Suicide plasmid vehicles for insertion mutagenesis in Rhizobium meliloti and related bacteria

We describe the construction and use of a set of plasmid vectors of the transposons Tn1, Tn5, and Tn9 that are suicidal in Rhizobium species and therefore suitable for mutagenesis with these three transposons. The vectors are composed of the p15A replicon which functions in Escherichia coli but not in Rhizobium species and a region encoding the N type of bacterial conjugation system which is very efficient in matings between E. coli and Rhizobium species. The usefulness of the vectors has been most extensively assessed in Rhizobium meliloti. It is likely that they will be useful for mutagenesis and genome manipulation in other bacteria as well.