摘要： 谷子弯孢病菌(Cochliobolus lunatus)为谷子上重要的叶部病害,发生严重时会影响谷子的产量及品质。为了解MAPK级联途径在谷子弯孢病菌发育及致病性中的作用,根据已知植物病原真菌MAPK基因的保守结构域设计简并引物,通过PCR扩增法获得了谷子弯孢病菌MAPK基因的同源片段,并利用RACE技术获得了基因的全长cDNA序列,该基因命名为Clmk-1。Clmk-1基因开放阅读框为1065 bp,编码354个氨基酸,并且含有MAPK基因的保守的TGY和CD基序。聚类分析结果表明,谷子弯孢病菌Clmk-1基因与其他植物病原真菌Hog1类似MAPK基因的同源性很高。利用Promoterscan软件发现,Clmk-1基因启动子区含有热激转录因子(HSF)、ADR转录因子和GCR转录因子的结合元件。MAPK途径特异性抑制剂U0126抑制谷子弯孢的孢子萌发及芽管发育。研究初步表明,Clmk-1基因为Hog1类似MAPK基因,可能与渗透胁迫相关,并且MAPK级联途径参与病菌孢子萌发及芽管形态建成。克隆的Clmk-1基因为进一步研究谷子弯孢病菌MAPK基因的功能奠定基础。

关键词: 谷子弯孢病菌, MAPK基因, 基因克隆, U0126

Abstract: Cochliobolus lunatus，a fungal pathogen of foxtail millet leaf disease，affect the yield and quality when?it is epidemic. In order to understand the function of MAPK signal transduction in Cochliobolus lunatus ，a MAPK?gene was cloned by polymerase chain reaction(PCR)amplification from degenerated primer sets designed on the basis of the conserved domain of other fungal MAPK gene and the gene was called as Clmk-1. The full length cDNA?sequence of Clmk-1 in Cochliobolus lunatus was cloned by RACE methods. The Clmk-1 gene contains a 1065 bp?ORF and the deduced protein consist of 354 amino acid residues，which has the conserved TGY motif and the CD?motif. Phylogenetic analysis showed Clmk-1 gene was high similar to Hog1-type MAPK of other filamentous fungi.?The promoter region contain the binding site of transcription factor such as HSF，ADR and GCR by the bioinformatic?analysis with Promoterscan software. The chemical of U0126 inhibited the conidial germination and development of?germinating tubes. The study showed Clmk-1 was stress-activated Hog1-type MAPK and MAPK cascades regulate?the conidial germination and development of germinating tubes. The cloning of the gene will benefit the undestanding of the MAPK gene functional in Cochliobolus lunatus.

Key words: Cochliobolus lunatus, MAPK gene, Gene cloning, U0126

中图分类号: 

• Q78