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

ABSTRACT: 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.

SUBMITTER: Wernegreen JJ 

PROVIDER: S-EPMC24705 | biostudies-literature | 1997 May

REPOSITORIES: biostudies-literature