Chen Deng, Cai Xuan, Xing Junjie, Chen Shen, Zhao Juan, Qu Zhiguang, Li Guotian, Liu Hao, Zheng Lu, Huang Junbin, Chen Xiao-Lin
State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China.
State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125 China.
aBIOTECH. 2023 Feb 18;4(2):108-123. doi: 10.1007/s42994-023-00098-5. eCollection 2023 Jun.
Lipid droplets are important storages in fungal conidia and can be used by plant pathogenic fungi for infection. However, the regulatory mechanism of lipid droplets formation and the utilization during fungal development and infection are largely unknown. Here, in , we identified a lipid droplet-associated protein Nem1 that played a key role in lipid droplets biogenesis and utilization. Nem1 was highly expressed in conidia, but lowly expressed in appressoria, and its encoded protein was localized to lipid droplets. Deletion of resulted in reduced numbers of lipid droplets and decreased content of diacylglycerol (DAG) or triacylglycerol (TAG). was required for asexual development especially conidia production. The Δ mutant was nearly loss of virulence to host plants due to defects in appressorial penetration and invasive growth. Remarkably, Nem1 was regulated by the TOR signaling pathway and involved in the autophagy process. The Ser303 residue of Nem1 could be phosphorylated by the cAMP-PKA signaling pathway and was important for biological function of Nem1. Together, our study revealed a regulatory mechanism of lipid biogenesis and metabolism during the conidium and appressorium formation of the rice blast fungus.
The online version contains supplementary material available at 10.1007/s42994-023-00098-5.
脂滴是真菌分生孢子中的重要储存物，可被植物病原真菌用于感染。然而，脂滴形成的调控机制以及在真菌发育和感染过程中的利用情况在很大程度上尚不清楚。在此，我们鉴定出一种与脂滴相关的蛋白Nem1，它在脂滴的生物合成和利用中起关键作用。Nem1在分生孢子中高度表达，但在附着胞中低表达，其编码蛋白定位于脂滴。缺失导致脂滴数量减少以及二酰甘油（DAG）或三酰甘油（TAG）含量降低。对于无性发育尤其是分生孢子产生是必需的。Δ突变体由于附着胞穿透和侵入性生长缺陷而对寄主植物几乎丧失毒力。值得注意的是，Nem1受TOR信号通路调控并参与自噬过程。Nem1的Ser303残基可被cAMP-PKA信号通路磷酸化，对Nem1的生物学功能很重要。总之，我们的研究揭示了稻瘟病菌分生孢子和附着胞形成过程中脂质生物合成和代谢的调控机制。
在线版本包含可在10.1007/s42994-023-00098-5获取的补充材料。
