Abstract：
Polarized growth is critical for the development of filamentous phytopathogens, and the CHY-type zinc finger protein Chy1 regulates microtubule assembly to influence polarized growth and thereby affect plant infections. However, the biological role of a Chy1 homolog MoChy1 remains unknown in Magnaporthe oryzae. We found here that the MoChy1-GFP was distributed in the cytoplasm outside the vacuole in hyphae and localized mainly to the vacuole compartments as the appressorium matured. The Mochy1 mutants showed an extremely slow growth rate, curved and branched mycelium, reduced conidiation, and a smaller size in the appressorium. Meanwhile, the Mochy1 mutants showed increased sensitivity to benomyl, damaged microtubule cytoskeleton, and mislocalized polarisome protein MoSpa2 and chitin synthase MoChs6 in hyphae. Compared to Guy11, the Mochy1 mutants exhibited increased sensitivity to H2O2, impaired ability to eliminate host-derived ROS and reduced penetration into host plants, resulting in a strong reduction in pathogenicity of Mochy1 mutants. Furthermore, the Mochy1 mutants also exhibited defects in chitin distribution, osmotic stress tolerance, and septin ring organization during appressorium differentiation and fungal development. Nonselective autophagy was negatively regulated in Mochy1 mutants compared to Guy11. In summary, MoChy1 plays multiple roles in fungal polar growth and full virulence of M. oryzae.
摘要：
极化生长对于丝状植物病原体的发育至关重要，CHY型锌指蛋白Chy1调节微管组装以影响极化生长，从而影响植物感染。然而,Chy1同源物MoChy1在稻瘟病中的生物学作用仍然未知。我们在这里发现，MoChy1-GFP分布在菌丝中液泡外的细胞质中，并随着敷层的成熟而主要定位于液泡区室。Mochy1突变体显示出极其缓慢的生长速度，弯曲和分枝的菌丝体，减少分生孢子，和一个较小的尺寸在附着室。同时,Mochy1突变体对苯菌灵的敏感性增加，受损的微管细胞骨架，和菌丝中错位的极化体蛋白MoSpa2和几丁质合成酶MoChs6。与Guy11相比，Mochy1突变体对H2O2的敏感性增加，消除宿主衍生的ROS的能力受损，并减少了对宿主植物的渗透，导致Mochy1突变体的致病性大大降低。此外，Mochy1突变体在几丁质分布上也表现出缺陷，渗透胁迫耐受性，和附睾分化和真菌发育过程中的间隔环组织。与Guy11相比，Mochy1突变体中的非选择性自噬受到负调控。总之,MoChy1在米曲霉的真菌极性生长和全毒力中起着多种作用。
