Barbara Kunkel

Barbara Kunkel

​Professor of Biology
PhD, Harvard University

contact info:

mailing address:

  • Washington University
    CB 1137
    One Brookings Drive
    St. Louis, MO 63130-4899

Professor Kunkel's research group is interested in the signaling and regulatory events that govern interactions between bacterial plant pathogens and their hosts.

Kunkel's group is studying the bacterial plant pathogen Pseudomonas syringae and one of its hosts, Arabidopsis thaliana, a system in which both pathogen and host are amenable to genetic and molecular analysis. The group's approach involves identifying and characterizing both pathogen and plant genes that govern whether interactions between these two organisms result in disease or not. The research currently focuses on two central areas: 1) The molecular basis of pathogenicity in P. syringae, and 2) The physiological processes and signaling pathways in the plant host that are modified by pathogen virulence factors.


Photo caption: Expression of the Pseudomonas syringae virulence factor avrRpt2 in plant cells promotes pathogen virulence. Disease symptoms caused by P. syringae on transgenic plants expressing the bacterial gene avrRpt2 (right) are much more severe than those on non-transgenic control plants (left).

recent courses

How Plants Work: Physiology, Growth, and Metabolism

This course introduces students to the fundamentals of how plants grow, metabolize and respond to their environment. Topics to be covered include the conversion of light energy into chemical energy through photosynthesis and carbon fixation, nitrogen assimilation, water and mineral uptake and transport, source-sink relationships and long-distance transport of carbon and nitrogen, cell growth and expansion, hormone physiology and physiological responses to a changing environment. Prerequisite: Bio 2970, or permission of instructors.

    Seminar in Plant and Microbial Bioscience

    This course emphasizing presentation skill and critical analysis counts towards the PMB Graduate Program's journal club course requirement. Students will be responsible for dividing and presenting 30 current research publications selected by the course masters. In addition to assembling brief PowerPoint presentations providing background and significance for their assigned articles, students are expected to provide classmates with a 1 page primer and short list of relevant references

      Selected Publications

      Lim, M. T. S., and B. N. Kunkel. (2004) The Pseudomonas syringae type III effector AvrRpt2 promotes virulence independently of RIN4, a predicted virulence target in Arabidopsis thalianaPlant J. 40:790-798. (Abstract/PDF)

      Brooks, D. M, G. Hernandez-Guzman, A. P. Kloek, F. Alarcn-Chaidez, A. Sreedharan, V. Rangaswamy, A. Pealoza-Vazquez, C. L. Bender and B. N. Kunkel. (2004) .Identification and characterization of a well-defined series coronatine biosynthetic mutants of Pseudomonas syringae pv. tomato DC3000. Molec. Plant-Microbe Interact. 17:162-274.

      Z. Chen, A. P. Kloek, A. Cuzick, D. Tang, W. Moeder, D. Klessig, J. McDowell, R. Innes, and B. N. Kunkel (2004) ThePseudomonas syringae AvrRpt2 protein functions downstream or independently of salicylic acid to promote virulence on Arabidopsis thalianaPlant J. 37:494-504. (Abstract/PDF)

      Preiter, K., Brooks, D. M., Penaloza-Vazquez, A., Sreedharan, A., Bender, C. L., and B. N. Kunkel. (2005) . Novel virulence gene of Pseudomonas syringae pathovar tomato strain DC3000. J. Bacteriol. 187: 7805-14. (Abstract/PDF)

      Lim, M. T. S. and B. N. Kunkel. (2005) The Pseudomonas syringae gene avrRpt2 contributes to the virulence on tomato.Molec. Plant-Microbe Interact 18:626-633.

      Brooks, D. M., Bender, C. L., and B. N. Kunkel. (2005) The Pseudomonas syringae phytotoxin coronatine promotes virulence by overcoming salicylic acid-dependent defences in Arabidopsis thaliana.Mol. Plant Pathol 6: 629-639. (Abstract/PDF)

      Laurie-Berry, N., Joardar, V., Street, I. H., and B. N. Kunkel. (2006) The Arabidopsis thaliana JASMONATE INSENSITIVE 1 gene is required for suppression of salicylic acid-dependent defenses during infection by Pseudomonas syringaeMolec. Plant-Microbe Interact. 19: 789-800.

