Direct avirulence effector-receptor interaction confers wheat immunity against insects

Abstract

Wheat immunity against the global pest Hessian fly operates on a gene-for-gene basis, yet molecular mechanisms underlying resistance-avirulence interactions have remained elusive for over five decades due to the absence of any cloned insect-resistance gene. Here, we cloned the H13 resistance gene encoding a coiled-coil/nucleotide-binding/leucine-rich repeat protein that protects wheat against multiple Hessian fly biotypes, and demonstrate direct molecular interaction with its cognate avirulence effector, vH13. H13-vH13 recognition activates effector-triggered immunity through calcium signaling, oxidative burst, jasmonic acid and ethylene, but not salicylic acid, signaling pathways, leading to larval antibiosis. Notably, H13 is evolutionarily unique, lacking similarity with other wheat disease- or plant insect-resistance proteins. This study provides a mechanistic model for understanding and engineering durable insect resistance in crops.