Specifically, we are studying a naturally occurring scab suppressive soil as a model system for insights on how to control this disease using beneficial bacteria. I am examining the role of Streptomyces cell densities in determining the fitness of the pathogen and of pathogen-inhibiting Streptomyces . Also, I am investigating the ability of pathogen-inhibiting Streptomyces to chemically communicate with each other for induction of antibiotic production, with the goal of discovering combinations of Streptomyces that work synergistically to inhibit the pathogen. I am also interested in investigating if the plant has the ability to preferentially support high populations of the pathogen-inhibiting Streptomyces . This work is being conducted in collaboration with Dr. Linda Kinkel's lab in the Plant Pathology Department at the University of Minnesota.
Streptomyces exist in close association with plant roots, including mycorrhizae.
Because mycorrhizal fungi are so prevalent and critical for plant growth, it is important to understand the effects of streptomycetes on mycorrhizal fungi. Some of this work has examined the effects of certain streptomycetes on fungal gene expression, and the ability of the streptomycetes to inhibit soilborne plant pathogens. Mycorrhizal-associated streptomycetes have the potential for use as coinoculants with beneficial mycorrhizal fungi in order to maximize plant growth and survival. This work is being conducted in collaboration with Dr. G. Krishna Podila's lab in the Biological Sciences Department at Michigan Technological University. Effects of mycorrhizal-associated streptomycetes on growth of Laccaria bicolor , Cenococcum geophilum , and Armillaria species and on gene expression in Laccaria bicolor .