부산대학교 도서관

The emergence of fungicide resistance severely threatens crop production by limiting the availability and application of established fungicides. Therefore, it is urgent to identify new fungicidal targets for controlling plant diseases. Here, we characterized the function of a conserved homoserine O-acetyltransferase (HOA) from the rice blast fungus Magnaporthe oryzae that could serve as the candidate antifungal target. Deletion of the MoMET2 and MoCYS2 genes encoding HOAs perturbed the biosynthesis of methionine and S-adenyl methionine, a methyl group donor for epigenetic modifications, and severely attenuated the development and virulence of M. oryzae. The ∆Momet2 mutant is significantly increased in 5-methylcytosine (5mC) modification that represses the expression of genes required for pathogenicity, including MoGLIK and MoCDH-CYT. We further showed that host-induced gene silencing (HIGS) targeting MoMET2 and MoCYS2 effectively controls rice blasts. Our studies revealed the importance of HOA in the development and virulence of M. oryzae, which suggests the potential feasibility of HOA as new targets for novel anti-rice blast measurements. Author summary: Despite the effectiveness of available antifungal agents in combating rice blasts, the emergence of resistance to these agents requires the reexamination of fungal pathogens, plant-fungi interactions, and virulence factors. Characterization of virulence factors is expected to improve the understanding of fungus pathogenesis and to help exploration for an antifungal drug target. We here reported that HOAs of the fungal original could serve as a potential target for antifungal agents. Specifically, we found that homoserine O-acetyltransferases MoMet2 and MoCys2 are important in the biosynthesis of methionine and S-adenyl methionine that are critical for the growth, development, and virulence of M. oryzae. We further demonstrated that MoMet2-mediated 5mC modification regulates gene expression and is required for infection by the rice blast fungus. Additionally, using host-induced gene silencing (HIGS) targeting MoMET2 and MoCYS2 genes provided protection against rice blasts. In all, the studies shed significant new insights in understanding the role of methionine synthesis in fungal pathogenicity and in identifying potential antifungal targets. [ABSTRACT FROM AUTHOR]