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AvrPm2 encodes an RN ase‐like avirulence effector which is conserved in the two different specialized forms of wheat and rye powdery mildew fungus
Author(s) -
Praz Coraline R.,
Bourras Salim,
Zeng Fansong,
SánchezMartín Javier,
Menardo Fabrizio,
Xue Minfeng,
Yang Lijun,
Roffler Stefan,
Böni Rainer,
Herren Gerard,
McNally Kaitlin E.,
BenDavid Roi,
Parlange Francis,
Oberhaensli Simone,
Flückiger Simon,
Schäfer Luisa K.,
Wicker Thomas,
Yu Dazhao,
Keller Beat
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14372
Subject(s) - blumeria graminis , powdery mildew , biology , genetics , gene , triticale , r gene , plant disease resistance , effector , nicotiana benthamiana , common wheat , mildew , conserved sequence , virulence , botany , peptide sequence , chromosome , microbiology and biotechnology
Summary 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 AvrPm3 a2/f2 that 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 RN ase‐like effectors, including Avr a13 from 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.