title: Frp1 is a Fusarium oxysporum F-box protein required for pathogenicity on tomato.
abstract: Fusarium oxysporum f. sp. lycopersici is the causal agent of tomato wilt disease. In order to identify genes involved in its pathogenicity, we performed insertional mutagenesis. Mutant N40 had lost its pathogenicity completely, when tested in bioassays with tomato seedlings. Molecular characterization of mutant N40 revealed that the plasmid insertion had occurred in a gene that codes for a 60.2 kDa protein containing an F-box motif. The gene was therefore designated as FRP1 (F-box protein required for pathogenicity). Targeted FRP1 disruptants had lost their pathogenicity completely, and became fully virulent again upon re-introduction of the FRP1 gene. This confirmed that the FRP1 gene is required for pathogenesis. In a yeast two-hybrid assay Frp1 interacts with Skp1, suggesting involvement of an SCF ubiquitin ligase complex in pathogenicity. FRP1 is constitutively expressed during infection and under different culture conditions. Although growth, spore formation and germination on artificial media were not impaired, confocal laser scanning microscopy of a GFP-marked mutant N40 and a GFP-marked targeted FRP1 disruptant revealed that they were unable to colonize the roots.
authors.affiliation: Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1091 SM Amsterdam, the Netherlands.
authors.forename: Roselinde G E
authors.initials: RG
authors.lastname: Duyvesteijn
authors.forename: Ringo
authors.initials: R
authors.lastname: van Wijk
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Boer
authors.forename: Martijn
authors.initials: M
authors.lastname: Rep
authors.forename: Ben J C
authors.initials: BJ
authors.lastname: Cornelissen
authors.forename: Michel A
authors.initials: MA
authors.lastname: Haring
mesh_terms: D000595:Amino Acid Sequence; D044783:F-Box Proteins / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005670:Fusarium / Q000235:genetics* / Q000472:pathogenicity*; D005800:Genes, Fungal; D018551:Solanum lycopersicum / Q000254:growth & development / Q000382:microbiology*; D008969:Molecular Sequence Data; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000378:metabolism; D044786:S-Phase Kinase-Associated Proteins / Q000378:metabolism; D014774:Virulence / Q000235:genetics
chemical_list: D044783:F-Box Proteins; D005656:Fungal Proteins; D044786:S-Phase Kinase-Associated Proteins