AvrPtoB: a bacterial type III effector that both elicits and suppresses programmed cell death associated with plant immunity

FEMS Microbiol Lett. 2005 Apr 1;245(1):1-8. doi: 10.1016/j.femsle.2005.02.025.

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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Apoptosis*
  • Bacterial Proteins / metabolism*
  • Gene Expression Regulation, Plant*
  • Immunity, Innate*
  • Plant Diseases / microbiology
  • Plant Proteins / metabolism
  • Protein Serine-Threonine Kinases / metabolism
  • Pseudomonas syringae / pathogenicity*
  • Solanum lycopersicum / microbiology*
  • Virulence

Substances

  • Bacterial Proteins
  • Plant Proteins
  • avrPto protein, Pseudomonas syringae
  • Pto protein, Lycopersicon
  • Protein Serine-Threonine Kinases