FIG 6.
Roles of QS genes in traRI expression. (A) The wild type and QS mutants containing traI-lacZ plasmids were grown in PY medium for 24 h. Gene expression was analyzed by measuring β-galactosidase levels and is reported in Miller units. traR represents the traR1-traR2 double mutant. (B) traI-lacZ expression in traI mutants grown in PY medium supplemented with 5% cell-free supernatants from ΔcinI ΔraiI ΔtraI mutants containing Ptac-cinI, Ptac-raiI, or Ptac-traI for 24 h. β-Galactosidase levels were then measured and are reported in Miller units. (C) The wild type and QS mutants containing traR1-lacZ plasmids were grown in PY medium for 24 h. Gene expression was analyzed by measuring β-galactosidase levels and is reported in Miller units. traR represents the traR1-traR2 double mutant. The amount of β-galactosidase of a wild type containing the pRA302 vector control under the same growth condition was <10 units. The data shown represent the means of three independent experiments, the standard deviations for which are indicated by the error bars.