Fig. 7. Root transcriptional qRT-PCR profile of selected genes related to sulphur metabolism in Col-0, cad2-1 , pad2-1 ,rax1-1 and cad1-3 Arabidopsis treated with 0 or 3 µM Hg for 72 h. Values are presented as log2-fold change of Hg-treated plants relative to control plants of each genotype. Statistically down-regulated genes when compared to Col-0 (at p < 0.05) are represented as green boxes, whereas grey boxes indicate no statistical difference. Data of genes encoding transcription factors () are shown in the inset box (). Light blue boxes highlight genes differentially expressed. See quantitative values and statistics in Supplementary Table 4.