A transmembrane protein confers the Yr26/Yr24/YrCH42/YrG22-mediated stripe rust resistance in wheat

Abstract

Stripe or yellow rust (YR), caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is a devastating fungal disease of wheat. Here, we report the map-based cloning of Yr26 (synonyms: Yr24, YrCH42, and YrG22), a major stripe rust resistance gene, and its validation by gene silencing, mutation analysis and transgenic complementation. Yr26, which firstly arises in emmer wheat and recently has introgressed into bread wheat, is a newly evolved gene encoding a transmembrane protein. AlphaFold v3.0 predictes a C-terminal four-helical bundle domain that is critical for triggering Ca2+-dependent cell death, a hallmark of the hypersensitive response. The cloning of Yr26 offers not only a genetic resource for pyramiding stripe rust resistance genes in wheat breeding but also an opportunity to study host–pathogen co-evolution. Yellow rust (YR) is a devastating fungal disease of wheat. Here, the authors report the cloning of Yr26 as a transmembrane protein and reveal its evolves within the Triticeae lineage as an orphan gene.