title: The LmSNF1 gene is required for pathogenicity in the canola blackleg pathogen Leptosphaeria maculans.
abstract: Leptosphaeria maculans is a fungal pathogen causing blackleg in canola. Its virulence has been attributed, among other factors, to the activity of hydrolytic cell wall degrading enzymes (CWDEs). Studies on the pathogenicity function of CWDEs in plant pathogenic fungi have been difficult due to gene redundancy. In microorganisms many CWDE genes are repressed by glucose and derepressed by the function of the sucrose non-fermenting protein kinase 1 gene (SNF1). To address the molecular function of SNF1 in L. maculans, the ortholog of SNF1 (LmSNF1) was cloned and functionally characterized using a gene knockout strategy. Growth of the LmSNF1 knockout strains was severely disrupted, as was sporulation, spore germination and the ability to attach on the plant surface. When inoculated on canola cotyledons, the LmSNF1 knockout strains could not cause any symptoms, indicating the loss of pathogenicity. The expression of 11 selected CWDE genes and a pathogenicity gene (LopB) was significantly down-regulated in the LmSNF1 knockout strains. In conclusion, knockout of LmSNF1 prevents L. maculans from properly derepressing the production of CWDEs, compromises the utilization of certain carbon sources, and impairs fungal pathogenicity on canola.
authors.affiliation: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, Alberta, Canada.
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Strelkov
authors.affiliation: Crop Diversification Centre North, Alberta Agriculture and Rural Development, Edmonton, Alberta, Canada.
authors.forename: Sheau-Fang
authors.initials: SF
authors.lastname: Hwang
mesh_terms: D001203:Ascomycota / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D029688:Brassica napus / Q000382:microbiology*; D002473:Cell Wall / Q000378:metabolism; D018548:Cotyledon / Q000382:microbiology; D015536:Down-Regulation / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D055785:Gene Knockdown Techniques; D055786:Gene Knockout Techniques; D005800:Genes, Fungal / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D018515:Plant Leaves / Q000382:microbiology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases