The hijacking of a receptor kinase-driven pathway by a wheat fungal pathogen leads to disease.

Abstract

Necrotrophic pathogens live and feed on dying tissue, but their interactions with plants are not well understood compared to biotrophic pathogens. The wheat <i>Snn1</i> gene confers susceptibility to strains of the necrotrophic pathogen <i>Parastagonospora nodorum</i> that produce the SnTox1 protein. We report the positional cloning of <i>Snn1</i>, a member of the wall-associated kinase class of receptors, which are known to drive pathways for biotrophic pathogen resistance. Recognition of SnTox1 by <i>Snn1</i> activates programmed cell death, which allows this necrotroph to gain nutrients and sporulate. These results demonstrate that necrotrophic pathogens such as <i>P. nodorum</i> hijack host molecular pathways that are typically involved in resistance to biotrophic pathogens, revealing the complex nature of susceptibility and resistance in necrotrophic and biotrophic pathogen interactions with plants.