Colletotrichum orbiculare MOR is crucial for regulation of appressorium development and pathogenesis by communicating with plant-derived signals
S. KODAMA (1), J. ishizuka (1), I. Miyashita (1), T. Ishii (1), T. Nishiuchi (2), H. Miyoshi (3), Y. Kubo (1) (1) Graduate School of Life & Env Sciences, Kyoto Prefectural University, Japan; (2) Advanced Science Research Center, Kanazawa University, Japan; (3) Graduate School of Agriculture, Kyoto University, Japan

Host infection by plant pathogenic fungi involves the differentiation of specialized infection structures called appressoria, initiated by fungal sensing and responding to plant surface signals. How plant fungal pathogens control infection-related morphogenesis in response to plant-derived signals has been unclear. We previously reported that cucumber anthracnose fungus Colletotrichum orbiculare KEL2, a Schizosaccharomyces pombe tea1 homolog is required for proper morphogenesis of appressoria on artificial surfaces but is dispensable on the host plant surface, suggesting a bypass pathway was activated by plant-derived signals independent of Kel2 function. By screening of insertional mutants, we identified that the morphogenesis-related NDR kinase pathway (MOR) plays a crucial role in the signal transduction pathway for appressorium development that is specifically induced by plant-derived cues. We found that the signal molecule for appressorium induction via MOR is the cutin monomer n-octadecanal degraded from the host plant cuticle by conidial surface esterases. Furthermore, based on genome-wide gene expression analysis, we revealed that the MOR contributes to regulating a subset of the plant-signal-induced genes with potential roles in pathogenicity. Our data demonstrate that MOR of C. orbiculare has crucial roles in regulating appressorium development and pathogenesis by communicating with plant-derived signals.   

Abstract Number: P7-179
Session Type: Poster