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

GIUSTI, M. A.; LOZANO, M. J.; TORRES TEJERIZO, G. A.; MARTINI, C; SALAS, M, E.; LOPEZ, J. L.; DRAGHI, W. O.; DEL PAPA, M.F.; PISTORIO, M.; LAGARES, A.

EUROPEAN JOURNAL OF SOIL BIOLOGY

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Lugar: Paris; Año: 2013 vol. 55 p. 9 - 12

1164-5563

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