高温胁迫下一氧化氮和脱落酸的信号功能研究

Study on the Signal Function of NO and ABA under Heat Stress

[目的]研究高温胁迫下ABA和NO的信号功能及相互作用关系。[方法]以2种不同耐热性的芦苇愈伤组织为材料,用不同浓度ABA、SNP、fluridone、L-NNA、cPTIO预处理24 h后,将材料置于45℃高温胁迫2 h,研究2种芦苇的相对生长量、相对电导率、丙二醛含量以及NOS活性、内源ABA、NO含量的变化。[结果]外源ABA和NO处理可以明显地降低高温胁迫在2种芦苇中所引起的相对电导率和MDA含量的增加,显著地缓解氧化损伤,减轻生长受抑的程度。Fluridone、L-NNA和cPTIO处理对沼泽芦苇没有明显影响,但是可以明显促进沙丘芦苇的相对电导率和MDA含量的增加。高温胁迫可以诱导沙丘芦苇愈伤组织ABA和NO含量的显著增加,NOS活性也显著升高,但对沼泽芦苇没有明显影响。在沙丘芦苇中,外源ABA处理能够提高NOS活性,促进NO的释放;Fluridone处理则抑制高温胁迫下NOS活性的升高,并抑制NO释放量的增加,而SNP以及NO的清除剂cPTIO和NOS抑制剂L-NNA对ABA含量均无明显影响。[结论]ABA在高温胁迫下的抗性作用可能是通过NO实现的。

[Objective] The signal function of NO and ABA and the relationship between them were studied.[Method] Taking two different heat-tolerant reed healing tissue as materials,effects of 45 ℃ on dune reed（DR） calluse and swamp reed（SR） calluse pretreated by ABA,SNP,fluridone,L-NNA,cPTIO in different concentration for 24 hours were studied.[Result] Application of exogenous NO and ABA alleviated heat stress induced ion leakage increase,MDA accumulation and growth inhibition in two calluses.Treatments of fluridone,L-NNA and cPTIO had little influence on SR callus while obviously enhanced the increase of ion leakage and the accumulation of MDA in DR callus under heat stress.In DR callus,exogenous ABA increased the activity of NOS and enhanced NO release while fluridone treatment inhibited the activity of NOS and reduced NO release.But the treatment of cPTIO and L-NNA had no influence on ABA content.[Conclusion] NO might acted as an intermediate molecular mediating the protective effect of ABA.