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Rhizobium gone native: unexpected plasmid stability of indigenous Rhizobium leguminosarum.

Publication ,  Journal Article
Wernegreen, JJ; Harding, EE; Riley, MA
Published in: Proceedings of the National Academy of Sciences of the United States of America
May 1997

Lateral transfer of bacterial plasmids is thought to play an important role in microbial evolution and population dynamics. However, this assumption is based primarily on investigations of medically or agriculturally important bacterial species. To explore the role of lateral transfer in the evolution of bacterial systems not under intensive, human-mediated selection, we examined the association of genotypes at plasmid-encoded and chromosomal loci of native Rhizobium, the nitrogen-fixing symbiont of legumes. To this end, Rhizobium leguminosarum strains nodulating sympatric species of native Trifolium were characterized genetically at plasmid-encoded symbiotic (sym) regions (nodulation AB and nodulation CIJT loci) and a repeated chromosomal locus not involved in the symbiosis with legumes. Restriction fragment length polymorphism analysis was used to distinguish genetic groups at plasmid and chromosomal loci. The correlation between major sym and chromosomal genotypes and the distribution of genotypes across host plant species and sampling location were determined using chi2 analysis. In contrast to findings of previous studies, a strict association existed between major sym plasmid and chromosomal genetic groups, suggesting a lack of successful sym plasmid transfer between major Rhizobium chromosomal types. These data indicate that previous observations of sym plasmid transfer in agricultural settings may seriously overestimate the rates of successful conjugation in systems not impacted by human activities. In addition, a nonrandom distribution of Rhizobium genotypes across host plant species and sampling site demonstrates the importance of both factors in shaping Rhizobium population dynamics.

Duke Scholars

Published In

Proceedings of the National Academy of Sciences of the United States of America

DOI

EISSN

1091-6490

ISSN

0027-8424

Publication Date

May 1997

Volume

94

Issue

10

Start / End Page

5483 / 5488

Related Subject Headings

  • Symbiosis
  • Rhizobium leguminosarum
  • Rhizobium
  • Population Dynamics
  • Polymorphism, Restriction Fragment Length
  • Plasmids
  • Plants, Medicinal
  • Phylogeny
  • Molecular Sequence Data
  • Humans
 

Citation

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ICMJE
MLA
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Wernegreen, J. J., Harding, E. E., & Riley, M. A. (1997). Rhizobium gone native: unexpected plasmid stability of indigenous Rhizobium leguminosarum. Proceedings of the National Academy of Sciences of the United States of America, 94(10), 5483–5488. https://doi.org/10.1073/pnas.94.10.5483
Wernegreen, J. J., E. E. Harding, and M. A. Riley. “Rhizobium gone native: unexpected plasmid stability of indigenous Rhizobium leguminosarum.Proceedings of the National Academy of Sciences of the United States of America 94, no. 10 (May 1997): 5483–88. https://doi.org/10.1073/pnas.94.10.5483.
Wernegreen JJ, Harding EE, Riley MA. Rhizobium gone native: unexpected plasmid stability of indigenous Rhizobium leguminosarum. Proceedings of the National Academy of Sciences of the United States of America. 1997 May;94(10):5483–8.
Wernegreen, J. J., et al. “Rhizobium gone native: unexpected plasmid stability of indigenous Rhizobium leguminosarum.Proceedings of the National Academy of Sciences of the United States of America, vol. 94, no. 10, May 1997, pp. 5483–88. Epmc, doi:10.1073/pnas.94.10.5483.
Wernegreen JJ, Harding EE, Riley MA. Rhizobium gone native: unexpected plasmid stability of indigenous Rhizobium leguminosarum. Proceedings of the National Academy of Sciences of the United States of America. 1997 May;94(10):5483–5488.
Journal cover image

Published In

Proceedings of the National Academy of Sciences of the United States of America

DOI

EISSN

1091-6490

ISSN

0027-8424

Publication Date

May 1997

Volume

94

Issue

10

Start / End Page

5483 / 5488

Related Subject Headings

  • Symbiosis
  • Rhizobium leguminosarum
  • Rhizobium
  • Population Dynamics
  • Polymorphism, Restriction Fragment Length
  • Plasmids
  • Plants, Medicinal
  • Phylogeny
  • Molecular Sequence Data
  • Humans