Open AccessConstruction and characterization of a Rhizobium leguminosarum biovar viciae strain designed to assess horizontal gene transfer in the environment
Author(s) -
Selbitschka Werner,
Jording Doris,
Nieman Stefan,
Schmidt Rainer,
Pühler Alfred,
Mendum Tom,
Hirsch Penny
Publication year - 1995
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1995.tb07533.x
Subject(s) - rhizobium leguminosarum , biology , plasmid , strain (injury) , rhizobiaceae , genetics , transposable element , population , rhizobium , transformation (genetics) , insert (composites) , microbiology and biotechnology , gene , mutant , bacteria , symbiosis , mechanical engineering , demography , anatomy , sociology , engineering
An integration vector was developed which inserts cloned DNA in a non‐essential site of the Rhizobium leguminosarum biovar viciae chromosome. The expression of integrated genes is under the control of the constitutive neomycin phosphotransferase II ( npt II) promotor of transposon Tn5. The design of the vector ensures that loss of vector sequences can be detected, enabling selection of progeny containing only the requisite DNA. The newly constructed vector was employed to insert the Escherichia coli gusA gene conferring GUS activity into R. leguminosarum bv. viciae strain LRS39401 which is cured of its symbiotic plasmid (pSym). One GUS‐positive transconjugant, strain CT0370, was shown to have lost all vector sequences. Conjugal transfer of pSym2004 (a Tn5‐tagged derivative of symbiotic plasmid pRL1JI, which specifies pea nodulation and symbiotic nitrogen fixation) to CT0370, restored the GUS‐positive strain's symbiotic proficiency. Strain CT0370 is presently being used in a field release experiment in order to assess the extent of pSym transfer in a natural R. leguminosarum bv. viciae population under environmental conditions.