title: AvrPm2 encodes an RNase-like avirulence effector which is conserved in the two different specialized forms of wheat and rye powdery mildew fungus.
abstract: There is a large diversity of genetically defined resistance genes in bread wheat against the powdery mildew pathogen Blumeria graminis (B. g.) f. sp. tritici. Many confer race-specific resistance to this pathogen, but until now only the mildew avirulence gene AvrPm3a2/f2that is recognized by Pm3a/f was known molecularly. We performed map-based cloning and genome-wide association studies to isolate a candidate for the mildew avirulence gene AvrPm2. We then used transient expression assays in Nicotiana benthamiana to demonstrate specific and strong recognition of AvrPm2 by Pm2. The virulent AvrPm2 allele arose from a conserved 12 kb deletion, while there is no protein sequence diversity in the gene pool of avirulent B. g. tritici isolates. We found one polymorphic AvrPm2 allele in B. g. triticale and one orthologue in B. g. secalis and both are recognized by Pm2. AvrPm2 belongs to a small gene family encoding structurally conserved RNase-like effectors, including Avra13from B. g. hordei, the cognate Avr of the barley resistance gene Mla13. These results demonstrate the conservation of functional avirulence genes in two cereal powdery mildews specialized on different hosts, thus providing a possible explanation for successful introgression of resistance genes from rye or other grass relatives to wheat.
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Coraline R
authors.initials: CR
authors.lastname: Praz
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Salim
authors.initials: S
authors.lastname: Bourras
authors.affiliation: Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China.|Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China.|College of Life Science, Wuhan University, Wuhan, 430072, China.
authors.forename: Fansong
authors.initials: F
authors.lastname: Zeng
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Javier
authors.initials: J
authors.lastname: Sánchez-Martín
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Menardo
authors.affiliation: Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China.|Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China.|College of Life Science, Wuhan University, Wuhan, 430072, China.
authors.forename: Minfeng
authors.initials: M
authors.lastname: Xue
authors.affiliation: Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China.|Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China.|College of Life Science, Wuhan University, Wuhan, 430072, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Roffler
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Rainer
authors.initials: R
authors.lastname: Böni
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Gerard
authors.initials: G
authors.lastname: Herren
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Kaitlin E
authors.initials: KE
authors.lastname: McNally
authors.affiliation: Institute of Plant Science, ARO-Volcani Center, Bet Dagan, 50250, Israel.
authors.forename: Roi
authors.initials: R
authors.lastname: Ben-David
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Francis
authors.initials: F
authors.lastname: Parlange
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Simone
authors.initials: S
authors.lastname: Oberhaensli
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Flückiger
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Luisa K
authors.initials: LK
authors.lastname: Schäfer
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wicker
authors.affiliation: Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China.|Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China.|College of Life Science, Wuhan University, Wuhan, 430072, China.
authors.forename: Dazhao
authors.initials: D
authors.lastname: Yu
authors.affiliation: Department of Plant and Microbial Biology, University of Zürich, Zürich, 8008, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Keller
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000235:genetics / Q000472:pathogenicity*; D017124:Conserved Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D056426:Genetic Loci; D055106:Genome-Wide Association Study; D008958:Models, Molecular; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000382:microbiology*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism*; D012434:Secale / Q000382:microbiology*; D014026:Nicotiana / Q000382:microbiology; D014908:Triticum / Q000382:microbiology*; D014774:Virulence
chemical_list: D005656:Fungal Proteins; D010940:Plant Proteins; D012260:Ribonucleases
keywords: 
  Blumeria graminis
  ; 
  Pm2
  ; RNAse-like; avirulence gene; powdery mildew; wheat