烟草赤星病是一种全球性的重要烟草病害，严重制约我国烟草的种植和生产。近年来，烟草赤星病菌的致病机制日益受到人们的关注。在前期研究中，项目组发现第三类组氨酸激酶AlHK1是烟草赤星病菌（Alternaria longipes）的关键致病因子，AlHK1通过负性调控方式参与A. longipes的致病过程。本项目拟以前期工作获得的A. longipes野生型、AlHK1基因点突变菌株和AlHK1基因敲除突变株为研究材料，通过抑制消减杂交技术和基于"Interolog"方法的生物信息学手段筛选出AlHK1调控的致病相关基因，并利用基因敲除技术获得部分基因的缺失突变株，比较突变株与野生型菌株在表型、致病能力和原因等方面的差异，明确它们在致病过程中的作用，最终建立"AlHK1-关键致病基因-表型效应"的致病模型，为阐明A. longipes的致病分子机制奠定基础，也为植物真菌病害的防治提供理论依据。

Tobacco brown spot disease (TBSD) is one of the important diseases of tobacco all over the world, which restricts tobacco planting and production in our country. In recent years, the mechanism study of pathogenicity of the pathogen of TBSD has been attracted attention. In the previous studies, our project group discovered the group III histidine kinase AlHK1 was a key pathogenic factor of Alternaria longipes, which performed the pathogenic function by a negative manner. In this project, firstly, we plan to choose wild-type strain, AlHK1 gene point mutant and AlHK1 gene disrupted mutant of A. longipes from our previous work as study materials. Then, use suppression subtractive hybridization technique and bioinformatics method which based the "Interolog" approach to identify pathogenicity associated genes which regulated by AlHK1. Next, some genes mutants will be obtained using gene knock-out technology, and compare the differences in phenotype, pathogenic ability and reasons etc between the wild-type strain and the genes disrupted mutants to clarify their functions in pathogenic process. Finally, found the pathogenic model of "AlHK1-key pathogenic factors-phenotypic effects", which will lay a foundation for interpreting the molecular mechanism of pathogenicity of A. longipes, and provide theoretical basis for prevention and cure of the fungal diseases of plants.