|Brodhagen, Marion - OSU|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2003
Publication Date: June 1, 2003
Citation: Brodhagen,M.,Henkels,M.D.,and Loper,J.E. Regulation of the antibiotic pyoluteorin in Pseudomonas fluorescens Pf-5 includes positive autoregulation and repression by 2,4-diacetylphloroglucinol and pyoluteorin. Phytopathology 93:S11 Technical Abstract: The biological control agent Pseudomona fluorescens Pf-5 produces a suite of antibiotics that antagonize seed- and root-rotting plant pathogens. These antibiotics include pyoluteorin (PLT), pyrrolnitrin (PRN) and 2,4-diacetylphloroglucinol (PHL). Using HPLC and transcriptional fusions, we found that , in Pf-5, PLT and PHL each positively regulated their own production while repressing one another's production. This phenomenon occured i) in the presence of low (nanomolar) concentrations of either compound, and ii) at the transcriptional level, for PLT. Additionally, PRN also repressed PLT biosynthetic gene transcription. We further characterized teh potential signaling role of PLT in Pf-5 by demonstrating PLT autoinduction in vivo, with cross-feeding experiments on seed and roots in pasteurized soil. Our experiments suggest i) crosstalk among antibiotics of Pf-5, and ii) a novel role for PLT as an intra-and intercellular signaling compound.