title: Rapid identification of the Leptosphaeria maculans avirulence gene AvrLm2 using an intraspecific comparative genomics approach.
abstract: Five avirulence genes from Leptosphaeria maculans, the causal agent of blackleg of canola (Brassica napus), have been identified previously through map-based cloning. In this study, a comparative genomic approach was used to clone the previously mapped AvrLm2. Given the lack of a presence-absence gene polymorphism coincident with the AvrLm2 phenotype, 36 L. maculans isolates were resequenced and analysed for single-nucleotide polymorphisms (SNPs) in predicted small secreted protein-encoding genes present within the map interval. Three SNPs coincident with the AvrLm2 phenotype were identified within LmCys1, previously identified as a putative effector-coding gene. Complementation of a virulent isolate with LmCys1, as the candidate AvrLm2 allele, restored the avirulent phenotype on Rlm2-containing B. napus lines. AvrLm2 encodes a small cysteine-rich protein with low similarity to other proteins in the public databases. Unlike other avirulence genes, AvrLm2 resides in a small GC island within an AT-rich isochore of the genome, and was never found to be deleted completely in virulent isolates.
authors.affiliation: Saskatoon Research Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2.|Department of Plant Science, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2.
authors.forename: Kaveh
authors.initials: K
authors.lastname: Ghanbarnia
authors.affiliation: INRA-Bioger, 78850, Thiverval-Grignon, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fudal
authors.affiliation: Saskatoon Research Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Larkan
authors.affiliation: Saskatoon Research Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2.|Department of Computer Science, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5C9.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Links
authors.affiliation: INRA-Bioger, 78850, Thiverval-Grignon, France.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Balesdent
authors.affiliation: INRA-Bioger, 78850, Thiverval-Grignon, France.
authors.forename: Bronislava
authors.initials: B
authors.lastname: Profotova
authors.affiliation: Department of Plant Science, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2.
authors.forename: W G Dilantha
authors.initials: WG
authors.lastname: Fernando
authors.affiliation: INRA-Bioger, 78850, Thiverval-Grignon, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Rouxel
authors.affiliation: Saskatoon Research Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2.
authors.forename: M Hossein
authors.initials: MH
authors.lastname: Borhan
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000235:genetics*; D001483:Base Sequence; D029688:Brassica napus / Q000382:microbiology*; D004271:DNA, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide
chemical_list: D004271:DNA, Fungal
keywords: Brassica napus; Leptosphaeria maculans; avirulence gene; comparative genomics