Location: Cereal Disease LabTitle: The Fusarium graminearum t-SNARE Sso2 is involved in growth, defense, and DON accumulation and virulence
|O'MARA, SEAN - University Of Minnesota|
|BOENISCH, MARIKE - University Of Minnesota|
|ZHONG, ZIXUA - University Of Minnesota|
|DONG, YANHONG - University Of Minnesota|
|Kistler, H - Corby|
Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/15/2020
Publication Date: 6/1/2020
Citation: O'Mara, S.P., Broz, K.L., Boenisch, M.J., Zhong, Z., Dong, Y., Kistler, H.C. 2020. The Fusarium graminearum t-SNARE Sso2 is involved in growth, defense, and DON accumulation and virulence. Molecular Plant-Microbe Interactions. https://doi.org/10.1094/MPMI-01-20-0012-R.
Interpretive Summary: By understanding the fundamental mechanisms by which fungi make and contaminate grain with mycotoxins, we may be able to develop novel control measures based on these essential processes. In this publication we describe two approaches by which the fungus, which causes head blight disease of wheat and barley, increases the concentration of mycotoxin contamination in grain infected by the fungus. These processes also may lead to resistance of the fungus to common agricultural fungicides. Our approach has the potential for long-term improvement and sustainability of U.S. agriculture by leading to the development of transgenic wheat and barley varieties with reduced DON content using the information generated here. Despite demonstrable progress, plant breeding approaches have not yet completely solved the FHB problem. Therefore, transgenic approaches may augment current strategies for long term improvement of small grain crops for FHB resistance and reduced mycotoxin content.
Technical Abstract: The plant pathogenic fungus Fusarium graminearum, causal agent of Fusarium Head Blight (FHB) disease on small grain cereals, produces toxic trichothecenes which require facilitated export for full virulence. Two potential modes of mycotoxin transport are membrane-bound transporters, which move toxins across cellular membranes, and 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 'sso2 deletion mutant with an ABC transporter deletion mutant ('abc1) 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.