Gene Symbol: hopAB2
Description: type III effector HopAB2
Alias: PSPTO3087, type III effector HopAB2
Species: Pseudomonas syringae pv. tomato str. DC3000

Top Publications

  1. Lin N, Martin G. An avrPto/avrPtoB mutant of Pseudomonas syringae pv. tomato DC3000 does not elicit Pto-mediated resistance and is less virulent on tomato. Mol Plant Microbe Interact. 2005;18:43-51 pubmed
    ..Our results indicate that AvrPto and AvrPtoB have phenotypically redundant avirulence activity on Pto-expressing tomato and additive virulence activities on susceptible tomato plants. ..
  2. Abramovitch R, Kim Y, Chen S, Dickman M, Martin G. Pseudomonas type III effector AvrPtoB induces plant disease susceptibility by inhibition of host programmed cell death. EMBO J. 2003;22:60-9 pubmed
    ..Thus, our results indicate that a type III effector can induce plant susceptibility to bacterial infection by inhibiting host PCD. ..
  3. He P, Shan L, Lin N, Martin G, Kemmerling B, N rnberger T, et al. Specific bacterial suppressors of MAMP signaling upstream of MAPKKK in Arabidopsis innate immunity. Cell. 2006;125:563-75 pubmed publisher
    ..Deletions of avrPto and avrPtoB from pathogenic P. syringae reduce its virulence. The studies reveal a fundamental role of MAMP signaling in nonhost immunity, and a novel action of type III effectors from pathogenic bacteria...
  4. Fouts D, Abramovitch R, Alfano J, Baldo A, Buell C, Cartinhour S, et al. Genomewide identification of Pseudomonas syringae pv. tomato DC3000 promoters controlled by the HrpL alternative sigma factor. Proc Natl Acad Sci U S A. 2002;99:2275-80 pubmed publisher
    ..Additional candidate effector genes, hopPtoA2, hopPtoB2, and an avrRps4 homolog, were preceded by Hrp promoter-like sequences, but these had HMM expectation values of relatively low significance and were not detectably activated by HrpL...
  5. de Torres M, Mansfield J, Grabov N, Brown I, Ammouneh H, Tsiamis G, et al. Pseudomonas syringae effector AvrPtoB suppresses basal defence in Arabidopsis. Plant J. 2006;47:368-82 pubmed publisher
    ..The success or failure of AvrPtoB in suppressing basal defences in Nd-1 depended on the timing of exposure of plant cells to the effector and the flagellin flg22 peptide...
  6. Kim Y, Lin N, Martin G. Two distinct Pseudomonas effector proteins interact with the Pto kinase and activate plant immunity. Cell. 2002;109:589-98 pubmed
    ..Thus, two distinct bacterial effectors activate plant immunity by interacting with the same host protein kinase through a similar structural mechanism...
  7. Gimenez Ibanez S, Hann D, Ntoukakis V, Petutschnig E, Lipka V, Rathjen J. AvrPtoB targets the LysM receptor kinase CERK1 to promote bacterial virulence on plants. Curr Biol. 2009;19:423-9 pubmed publisher
    ..Our results reveal a new pathway for plant immunity against bacteria and a role for AvrPtoB E3-ligase activity in suppressing PTI...
  8. Cohn J, Martin G. Pseudomonas syringae pv. tomato type III effectors AvrPto and AvrPtoB promote ethylene-dependent cell death in tomato. Plant J. 2005;44:139-54 pubmed publisher
    ..AvrPto and AvrPtoB therefore appear to promote enhanced disease in tomato leaves, in part, by upregulating genes involved in ethylene production...
  9. Jamir Y, Guo M, Oh H, Petnicki Ocwieja T, Chen S, Tang X, et al. Identification of Pseudomonas syringae type III effectors that can suppress programmed cell death in plants and yeast. Plant J. 2004;37:554-65 pubmed
    ..The high proportion of effectors that suppress PCD suggests that suppressing plant immunity is one of the primary roles for DC3000 effectors and a central requirement for P. syringae pathogenesis. ..

More Information


  1. Navarro L, Jay F, Nomura K, He S, Voinnet O. Suppression of the microRNA pathway by bacterial effector proteins. Science. 2008;321:964-7 pubmed publisher
    ..These results provide evidence that, like viruses, bacteria have evolved to suppress RNA silencing to cause disease. ..
  2. G hre V, Spallek T, H weker H, Mersmann S, Mentzel T, Boller T, et al. Plant pattern-recognition receptor FLS2 is directed for degradation by the bacterial ubiquitin ligase AvrPtoB. Curr Biol. 2008;18:1824-32 pubmed publisher
  3. Rosebrock T, Zeng L, Brady J, Abramovitch R, Xiao F, Martin G. A bacterial E3 ubiquitin ligase targets a host protein kinase to disrupt plant immunity. Nature. 2007;448:370-4 pubmed
    ..Various wild species of tomato were found to exhibit immunity in response to AvrPtoB(1-387 )and not to full-length AvrPtoB. Thus, by acquiring an E3 ligase domain, AvrPtoB has thwarted a highly conserved host resistance mechanism. ..
  4. Abramovitch R, Janjusevic R, Stebbins C, Martin G. Type III effector AvrPtoB requires intrinsic E3 ubiquitin ligase activity to suppress plant cell death and immunity. Proc Natl Acad Sci U S A. 2006;103:2851-6 pubmed
    ..Overall, these data reveal a unique bacterial pathogenesis strategy, where AvrPtoB manipulates the host Ub system and requires intrinsic E3 Ub ligase activity to suppress plant immunity. ..
  5. Hann D, Rathjen J. Early events in the pathogenicity of Pseudomonas syringae on Nicotiana benthamiana. Plant J. 2007;49:607-18 pubmed
    ..This observation separates the respective mechanisms of the two effectors, and suggests that AvrPtoB may target the defence machinery directly for its suppressive effect. ..
  6. Janjusevic R, Abramovitch R, Martin G, Stebbins C. A bacterial inhibitor of host programmed cell death defenses is an E3 ubiquitin ligase. Science. 2006;311:222-6 pubmed
    ..These results show that Pseudomonas syringae uses a mimic of host E3 ubiquitin ligases to inactivate plant defenses. ..
  7. de Torres Zabala M, Truman W, Bennett M, Lafforgue G, Mansfield J, Rodriguez Egea P, et al. Pseudomonas syringae pv. tomato hijacks the Arabidopsis abscisic acid signalling pathway to cause disease. EMBO J. 2007;26:1434-43 pubmed publisher
    ..Our data suggest that a major virulence strategy is effector-mediated manipulation of plant hormone homeostasis, which leads to the suppression of defence responses...
  8. Ntoukakis V, Mucyn T, Gimenez Ibanez S, Chapman H, Gutierrez J, Balmuth A, et al. Host inhibition of a bacterial virulence effector triggers immunity to infection. Science. 2009;324:784-7 pubmed publisher
    ..Pto avoids this by phosphorylating and inactivating the AvrPtoB E3 domain. Thus, inactivation of a pathogen virulence molecule is one mechanism by which plants resist disease. ..
  9. de Vries J, Andriotis V, Wu A, Rathjen J. Tomato Pto encodes a functional N-myristoylation motif that is required for signal transduction in Nicotiana benthamiana. Plant J. 2006;45:31-45 pubmed publisher
    ..Consistent with this idea, AvrPtoB was also found to be a soluble protein. The data indicate an important role(s) for the myristoylated N-terminus in Pto signalling...