Fig. 4. CPL3 gene expression. (A) Real-time PCR analysis of CPL3 gene expression in Arabidopsis organs. Total RNA was isolated from the indicated tissues. (B-E) In situ hybridization patterns of CPC-homologous genes at the shoot apex. Arrowheads in B and C indicate CPC and ETC1 signals evident in young trichomes. No signal for either ETC2 or CPL3 was detected in D and E. (F-M) Activity of CPL3p::GUS reporter in 2-week-old leaves (F), in 5-day-old cotyledons (G), hypocotyls (H) and roots (I), in 4-week-old inflorescence (J,K) and silique (L,M). (N) Localization of CPL3-GFP fusion protein. Fluorescence from the GFP fusion protein (green) and propidium iodide (red) was observed with confocal laser scanning microscopy. CPL3p::CPL3:GFP signal localization in 2-week-old leaves. Scale bars: 50 µm in B for B-E and in G,H,N; 100 µm in I; 200 µm in K,M; 1 mm in F,J,L.