Fig. 7. Tissue distribution of the CPC:GFP fusion protein expressed under the control of heterologous promoters. The figure shows longitudinal (A,D) and transverse (B,E) CLSM images with GFP (green) and PI fluorescence (red) in SHRp::CPC:GFP (A,B) and EGL3p::CPC:GFP (D,E) transgenic plants at 5 days post germination, and the corresponding root hair phenotypes (C,F). (A) Images are focused on the stele. When CPC:GFP is controlled by the stele-specific SHR promoter, the GFP signal is restricted to stele cells, where it is distributed throughout the cytoplasm (A). No signal was detected in the root cortex or the epidermis (B). No ectopic root hairs were observed in these plants (C). By contrast, GFP fluorescence was restricted to the epidermis when CPC:GFP expression was controlled by the hair cell-specific EGL3 promoter (D,E). The signal occurred in all epidermal cells and accumulated in nuclei. Root hairs were formed ectopically in these plants (F). Insets in A,D show the distribution of GFP fluorescence in SHRp::GFP and EGL3p::GFP control plants, respectively. The asterisk in D highlights a hair-cell file. ep, epidermis; co, cortex; en, endodermis. Scale bars: 50 µm in A,B; 200 µm in C,F.