FUS3 is expressed and functions postembryonically. (A) Relative expression of the FUS3 gene at various time points after germination. Quantitative RT-PCR was performed on germinating wild-type seeds imbibed for 6 hours, 1 day, 2 days and 5 days in minimal medium (MS). Transcript levels were normalized using ACTIN7 as an internal control. Results from triplicate samples are shown with error bars (SD). Experiments were repeated twice with similar results. Data from one of these replicates are shown. (B) Histochemical staining of FUS3:GUS seedlings at 1, 2, 3 and 5 days after germination in MS. Arrows indicate emerging leaf primordia showing β-glucuronidase (GUS) staining. Scale bars = 0.2 mm (day 1) and 0.4 mm (days 2, 3 and 5). (C) Wild-type and fus3 FUS3:FUS3-GR seeds germinated in MS without dexamethasone (DEX) (-DEX) or on 10 μM DEX (+DEX) for 2 days, then transferred to soil until bolting. Of the plants analyzed, 8.3% showed a full rescue of the rosette leaf morphology, and an example is shown (full rescue). A partial rescue was obtained for 62.5% of the plants, and an example is shown (partial rescue). The morphologies of the first six to eight fus3 FUS3:FUS3-GR leaves were rescued, but those of subsequent leaves were variable. Twenty-one to twenty-four plants were analyzed, constituting a representative profile. Scale bar = 1.0 cm. (D) Percentage of abaxial trichomes in wild-type rosettes and in fus3 FUS3:FUS3-GR rosettes of plants grown with (+) or without (-) DEX.