Allelic variation of Avr genes in highly virulent strains explains severe wheat stem rust epidemics.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41688466.
- Also identified by DOI 10.1038/s41467-026-69508-8 and PMC identifier 13013614.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Wheat stem rust is a disease of global importance caused by the fungal pathogen Puccinia graminis f. sp. tritici (Pgt). Here we generate chromosome-level, nuclear-phased genome references for Pgt isolates ETH2013-1 and ITA2018-1, representing races TKTTF and TTRTF respectively, that have caused major epidemics in Africa and Europe. The nuclear haplotypes of ETH2013-1 and ITA2018-1 are unique and unrelated to those of Ug99 and Pgt21. Pgt nuclear haplotypes show extensive variation in sequence and copy number of six known Avr genes and AvrSr33, which we identify through an effector gene library screen. Recognition properties of 22 novel Avr gene variants explain the race virulence phenotypes and the outbreak of TTRTF on durum cultivars containing Sr13b, since ITA2018-1 carries a homozygous deletion of AvrSr13. This work establishes an Avr gene atlas for Pgt that can inform wheat breeding and enable development of sequence-based virulence diagnostic tools for pathogen surveillance.
Medical subject headings
- Triticum
- Plant Diseases
- Puccinia
- Basidiomycota
- Genes, Fungal