title: Lack of association between cerato-ulmin production and virulence in Ophiostoma novo-ulmi.
abstract: Cerato-ulmin (CU), a hydrophobin produced by Ophiostoma novo-ulmi, has been implicated in the pathogenicity of this fungus on elm. We have generated a CU- mutant by transformation-mediated gene disruption of a highly virulent (aggressive) strain of O. novo-ulmi. The inability of the mutant to synthesize CU was confirmed by transcript analysis as well as turbidity and immunological measurements. Bioassay of the CU- strain in highly susceptible elm trees indicated no difference in the virulence parameters, percent vascular discoloration, and percent foliar wilting, when compared with the wild type. Our results indicate that the inability to produce CU had no measurable effect on the ability of O. novo-ulmi to produce symptoms of Dutch elm disease on inoculated elms.
authors.affiliation: Department of Botany, University of Toronto, Mississauga, Ontario, Canada.
authors.forename: C G
authors.initials: CG
authors.lastname: Bowden
authors.forename: E
authors.initials: E
authors.lastname: Smalley
authors.forename: R P
authors.initials: RP
authors.lastname: Guries
authors.forename: M
authors.initials: M
authors.lastname: Hubbes
authors.forename: B
authors.initials: B
authors.lastname: Temple
authors.forename: P A
authors.initials: PA
authors.lastname: Horgen
mesh_terms: D017931:DNA Primers; D005656:Fungal Proteins / Q000096:biosynthesis*; D005800:Genes, Fungal; D009183:Mycotoxins / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic; D014197:Trees / Q000382:microbiology*; D014774:Virulence; D013098:Xylariales / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*
chemical_list: D017931:DNA Primers; D005656:Fungal Proteins; D009183:Mycotoxins; C079060:CU protein, Ophiostoma ulmi