Barbara N. Kunkel, PhD


Plant and Microbial Biosciences Program
Molecular Microbiology and Microbial Pathogenesis Program
Molecular Genetics and Genomics Program

  • 314-935-7284

  • 314-935-4728

  • 314-935-4432

  • 319 Bayer Laboratory of the Life Sciences



  • plant-microbe interactions, bacterial pathogenesis, auxin, IAA, Type III effector protein, genetics, plant biology

  • Molecular genetic analysis of disease development in Pseudomonas syringae-Arabidopsis interactions

Research Abstract:

Our research focuses on the mechanisms regulating the interactions between bacterial plant pathogens and their hosts. Specifically, we want to understand the molecular and physiological bases of pathogenesis and disease development, and are identifying and characterizing pathogen virulence factors and their targets in plant cells. We study the bacterial plant pathogen Pseudomonas syringae and two of its hosts, Arabidopsis thaliana and tomato. Both pathogen and host are amenable to genetic and molecular analyses in these systems.

We are currently focusing on investigating three main questions related to pathogen virulence strategies: 1) What are the roles of auxin, a plant hormone and microbial signaling molecule, during pathogenesis? 2) How does P. syringae strain DC3000 sense and respond to auxin? 3) What mechanisms regulate bacterial virulence gene expression during infection?

Selected Publications:

2005 - 2022:

Chung, K. M., Demianski, A. J., Harrison, G. J., Laurie-Berry, N., Mitsuda, N., Kunkel, B. N. 2022. Jasmonate Hypersensitive 3 (JAH3) negatively regulates both jasmonate and ethylene-mediated responses in Arabidopsis. J. Exp. Bot. In Press. erac208,

Djami-Tchatchou, A. T., Li, A., Li, Stodghill, P., Filiatrault, M. J. and Kunkel, B. N. Identification of IAA-regulated genes in Pseudomonas syringae pv. tomato strain DC3000. 2022. J. Bacteriol. 204. e00380-21

B. N. Kunkel and J. Johnson. 2021. Auxin plays multiple roles during plant-pathogen interactions. Cold Spring Harbor Perspectives: Auxin Signaling. Editors: Dolf Weijers, Karin Ljung, Mark Estelle, and Ottoline Leyser.Cold Spring Harb Perspect Biol doi: 10.1101/cshperspect.a040022.

Djami-Tchatchou, A. Harrison, G., Harper, C., Wang,R., Prigge, M. J., Estelle, M. and Kunkel, B. N. 2020. Dual role of auxin in regulating plant defense and bacterial virulence gene expression during Pseudomonas syringae PtoDC3000 pathogenesis. Molec. Plant-Microbe Interact. 33: 1059–1071.

McClerklin, S. A., Lee, S. G., Harper, C. P., Nwumeh, R., Jez, J.M.andKunkel, 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.

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

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. 2016 Mar 14. g3.115.025585

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

Melotto, M. and Kunkel, B.N. (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: doi: 10-1007/978-3-642-30141-4_62.

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

Mellgren EM, Kloek AP, and Kunkel BN. (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.

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

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

Brooks DM, Bender CL, and Kunkel BN. The Pseudomonas syringae phytotoxin coronatine promotes virulence by overcoming salicylic acid-dependent defences in Arabidopsis thaliana. Mol Plant Pathol 2005 6: 629-639.

Preiter K, Brooks DM, Penaloza-Vazquez A, Sreedharan A, Bender CL, and Kunkel BN. Novel virulence gene of Pseudomonas syringae pathovar tomato strain DC3000. J Bacteriol 2005 187: 7805-7814.

Last Updated: 6/4/2022 12:14:33 PM

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