Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Mar 1995, 890-898, Vol 61, No. 3
LS van Overbeek and JD van Elsas
Tn5-B20 (lacZ as reporter gene) transcriptional fusion mutants of
Pseudomonas fluorescens R2f were screened for their response to wheat root
exudate. Several mutants showed (beta)-galactosidase activity under the
influence of wheat root exudate. In one such mutant, RIWE8, gene expression
was specifically induced by proline but not by 125 other substrates. This
mutant also showed reporter gene induction, albeit to a lesser extent, by
exudate of maize and grass roots but not by that of clover roots. In situ
promoter activity of RIWE8 was found in Flevo silt loam soil amended with
proline but not in water-, arginine-, glutamic acid-, or malic acid-amended
soils. Reporter gene expression in RIWE8 was triggered in a model
rhizosphere-soil system in the presence of wheat, maize, and grass roots
but not in the presence of clover roots or in root-free (bulk) soil. The
induction of expression of the reporter gene in soil, using this approach,
is suggestive that promoter activity in RIWE8 may be useful for the
construction of organisms with rhizosphere-controlled beneficial genes.
Copyright © 1995, American Society for Microbiology
Root Exudate-Induced Promoter Activity in Pseudomonas fluorescens Mutants in the Wheat Rhizosphere
Research Institute for Plant Protection (IPO-DLO), 6700 GW Wageningen, The Netherlands
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|