Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2002
Publication Date: N/A
Technical Abstract: The compound 2,4-diacetylphloroglucinol (DAPG) is important as a key antifungal metabolite produced in the rhizosphere of wheat by Pseudomonad populations responsible for natural take-all decline. Take-all, one of the most devastating root diseases of wheat world-wide, is incited by the fungus Gaeumannomyces graminis var. tritici. In studies to develop DAPG-producing strains of P. fluorescens as agents for biological control of take-all, DAPG concentrations of >0.05 g/L inhibited the growth and lowered the viability of this bacterium in production cultures; and delivery of as little as 50 mg DAPG/g seed inhibited wheat germination rates depending on presence of other culture components. The combination of proline with glucose and urea as carbon and nitrogen sources could be manipulated to regulate DAPG production by P. fluorescens wild-type strain Q8R1 and overproducing strain Q69c-80:miniTn5:phl20. Strategies of managing DAPG production by the biocontrol agent are needed to optimize the production yield of viable biocontrol agent and the formulation conditions needed to foster storage stability, seed compatibility, and bioefficacy.