Overview

Our goal is to understand the molecular mechanisms that enable bacteria to attack plants. Much of our current work is focused on Pseudomonas syringae pv. tomato DC3000, which is a pathogen of tomato and the model plant Arabidopsis thaliana. Like many host-specific plant pathogens, P. syringae is a "stealth" parasite that can multiply for several days in host tissues before symptoms, such as necrotic spots, develop. We have learned that the ability of P. syringae to multiply in the intercellular spaces of plant leaves and cause disease is dependent on a "type III" secretion system that injects virulence effector proteins into host cells. Variants of this injector system are also used by many important animal pathogens (for example, Yersinia pestis, the plague pathogen) to deliver their virulence proteins. What is the complete repertoire of effectors and injectisome components secreted by P. syringae? How do effectors subvert host defenses? What other adaptations does this sophisticated parasite have for life in plants? To answer these questions, we and a team of researchers from the USDA/ARS Plant-Microbe Interaction research group at Cornell and the Boyce Thompson Institute for Plant Research have been characterizing the genome sequence of DC3000 and developing a variety of bioinformatic, biochemical, genetic, and cell biological tools to support a genome-wide study of virulence mechanisms and to foster functional genomic investigations by the worldwide research community.

Research Focus

The focus of our research is on the functional genomics of virulence in the plant pathogenic bacterium Pseudomonas syringae.

Outreach and Extension Focus

The major outreach activity of the Pseudomonas-Plant Interaction (PPI) project is "High School Connect." This is a series of interlinked lab modules, which are integrated with an interactive website that is part of the PPI website (http://pseudomonas-syringae.org) and designed to meet the requirements for the Living Environment Curriculum and State Standards in Science and Math Education for New York State Regents and AP biology high school students. The High School Connect lab modules use P. syringae-plant interactions to engage students in investigative activities that begin with bacterial elicitation of programmed cell death in plants(module 1: Attack and Defense: Plant-Bacterium Interactions), progress to microbial genetics(module 2: Bacterial Conjugation: The Great Genetic Mix-up ) and molecular biology (module 3: Gene Hunt in the Lab ), and culminate with host defenses against microbes (module 4:Gene-for-Gene Disease Resistance). The experiments and website connect biology with social sciences, students with active research frontiers, and high school students with graduate students and their career choices through Quicktime videos and other web resources. The modules are distributed through the CIBT Lending Library. PPI project personnel, including graduate students, participate in facilitating the use of the modules through presentations at weekend and summer CIBT events for teachers and by visiting high school classrooms. The High School Connect project has also enabled graduate students to get teaching experience with high school students and high school teachers to gain further research experience.

Instruction Focus

PlPa 601 Concepts of Plant Pathology Spring semester 3 credits The course is intended to be a core course for graduate students with a major or minor in the Field of Plant Pathology and Plant-Microbe Biology. The course concerns concepts in host-pathogen relationships with an emphasis on the roles of molecules and cell structures in determining the outcome of an interaction. Evidence for the role of putative disease determinants is explored in the context of universal stages of pathogenesis and representative pathosystems. Discussion periods provide time for analysis of special topics, critiquing of research papers, comparisons of pathosystems, evaluation of grant proposals, and review sessions. Students develop a personal computer-based reference collection for use in several aspects of the course. Students also write a grant proposal and review each others proposals in mock panels. The final discussion session of the semester is used for the Big Picture Game, in which student teams compete in the development of a comprehensive picture of plant-pathogen interactions. The final exam includes both written and oral components.

Additional Links

• http://pseudomonas-syringae.org
• Collmer Lab Page
• Collmer lab: Genome-enabled investigations of Pseudomonas syringae virulence mechanisms
• Link to CALS Research portal
• Link to CALS Impact statements

Honors, Awards and Appointments

• Noel T. Keen Award for Research Excellence In Molecular Plant Pathology, American Phytopathological Society - 2003
• Fellow of the American Academy of Microbiology - 2000
• Fellow of the American Phytopathological Society - 1996

