水稻茉莉酸合成基因OsAOS1在稻瘟病抗性中的功能分析

Functional Analysis of Rice Jasmonic Acid Synthesis Gene OsAOS1 in Rice Blast Resistance

稻瘟病是水稻生产中的三大病害之一。为探究水稻丙二烯氧化物合成酶基因(Allene Oxide Synthase,OsAOS1)在水稻诱导抗稻瘟病反应中的作用,采用稻瘟病菌(Magnaporthe oryzae)喷雾接种法和叶鞘接种法对突变体osaos1进行了稻瘟病抗性鉴定,结果显示在突变体osaos1中病斑面积和侵染菌丝扩展较野生型明显增多。进一步利用实时定量PCR(quantitative real-time PCR,RT-qPCR)检测了OsAOS1在稻瘟病菌接种后的响应情况以及防卫相关基因在野生型和突变体osaos1中的表达差异,结果表明,OsAOS1的表达受稻瘟病菌诱导,且与野生型相比,突变体osaos1中防卫相关基因OsPR1a、OsPR1b、OsPR10与OsPAL1表达量均显著下调。此外,Os AOS1突变会导致几丁质诱导的ROS积累量降低以及基础免疫标记基因OsKS4和OsPAL的表达量降低。这些结果表明OsAOS1正向调控水稻对稻瘟病的抗性。

Rice blast is one of the three major diseases in rice production.In order to explore the role of rice allene oxide synthase gene(OsAOS1)in resistance against rice blast,Magnaporthe oryzae spray infection and leaf sheath inoculation assays were conducted with the osaos1 mutant.The results showed that mutant osaos1 is more susceptible than wild-type to rice blast.Quantitative real-time quantitative PCR(RT-qPCR)was used to detect the expression level of Os AOS1 gene after inoculation with M.oryzae in the wild-type rice plants and the expression levels of defense-related genes in the wild-type and osaos1.Compared with wild-type,the expression of defense related genes,including OsPR1a,OsPR1b,OsPR10 and OsPAL1,were all significantly lower in the osaos1.In addition,mutation in Os AOS1 leads to decreased chitin-induced ROS accumulation and expression of the basal immunity marker genes OsKS4 and Os PAL.All these results suggested that OsAOS1 positively regulates the resistance of rice against rice blast.