Please use this identifier to cite or link to this item:
|Title:||LacZ Tagging of Phosphate Solubilizing Pseudomonas striata for Rhizosphere Colonization|
Jauhri, K S
|Keywords:||Phosphobacteria;Tn5-lacZ marker;Ecological monitoring|
|Abstract:||The Tn5-lacZ marker was used for detection of phosphobacteria, Pseudomonas striata (P-27) in the soybean rhizosphere. The chromogenic marker lacZ (structural gene for β-galactosidase) was introduced into P. striata (P-27) by transposition of Tn5-lacZ from Escherichia coli (S17-1). The mutants, which expressed β-galactosidase activity on selective media seeded with X-gal and IPTG, were screened for P-solubilization and IAA production. Mutant strains (lacZ marked) designated as superior, inferior and isogenic to wild type (P-27) with respect to P-solubilization (T-80, T-125, T-125) and IAA production (T-49, T-57, T-57) were inoculated to soybean in a pot experiment. The inoculated strains were recovered from the rhizosphere at different periods of plant growth by plating on selective medium using lac+ phenotype. A comparison between various mutants in terms of their abilities to colonize the soybean rhizosphere revealed that lacZ insertion or mutational over-expression of plant growth promoting traits did affect the establishment, population dynamics and ecological fitness of phosphobacteria. The technique of monitoring the tagged strains by direct plating on selective medium was found to be superior compared to conventional techniques.|
|ISSN:||0975-0967 (Online); 0972-5849 (Print)|
|Appears in Collections:|| IJBT Vol.01(3) [July 2002]|
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.