Courtesy Assistant Professor
My goals are to understand the mechanisms that bacteria use to colonize and cause disease in plants. Plants have a multi-layered immune system that confronts invading microbes with a barrage of stressors, preventing growth of most microbes. However, successful pathogens have adapted to overcome and survive the plant’s defenses. Bacterial phytopathogens encode a variety of systems that enable them to enter plant tissues and grow in the intercellular spaces. These systems interfere with the plant’s immune response and enable the bacteria to tolerate antimicrobial defenses produced by the plant. We are interested in identifying and characterizing adaptions that facilitate this process. Understanding how bacteria manage these stresses also provides a route to discover and investigate the strategies that plants use to suppress microbial growth. Our greater goal is to contribute to an integrated understanding of plant-pathogen interactions, helping to provide a basis for developing new approaches to limit pathogen damage in agricultural and post harvest contexts.
We use Pseudomonas syringae as a model to study the molecular systems that enable bacteria to adjust and thrive in plants and other environments. Our research focuses on identifying the genes and products necessary for bacterial survival in response to environmental factors. We use a variety of genomic approaches that aim to functionally analyze P. syringae genes en masse while the entire system is in operation. The hypotheses generated from these global studies are investigated individually using molecular biology and genetic approaches to gain a detailed understanding of the functional components and their regulation.
We also have an interest in developing methods that improve or enable genetic analysis of P. syringae. This work has led to the development of a recombination-mediated genetic engineering (recombineering) system that can be used for efficient manipulation of P. syringae genomic sequences.
Outreach and Extension Focus
My program activities are strongly oriented towards basic research. However, our lab has provided diagnostics services for pathogenic P. syringae strains in agricultural and horticultural samples provided by regional growers. We use molecular methods to survey samples for the presence of exotic and/or harmful P. syringae strains.
- Swingle, B., Markel, E., Costantino, N., Bubunenko, M.G., Cartinhour S., Court, D. L. 2010. Oligonucleotide Recombination in Gram Negative Bacteria. Molecular Microbiology. 75(1) 138-48.
- Swingle, B., Markel, E., Cartinhour, S., 2010 Oligonucleotide Recombination: A hidden treasure. Bioengineered Bugs. 1(4) 263-6.
- Butcher, B. G., Bronstein, P. A., Myers, C. R., Stodghill,, P. V., Bolton, J. J., Markel, E. J., Filiatrault, M. J., Swingle, B, Gaballa, A, Helmann, J. D., Cartinhour, S. W. 2011 Characterization of the Fur regulon of Pseudomonas syringae pv. tomato DC3000. Journal of Bacteriology. 193(18) 4598-4611.
- Markel, E, Maciak, C, Butcher, B. G., Myers, C. R., Stodghill, P., Bao, Z., Cartinhour, S,. Swingle, B. 2011. An ECF sigma factor mediated cell surface signaling system in Pseudomonas syringae pv. tomato DC3000 regulates gene expression in response to heterologous siderophores. Journal of Bacteriology. 193(20) 5775-5783.
- Bao, Z., Cartinhour, S., Swingle, B. 2012. Substrate and target sequence lengths influence RecTEPsy recombineering efficiency in Pseudomonas syringae. PLoS One. 7(11) e50617.