Professional Activities

• Genomics of plant pathogens. Conferences on Convergence of Genomics and the Land Grant Mission: Emerging Trends in the Application of Genomics in Agricultural Research. Purdue University, West Lafayette, IN. - September 2007
• Pseudomonas syringae lytic transglycosylases associated with the type III secretion system promote suppression of basal resistance. Symposium on Non-specific and specific innate and acquired plant resistance, Budapest, Hungary. - September 2006
• Functional genomics of the plant pathogen Pseudomonas syringae. European Conference on Prokaryotic Genomes 2005, Goettingen, Germany. - September 2005
• Pseudomonas syringae: functional genomics and plant pathogenicity. Pseudomonas 2003 International Meeting, Quebec City, Quebec. - September 2003
• Functional Genomics of the Interactions of Tomato and Pseudomonas syringae pv tomato DC3000. NSF Plant Genomics Awardees Meeting. Washington, DC. - September 2000
• Pseudomonas syringae: functional genomics and plant pathogenicity. Korean Society of Plant Pathology 20th Annual Meeting, Pyeongchang, Korea. - October 2004
• Pseudomonas syringae functional genomics: searching for Hrp effectors and their functions. Department of Plant Pathology, NYSAES, Geneva. - October 2004
• Pseudomonas syringae functional genomics: A case study for integrating computational and experimental biology. BioQuest Workshop (with David Schneider). Cornell Theory Center. - October 2003
• Type III secretion system of the plant pathogen Pseudomonas syringae. Juan March Foundacion Conference on Finding the Way Out: Protein Traffic in Bacteria, Madrid. - October 2003
• Functional genomics of Pseudomonas-plant interactions. Second Annual U.S.-Korea Symposium, Ithaca. - October 2002
• Pseudomonas syringae plant pathogenicity: From the type III secretion system to genomics. Microbiology Seminar Series, Cornell University. - October 2002
• Genomics and Plant Health. Part of Seminar on The Impact of Genomics on Global Food Security and Plant Health, presented at the 50th Annual Meeting of the Cornell University Board of Trustees and the Cornell University Counci. - October 2000
• Exploring the functions of proteins secreted by the Hrp type III secretion system of Pseudomonas syringae. 7th International Conference on Pseudomonas syringae Pathovars and Related Pathogens. Agadir, Morocco. - November 2006
• Functional Genomic Analysis of Pseudomonas syringae-Plant Interactions, U.S.-Japan Seminar in Molecular Plant Pathology, Shizuoka, Japan. - November 2003
• Functional Genomic Analysis of Pseudomonas syringae, National Chung Hsing University, Taichung, Taiwan. - November 2003
• Functional Genomics of Pseudomonas-Plant Interactions. Plant Biology Seminar Series, Cornell University. - November 2002
• Mining for type III secretion system effectors in the Pseudomonas syringae genome. Distinguished Seminar Series in Plant Biology, Ohio State University. - November 2002
• Exploring Pseudomonas syringae plant pathogenicity: from type III protein secretion systems to pathogenicity islands and genomics. Department of Microbiology and Immunology, University of Illinois at Chicago College of Medicine. - November 2000
• Genome-enabled insights into the virulence and host-specificity of Pseudomonas syringae pv. tomato. Citrus Research and Education Center, University of Florida, Lake Alfred, FL. - May 2007
• The Pseudomonas syringae type III secretion system from the outside in. Boyce Thompson Institute Post-Graduate Society Seminar. - May 2006
• Pseudomonas syringae functional genomics: patterns and pathogenesis, Department of Plant Pathology, University of California, Davis. - May 2005
