This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Deng, W.-L.
Right arrow Articles by Collmer, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Deng, W.-L.
Right arrow Articles by Collmer, A.

 Previous Article  |  Next Article 

Journal of Bacteriology, April 2003, p. 2592-2602, Vol. 185, No. 8
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.8.2592-2602.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Pseudomonas syringae Exchangeable Effector Loci: Sequence Diversity in Representative Pathovars and Virulence Function in P. syringae pv. syringae B728a

Wen-Ling Deng, Amos H. Rehm, Amy O. Charkowski,{dagger} Clemencia M. Rojas, and Alan Collmer*

Department of Plant Pathology, Cornell University, Ithaca, New York 14853

Received 30 August 2002/ Accepted 23 January 2003

Pseudomonas syringae is a plant pathogen whose pathogenicity and host specificity are thought to be determined by Hop/Avr effector proteins injected into plant cells by a type III secretion system. P. syringae pv. syringae B728a, which causes brown spot of bean, is a particularly well-studied strain. The type III secretion system in P. syringae is encoded by hrp (hypersensitive response and pathogenicity) and hrc (hrp conserved) genes, which are clustered in a pathogenicity island with a tripartite structure such that the hrp/hrc genes are flanked by a conserved effector locus and an exchangeable effector locus (EEL). The EELs of P. syringae pv. syringae B728a, P. syringae strain 61, and P. syringae pv. tomato DC3000 differ in size and effector gene composition; the EEL of P. syringae pv. syringae B728a is the largest and most complex. The three putative effector proteins encoded by the P. syringae pv. syringae B728a EEL—HopPsyC, HopPsyE, and HopPsyV—were demonstrated to be secreted in an Hrp-dependent manner in culture. Heterologous expression of hopPsyC, hopPsyE, and hopPsyV in P. syringae pv. tabaci induced the hypersensitive response in tobacco leaves, demonstrating avirulence activity in a nonhost plant. Deletion of the P. syringae pv. syringae B728a EEL strongly reduced virulence in host bean leaves. EELs from nine additional strains representing nine P. syringae pathovars were isolated and sequenced. Homologs of avrPphE (e.g., hopPsyE) and hopPsyA were particularly common. Comparative analyses of these effector genes and hrpK (which flanks the EEL) suggest that the EEL effector genes were acquired by horizontal transfer after the acquisition of the hrp/hrc gene cluster but before the divergence of modern pathovars and that some EELs underwent transpositions yielding effector exchanges or point mutations producing effector pseudogenes after their acquisition.

* Corresponding author. Mailing address: Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Phone: (607) 255-7843. Fax: (607) 255-4471. E-mail: arc2{at}cornell.edu.

{dagger} Present address: Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706.

Journal of Bacteriology, April 2003, p. 2592-2602, Vol. 185, No. 8
0021-9193/03/$08.00+0     DOI: 10.1128/JB.185.8.2592-2602.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Mohr, T. J., Liu, H., Yan, S., Morris, C. E., Castillo, J. A., Jelenska, J., Vinatzer, B. A. (2008). Naturally Occurring Nonpathogenic Isolates of the Plant Pathogen Pseudomonas syringae Lack a Type III Secretion System and Effector Gene Orthologues. J. Bacteriol. 190: 2858-2870 [Abstract] [Full Text]  
  • Lewis, J. D., Abada, W., Ma, W., Guttman, D. S., Desveaux, D. (2008). The HopZ Family of Pseudomonas syringae Type III Effectors Require Myristoylation for Virulence and Avirulence Functions in Arabidopsis thaliana. J. Bacteriol. 190: 2880-2891 [Abstract] [Full Text]  
  • Araki, H., Innan, H., Kreitman, M., Bergelson, J. (2007). Molecular Evolution of Pathogenicity-Island Genes in Pseudomonas viridiflava. Genetics 177: 1031-1041 [Abstract] [Full Text]  
  • Fletcher, J., Bender, C., Budowle, B., Cobb, W. T., Gold, S. E., Ishimaru, C. A., Luster, D., Melcher, U., Murch, R., Scherm, H., Seem, R. C., Sherwood, J. L., Sobral, B. W., Tolin, S. A. (2006). Plant Pathogen Forensics: Capabilities, Needs, and Recommendations. Microbiol. Mol. Biol. Rev. 70: 450-471 [Abstract] [Full Text]  
  • Jackson, R. W., Preston, G. M., Rainey, P. B. (2005). Genetic Characterization of Pseudomonas fluorescens SBW25 rsp Gene Expression in the Phytosphere and In Vitro. J. Bacteriol. 187: 8477-8488 [Abstract] [Full Text]  
  • Rose, L. E., Langley, C. H., Bernal, A. J., Michelmore, R. W. (2005). Natural Variation in the Pto Pathogen Resistance Gene Within Species of Wild Tomato (Lycopersicon). I. Functional Analysis of Pto Alleles. Genetics 171: 345-357 [Abstract] [Full Text]  
  • Petnicki-Ocwieja, T., van Dijk, K., Alfano, J. R. (2005). The hrpK Operon of Pseudomonas syringae pv. tomato DC3000 Encodes Two Proteins Secreted by the Type III (Hrp) Protein Secretion System: HopB1 and HrpK, a Putative Type III Translocator. J. Bacteriol. 187: 649-663 [Abstract] [Full Text]  
  • Rezzonico, F., Defago, G., Moenne-Loccoz, Y. (2004). Comparison of ATPase-Encoding Type III Secretion System hrcN Genes in Biocontrol Fluorescent Pseudomonads and in Phytopathogenic Proteobacteria. Appl. Environ. Microbiol. 70: 5119-5131 [Abstract] [Full Text]  
  • Bretz, J. R., Hutcheson, S. W. (2004). Role of Type III Effector Secretion during Bacterial Pathogenesis in Another Kingdom. Infect. Immun. 72: 3697-3705 [Full Text]  
  • Oguiza, J. A., Rico, A., Rivas, L. A., Sutra, L., Vivian, A., Murillo, J. (2004). Pseudomonas syringae pv. phaseolicola can be separated into two genetic lineages distinguished by the possession of the phaseolotoxin biosynthetic cluster. Microbiology 150: 473-482 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»