玉米大斑病菌MAPK超家族的全基因组鉴定及途径模型建立  

Genome-Wide Identification MAPK Superfamily and Establishment of the Model of MAPK Cascade Pathway in Setosphaeria turcica

作　　者：巩校东[1] 张晓玉[1] 田兰[1] 王星懿[1] 李坡[2] 张盼[1] 王玥[1] 范永山[3] 韩建民[1] 谷守芹[1] 董金皋[1] 

机构地区：[1]河北农业大学真菌毒素与植物分子病理学实验室,河北保定071001 [2]河北省农林科学院植物保护研究所,河北保定071000 [3]唐山师范学院生命科学系,河北唐山063000

出　　处：《中国农业科学》2014年第9期1715-1724,共10页Scientia Agricultura Sinica

基　　金：国家自然科学基金项目(31171805;31271997;31371897);河北省自然科学基金项目(C2012204033;C2013204061)

摘　　要：【目的】从全基因组水平鉴定玉米大斑病菌(Setosphaeria turcica)的MAPK超家族基因,并对其进行系统进化、基因结构、多重序列比对及保守位点分析,构建玉米大斑病菌中的MAPK级联途径模型,为深入研究该植物病原菌中MAPK级联途径的功能奠定基础。【方法】利用玉米大斑病菌基因组数据库,通过基于隐马尔科夫模型的HMMER 3.0软件搜索基因组,鉴定并获得MAPK超家族成员序列、基因组定位信息;采用MEGA 5.0软件进行系统进化分析;通过GSDS工具进行基因结构分析;利用ClustalX、MEME工具分析MAPK蛋白激酶区的保守性及保守位点。【结果】在玉米大斑病菌基因组中发现了4个MAPK基因、3个MAPKK基因和3个MAPKKK基因。系统进化分析将MAPK分为Kss1/Fus3、Slt2、Hog1及Ime2 4类;MAPKK分为Pbs2、Ste7及Mkk1 3类;MAPKKK分为Ste11、Bck1及Ssk2 3类。基因组定位及基因结构分析表明,MAPK超家族散布在基因组中,且MAPK基因的结构最为复杂多样,MAPKK次之,MAPKKK结构最简单。多重序列比对与保守位点分析表明,玉米大斑病菌MAPK超家族的激酶结构域均高度保守,其中MAPK具有保守的"-TxY-"磷酸化位点,MAPKK含有保守的"-SD[V/I]WS-"磷酸化位点,MAPKKK含有"-G[S/T][V/P][F/M][W/Y]M[A/S]PEV-"特异性保守位点。【结论】全基因组分析表明,玉米大斑病菌中包括4个MAPK基因、3个MAPKK基因和3个MAPKKK基因。通过系统进化、基因结构及多重序列比对和保守位点分析,在玉米大斑病菌中构建了Fus3/Kss1-homolog、Slt2-homolog、Hog1-homolog和Ime2-homolog4条MAPK级联途径,其中Ime2 homolog为一条新发现的MAPK级联途径。该信息为深入解析植物病原真菌MAPK超家族的功能奠定了基础。[Objective] Identification of MAPK superfamily genes from wide genome, and analysis of phylogeny, gene structure, multiple sequence alignment and conservative sites in Setosphaeria turcica will be useful for further research on the functions of MAPK cascade pathway in plant pathogenic fungus. [Method] Based on S. turcica genome database and genome searching with HMMER 3.0, MAPK superfamily genes were identified and their gene sequences, and genome location were obtained. The conservative protein kinase domains and sites were analyzed with ClustalX, MEME tools. [Result] Four MAPK genes, three MAPKK genes and three MAPKKK genes in S. turcica genome were found, and the MAPK was classified into Kssl/Fus3, Slt2, Hogl and Ime2 four classes, MAPKK was classified into Pbs2, Ste7 and Mkkl three classes, MAPKKK was classified into Stel 1, Bckl and Ssk2 three classes. Genome location and gene structure analysis showed that MAPK superfamily genes extensively distributed in the genome, and the structure of MAPK genes was the most complicated, MAPKK taken the second place, and MAPKKK structure was the simplest. Multiple sequence alignment and conservative sites analysis showed that the MAPK superfamily of kinase domain structure was highly conserved in S. turcica, and MAPK contained phosphorylation sites （-TxY-）, MAPKK contained conservative phosphorylation sites （-SD[V/I]WS-）, MAPKKK contained specificity conservative sites （-G[S/T] [V/P][F/M][W/Y]M[A/S]PEV-）. [ Conclusion] Genome-wide analysis showed that there were four MAPK genes, three MAPKK genes and three MAPKKK genes in S. turcica. Phylogenetic, gene structure, multiple sequence alignment and conservative site analysis showed that there were Fus3/Kssl-homolog, Slt2-homolog, Hogl-homolog and Ime2-homolog four MAPK cascade pathways, and Ime2 homolog may be a newly discovered MAPK cascade pathway in S. turcica. These results are helpful for the further functional research of MAPK superfamily in plant pathogenic fungus.

关 键 词：玉米大斑病菌 MAPK基因超家族 系统进化 保守基序 

分 类 号：S435.131.4[农业科学—农业昆虫与害虫防治]