Submitted to: International Plant Growth Promoting Rhizobacteria Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2006
Publication Date: 5/20/2006
Citation: Blouin-Bankhead, S., Peterson, J.M., Son, M.Y., Thomashow, L.S., Weller, D.M. 2006. Rhizosphere colonization of transgenic and wild-type pseudomonas fluorescens is modulated by the crop species. International Plant Growth Promoting Rhizobacteria Workshop. P66, page 72.
Technical Abstract: Pseudomonas fluorescens strain Q8r1-96 (genotype D) produces 2,4-diacetylphloroglucinol (DAPG). Transgenic strain Z30-97, constructed by stably inserting the phenazine-1-carboxylic acid (PCA) biosynthetic locus from P. fluorescens 2-79 into Q8r1-96, produces both antibiotics in vitro and in situ. The population dynamics of Q8r1-96 and Z30-97 were monitored in the rhizosphere of greenhouse-grown wheat, barley, pea, and navy bean during multiple growth cycles after introducing the bacteria alone and together into a Shano sandy loam. When introduced individually, strains Z30-97 and Q8r1-96 did not differ in ability to colonize the rhizosphere of wheat and pea, but Z30-97 colonized the barley and bean rhizospheres to a lesser extent than Q8r1-96. When the two strains were introduced together, Q8r1-96 out-competed Z30-96 in the wheat, barley and bean rhizospheres, but the opposite occurred in the pea rhizosphere. These studies indicate that the crop species impacts both rhizosphere colonization and competitive interactions of transgenic and parental strains.