Die Another Day: molecular mechanisms of effector-triggered immunity elicited by type III secreted effector proteins.

Bacterial pathogens inject type III secreted effector (T3SE) proteins into their hosts where they display dual roles depending on the host genotype. T3SEs promote bacterial virulence in susceptible hosts, and elicit immunity in resistant hosts. T3SEs are typically recognized when they modify a host target that is associated with a NOD-like receptor protein. We focus on the molecular mechanisms of T3SE recognition in plants. Plants guard multiple nodes of the immune signaling pathway, from recognition at the cell surface by receptor-like kinases to nuclear signaling. Some nodes are bacterial virulence targets, while other nodes are decoys that resemble true virulence targets.