Fig. 3 (a) Glutathione reductase (GR) in gel activity, and (b) γ−glutamylcysteine synthetase ( γECS) and glutathione reductase (GR) immunodetection in wild type (Col-0),cad2-1 , pad2-1 , rax1-1 and cad1-3 Arabidopsis thaliana treated with 0 and 3 µM Hg for 72 h. Coomassie-blue staining was used to assure an equivalent protein loading of samples. Numbers represent the fold-change relative to the control Col-0, with asterisks marking decreases and decreases ≥ 20%.