• Pseudomonas syringae functional genomics: searching for patterns of pathogenesis. Keynote lecture for Annual Meeting of Phytophthora Molecular Genetics Network, New Orleans. - May 2004
• Functional genomic analysis of the Pseudomonas syringae pv. tomato DC3000 type III effector repertoire. XIII International Congress on Molecular Plant-Microbe Interactions. Sorrento, Italy. - July 2007
• Functional genomics of Pseudomonas syringae virulence: from Hops to Gene Ontology. Keynote Lecture for 11th International Conference on Plant Pathogenic Bacteria. Edinburgh, Scotland. - July 2006
• The Pseudomonas-Plant Interaction Project High School Connect Program. Cornell Institute for Biology Teachers Summer Workshop, Ithaca. - July 2005
• Pseudomonas syringae: functional genomics and plant pathogenicity. XI International Congress on Molecular Plant-Microbe Interactions, St. Petersburg, Russia. - July 2003
• Pseudomonas syringae pv. tomato DC3000: Genomics and phytopathogenicity. Symposium on Functional Genomics of Plant-Pathogen Interactions. American Phytopathological Society Annual Meeting, Milwaukee. - July 2002
• Functional Genomic Analysis of Pseudomonas syringae-Plant Interactions, Department of Horticultural Sciences, NYSAES, Geneva. - January 2004
• Pseudomonas syringae: functional genomics and plant pathogenicity. 3rd Annual ASM/TIGR Conference on Microbial Genomes, New Orleans. - January 2003
• Genomes, Microbes and Disease. Cornell Institute for Biology Teachers - Summer Workshop. - Ithaca, July 2002
• Genomics and pathogenic microbiology. Science Colloquium, Wells College. - December 2002
• Pseudomonas-plant interactions: from type III protein secretion to genomics, Seminars in Infection and Immunity, Department of Microbiology and Immunology, Cornell Veterinary College. - December 2001
• Pseudomonas syringae pathogenicity explored from the perspective of type III secretion systems and comparative genomics. Annual Meeting of the American Phytopathological Society, Anaheim, CA. - August 2004
• Pseudomonas syringae: An integrated functional genomics approach. National Citrus Genomics Workshop, Fort Pierce, FL. - August 2002
• Genomics approaches to exploring the pathogenicity of Pseudomonas syringae and Erwinia chrysanthemi . Symposium on Genomics Technologies and Applications for Plant/Pathogen Interactions, American Phytopathological Society Annual Meeting, New Orleans. - August 2000
• The model plant pathogen Pseudomonas syringae: From genes to genomes to systems. Land Grant University-Industry Consortium. Rochester, NY. - April 2007
• Hrp (type III) secretion systems and the virulence of Erwinia chrysanthemi and Pseudomonas syringae. Genetical Society Spring Meeting on Hosts, Parasites and Pathogens, University of Warwick,UK. - April 2000.
• Lessons from bacterial genomes. APS Workshop on Genomic Analysis of Plant-Associated Microbes, Washington, DC. - April, 2002
• Functional genomics of the type III secretion system in the model plant pathogen Pseudomonas syringae pv. tomato DC3000: Jiatong University, Shanghai; Nanjing Agricultural University, Nanjing; Zhezhiang University, Hangzhou; National Institute for Biological Sciences, Beijing - 2008 (May-June)
• Looking at Pseudomonas syringae-plant interactions through the aperture of the type III secretion system, Department of Plant Biology and DOE Plant Research Laboratory, Michigan State University, East Lansing. - 2008 (February)
• The ins and outs of the Pseudomonas syringae type III secretion system, Department of Plant Pathology, University of Wisconsin, Madison. - 2007 (November)
• Pseudomonas syringae pv. tomato DC3000: Genomics and phytopathogenicity. Plant, Animal and Microbe Genomes X, San Diego. - 2002

