Broad Host Range and Promoter Selection Vectors for Bacteria that Interact with Plants. Guy Van den Eede. Laboratorium voor Genetica, Universiteit Gent, B-9000 Gent, Belgium. Rolf Deblaere, Koen Goethals, Marc Van Montagu, and Marcelle Holsters. Laboratorium voor Genetica, Universiteit Gent, B-9000 Gent, Belgium.. MPMI 5:228-234. Accepted 20 January 1992. Copyright 1992 The American Phytopathological Society.

A plasmid vector, pGV910, and a derived cosmid, pRG930, have been constructed. Both contain the ColE1 and pVS1 origins of replication and are stably maintained in Escherichia coli, Agro-bacterium tumefaciens, and Azorhizobium caulinodans ORS571. They are compatible with commonly used IncP cloning vectors, although pVS1 was classified as an IncP plasmid, unable to replicate in E. coli (Y. Itoh, J. M. Watson, D. Haas, and T. Leisinger, Plasmid 11:206-220, 1984). Promoter selection vectors were derived from both of these plasmids by using a promoterless Beta-glucuronidase and/or Beta-galactosidase gene. These vectors facilitate the study of gene expression in bacteria under particular environmental conditions. This is illustrated by the expression of the gusA gene under the control of a nod promoter in A. caulinodans nodulating stem-located infection sites on Sesbania rostrata.