Dr. Dawn Bignell - November 21

The Streptomyces scabies coronafacoyl phytotoxins: structure, biosynthesis, bioactivity and regulation

Microbial secondary metabolites are small molecules that are nonessential for growth and survival, but instead are thought to confer a selective advantage to the producing organism in its natural habitat. Bacteria belonging to the genus Streptomyces are considered powerhouses of secondary metabolism, the products of which include many of the antibiotics that are currently used in human and in veterinary medicine. Secondary metabolites produced by Streptomyces spp. have been proposed to function as agents in inter-microbial warfare, as signaling molecules for intercellular communication, or as mediators of symbiotic relationships between Streptomyces spp. and eukaryotes. Such symbiotic relationships include parasitic interactions between phytopathogenic Streptomyces spp. and their plant hosts, interactions which lead to the development of economically important crop diseases. My lab is interested in understanding the role of secondary metabolites in mediating host-pathogen interactions involving Streptomyces scabies, which is the causative agent of potato common scab disease. Current research in my lab is focused on the S. scabies coronafacoyl phytotoxins, which are secondary metabolites that are predicted to function in the suppression of plant immune responses. This seminar will provide an overview of our studies on the structural elucidation, biosynthesis, bioactivity and regulation of the coronafacoyl phytotoxins. Future directions of our research, including our investigation of other S. scabies secondary metabolites, will also be discussed.