Selected Publications

• Munkvold, K.R., Martin, M.E., Bronstein, P.A., and Collmer, A. 2008. A survey of the Pseudomonas syringae pv. tomato DC3000 type III secretion system effector repertoire reveals several effectors that are deleterious when expressed in Saccharomyces cerevisiae. Mol. Plant-Microbe Interact. 21:490-502.
• Lindeberg, M., Myers, C., Collmer, A., and Schneider, D. 2008. Roadmap to new virulence determinants in Pseudomonas syringae: Insights from comparative genomics and genome organization. Mol. Plant-Microbe Interact. 21:685-700.
• Kvitko, B.H., Ramos, A.R., Morello, J.E., Oh, H.-S., and Collmer, A. 2007. Identification of harpins in Pseudomonas syringae pv. tomato DC3000, which are functionally similar to HrpK1 in promoting translocation of type III secretion system effectors. J. Bacteriol. 189:8059-8072.
• Wei, C.-F., Kvitko, B.H., Shimizu, R., Crabill, E., Alfano, J.R., Lin, N.-C., Martin, G.B., Huang, H.-C., and Collmer, A. 2007. A Pseudomonas syringae pv. tomato DC3000 mutant lacking the type III effector HopQ1-1 is able to cause disease in the model plant Nicotiana benthamiana. Plant J. 51:32-46.
• Ramos, A.R., Morello, J.E., Ravindran, S., Deng, W.-L., Huang, H.-C., and Collmer, A. 2007. Identification of Pseudomonas syringae pv. syringae 61 type III secretion system Hrp proteins that can travel the type III pathway and contribute to the translocation of effector proteins into plant cells. J. Bacteriol. 189:5773-5778.
• Oh, H.-S., Kvitko, B.H., Morello, J.E., and Collmer, A. 2007. Pseudomonas syringae lytic transglycosylases co-regulated with the type III secretion system contribute to the translocation of effector proteins into plant cells. J. Bacteriol. 189:8277-8289.
• Lindeberg, M., S. Cartinhour, C. R. Myers, L. M. Schechter, D. J. Schneider, and A. Collmer. 2006. Closing the circle on the discovery of genes encoding Hrp regulon members and type III secretion system effectors in the genomes of three model Pseudomonas syringae strains. Mol. Plant Microbe Interact. 19:1151-1158.
• Lopez-Solanilla, E., P. A. Bronstein, A. R. Schneider, and A. Collmer. 2004. HopPtoN is a Pseudomonas syringae Hrp (type III secretion system) cysteine protease effector that suppresses pathogen-induced necrosis associated with both compatible and incompatible plant interactions. Mol. Microbiol. 54:353-365.
• Schechter, L. M., Roberts, K. A., Jamir, Y., Alfano, J. R., and Collmer, A. 2004. Pseudomonas syringae type III secretion system targeting signals and novel effectors studied with a Cya translocation reporter. J. Bacteriol. 186:543-555.
• Buell, C. R., Joardar, V., Lindeberg, M., Selengut, J., Paulsen, I. T., Gwinn, M. L., Dodson, R. J., Deboy, R. T., Durkin, A. S., Kolonay, J. F., Madupu, R., Daugherty, S., Brinkac, L., Beanan, M. J., Haft, D. H., Nelson, W. C., Davidsen, T., Liu, J., Yuan, Q., Khouri, H., Fedorova, N., Tran, B., Russell, D., Berry, K., Utterback, T., Vanaken, S. E., Feldblyum, T. V., D`Ascenzo, M., Deng, W.-L., Ramos, A. R., Alfano, J. R., Cartinhour, S., Chatterjee, A. K., Delaney, T. P., Lazarowitz, S. G., Martin, G. B., Schneider, D. J., Tang, X., Bender, C. L., White, O., Fraser, C. M., and Collmer, A. 2003. The complete sequence of the Arabidopsis and tomato pathogen Pseudomonas syringae pv. tomato DC3000. Proc. Natl. Acad. Sci. USA 100:10181-10186.
• Petnicki-Ocwieja, T., Schneider, D. J., Tam, V. C., Chancey, S. T., Shan, L., Jamir, Y., Schechter, L. M., Buell, C. R., Tang, X., Collmer, A., and Alfano, J. R. 2002. Genomewide identification of proteins secreted by the Hrp type III protein secretion system of Pseudomonas syringae pv. tomato DC3000. Proc. Natl. Acad. Sci. USA 99:7652-7657.
• Fouts, D. E., Abramovitch, R. B., Alfano, J. R., Baldo, A. M., Buell, C. R., Cartinhour, S., Chatterjee, A. K., D`Ascenzo, M., Gwinn, M. L., Lazarowitz, S. G., Lin, N.-C., Martin, G. B., Rehm, A. H., Schneider, D. J., van Dijk, K., Tang, X., and Collmer, A. 2002. Genomewide identification of Pseudomonas syringae pv. tomato DC3000 promoters controlled by the HrpL alternative sigma factor. Proc. Natl. Acad. Sci. USA 99:2275-2280.
• Alfano, J. R., Charkowski, A. O., Deng, W.-L., Badel, J. L., Petnicki-Ocwieja, T., van Dijk, K., and Collmer, A. 2000. The Pseudomonas syringae Hrp pathogenicity island has a tripartite mosaic structure composed of a cluster of type III secretion genes bounded by exchangeable effector and conserved effector loci that contribute to parasitic fitness and pathogenicity in plants. Proc. Natl. Acad. Sci. USA 97:4856-4861.

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