可溶性糖含量。以探讨NO对NaCl胁迫下的紫花苜蓿幼苗叶片抗氧化系统的影响。结果表明,外源NO可以缓解NaCl胁迫对紫花苜蓿种子萌发的抑制作用,促进NaCl胁迫下紫花苜蓿种子活力,促进脯氨酸和可溶性糖含量的积累,能缓解NaCl胁迫引起的膜脂过氧化产物MDA含量的增加、缓解活性氧代谢引发的H2O2含量的增加及叶绿素的降解,抑制O2-产生速率,提高SOD、POD、CAT的活性。这种保护效应与NO的浓度明显相关,0.1mmol/L SNP处理效果显著优于1.0mmol/L SNP处理。1） Medicago sativa seeds were soaked in two concentrations （0.1 and 1.0 retool/L） of sodium nitro- prusside （SNP） for 48 h. Samples of 50 seeds taken on 10 consecutive days were cultured in dishes under condi- tions of constant light and temperature at （25±1）℃. NaC1 solution （6 mL 0.15%） was added to investigate the effects of exogenous nitric oxide on seed germination under NaCI stress. 2） The influence of the exogenous ni- tric oxide donor （SNP） at concentrations of 0.1 and 1.0 mmol/L on M. sativa seedling leaf oxidative damage under 0.15% NaC1 stress were studied for 8 days of treatment. The treatments were, TI： CK （distilled wa- ter） ; T2： 0.15% NaC1; T3：0.1 mmol/L SNP＋0.15% NaC1; T4：1.0 mmol/L SNP＋0.15%0 NaC1. The re- sults indicated that germination rate （P〈0.01）, germination energy, germination index （P〈0.05） and vigor index （P〈0.05） of M. sativa seeds were dramatically promoted by SNP treatments during germination under 0.15% NaC1 stress. The activities of antioxidant enzymes such as superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT）, were increased, which is consistent with the up-regulation of proline and soluble sugars, and with the down-regulation of 02 production, speed and content of malondialdehyde （MDA）, H2 02 and chlorophyll in M. sativa seedling leaves compared with those under salt stress. Meanwhile, the protective ability of concentrations of 0.1 mmol/L was significantly better than those of 1.0 mmol/L.

关 键 词：外源NO 紫花苜蓿 NACL胁迫 种子萌发 氧化损伤 

分 类 号：S541.9[农业科学—作物学]