title: Atg24-assisted mitophagy in the foot cells is necessary for proper asexual differentiation in Magnaporthe oryzae.
abstract: Macroautophagy-mediated glycogen catabolism is required for asexual differentiation in the blast fungus, Magnaporthe oryzae. However, the function(s) of selective subtypes of autophagy has not been studied therein. Here, we report that mitophagy, selective autophagic delivery of mitochondria to the vacuoles for degradation, occurs during early stages of Magnaporthe conidiation. Specifically, mitophagy was evident in the foot cells while being undetectable in aerial hyphae and/or conidiophores. We show that loss of MoAtg24, a sorting nexin related to yeast Snx4, disrupts mitophagy and consequently leads to highly reduced conidiation, suggesting that mitophagy in the foot cells plays an important role during asexual development in Magnaporthe. Ectopic expression of yeast ScATG32 partially suppressed the conidiation initiation defects associated with MoATG24 deletion. MoAtg24 was neither required for pexophagy nor for macroautophagy, or for MoAtg8 localization per se, but directly associated with and likely recruited mitochondria to the autophagic structures during mitophagy. Lastly, MoAtg24 was also required for oxidative stress response in Magnaporthe.
authors: Temasek Life Sciences Laboratory and Department of Biological Sciences; National University of Singapore; Singapore.
authors: Yunlong
authors: Y
authors: He
authors: Yi Zhen
authors: YZ
authors: Deng
authors: Naweed I
authors: NI
authors: Naqvi
mesh_terms: D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D025301:Hyphae / Q000166:cytology* / Q000378:metabolism*; D020082:Magnaporthe / Q000166:cytology* / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D063306:Mitophagy; D009154:Mutation / Q000235:genetics; D018384:Oxidative Stress; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012100:Reproduction, Asexual; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins
keywords: Magnaporthe oryzae; MoAtg24; conidiation; foot cell; mitophagy; reactive oxygen species; redox; sorting nexin