CmAim24 Is Essential for Mitochondrial Morphology, Conidiogenesis, and Mycoparasitism in Coniothyrium minitans

is an important mycoparasite of the notorious phytopathogenic fungus The mycoparasitism system of - is unique and important in probing fungi and fungal interactions. Here, we report a conidiation-deficient mutant, ZS-1TN1961, which was screened from a transfer DNA (T-DNA) insertional library of A single-copy gene, encoding a protein with high sequence similarity to Aim24 (altered inheritance of mitochondria protein 24) in , was disrupted by T-DNA insertion in this mutant. Gene replacement and complementation experiments confirmed that mutants lacking exhibited significantly reduced conidial production and germination as well as reduced sclerotial mycoparasitic ability. Furthermore, cellular localization assays showed that CmAim24 localized to mitochondria, and abnormal mitochondria were observed in the ΔCmAim24 mutant. The ΔCmAim24 mutant exhibited significant accumulation of reactive oxygen species (ROS) and a reduced ATP content in mycelia. In summary, our results suggest that CmAim24 plays a key role in mitochondrial architecture and function, conidiogenesis, and mycoparasitism in Aim24 proteins are involved in mitochondrial biogenesis and accumulate between the two membranes of a mitochondrion. Their function in prokaryotes and filamentous fungi is as yet unknown. In the present study, we characterized an Aim24 protein, CmAim24, in the mycoparasite and proved its critical role in mitochondrial morphology and function, conidiogenesis, conidial germination, and mycoparasitism to .