Structure of the <i>Arabidopsis RPM1</i> Gene Enabling Dual Specificity Disease Resistance

TLDR

Plants use disease‑resistance genes to recognize pathogens that carry matching avirulence genes, yet the molecular basis of this gene‑for‑gene specificity remains unknown. The Arabidopsis RPM1 gene confers resistance to two distinct Pseudomonas syringae avirulence genes, shares features with single‑specificity R genes, yet is absent from naturally disease‑susceptible accessions.

Abstract

Plants can recognize pathogens through the action of disease resistance (R) genes, which confer resistance to pathogens expressing unique corresponding avirulence (avr) genes. The molecular basis of this gene-for-gene specificity is unknown. The Arabidopsis thaliana RPM1 gene enables dual specificity to pathogens expressing either of two unrelated Pseudomonas syringae avr genes. Despite this function, RPM1 encodes a protein sharing molecular features with recently described single-specificity R genes. Surprisingly, RPM1 is lacking from naturally occurring, disease-susceptible Arabidopsis accessions.