Figure 1

GFP fluorescence in embryogenic callus cultures transformed with A. tumefaciens and in derived somatic embryos. Transient expression in embryogenic callus 5 days after co-cultivation, bar scale = 50 μM (A). Stable expression in embryogenic callus culture 30 days after co-cultivation, bar scale = 50 μM (B). Stable expression in globular and heart stage 6 months after co-cultivation, bar scale = 100 μM (C). Stable expression in torpedo mature somatic embryos 7 months after co-cultivation, bar scale = 500 μM (D). Images were obtained using a Leica MZ Fluo III (optic 0.63 Zeiss) fluorescence microscope supplied with a DC 300F camera (Leica Microsystems, Welzlar, Germany) with plant GFP filter no. 3 from Leica: excitation wavelengths: 470-540 nm (BP), emission wavelengths: 525-550 nm (BP).