Abstract: MAPK cascade signal pathway plays a key role in the growth, development, reproduction and pathogenicity of plant pathogenic fungi. According to the published genome-wide data of 5 rice sheath blight pathogen (Rhizoctonia solani), this paper identified the MAPK cascade signal pathway genes by bioinformatics, and predicted the MAPK signal pathways of rice sheath blight pathogen Rhizoctonia solani. The results of protein domain and motif analysis showed that the MAPK signal pathway genes of Rhizoctonia solani all contained serine/threonine protein kinase domain, and the gene sequences were conservatized. The results of multiple sequence alignment indicated that there were 11 MAPKKK genes, respectively belonging to Ste11, Bck1 and Ssk2; 10 MAPKK genes belonging to Ste7, Pbs2 and Mkk1; 12 MAPK genes were classified as Kss1/Fus3, Hog1, Slt2 and Ime2. Among the genome of the 5 rice sheath blight pathogen, MAPK cascade signal pathways of Fus3/Kss1-MAPK, Hog1-MAPK, Slt2-MAPK and Ime2-MAPK were found in R. solani (taxid: 456999) and AG-3 Rhs 1AP (taxid: 1086054). In genome of AG-1 IB (taxid: 1108050), there were Kss1/Fus3-MAPK, Hog1-MAPK, and Slt2-MAPK signal pathway. And there was only Hog1-MAPK signal pathway in genome of AG-8 WAC10335 (taxid: 1287689). While, 2 MAPKKK genes in genome of AG-1 IA (taxid: 983506) could not find complete signal pathway. Based on the above results, the signal pathway models of Kss1/Fus3, Hog1, Slt2 and Ime2 were predicted in R. solani. These results provided theoretical basis for further studying the function of MAPK family in R. solani.

Key words: Rhizoctonia solani, MAPK cascade signal pathway, whole-genome, signal path model

摘要： MAPK级联信号途径在植物病原真菌的生长、发育、繁殖及致病性等方面起着重要作用。根据已公布的5个水稻纹枯病菌（Rhizoctonia solani）全基因组数据利用生物信息学方法对该病原菌的MAPK（mitogen-activated protein kinase）级联信号途径基因进行了鉴定，并预测水稻纹枯病菌MAPK级联途径图。蛋白结构域和motif分析结果表明，水稻纹枯病菌的MAPK信号途径基因均含有丝氨酸/苏氨酸蛋白激酶结构域，并且基因序列具有较高保守性。多重序列比对结果表明，水稻纹枯病菌基因组中存在11个MAPKKK基因，分属于Ste11、Bck1和Ssk2类；10个MAPKK基因，分别为Ste7、Pbs2及Mkk1类；12个MAPK基因，被分类为Kss1/Fus3、Hog1、Slt2和Ime2。在5个水稻纹枯病菌基因组中，水稻纹枯病菌（taxid:456999）和AG-3 Rhs 1 AP（taxid:1086054）基因组中存在Kss1/Fus3-MAPK、Hog1-MAPK、Slt2-MAPK和Ime2-MAPK信号通路，AG-1 IB（taxid:1108050）基因组中存在Kss1/Fus3-MAPK、Hog1-MAPK和Slt2-MAPK通路，AG-8 WAC10335（taxid:1287689）基因组中仅存在Hog1-MAPK通路，而AG-1 IA（taxid:983506）基因组中只有2个MAPKKK基因未找到完整的信号通路。依据上述研究结果预测了水稻纹枯病菌的Kss1/Fus3、Hog1、Slt2和 Ime2级联途径模型，此结果为深入研究水稻纹枯病菌的MAPK家族功能奠定了重要的理论基础。

关键词: 水稻纹枯病菌, MAPK级联途径, 全基因组, 信号通路模型