ISSN:
1432-072X
Keywords:
Rhizobium meliloti
;
Symbiosis
;
Influence of the RP4 plasmid on effectivity
;
Cryptic plasmids
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The occurrence of endogenous plasmid DNA in Rhizobium meliloti is reported. R. meliloti strains carrying RP 4 were used to work out a suitable plasmid isolation method. By sarcosyl lysis RP 4 plasmid DNA as well as cryptic plasmid DNA was isolated. Cryptic plasmid DNA possesses a buoyant density of 1.717 g cm-3 and shows a heterogeneity in contour length. Large plasmid molecules of 130 μm length were detected in the electron microscope. We also found that RP4 is able to restore the nitrogen fixation capacity of an ineffective R. meliloti strain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00409198