The microtubule end‐binding protein FgEB1 regulates polar growth and fungicide sensitivity via different interactors in Fusarium graminearum

Abstract

In yeasts, the end-binding protein 1 (EB1) homologs regulate microtubule dynamics, cell polarization, and chromosome stability. However, functions of EB1 orthologs in plant pathogenic fungi have not been characterized yet. Here, we observed that the FgEB1 deletion mutant (ΔFgEB1) of Fusarium graminearum exhibits twisted hyphae, increased hyphal branching and curved conidia, indicating that FgEB1 is involved in the regulation of cellular polarity. Microscopic examination further showed that the microtubules of ΔFgEB1 exhibited less organized in comparison with those of the wild type. In addition, the lack of FgEB1 also altered the distribution of polarity-related class I myosin via the interaction with the actin. On the other hand, we identified four core septins as FgEB1-interacting proteins, and found that FgEB1 and septins regulated conidial polar growth in the opposite orientation. Interestingly, FgEB1 and FgKar9 constituted another complex that modulated the response to carbendazim, a microtubule-damaging agent specifically. In addition, the deletion of FgEB1 led to dramatically decreased deoxynivalenol (DON) biosynthesis. Taken together, results of this study indicate that FgEB1 regulates cellular polarity, fungicide sensitivity and DON biosynthesis via different interactors in F. graminarum, which provides a novel insight into understanding of the biological functions of EB1 in filamentous fungi.

The fungal myosin I is essential for Fusarium toxisome formation

“…Three myosins: an essential class II myosin FgMyo2 (FGSG_08719), a class V myosin FgMyo2B (FGSG_07469), and the essential class I myosin FgMyo1 (FGSG_01410) are recognized in F . graminearum [ 47 ]. FgMyo2 is specifically localized to the delimiting septum of phialides and conidia, and required for septation [ 48 ].…”

PHI-Nets: A Network Resource for Ascomycete Fungal Pathogens to Annotate and Identify Putative Virulence Interacting Proteins and siRNA Targets

“…The associated F. graminearum gene FG_22771 encodes the end-binding protein 1 (FgEb1) regulating microtubule dynamics. A deletion mutant of this gene shows increased hyphal branching and highly reduced sesquiterpene deoxynivalenol (DON) mycotoxin biosynthesis (Liu et al, 2017).…”

The Dis1/Stu2/XMAP215 Family Gene FgStu2 Is Involved in Vegetative Growth, Morphology, Sexual and Asexual Reproduction, Pathogenicity and DON Production of Fusarium graminearum

“…The PH-1 strain is the standard strain of F. graminearum which was completely sequenced in Cuomo et al (2007). In the recent years, PH-1 strain has become a model strain in plant pathology and fungal genetics (Liu et al, 2017;Chen et al, 2019;Jiang et al, 2020). More importantly, the genetic transformation and fluorescence labeling technologies of PH-1 are now perfect and convenient.…”

“…For visualize the localization FgTri1p (also known as "toxisomes") in FgStu2-Si mutant and wild-type strain PH-1, we cloned FgTri1 gene into PDL2 plasmid as previous described (Liu et al, 2017). The recombinant plasmid was identified by PCR, and sequencing.…”