Submitted to: Rhizosphere 2004
Publication Type: Abstract Only
Publication Acceptance Date: 9/10/2004
Publication Date: 9/10/2004
Citation: Blouin Bankhead, S., Schroeder, K., Brown, A., Son, M., Thomashow, L.S., Weller, D.M. 2004. Population dynamics and movement of trangenic pseudomonas fluorescens in the rhizosphere of field grown wheat. Rhizosphere 2004, Munich, Germany, Book of Abstracts, p.74(Project Plan 5).
Technical Abstract: Pseudomonas fluorescens strain Q8R1-96 produces the antibiotic 2, 4-diacetylphoroglucinol (DAPG) and is a Biocontrol agent to take-all disease of wheat. Transgenic strains Z30-97, Z32-97, and Z34-97 were constructed by introducing the phenazine-1-carboxylic acid (PCA) biosynthetic locus into strain Q8R1-96. The transgenic strains produce both DAPG and PCA and have enhanced Biocontrol activity as compared to Q8R1-96. These strains were introduced individually as seed treatments only in the first field season. The population dynamics of these strains in rhizosphere of spring wheat (Triticum aestivum L.) and their movement in the field was monitored for two field seasons. In general, the transgenic strains did not differ from strain Q8R1-96 in ability to colonize the rhizosphere of wheat, move within the field, and survive between field seasons. However, when Q8R1-96 and a transgenic strain colonized the same rhizosphere, strain Q8R1-96 often out-competed the transgenic strain. These studies indicate that introducing the ability to produce a second antibiotic (PCA) into strain Q8R1-96 does not enhance its competitiveness in the rhizosphere.