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

Abstract

Coniothyrium minitans is an important mycoparasite of the notorious phytopathogenic fungus Sclerotinia sclerotiorum. The mycoparasitism system of C. minitans-S. sclerotiorum 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 C. minitans. A single-copy gene, encoding a protein with high sequence similarity to Aim24 (altered inheritance of mitochondria protein 24) in Saccharomyces cerevisiae, was disrupted by T-DNA insertion in this mutant. Gene replacement and complementation experiments confirmed that mutants lacking CmAim24 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 C. minitans. IMPORTANCE 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 Coniothyrium minitans and proved its critical role in mitochondrial morphology and function, conidiogenesis, conidial germination, and mycoparasitism to S. sclerotiorum.

A Putative D-Arabinono-1,4-lactone Oxidase, MoAlo1, Is Required for Fungal Growth, Conidiogenesis, and Pathogenicity in Magnaporthe oryzae

“…Similar to S. cerevisiae, MoAlo1 is located in the mitochondria (Figure 1C), suggesting that MoAlo1 may function as ScAlo1. Disruption of some mitochondrial proteins showed significant conidiogenesis and germination defects [32], consistent with ∆Moalo1. Mitochondria are some of the most important organelles of cells.…”

Endosomal sorting complexes required for transport‐0 (ESCRT‐0) are essential for fungal development, pathogenicity, autophagy and ER‐phagy in Magnaporthe oryzae

“…In addition, a series of mitochondrial proteins, such as mitochondrial carrier proteins, altered inheritance of mitochondrial proteins 24 and some genes related to cytochrome proved to have connections with mitochondria, as identified by mass spectrometry of MoHse1, which revealed that its absence may affect mitochondrial function. Research on CmAim24 exhibited significantly reduced conidial production and germination as well as reduced sclerotial mycoparasitic ability (Yang et al ., 2020). Overexpression of the mitochondrial carrier protein Ant1 will cause EGR1, eEF1a and ubiquitin C to be upregulated, which are known to promote autophagy, protein targeting to aggresomes and the processing of protein aggregates, respectively (Liu et al ., 2019).…”

Botrytis cinerea type II inhibitor of apoptosis BcBIR1 enhances the biocontrol capacity of Coniothyrium minitans

“…Among them, several previously reported signalling pathways, including those associated with mitochondrial structure and function, ROS accumulation and peroxisomes, are upstream of the intrinsic apoptotic pathway (Albert & Sellem, 2002; Jiang & Wang, 2004; Osiewacz & Borghouts, 2000; Scheckhuber et al., 2007; Sharon et al., 2009; Smith et al., 2010; Tanaka et al., 2019). Certain genes, such as CmNox1 , CmPEX6 , CmAim24 and PIF1 , play essential roles in ROS generation, oxidant production, mitochondrial morphology regulation and maintaining mitochondrial stability (Rogers et al., 2008; Wei et al., 2013, 2016; Yang et al., 2020), indicating their critical involvement in regulating conidiation and mycoparasitism through the mitochondrion‐dependent apoptosis pathway.…”