Expression of an agrocin‐encoding plasmid of Agrobacterium tumefaciens in Rhizobium meliloti

Abstract

Plasmid RP4 was used to mobilize the agrocin 84‐encoding plasmid, pAg396, from Agrobacterium tumefaciens strain 396 to A. tumefaciens C58 and C58CI as well as Rhizobium meliloti. It was transferred to, but not stably maintained in, R. leguminosarum. It could not be transferred to R. lupini, R. japonicum or R. trifolii. Plasmid pAg396 did not segregate in R. meliloti and produced levels of agrocin comparable to the parental strain A. tumefaciens 396. The potential of agrocin producing R. meliloti in biological control of crown gall is being investigated.

Enhanced competitiveness for nodulation of Medicago sativa by Rhizobium meliloti transconjugants harbouring the root-inducing plasmids of Agrobacterium rhizogenes strain 15834

“…The mobilization of Agrobacteriurn plasmids into Rhizobium genomes was shown to result in transconjugants stably inheriting and expressing endogenous plasmids [3][4][5][6]26,27] and what is more, virulence gene expression was demonstrated in these strains [3][4][5][6]28]. The transconjugants of R. meliloti remained non-pathogenic while they possessed an increased nodulation ability [4,6,29].…”