Open AccessRapid identification of the L eptosphaeria maculans avirulence gene AvrLm2 using an intraspecific comparative genomics approach
Author(s) -
Ghanbarnia Kaveh,
Fudal Isabelle,
Larkan Nicholas J.,
Links Matthew G.,
Balesdent MarieHélène,
Profotova Bronislava,
Fernando W. G. Dilantha,
Rouxel Thierry,
Borhan M. Hossein
Publication year - 2015
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12228
Subject(s) - biology , genetics , leptosphaeria maculans , gene , complementation , genome , virulence , coding region , genomics , phenotype
Summary Five avirulence genes from L eptosphaeria maculans , the causal agent of blackleg of canola ( B rassica 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.