A Putative ABC Transporter Confers Durable Resistance to Multiple Fungal Pathogens in Wheat

TLDR

Durable resistance to wheat fungal pathogens such as leaf rust, stripe rust, and powdery mildew is often conferred by genes like Lr34, which has provided long‑term protection for over 50 years across global cultivars. We demonstrate that the Lr34 protein is an ABC transporter of the pleiotropic drug resistance subfamily, with resistance or susceptibility alleles differing by three polymorphisms, and that the gene promotes senescence‑like changes in flag leaf tips and edges during adult plant growth.

Abstract

Agricultural crops benefit from resistance to pathogens that endures over years and generations of both pest and crop. Durable disease resistance, which may be partial or complete, can be controlled by several genes. Some of the most devastating fungal pathogens in wheat are leaf rust, stripe rust, and powdery mildew. The wheat gene Lr34 has supported resistance to these pathogens for more than 50 years. Lr34 is now shared by wheat cultivars around the world. Here, we show that the LR34 protein resembles adenosine triphosphate-binding cassette transporters of the pleiotropic drug resistance subfamily. Alleles of Lr34 conferring resistance or susceptibility differ by three genetic polymorphisms. The Lr34 gene, which functions in the adult plant, stimulates senescence-like processes in the flag leaf tips and edges.