Contribution of the Symbiotic Plasmid to the Competitiveness of Rhizobium leguminosarum

Microbiology ◽  
1983 ◽  
Vol 129 (10) ◽  
pp. 2973-2977 ◽  
Author(s):  
N. J. Brewin ◽  
E. A. Wood ◽  
J. P. W. Young
Keyword(s):  
Rhizobium Leguminosarum ◽  
Symbiotic Plasmid

scholarly journals Symbiotic Plasmid Rearrangement in Rhizobium leguminosarum bv. viciae VF39SM

2001 ◽  
Vol 183 (6) ◽  
pp. 2141-2144 ◽  
Author(s):  
Xue-Xian Zhang ◽  
Bob Kosier ◽  
Ursula B. Priefer
Keyword(s):  
Parent Strain ◽  
Rhizobium Leguminosarum ◽  
Plasmid Profile ◽  
The Other ◽  
Dna Fragments ◽  
Symbiotic Genes ◽  
Symbiotic Plasmid ◽  
Other Hand

ABSTRACT A rearrangement between the symbiotic plasmid (pRleVF39d) and a nonsymbiotic plasmid (pRleVF39b) in Rhizobium leguminosarumbv. viciae VF39 was observed. The rearranged derivative showed the same plasmid profile as its parent strain, but hybridization to nod, fix, and nif genes indicated that most of the symbiotic genes were now present on a plasmid corresponding in size to pRleVF39b instead of pRleVF39d. On the other hand, some DNA fragments originating from pRleVF39b now hybridized to the plasmid band at the position of pRleVF39d. These results suggest that a reciprocal but unequal DNA exchange between the two plasmids had occurred.

Isolation from soil of Rhizobium leguminosarum lacking symbiotic information

1989 ◽  
Vol 35 (4) ◽  
pp. 464-468 ◽  
Author(s):  
Gloria Soberón-Chávez ◽  
Rebeca Nájera
Keyword(s):  
Nitrogen Fixation ◽  
Rhizobium Leguminosarum ◽  
Plasmid Transfer ◽  
First Report ◽  
Symbiotic Plasmid

Bacteria resembling Rhizobium leguminosarum, but lacking symbiotic information, were isolated from soil of two different geographical origins. One of these bacteria belongs to a previously described Rhizobium leguminosarum bv. phaseoli somatic serogroup, is fully complemented for nodulation and nitrogen fixation by an R. leguminosarum bv. phaseoli symbiotic plasmid, and is able to compete for bean nodulation with indigenous R. leguminosarum bv. phaseoli strains. This is the first report giving evidence for persistence in soil of Rhizobium lacking symbiotic information.Key words: Rhizobium ecology, symbiotic plasmid, nodulation, plasmid transfer.

Unusual localization of nod and nif genes in Rhizobium leguminosarum bv. viciae

1997 ◽  
Vol 43 (4) ◽  
pp. 399-402 ◽  
Author(s):  
Sylvie-Isabelle Mazurier ◽  
Gisele Laguerre
Keyword(s):  
Plasmid Dna ◽  
Genomic Dna ◽  
Rhizobium Leguminosarum ◽  
Large Plasmid ◽  
Nif Genes ◽  
Symbiotic Genes ◽  
Nod Genes ◽  
Symbiotic Plasmid ◽  
Wild Strains ◽  
Sym Plasmid

Genomic DNA from seven strains of Rhizobium leguminosarum bv. viciae isolated from nodules of field-grown lentils showed homology to nod and nif gene probes, whereas plasmid DNA did not hybridize with these probes. The results suggest that symbiotic genes could be located on the chromosome or perhaps on a very large plasmid that could not be resolved in Eckhardt gels. Each strain contained one plasmid that hybridized with a pSym isolated from a R. leguminosarum strain of the same field population. This finding led us to hypothesize that the nod and nif genes of the seven strains might have originated from a Sym plasmid and have been integrated into another replicon. The ability to nodulate vetch was confirmed for all of the seven strains. Thus, wild strains of R. leguminosarum bv. viciae that nodulate vetch carry nod and nif genes either on the chromosome or on an extrachromosomal replicon of size much larger than the pSyms hitherto described.Key words: Rhizobium leguminosarum, nod genes, nif genes, chromosome, symbiotic plasmid, megaplasmid.

Expression of the symbiotic plasmid from Rhizobium leguminosarum biovar trifolii in Sphingobacterium multivorum

1994 ◽  
Vol 40 (10) ◽  
pp. 873-879 ◽  
Author(s):  
M. Fenton ◽  
B. D. W. Jarvis
Keyword(s):  
Gene Transfer ◽  
White Clover ◽  
Microscopic Examination ◽  
Rhizobium Leguminosarum ◽  
Atmospheric Nitrogen ◽  
Symbiotic Genes ◽  
Symbiotic Plasmid ◽  
Spontaneous Transfer ◽  
Inoculant Strain ◽  
Rhizobium Leguminosarum Biovar Trifolii

An inoculant strain of Rhizobium leguminosarum biovar trifolii containing a Tn5 marked symbiotic plasmid transferred this plasmid by conjugation to Sphingobacterium multivorum, an organism that can be found in soil. The transconjugant bacteria nodulated the roots of white clover (Trifolium repens) seedlings but did not fix atmospheric nitrogen. Microscopic examination revealed abnormal nodule structures. Bacteria isolated from the nodules were shown to be closely related to the recipient S. multivorum and Southern blots of genomic digests probed with nodA DNA confirmed that the transconjugants contained symbiotic genes. This is the first report of the spontaneous transfer, by conjugation, of a symbiotic plasmid from R. leguminosarum biovar trifolii to S. multivorum.Key words: Rhizobium, Sphingobacterium, nodulation, nod gene transfer.

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