Symbiotic plasmid transfer in Rhizobium leguminosarum biovar trifolii and competition between the inoculant strain icmp2163 and transconjugant soil bacteria

1994 ◽  
Vol 26 (3) ◽  
pp. 339-351 ◽  
Author(s):  
J.R. Rao ◽  
M. Fenton ◽  
B.D.W. Jarvis
Keyword(s):  
Soil Bacteria ◽  
Rhizobium Leguminosarum ◽  
Plasmid Transfer ◽  
Symbiotic Plasmid ◽  
Inoculant Strain ◽  
Rhizobium Leguminosarum Biovar Trifolii

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.

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.

The nodDABC Genes of Rhizobium leguminosarum biovar trifolii Confer Root-Hair Curling Ability to a Diverse Range of Soil Bacteria and the Ability to Induce Novel Root Swellings on Beans

1994 ◽  
Vol 21 (3) ◽  
pp. 311 ◽  
Author(s):  
J Plazinski ◽  
RW Ridge ◽  
IA Mckay ◽  
MA Djordjevic
Keyword(s):  
Root Hair ◽  
Soil Bacteria ◽  
Rhizobium Leguminosarum ◽  
Plant Root ◽  
Root Hairs ◽  
Infection Threads ◽  
Wide Range ◽  
Hair Curling ◽  
Root Hair Curling ◽  
Rhizobium Leguminosarum Biovar Trifolii

Cloned DNA fragments coding for the nodDABC genes of Rhizobium leguminosarum biovar trifolii strain ANU843 were introduced into Rhizobium strains possessing Sym plasmid deletions. These strains were able to: (a) synthesise four butanol-soluble Nod metabolites; (b) affect the normal growth pattern of plant root hairs of a wide range of host and non-host legumes; and (c) induce many root outgrowths on Phaseolus plants. The four Nod metabolites produced by these strains were labelled by supplying cultures with 14C-acetate in the presence of a flavonoid inducer of nod gene expression. In contrast, more than ten Nod metabolites were synthesised by wild-type strains or constructed strains containing the full complement of R. leguminosarum biovar. trifolii nodulation and host specific nodulation genes. Strain ANU845 containing nodDABC did not induce infection threads or nodule initiation sites but distorted and curled cells in plant root hairs. However strain ANU845 induced root outgrowths on beans (Phaseolus vulgaris) that appeared to result from a proliferation of the epidermal tissue. Transfer of plasmids bearing nodDABC to various Gram-negative bacteria, Agrobacterium tumefaciens, Pseudomonas aeruginosa, Lignobacter sp., Azospirillum brasilense and Escherichia coli, and different non-nodulating mutant rhizobia conferred on these strains the ability to cause root-hair curling and distortions. Several strains induced root-hair curling on clover and a range of other non-host legumes. We suggest that the expression of nodDABC in a range of soil bacteria may extend or alter the effects of these soil bacteria on the roots of host plants.

scholarly journals Transfer of the symbiotic plasmid from Rhizobium leguminosarum biovar trifolii to Agrobacterium tumefaciens.

1998 ◽  
Vol 44 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Mikiko Abe ◽  
Ryoichi Kawamura ◽  
Shiro Higashi ◽  
Seiichiro Mori ◽  
Motoyoshi Shibata ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Rhizobium Leguminosarum ◽  
Symbiotic Plasmid ◽  
Rhizobium Leguminosarum Biovar Trifolii

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

Slow rehydration improves the recovery of dried bacterial populations

1992 ◽  
Vol 38 (6) ◽  
pp. 520-525 ◽  
Author(s):  
J. W. Kosanke ◽  
R. M. Osburn ◽  
G. I. Shuppe ◽  
R. S. Smith
Keyword(s):  
Relative Humidity ◽  
Rhizobium Leguminosarum ◽  
Moisture Absorption ◽  
Rhizobium Meliloti ◽  
Bacterial Populations ◽  
Bulk Powder ◽  
Alfalfa Seed ◽  
Powder Samples ◽  
Cellular Stresses ◽  
Rhizobium Leguminosarum Biovar Trifolii

Slow rehydration of bacteria from dried inoculant formulations provided higher viable counts than did rapid rehydration. Estimates were higher when clay and peat powder formulations of Rhizobium meliloti, Rhizobium leguminosarum biovar trifolii, and Pseudomonas putida, with water activities between 0.280 and 0.650, were slowly rehydrated to water activities of approximately 0.992 before continuing the dilution plating sequence. Rhizobium meliloti populations averaged 6.8 × 108 cfu/g and 1328 cfu/alfalfa seed greater when slowly rehydrated from bulk powder and preinoculated seeds, respectively. Bulk powder samples were slowly rehydrated to 0.992 water activity by the gradual addition of diluent, followed by a 10-min period for moisture equilibration. Preinoculated seed samples were placed in an environmental chamber at 24 °C with relative humidity greater than 80% for 1 h to allow moisture absorption. "Upshock," osmotic cellular stresses that occur during rehydration, was reduced when dried microbial formulations were slowly rehydrated and equilibrated before becoming fully hydrated in the dilution plating sequence. These procedures may also be applicable when estimating total viable bacterial populations from dried soil or other dry formulations. Key words: rehydration procedure, microbial rehydration, desiccation, Rhizobium, Pseudomonas.

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