|Bin Umer, Anwar|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/4/2008
Publication Date: 12/4/2008
Citation: Bin Umer, A., McLaughlin, J.R., Pu, D., Mendez, N., Mccormick, S.P., Tumer, N. 2008. A Genomics Approach to Characterize Trichothecene Mode of Action Reveals a Cellular-Wide Response in Yeast [abstract]. Proceedings of the 2008 National Fusarium Head Blight Forum. Poster No. 45. p. 105. Interpretive Summary:
Technical Abstract: Trichothecene constitute a large family of low-molecular weight sesquiterpenoid mycotoxins produced by various species of Fusarium, Trichoderma, Cephalosporium, and other fungi. Identified by their characteristic trichothecene ring, these toxins include deoxynivalenol (DON), diacetoxyscirpenol (DAS), T-2, and trichothecin (T-cin). Each toxin varies with regard to toxicity and as a group is known to have a wide variety of effects in plants, animals, and humans. The plant pathogen Fusarium graminearum causes Fusarium head light (FHB) in both wheat and barley resulting in reduced plant yield and contamination of cereal grains with trichothecenes, in particular DON. DON is an inhibitor of translation. However, the inhibitory effects of trichothecene are often not limited to translation and information on other downstream targets of trichothecenes is lacking. To obtain a comprehensive picture of the pathways involved in trichothecene metabolism and resistance we have used the yeast Saccharomyces cerevisiae, as model organisms to study the impact of trichothecenes on eukaryotic cells. We screened the yeast knockout (YKO) collection, composed of 4700 strains, to identify mutants that exhibit hypersensitivity to T-cin. We selected T-cin over DON to screen the library because yeast is sensitive to micromolar levels of T-cin compared to millimolar levels of DON. Bioinformatic analyses of the selected sensitive mutants have revealed components of pathways that play a role in trichothecene resistance, such as mitogen-activated protein (MAP) kinases, components of protein synthesis, vacuolar protein sorting, and ribotoxic stress pathways, suggestion a cellular-side response. These genes represent new candidates for engineering resistance to DON and FHB cereals. Further characterization of these genes will provide important new insights into the trichothecene metabolism.