Leaf rust, caused by Puccinia hordei, is one of the most widespread and damaging foliar diseases affecting barley. The barley leaf rust resistance locus Rph7 has been shown to have unusually high sequence and haplotype divergence. In this study, we isolate the Rph7 gene using a fine mapping and RNA-Seq approach that is confirmed by mutational analysis and transgenic complementation. Rph7 is a pathogen-induced, non-canonical resistance gene encoding a protein that is distinct from other known plant disease resistance proteins in the Triticeae. Structural analysis using an AlphaFold2 protein model suggests that Rph7 encodes a putative NAC transcription factor with a zinc-finger BED domain with structural similarity to the N-terminal DNA-binding domain of the NAC transcription factor (ANAC019) from Arabidopsis. A global gene expression analysis suggests Rph7 mediates the activation and strength of the basal defence response. The isolation of Rph7 highlights the diversification of resistance mechanisms available for engineering disease control in crops.

CSIRO Agriculture and Food Commonwealth Scientific and Industrial Research Organisation GPO Box 1700 Canberra ACT 2601 Australia

Institute of Experimental Botany Centre of Plant Structural and Functional Genomics Olomouc CZ 77900 Czech Republic

La Trobe Institute for Sustainable Agriculture and Food Department of Animal Plant and Soil Sciences La Trobe University Melbourne VIC 3086 Australia

The University of Southern Queensland School of Agriculture and Environmental Science Centre for Crop Health Toowoomba QLD 4350 Australia

The University of Sydney Faculty of Science Plant Breeding Institute Cobbitty NSW 2570 Australia

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