title: Insight into the molecular requirements for pathogenicity of Fusarium oxysporum f. sp. lycopersici through large-scale insertional mutagenesis.
abstract: BACKGROUND
  Fusarium oxysporum f. sp. lycopersici is the causal agent of vascular wilt disease in tomato. In order to gain more insight into the molecular processes in F. oxysporum necessary for pathogenesis and to uncover the genes involved, we used Agrobacterium-mediated insertional mutagenesis to generate 10,290 transformants and screened the transformants for loss or reduction of pathogenicity.
  
  
  RESULTS
  This led to the identification of 106 pathogenicity mutants. Southern analysis revealed that the average T-DNA insertion is 1.4 and that 66% of the mutants carry a single T-DNA. Using TAIL-PCR, chromosomal T-DNA flanking regions were isolated and 111 potential pathogenicity genes were identified.
  
  
  CONCLUSIONS
  Functional categorization of the potential pathogenicity genes indicates that certain cellular processes, such as amino acid and lipid metabolism, cell wall remodeling, protein translocation and protein degradation, seem to be important for full pathogenicity of F. oxysporum. Several known pathogenicity genes were identified, such as those encoding chitin synthase V, developmental regulator FlbA and phosphomannose isomerase. In addition, complementation and gene knock-out experiments confirmed that a glycosylphosphatidylinositol-anchored protein, thought to be involved in cell wall integrity, a transcriptional regulator, a protein with unknown function and peroxisome biogenesis are required for full pathogenicity of F. oxysporum.
authors.affiliation: Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands. c.b.michielse@uva.nl
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Michielse
authors.forename: Ringo
authors.initials: R
authors.lastname: van Wijk
authors.forename: Linda
authors.initials: L
authors.lastname: Reijnen
authors.forename: Ben J C
authors.initials: BJ
authors.lastname: Cornelissen
authors.forename: Martijn
authors.initials: M
authors.lastname: Rep
mesh_terms: D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology; D005670:Fusarium / Q000235:genetics / Q000472:pathogenicity*; D005800:Genes, Fungal; D018551:Solanum lycopersicum / Q000382:microbiology; D016254:Mutagenesis, Insertional / Q000379:methods*; D010935:Plant Diseases / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins