  Common wheat (Triticum aestivum L.) is one of the most important cereal
crops. Wheat powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is
a continuing threat to wheat production. The Pm21 gene, originating from
Dasypyrum villosum, confers high resistance to all known Bgt races and has been
widely applied in wheat breeding in China. In this research, we identify Pm21
as a typical coiled-coil, nucleotide-binding site, leucine-rich repeat gene by
an integrated strategy of resistance gene analog (RGA)-based cloning via
comparative genomics, physical and genetic mapping, BSMV-induced gene silencing
(BSMV-VIGS), large-scale mutagenesis and genetic transformation.
