Fig. 3. Direct regulation of CPC transcription by the WER. (A) Schematic diagram of P_35S:WER-GR gene construct. The stop codon of the WER was deleted for the translational fusion with the hormone-binding domain of the glucocorticoid receptor (GR HBD; from the 519th amino acid to the end). (B) Expression of the P_CPC:GUS reporter gene in the epidermis of 4-day-old seedlings. Seedlings were stained for 8 hours. (C) Expression of the P_GL2:GUS reporter gene in the epidermis of 4-day-old seedlings. (Top) The seedlings were stained for 6 hours without any treatment. wt, wild type. (Bottom) The seedlings harboring P_35S:WER-GR (P_35S:WER-GR wer-1) were untreated (–DEX), treated with 10 µM of cycloheximide (CHX) alone, treated with 1 µM of dexamethasone (+DEX) alone, or treated with both (+DEX, +CHX). Seedlings were pre-treated with 10 µM of CHX for 20 minutes before treatment with CHX and DEX. Seedlings were stained for 6 hours. (D) Accumulation of CPC transcripts in transgenic plants harboring P_35S:WER-GR. P_35S:WER-GR wer-1 seedlings (4-day-old) were treated as described in C. Northern blot analysis was carried out with total RNA extracted from the root tips using radiolabeled CPC DNA fragment as a probe (Lee and Schiefelbein, 2002). Resulting signal was detected using BAS-2500 (Fujifilm).