Fig. 5.

AI-2 signals involved in the plasmid transfer under QACs in the intragenera conjugation model. (a) Concentration of DPD and (b) The gene expression level of LuxS in the mating pair system under exposure of QACs at 0.4 mg/L. (c) The effects of exogenous DPD (0.8, 4 μM) on the cell number of transconjugants. (d) DPD (4 μM) regulated the gene expression level of trbB and trfA. (e) The schematic diagram of AI-2 signals regulated the plasmid conjugation under QACs exposure. The Independent-sample t-test was used to compare the differences between QACs-treated and the control group, and are indicated by * P < 0.05, **P < 0.01 and **P < 0.001.