(A–F) Green fluorescence signals in transgenic plants harboring the CTL1-EGFP construct. Choline transporter-like 1 enhanced green fluorescent protein (CTL1-EGFP) signals were detected in the primary root (A), lateral root primordium (D), and emerged lateral root (E) of 5-day-old seedlings (Bars = 50 μm). The transection view of CTL1-GFP at the GFP channel (B) and the differential interference contrast (DIC) channel (C) shows GFP signal in all cell types in the meristem region of a primary root from a 5-day-old seedling. Bars = 25 μm. (F) CTL1-EGFP signals in a 3-day-old etiolated seedling. Arrows indicate the sites of strong expression. Bars = 1 mm. (G–N) Histochemical analysis of CTL1 promoter–β-glucuronidase (GUS) expression in transgenic plants. (G–J) GUS staining of a 5-day-old seedling (G), showing expression in shoot (H), emerging lateral root (I), and primary root (J). (K–N) GUS staining of a 7-day-old seedling (K), showing expression in cotyledon (L), the first pair of true leaves (M), and the hypocotyl (N). The scale bars in (I) and (J) are 100 μm, and other bars are 1 mm.