Transfer of Rhizobium leguminosarum Sym plasmids to R. meliloti and stability of resident and transferred plasmids

✍ Scribed by Dr. G. Miksch; P. Lentzsch

• Book ID: 102910129
• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 776 KB
• Volume: 28
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.3620280705

✦ Synopsis

The recombinant symbiotic (Sym) plasmids pIJ1008 and pIJ1019 and the natural Sym plasmid pJBSJI of Rhizobium leguminosarum were transferred to derivatives of the Rhizobium meliloti strain Rm41 and to local wild strains of R. meliloti to investigate their transfer frequency and stability. Transfer to the latter strains was only successful through two-step conjugations, i.e. transfer to a compatible R . meliloti strain followed by transfer to wild strains. The transferred Sym plasmids and the resident plasmids of R . meliloti with a molecular weight up to approximately 300 Md showed instability, resulting in the elimination of the latter, whereas the R. meliloti megaplasmids and their symbiotic properties were maintained. The natural plasmid pJB5JI was stable in free living transconjugants as well as those in symbiosis with alfalfa or pea. The two recombinant Sym plasmids showed deletions or structural changes dependending on the genotype of the recipient and the transferred plasmids. During symbiosis these plasmids may be further deleted or completely eliminated. The consequences for gene transfer programs are discussed in the paper.