The suite of pathogenicity factors in Pseudomonas syringae
The goal of our project is to understand how bacterial pathogens cause disease on their hosts. We are working with a plant pathogen, Pseudomonas syringae. Bacterial pathogens of both animals and plants express suites of pathogenicity factors that cause disease on their hosts. Many pathogenicity factors depend on the Type III secretion system for their expression and function in the host. Because they are the protein effectors of disease, they are called Type III effectors. Comparison of over 50 P. syringae Type III effectors has not indicated that they have common functions. In fact, they share little sequence homology to each other or to proteins of known function from other organisms. Instead, they may perform a variety of functions, presumably acting on diverse plant targets. The goal of our research is to use a genomics approach to identify as many of the P. syringae Type III effectors as possible. Then we intend to discover how each effector interacts with its host to cause disease. We are currently developing tools to assay the effector-host interaction in collaboration with Jeffery Dangl’s lab in the Department of Biology, UNC-CH.