A single NLR gene confers resistance to leaf and stripe rust in wheat

Nucleotide-binding site leucine-rich repeat (NLR) disease-resistance genes typically confer resistance against races of a single pathogen. We report that Lr/Yr548, an NLR gene from Aegilops sharonensis and Aegilops longissima, confers specific resistance against Puccinia triticina (Pt) and P. striiformis tritici (Pst) that cause leaf and stripe rust, respectively. Lr/Yr548 prevented disease development in wheat introgression as well as transgenic wheat lines. Comparative analysis of Lr/Yr548 and all cloned Triticeae NLR disease-resistance genes showed that Lr/Yr548 contains a distinctive coiled-coil domain and that it is unique to Ae. sharonensis and Ae. longissima. A phylogenetic analysis indicated multiple events of gene flow of Lr/Yr548 between the two species, and suggested loss of resistance in susceptible isolates. The confinement of Lr/Yr548 to Ae. longissima and Ae. sharonensis and the cross resistance that it confers against Pt and Pst in wheat highlight the potential of these species as sources of novel disease-resistance genes for wheat improvement.