      Sreedharan, A., Penaloza-Vazquez, A., Kunkel, B. N., and Bender, C. L. 2006. CorR regulates multiple components of virulence in Pseudomonas syringae pv. tomato DC3000. Molec. Plant-Microbe Interact. 19: 768-779. (Abstract/PDF)

      Uppalapati, S. R, Ishiga, Y. Wangdi, W., Kunkel, B. N. Anand, A., Mysore, K. S and C. L. Bender. 2007. The phytotoxin coronatine contributes to pathogen fitness and is required for suppression of salicylic acid accumulation in tomato inoculated with Pseudomonas syringae pv. tomato DC3000. Molec. Plant-Microbe Interact. 20:955-965. (Abstract/PDF)

      Chen, Z., Agnew, J. L., Cohen, J. D., He, P., Shan, L.,Sheen, J. and B. N. Kunkel. 2007. Pseudomonas syringae type III effector AvrRpt2 alters Arabidopsis thaliana auxin physiology. Proc. Nat. Acad. Sci. USA. 104: 20131-20136. (Abstract/PDF)

      Mellgren, E. M., Kloek, Andrew P. and B. N. Kunkel, 2009. Mqo, a tricarboxylic acid cycle enzyme, is required for virulence of Pseudomonas syringae pv. tomato strain DC3000 on Arabidopsis thaliana. J. Bacteriol. 191:3132-3141. (Abstract/PDF)

      Demianski. A. J., Chung, K. Mi, and B. N. Kunkel. 2012.  Analysis of JAZ gene expression during Pseudomonas syringae pathogenesis reveals that JIN1/AtMYC2 regulates only a subset of JAZ genes and that JAZ10 is a negative regulator of disease symptom development. Mol Plant Pathol. 13: 46–57. (Abstract/PDF)

      Melotto, M. and B. N. Kunkel, 2013. Virulence strategies of plant pathogenic bacteria. In: The Prokaryotes, 4th Ed. Rosenberg E, Stackebrand E, DeLong EF, Thompson F, Lory S (eds). Springer-Verlag, Berlin. (Abstract/PDF)

      Mutka, A. M., Fawley, S., Tsao, T., and B. N. Kunkel. 2013. Auxin promotes susceptibility to Pseudomonas syringae via a mechanism independent of suppression of salicylic acid-mediated defenses. Plant J. 74: 746–754 (Abstract/PDF)

      Cui, F., Wu, S., Sun, W., Coaker, G., Kunkel, B. N., He, P.  and Shan, L. 2013. Pseudomonas syringae type III effector AvrRpt2 promotes pathogen virulence via stimulating Arabidopsis Aux/IAA protein turnover. Plant Physiol. 162: 1018–1029 (Abstract/PDF)

      Prigge, M., Greenham, K., Zhang, Y., Santner, A., Castillejo, C., Mutka, A. M., O'Malley, R. C., Ecker, J.R., Kunkel, B. N., and Estelle, M. 2016. The Arabidopsis Auxin Receptor F-box proteins AFB4 and AFB5 are Required for Response to the Synthetic Auxin Picloram. Genes Genomes Genetics 6:1383-90.  (Abstract/PDF)

      McClerklin, S. A., Lee, S. G., Harper, C. P., Nwumeh, R., Jez, J.M. and Kunkel, B.N. 2018. Indole-3-acetaldehyde dehydrogenase-dependent auxin synthesis contributes to virulence of Pseudomonas syringae strain DC3000. PLoS Pathog. 2018 Jan 2;14(1):e1006811. doi: 10.1371/journal.ppat.1006811. (Abstract/PDF)

      Kunkel, B. N. and Harper, C. P. 2018. The roles of auxin during interactions between bacterial plant pathogens and their hosts. J. Exp. Bot. 69:245-254.