FIG 7.

The combination of METH and sucrose induces the expression of the S. mutans glucosyltransferase genes gtfB and gtfC. The differential expression of S. mutans glucosyltransferase-encoding genes (gtfB, gtfC, and gtfD) was measured using reverse transcriptase PCR. Bacteria were cultured in the absence or presence of 25 μM METH, 2% sucrose, or the combination for 24 h. 16S rRNA was used as the housekeeping gene control. Violin plots represent the averages and distributions from three independent measurements in triplicates. Symbols (*, #, and ϕ) indicate significantly higher expression levels than in the untreated, 25 μM METH, or 2% sucrose group, respectively. Each symbol denotes P value significance (P < 0.05) calculated by ANOVA and adjusted by the use of Tukey’s multiple-comparison test.