Résumé
Pathogens secrete effector proteins to promote virulence. Despite their recognition by barley Mla resistance genes, the structurally-related Blumeria hordei (Bh) AVR A effectors are maintained in the Bh genome, suggesting virulence functions critical for fungal pathogenicity.</p><p>Using proximity-dependent protein labelling in transgenic barley, we detected distinct host protein interactomes for five AVR A s despite their structural homology and convergence on MLAs. We report the specific interaction of the highly conserved AVR A13 effector with the barley cell-surface receptor SRF3. AVR A13 disrupts HvSRF3-HvBAK1 interaction and alters HvSRF3 plasma membrane levels. AVR a13 -expression desensitizes iron-induced restriction of Bh growth, suggesting that AVR A13 facilitates fungal proliferation by manipulating SRF3mediated iron homeostasis. Our results suggest that MLAs have diversified to specifically detect the residues that underly Bh effector neo-functionalization and intrinsic AVR A virulence functions. Together, these findings identify SRF3 as molecular link between pathogen virulence, immune recognition, and iron homeostasis.