State Key Lab of Rice Biology, China National Rice Research Institute, Hangzhou 311400, China.
Hubei Key Lab of Plant Pathology, and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Int J Mol Sci. 2022 May 10;23(10):5311. doi: 10.3390/ijms23105311.
Mitophagy refers to the specific process of degrading mitochondria, which is an important physiological process to maintain the balance of mitochondrial quantity and quality in cells. At present, the mechanisms of mitophagy in pathogenic fungi remain unclear. (Syn. ), the causal agent of rice blast disease, is responsible for the most serious disease of rice. In , mitophagy occurs in the foot cells and invasive hyphae to promote conidiation and infection. In this study, fluorescent observations and immunoblot analyses showed that general stress response protein MoWhi2 is required for mitophagy in . In addition, the activation of the autophagy, pexophagy and cytoplasm-to-vacuole targeting (CVT) pathway upon nitrogen starvation was determined using the , and strains and the Δ mutant in these backgrounds. The results indicated that MoWhi2 is specifically required for mitophagy in . Further studies showed that mitophagy in the foot cells and invasive hyphae of the Δ was interrupted, leading to reduced conidiation and virulence in the Δ mutant. Taken together, we found that MoWhi2 contributes to conidiation and invasive growth by regulating mitophagy in .
自噬是指特定的线粒体降解过程，是细胞中线粒体数量和质量平衡的重要生理过程。目前，致病真菌的自噬机制尚不清楚。稻瘟病菌（Magnaporthe oryzae）是引起稻瘟病的主要病原菌，稻瘟病菌中的自噬发生在游动孢子和侵染菌丝中，以促进产孢和感染。在本研究中，荧光观察和免疫印迹分析表明，一般应激反应蛋白 MoWhi2 是稻瘟病菌自噬所必需的。此外，利用 、 和 菌株以及这些背景下的 Δ 突变体，确定了氮饥饿时自噬、pexophagy 和细胞质到液泡靶向 (CVT) 途径的激活。结果表明，MoWhi2 特异性地参与了稻瘟病菌的自噬。进一步的研究表明，Δ 中的游动孢子和侵染菌丝中的自噬被打断，导致 Δ 突变体产孢和毒力降低。总之，我们发现 MoWhi2 通过调节稻瘟病菌中的自噬来促进产孢和侵染生长。
