ウリ類炭疽病菌におけるホメオボックス転写制御因子の機能分析

Abstract

ウリ類炭疽病菌の感染メカニズムの解析のため、AtMT法を用いてウリ類炭疽病菌の推定病原性関連遺伝子を得た。そのうちの1つのホメオボックス遺伝子CoHox1について、遺伝子破壊による解析を行った結果、CoHox1は宿主植物内での侵入菌糸の形態分化に関与することが示唆された。ホメオボックス転写因子CoHox3についても同様に解析を行った結果、付着器の形成に関与することがわかった。よって、ホメオボックス転写因子はウリ類炭疽病菌の宿主への感染と病原性の発現に重要な因子である。 In order to analyze the infection mechanism of Colletotrichum orbiculare, which is the causal agent of cucumber anthracnose, putative pathogenesis-related genes of C.orbiculare were obtained by AtMT (Agrobacterium tumefaciens mediated transformation)method. One of the putative pathogenesis-related genes, the homeobox gene CoHox1 was analyzed by gene disruption. As a result, CoHox1 disruption mutants lost pathogenicity and the infection hyphae of CoHox1 disruption mutants did not extend from the penetrated host cell into neighboring cells. Therefore, CoHox1 has been suggested to be involved in morphogenesis of infection hyphae in host plants. The homeobox gene CoHox3 also was analyzed by similar investigation. As a result, it was found that CoHox3 is involved in morphogenesis of the appressorium. Thus, the homeobox transcription factors may be involved in various stages of infection processes in C.orbiculare.