ISSN:
1617-4623
Keywords:
Agrobacterium tumefaciens C58
;
Nitrogen regulation (ntr)
;
Opine and arginine catabolism
;
Glutamine synthetase
;
Tn5 mutagenesis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The ntrC locus of Agrobacterium tumefaciens C58 has been cloned using the Azorhizobium sesbaniae ORSS571 ntrC gene as a DNA hybridization probe. Transposon Tn5 mutagenesis of the cloned ntrC locus was carried out and one Tn5 insertion within the region of highest DNA homology with A. sesbaniae ORS571 ntrC was used for gene replacement of the wild-type C58 ntrC gene. The A. tumefaciens ntrC::Tn5 mutant was found to be unable to grow on nitrate as sole nitrogen (N) source, to lack glutamine synthetase (GSII) activity and to be unable to use arginine (or ornithine) as sole N source, unless the Ti-encoded arginine catabolism pathway was induced with small amounts of nopaline. Thus the A. tumefaciens ntrC regulatory gene is essential for (transcriptional) activation of the GSII and nitrate reductase genes, as well as for the chromosomal but not the Ti-borne arginine catabolism pathways.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00331144