title: AvrPtoB: a bacterial type III effector that both elicits and suppresses programmed cell death associated with plant immunity.
abstract: Pseudomonas syringae pv. tomato DC3000 is a model pathogen for studying the molecular basis of plant immunity and disease susceptibility in tomato and Arabidopsis. DC3000 uses a type III secretion system to inject effector proteins into the plant cell. Type III effectors are thought to promote bacterial virulence by suppressing plant defenses and enhancing access to nutrients trapped in the plant cell. The AvrPtoB type III effector elicits immunity-associated programmed cell death (PCD) when expressed in tomato plants carrying the Pto resistance protein. However, in the absence of Pto, AvrPtoB functions to suppress PCD and immunity in tomato. Here, we review current research examining the molecular basis of AvrPtoB-mediated elicitation and suppression of plant PCD. In addition, the "trump model" is proposed to explain how resistance proteins successfully elicit immunity-associated PCD in response to effectors that suppress PCD.
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Abramovitch
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Martin
mesh_terms: D017209:Apoptosis; D001426:Bacterial Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate; D018551:Solanum lycopersicum / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D044224:Pseudomonas syringae / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; C081695:avrPto protein, Pseudomonas syringae; C084354:Pto protein, Lycopersicon; D017346:Protein Serine-Threonine Kinases