The endosome as an effector target to mediate plant immunity?

Abstract

Membrane trafficking is key for different aspects of plant immunity such as the formation of papillae and haustorial encasements. These block ingress or slow the development of filamentous pathogens respectively, while the hypersensitive response (HR) is a localized cell death to halt the spread of such pathogens. Guanine nucleotide exchange factors (GEFs) activate Rab GTPases which regulate membrane trafficking. Now, Liao et al. (2023) have found that the GEF Monensin Sensitivity 1 (MON1) is required for components of plant immunity including haustorial encasement formation and the HR. MON1 interacts with the Blumeria hordei-secreted effector CSEP0162. Therefore, MON1 is a likely target for the effector CSEP0162 to promote Bh infection.