Paired NLRs originated from Triticum dicoccoides coordinately confer resistance to powdery mildew in wheat.

Abstract

Wheat has evolved diverse resistance genes against powdery mildew, typically controlled by single-gene-encoded proteins. Here, we report the map-based cloning of PmWR183, a resistance locus encoding two adjacent NLR proteins (PmWR183-NLR1 and PmWR183-NLR2) from wild emmer wheat. Stable transformation and CRISPR/Cas9 knockout experiments demonstrate that the two NLRs function cooperatively: neither gene alone confers resistance, but their co-expression restores immunity, while disruption of either gene abolishes resistance. PmWR183 mediates a developmental stage-dependent response, with susceptibility at the seedling stage and strong resistance at the adult stage. Protein interaction assays reveal constitutive association of PmWR183-NLR1 and PmWR183-NLR2, supporting their cooperative role. Geographical and haplotype analyses show the locus originates from wild emmer and is rare in cultivated wheat, exhibiting at least nine haplotypes. Together, our findings uncover a rare NLR gene pair conferring effective resistance to powdery mildew, providing valuable resources for wheat breeding.