Fig. 3. Transient expression of GFP fusions in wild-type tobacco leaf protoplasts. (A) Expression of the THI50-GFP construct. (B) Dual targeting to plastid and mitochondria by SYCO-GFP (Peeters et al., 2000). (C) Expression of the THI501-GFP construct. (D) Mitochondrial targeting of GFP mediated by ß-GFP construction (Duby et al., 2001). (E) Expression of the THImet2-GFP construct. (F) Expression of the THI502-GFP construct. (G) Plastid targeting of GFP by RecA-GFP (Köhler et al., 1997). The images were taken by epifluorescence microscope Axioplan 2. The fluorescence of GFP was observed at an excitation wavelength of 450-490 nm and emission wavelength of 520 nm (A-G, left panel). The autofluorescence of chloroplasts was observed at an excitation wavelength of 488 nm and emission wavelength of 664-696 nm (A-G, middle panel). The merged images of GFP and chlorophyll fluorescence are show in the right panel.