Conjugal transfer of a Sinorhizobium meliloti cryptic plasmid evaluated during a field release and in soil microcosms

• Published in: European journal of soil biology 2013-03, Vol.55, p.9-12
• Main Authors: Giusti, María de los Ángeles, Lozano, Mauricio J., Torres Tejerizo, Gonzalo A., Martini, María Carla, Salas, María Eugenia, López, José Luis, Draghi, Walter O., Del Papa, María Florencia, Pistorio, Mariano, Lagares, Antonio
• Format: Article
• Language: English
• Subjects: agar; Agronomy. Soil science and plant productions; alfalfa; Biochemistry and biology; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Cryptic plasmid; Fundamental and applied biological sciences. Psychology; Horizontal gene transfer; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plasmids; Rhizobia; rhizosphere; seed inoculation; Sinorhizobium meliloti; soil; soil bacteria; Soil inoculation; Soil science; trapping
• ISSN: 1164-5563
• DOI: 10.1016/j.ejsobi.2012.11.005

Horizontal gene transfer (HGT) is a central evolutionary mechanism that mediates the diversification and adaptation of bacteria in general and of rhizobia in particular. The few quantitative data on the conjugal transfer of rhizobial plasmids in soil correspond to the pSym (symbiotic genes-carrying replicons), with no information available regarding transfer frequencies in soil of other (namely accessory/cryptic) plasmids that are present in several rhizobial species. Thus, we examined here the conjugal transfer in non-sterile soil of the model Sinorhizobium meliloti cryptic plasmid pSmeLPU88b. Under field conditions the proportion of nodules containing indigenous rhizobia that acquired the plasmid pSmeLPU88b and then nodulated the trapping plants could be estimated as