The Endoplasmic Reticulum Cargo Receptor FgErv14 Regulates DON Production, Growth and Virulence in Fusarium graminearum

Abstract

Fusarium graminearum is a plant filamentous pathogenic fungi and the predominant causal agent of Fusarium head blight (FHB) in cereals worldwide. The regulators of the secretory pathway contribute significantly to fungal mycotoxin synthesis, development, and virulence. However, their roles in these processes in F. graminearum remain poorly understood. Here, we identified and functionally characterized the endoplasmic reticulum (ER) cargo receptor FgErv14 in F. graminearum. Firstly, it was observed that FgErv14 is mainly localized in the ER. Then, we constructed the FgErv14 deletion mutant (ΔFgerv14) and found that the absence of the FgErv14 caused a serious reduction in vegetative growth, significant defects in asexual and sexual reproduction, and severely impaired virulence. Furthermore, we found that the ΔFgerv14 mutant exhibited a reduced expression of TRI genes and defective toxisome generation, both of which are critical for deoxynivalenol (DON) biosynthesis. Importantly, we found the green fluorescent protein (GFP)-tagged FgRud3 was dispersed in the cytoplasm, whereas GFP-FgSnc1-PEM was partially trapped in the late Golgi in ΔFgerv14 mutant. These results demonstrate that FgErv14 mediates anterograde ER-to-Golgi transport as well as late secretory Golgi-to-Plasma membrane transport and is necessary for DON biosynthesis, asexual and sexual reproduction, vegetative growth, and pathogenicity in F. graminearum.

ERV14 receptor impacts mycelial growth via its interactions with cell wall synthase and transporters in Aspergillus niger

“…In the liquid medium, the spore-emerging mycelium also does not extend polarly as in the control strain. Deletion of FgErv14 in F. graminearum also results in a similar phenotype ( Sun et al, 2022 ). Moreover, we identify some proteins’ role in the establishment of cell polarity in the interactome and proteome, although without further validation.…”

Fusarium graminearum GGA protein is critical for fungal development, virulence and ascospore discharge through its involvement in vesicular trafficking

“…Unexpectedly, although the absence of full‐length FgGga1 disrupted TGN‐to‐PM transport, the deletion of any of the five domains did not affect TGN‐to‐PM trafficking, suggesting the functional redundancy of FgGga1 domains in regulating TGN‐to‐PM transport. Vascular trafficking regulators of different organelles have been widely reported to be involved in the vegetative growth and virulence of F. graminearum , such as FgErv14 and FgRab1 (Sun et al, 2022; Zheng et al, 2015), which are the regulators of transport between ER and Golgi apparatus; and FgRab6 (Zheng et al, 2015), which is the regulator of intra‐Golgi transport, etc. It has also been reported that the TGN‐to‐PM transport regulators FgSec2A and FgRab8 (Sec4 in yeast) are necessary for vegetative growth and virulence in F. graminearum (Zheng, Li, et al, 2018); our finding that FgGga1‐mediated TGN‐to‐PM transport also plays a key role in vegetative growth and full virulence is in consistence with that.…”

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

“…FgErv14 was identified as an endoplasmic reticulum (ER) cargo receptor in F. graminearum. Two weeks after fertilization, the ∆fgerv14 mutant showed a complete absence of perithecia production [47]. Systematic investigation of Phox homology domaincontaining proteins in F. graminearum revealed that FgBem1 plays a crucial role in both sexual development and virulence.…”