The plant-pathogenic fungus Fusarium graminearum, causal agent of Fusarium head blight (FHB) disease on small grain cereals, produces toxic trichothecenes that require facilitated export for full virulence. Two potential modes of mycotoxin transport are membrane-bound transporters, which move toxins across cellular membranes, and N-ethylmaleimidesensitive factor attachment receptor (SNARE)-mediated vesicular transport, by which toxins may be packaged as cargo in vesicles bound for organelles or the plasma membrane. In this study, we show that deletion of a gene (Sso2) for a subapically localized t-SNARE protein results in growth alteration, increased sensitivity to xenobiotics, altered gene expression profiles, and reduced deoxynivalenol (DON) accumulation in vitro and in planta as well as reduced FHB symptoms on wheat. A double deletion mutant generated by crossing the Dsso2 deletion mutant with an ATP-binding cassette transporter deletion mutant (Dabc1) resulted in an additive reduction in DON accumulation and almost complete loss of FHB symptoms in planta. These results suggest an important role of Sso2-mediated subapical exocytosis in FHB progression and xenobiotic defense and are the first report of an additive reduction in F. graminearum DON accumulation upon deletion of two distinct modes of cellular export. This research provides useful information which may aid in formulating novel management plans of FHB or other destructive plant diseases.
Bibliographical noteFunding Information:
Funding was provided by United States Department of Agriculture, United States Wheat and Barley Scab Initiative (award FY18-KI-021) and from the Agriculture and Food Research Initiative of the National Institute of Food and Agriculture, United States Department of Agriculture (award 2018-67013-28512). The authors acknowledge the Minnesota Supercomputing Institute (MSI) at the University of Minnesota for providing resources that contributed to the research results reported within this paper.
Funding: Funding was provided by United States Department of Agriculture, United States Wheat and Barley Scab Initiative (award FY18-KI-021) and from the Agriculture and Food Research Initiative of the National Institute of Food and Agriculture, United States Department of Agriculture (award 2018-67013-28512).
- Fungus-plant interactions
- Fusarium head blight