Genes essential for nod factor production and nodulation are located on a symbiotic amplicon (AMPRtrCFN299pc60) in Rhizobium tropici.

ABSTRACT: Amplifiable DNA regions (amplicons) have been identified in the genome of Rhizobium etli. Here we report the isolation and molecular characterization of a symbiotic amplicon of Rhizobium tropici. To search for symbiotic amplicons, a cartridge containing a kanamycin resistance marker that responds to gene dosage and conditional origins of replication and transfer was inserted in the nodulation region of the symbiotic plasmid (pSym) of R. tropici CFN299. Derivatives harboring amplifications were selected by increasing the concentration of kanamycin in the cell culture. The amplified DNA region was mobilized into Escherichia coli and then into Agrobacterium tumefaciens. The 60-kb symbiotic amplicon, which we termed AMPRtrCFN299pc60, contains several nodulation and nitrogen fixation genes and

SUBMITTER: Mavingui P 

PROVIDER: S-EPMC107251 | biostudies-literature | 1998 Jun

REPOSITORIES: biostudies-literature