Electronic Thesis and Dissertation Repository


Master of Science




Dr. Mark A Bernards


Previous work on identifying the molecular mechanisms mediating plant-pathogen interactions and reciprocal host responses have little emphasis on developing models that closely resemble host-microbe interaction in planta. This work establishes an amalgamated model of interaction wherein successful pathogens elicit and overcome host defenses activated by microbial signatures and virulence factors. Using a hydroponic co-cultivation model, we assessed the responses of Arabidopsis thaliana Col-0 to Agrobacterium tumefaciens C58 to ameliorate limitations of previous approaches. Comparisons of differential gene expression between directly and indirectly affected host sites by microarray analysis revealed both reactive and pro-active defense responses, respectively. Selected homozygous single-gene knockouts for proactive defenses show variable A. tumefaciens root surface attachment and root secretion profiles. Studying host-microbe responses using hydroponics may improve priming of cash crops against pathogens and in part, may also improve the use of A. tumefaciens as a vector for generation of transgenic crops.