FIG. 3.

Comparison of culture-dependent and culture-independent quantification of gene transfer in the A. thaliana rhizosphere. Donor strain SPR044(pJP4) and the R. eutropha recipient were coinoculated into the rhizosphere, and exconjugants were retrieved after 42 days. The numbers of donors, recipients, and exconjugants were determined by plating on rich medium and minimal medium with 2,4-D for selection of R. eutropha(pJP4). Alternatively, cells were detected in situ by a combination of fluorescent in situ hybridization with P. chlororaphis-specific oligonucleotide Pchl454 (A) or R. eutropha-specific oligonucleotide Bet42a (B) and TrbF-specific immunofluorescence staining. The data are the results of six independent experiments, and the mean deviations are indicated.