Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Acquisition of genes from indigenous bacteria

Quantitative data and information are being compiled on the acquisition of genetic material by bacterial inoculants in the field and on the types of material involved in transfer, using rhizobia, currently the most important plant inoculants in Europe and worldwide. Data is being obtained from field sites where marked strains of Rhizobium and Bradyrhizobium released as inoculants in the past have become established. Recovered strains are being screened for evidence of acquisition of new genetic elements (bacterial plasmids, prophages, and transposable elements) during their time in the field. These are widespread in natural bacterial populations, can serve as markers of gene transfer, and may themselves confer significant new properties.

Plasmid replication origins and insertion elements not present in the inoculant strains but which exist in indigenous populations has been identified. Rhizobium has been constructed with a glucuronidase (GUS) marker gene designed to facilitate screening for acquisition of plasmids from indigenous rhizobia, to be released in the field.
Novel polymerase chain reaction (PCR) based methods for screening the genetic diversity of populations have been developed and detection limits of 1 genetically marked cell amongst 1E4 unmarked cells have been established.

Reported by

Rothamsted Research
Rothamsted Research
AL5 2JQ Harpenden
United Kingdom