Map-based cloning of the gene Pm21 that confers broad spectrum resistance to wheat powdery mildew

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.