FgCsn12 Is Involved in the Regulation of Ascosporogenesis in the Wheat Scab Fungus Fusarium graminearum

Abstract

Fusarium head blight (FHB), caused by the fungal pathogen Fusarium graminearum, is a destructive disease worldwide. Ascospores are the primary inoculum of F. graminearum, and sexual reproduction is a critical step in its infection cycle. In this study, we characterized the functions of FgCsn12. Although the ortholog of FgCsn12 in budding yeast was reported to have a direct interaction with Csn5, which served as the core subunit of the COP9 signalosome, the interaction between FgCsn12 and FgCsn5 was not detected through the yeast two-hybrid assay. The deletion of FgCSN12 resulted in slight defects in the growth rate, conidial morphology, and pathogenicity. Instead of forming four-celled, uninucleate ascospores, the Fgcsn12 deletion mutant produced oval ascospores with only one or two cells and was significantly defective in ascospore discharge. The 3′UTR of FgCsn12 was dispensable for vegetative growth but essential for sexual reproductive functions. Compared with those of the wild type, 1204 genes and 2240 genes were up- and downregulated over twofold, respectively, in the Fgcsn12 mutant. Taken together, FgCsn12 demonstrated an important function in the regulation of ascosporogenesis in F. graminearum.

Wheat Fusarium Head Blight Automatic Non-Destructive Detection Based on Multi-Scale Imaging: A Technical Perspective

“…Early detection and monitoring of wheat FHB fungus can provide agronomists with information on the concentration and quantity of pathogenic fungus and help them accurately predict the severity of the disease and implement necessary control measures [62]. Before the rapid development of artificial intelligence (AI), Polymerase Chain Reaction (PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) were some of the common chemical methods to detect fungal spores [56,57].…”

Advances in Understanding Fusarium graminearum: Genes Involved in the Regulation of Sexual Development, Pathogenesis, and Deoxynivalenol Biosynthesis

“…The COP9 signalosome (Csn) complex is a highly conserved protein complex that plays a role in regulating various essential cellular processes across evolution [60]. The subunit of COP9 signalosome FgCsn12 is also involved in regulating ascosporeogenesis and sexual development [61]. FgBUD14 encodes a protein with homology to yeast Bud14, and deleting FgBUD14 greatly decreases the formation of croziers and the development of asci [62].…”

Csn5 inhibits autophagy by regulating the ubiquitination of Atg6 and Tor to mediate the pathogenicity of Magnaporthe oryzae

“…The mammalian CSN plays a complex regulatory role in a series of different biological processes, such as signal transduction, autophagy, circadian rhythm, and cell development [ 22 – 24 ]. In pathogenic fungi, CSNs play indispensable roles in autophagy, ubiquitin protein degradation, aerial hyphal growth, and pathogenicity [ 25 ]. The absence of any CSN subunit is fatal for higher eukaryotes but not for fungi; thus, fungi are good models for studying the molecular mechanism of the CSN.…”