title: Transgenic Arabidopsis thaliana expressing a barley UDP-glucosyltransferase exhibit resistance to the mycotoxin deoxynivalenol.
abstract: Fusarium head blight (FHB), caused by Fusarium graminearum, is a devastating disease of small grain cereal crops. FHB causes yield reductions and contamination of grain with trichothecene mycotoxins such as deoxynivalenol (DON). DON inhibits protein synthesis in eukaryotic cells and acts as a virulence factor during fungal pathogenesis, therefore resistance to DON is considered an important component of resistance against FHB. One mechanism of resistance to DON is conversion of DON to DON-3-O-glucoside (D3G). Previous studies showed that expression of the UDP-glucosyltransferase genes HvUGT13248 from barley and AtUGt73C5 (DOGT1) from Arabidopsis thaliana conferred DON resistance to yeast. Over-expression of AtUGt73C5 in Arabidopsis led to increased DON resistance of seedlings but also to dwarfing of transgenic plants due to the formation of brassinosteroid-glucosides. The objectives of this study were to develop transgenic Arabidopsis expressing HvUGT13248, to test for phenotypic changes in growth habit, and the response to DON. Transgenic lines that constitutively expressed the epitope-tagged HvUGT13248 protein exhibited increased resistance to DON in a seed germination assay and converted DON to D3G to a higher extent than the untransformed wild-type. By contrast to the over-expression of DOGT1 in Arabidopsis, which conjugated the brassinosteriod castasterone with a glucoside group resulting in a dwarf phenotype, expression of the barley HvUGT13248 gene did not lead to drastic morphological changes. Consistent with this observation, no castasterone-glucoside formation was detectable in yeast expressing the barley HvUGT13248 gene. This barley UGT is therefore a promising candidate for transgenic approaches aiming to increase DON and Fusarium resistance of crop plants without undesired collateral effects.
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, 411 Borlaug Hall, 1991 Buford Circle, St Paul, MN 55108, USA.
authors.forename: Sanghyun
authors.initials: S
authors.lastname: Shin
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Torres-Acosta
authors.forename: Shane J
authors.initials: SJ
authors.lastname: Heinen
authors.forename: Susan
authors.initials: S
authors.lastname: McCormick
authors.forename: Marc
authors.initials: M
authors.lastname: Lemmens
authors.forename: Maria Paula Kovalsky
authors.initials: MP
authors.lastname: Paris
authors.forename: Franz
authors.initials: F
authors.lastname: Berthiller
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Muehlbauer
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D060406:Brassinosteroids / Q000378:metabolism; D035264:Flowers / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D015870:Gene Expression; D018525:Germination / Q000187:drug effects; D005960:Glucosides / Q000378:metabolism; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D001467:Hordeum / Q000201:enzymology* / Q000235:genetics; D008658:Inactivation, Metabolic; D010641:Phenotype; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D019076:Transgenes; D014255:Trichothecenes / Q000494:pharmacology*; D037521:Virulence Factors
chemical_list: D060406:Brassinosteroids; D005960:Glucosides; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D014255:Trichothecenes; D037521:Virulence Factors; D005964:Glucosyltransferases; C007262:deoxynivalenol