Characterization of Influences Affecting Expression of pltR, a Gene Predicted to Regulate Pyoluteorin Biosynthesis
Presented by: Cara Taormina
Mentor: Joyce Loper
USDA

Abstract
The gene pltR is believed to be the putative regulator of the pyoluteorin biosynthesis gene cluster in Pseudomonasfluorescens Pf-5. Pyoluteorin is a polyketide antifungal metabolite inhibitory to the fungus Pythium ultimum, making Pf-5 a possible biocontrol agent. Sequencing ofpltR revealed it is a member of the LysR family of transcriptional activators. My research is focused on the effects of environmental factors, known to vary pyoluteorin production, on pltR gene transcription. A promoter-probe vector with a transcriptional fusion of the pltR promoter region and lacZ reporter gene is being used to analyze the transcriptional activity of pltR; color production will allow the promoter activity to be recognized. The promoter-probe vector has been transformed into Pf-5 and will be derived to contain a full-length lacZ gene. A stability test of the promoter-probe vector has also been done, confirming that the vector is stable in Pf-5 for a suitable amount of time to perform the varying environmental tests. Now, I will determine if the carbon sources that affect pyoluteorin production and the transcription of the pyoluteorin biosynthesis genes also affect transcription ofpltR in the same manner.