Fig. 2. Changes in the transcripts level of HbPIP1;1, HbPIP2;1 and HbTIP1;1 in the inner bark (A–C) or latex (D–F) in response to auxin (A and D), salicylic acid (B and E) and abscisic acid (C and F) bark treatments of virgin trees from the PB217 rubber clone. The 40S gene was used as an endogenous control. Expression levels are presented as the expression ratio treated/control, which was set to 1. Data correspond to the mean of three independent replicates and SE (n = 9). Double asterisks indicate highly significant differences in fold expression of transcripts between untreated control and hormones-treated trees (Tukey's test, one-way ANOVA; P < 0.01).