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.

中文翻译：

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蛋氨酸生物合成酶 MoMet2 通过减少 5mC 修饰促进毒力基因表达，是稻瘟病菌致病性所必需的。

杀菌剂抗性的出现限制了现有杀菌剂的可用性和应用，严重威胁作物生产。因此，迫切需要寻找新的杀菌靶点来控制植物病害。在这里，我们表征了来自稻瘟病菌 Magnaporthe oryzae 的保守高丝氨酸 O-乙酰转移酶 (HOA) 的功能，该酶可以作为候选抗真菌靶点。编码 HOA 的 MoMET2 和 MoCYS2 基因的缺失扰乱了甲硫氨酸和 S-腺苷甲硫氨酸（表观遗传修饰的甲基供体）的生物合成，并严重减弱了米霉的发育和毒力。ΔMomet2 突变体的 5-甲基胞嘧啶 (5mC) 修饰显着增加，抑制致病性所需基因的表达，包括 MoGLIK 和 MoCDH-CYT。我们进一步表明，针对 MoMET2 和 MoCYS2 的宿主诱导基因沉默（HIGS）可有效控制稻瘟病。我们的研究揭示了 HOA 在米霉的发育和毒力中的重要性，这表明 HOA 作为新型抗稻瘟病检测的新靶点的潜在可行性。