Expression of EPF1. (A) RT–PCR analysis for EPF1 using RNA from roots (R), rosette leaves (RL), cauline leaves (CL), stems (St), and floral buds (FB). 18S rRNA was used as a control target. (B) RNA gel blot analysis using RNA from cotyledons (Co), rosette leaves of different developmental stages (1–12), and shoot apex of 16-d-old wild-type plants. EPF1, TMM, SDD1, and 18S rRNA were used as probes. (C–E) In situ hybridization for abaxial side of rosette leaves, probed with antisense EPF1 (C), sense EPF1 (D), and antisense SDD1 (E). Arrows indicate mature stomata and arrowheads indicate hybridization signal. (F) GUS expression in 14-d-old Arabidopsis transformed with PromoterEPF1-GUS. (G) Expression of PromoterEPF1∷GFP (green) in abaxial rosette leaf. To highlight the outline of cells, leaves were stained with FM4-64, which accumulates in membranes (red color). The arrow and arrowhead indicate a meristemoid and a GMC, respectively. Bars: B,F, 5 mm; C–E,G, 50 μm.