水稻纹枯病菌RsCat基因的克隆及其表达分析

Cloning and expression analyses of RsCat in Rhizoctonia solani AG-1 IA

为阐明水稻纹枯病菌(Rhizoctonia solani AG-1IA)过氧化氢酶基因(RsCat)的功能,采用常规PCR和RT-PCR技术克隆得到RsCat基因。生物信息学分析表明,RsCat基因DNA和cDNA的全长序列分别为1814bp和1 395bp,开放阅读框(ORF)编码464个氨基酸。保守结构域分析显示,RsCat蛋白具有过氧化氢酶超家族结构域和过氧化氢酶相关免疫反应结构域。系统进化分析显示:水稻纹枯病菌不同融合群的RsCat基因具有较高的序列同源性。荧光定量PCR(qRT-PCR)分析表明:RsCat基因的表达受儿茶酚的诱导,随着儿茶酚质量浓度增大,表达量上调,而随着儿茶酚质量浓度增大,CAT活性降低。说明RsCat基因的转录表达和CAT酶活不存在对应性。推测RsCat基因可能存在转录后或表达产物翻译后修饰。

In order to elucidate the function of the catalase(CAT)gene(RsCat)in Rhizoctonia solani Kühn AG-1 IA,the causal agent of rice sheath blight,the gene was cloned with PCR and RT-PCR.Result of bioinformatics analysis showed that the full-length DNA and cDNA sequences of RsCat gene were 1 814 bp and 1 395 bp,with an open reading frame(ORF)encoding 464 amino acids.Result of conserved domain analysis showed that the RsCat protein has the domains of catalase-like super family with catalase-related immune-response.Result of phylogenetic tree analysis showed that the RsCat gene in different anastomosis groups(AGs)of R.solani has a high sequence homology.Result of quantitative real-time PCR(qRT-PCR)analysis showed that RsCat gene expression was induced by catechol.The expression levels of RsCat gene were up-regulated with the increase of catechol concentrations,whereas the activity of catalase(CAT)decreased with the increase of catechol concentrations,indicating that there is no corresponding between the transcriptional expression of RsCat gene and CAT activity.The RsCat gene may produce post transcriptional or post translational modifications.It will provide a foundation for further studying the regulatory mechanisms of melanin formation and ROS metabolism with RsCat of R.solani AG-1 IA.