title: A game of hide and seek between avirulence genes AvrLm4-7 and AvrLm3 in Leptosphaeria maculans.
abstract: Extending the durability of plant resistance genes towards fungal pathogens is a major challenge. We identified and investigated the relationship between two avirulence genes of Leptosphaeria maculans, AvrLm3 and AvrLm4-7. When an isolate possesses both genes, the Rlm3-mediated resistance of oilseed rape (Brassica napus) is not expressed due to the presence of AvrLm4-7 but virulent isolates toward Rlm7 recover the AvrLm3 phenotype. Combining genetic and genomic approaches (genetic mapping, RNA-seq, BAC (bacterial artificial chromosome) clone sequencing and de novo assembly) we cloned AvrLm3, a telomeric avirulence gene of L. maculans. AvrLm3 is located in a gap of the L. maculans reference genome assembly, is surrounded by repeated elements, encodes for a small secreted cysteine-rich protein and is highly expressed at early infection stages. Complementation and silencing assays validated the masking effect of AvrLm4-7 on AvrLm3 recognition by Rlm3 and we showed that the presence of AvrLm4-7 does not impede AvrLm3 expression in planta. Y2H assays suggest the absence of physical interaction between the two avirulence proteins. This unusual interaction is the basis for field experiments aiming to evaluate strategies that increase Rlm7 durability.
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Plissonneau
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Daverdin
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Ollivier
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Blaise
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Degrave
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fudal
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Rouxel
authors.affiliation: INRA, UMR INRA-AgroParisTech 1290-Bioger, Avenue Lucien Brétignières, BP 01, F-78850, Thiverval-Grignon, France.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Balesdent
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000235:genetics* / Q000472:pathogenicity*; D001483:Base Sequence; D029688:Brassica napus / Q000235:genetics / Q000382:microbiology; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005800:Genes, Fungal; D017343:Genes, Plant; D056426:Genetic Loci; D058977:Molecular Sequence Annotation; D009691:Nucleic Acid Denaturation; D010641:Phenotype; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000382:microbiology; D011110:Polymorphism, Genetic; D011485:Protein Binding; D015203:Reproducibility of Results; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins
keywords: Brassica napus; Leptosphaeria maculans; avirulence; durable resistance; interaction; next-generation sequencing (NGS); oilseed rape