Figure 1.

The effect of thymol on the growth of tobacco seedlings under Cd stress. (A) The roots of seedlings were treated with CdCl₂ at 0–80 μM for 72 h for the measurement of root length; (B) In the presence of CdCl₂ at 20 μM, the roots of seedlings were treated with thymol at different concentrations (0–400 μM) for 72 h. Then the root length was measured; (C) The roots of seedlings were exposed to 20 μM of CdCl₂ and 100 μM of thymol simultaneously for 6, 12, 24, 48, and 72 h, respectively, for the measurement of root length; (D) The roots of seedlings were treated with water, 20 μM of CdCl₂, 100 μM of thymol, alone, or their combinations for 72 h. Then the shoots and roots were harvested, respectively, for the quantification of fresh weight. Each value was represented as the mean of three replicates with SD. Different letters in (B) and (D) indicate that the mean values are significantly different between the treatments (p < 0.05, ANOVA, LSD). Different letters in (C) indicate that the mean values are significantly different among four treatments at a particular point in time (p < 0.05, ANOVA, LSD). The asterisk in (B) indicates that the mean value was significantly different between thymol + Cd treatment and Cd treatment alone (p < 0.05).