Figure 4: Profiles of Pol II and of H3K4me3 at the non-trainable and trainable genes.

(a) Schematic diagram of the genes, with the promoter region (to left), the 5′ untranslated region (grey box), exons (dark box), introns (thin lines between exons) and indicating the regions (1 to 6) analysed by chromatin immunoprecipitation and real-time qPCR (ChIP–qPCR). (b–d) ChIP–qPCR analysis of the amounts of specific modifications present at regions 1–6 for the non-stressed watered (W, dark blue), singly stressed (S1, red) and trained plants (three stress cycles) before recovery (R3, brown) or during a fourth dehydration stress (S4, light blue). The results with ACT7 are shown as an internal control; (b) distribution profiles of Ser2P Pol II; (c) distribution profiles of Ser5P Pol II; (d) distribution profiles of H3K4me3. Experiments were repeated at least four times, each with three replicates, and the representative experiment shown indicates the mean±s.e.m., n=3 replicates.