水稻丙二烯氧化物合成酶基因OsAOS1的表达研究

茉莉酸(Jasmonate,JA)为植物病虫害抗性反应中重要的信号分子,茉莉酸类物质生物合成途径中的关键酶为丙二烯氧化物合成酶(Allene oxide synthase,AOS)。已知水稻AOS基因家族包括4个成员,Os-AOS1～OsAOS4。已有研究表明,水稻OsAOS2基因的过量表达提高了内源PR1基因的表达、增强了水稻对稻瘟病的抗性。本研究分析了OsAOS1基因表达的组织和器官特异性以及外源JA处理对OsAOS1基因表达的影响,同时利用转基因技术研究了OsAOS1基因在调控内源PR1基因表达中的作用。研究结果表明:OsAOS1基因表达的组织和器官特异性不同于OsAOS2基因;外源JA处理诱导OsAOS1基因的瞬时表达,然而OsAOS2基因的诱导表达延迟;OsAOS1过量表达抑制烟草中内源PR1基因的表达。据此推测OsAOS1基因可能不参与依赖于PR1的抗病反应。

Expression Analysis of Allene Oxide Synthase Gene, OsAOS1, in Rice

JA is an important signal molecule inducing resistance to pathogen infection.Allene oxide synthase(AOS) is a key enzyme in the biosynthesis of jasmonates(JAs).Rice AOS gene family is composed of 4 members,OsAOS1~OsAOS4.It has been reported that overexpression of OsAOS2 in rice increased the expression levels of endogenous PR1 genes and host resistance to M.grisea.In this work,the tissue-and organ-specific expression of OsAOS1 gene and effects of exogenous JA on the expression of OsAOS1 gene were investigated;the role of OsAOS1 gene in regulating the expressions of endogenous PR1 genes were analyzed by transgenic technology.The results showed that tissue-and organ-specificity of OsAOS1 gene expression was different from OsAOS2 gene.After treated with exogenous JA,OsAOS1 gene was transiently and rapidly induced,while OsAOS2 gene was delayed.The expressions of endogenous PR1 genes were repressed when OsAOS1 gene was overexpressed.It demonstrated that OsAOS1 gene probably didn't involve in the disease resistance depending on PR1 genes.