Figure 3. The effect of the explant age on the transformation efficiency. The leaf explants from the plantlets at different weeks after germination were transformed with the constructs indicated, under the optimal conditions referred to in the text. After the GUS histochemical assay, the leaves were blanched with successive ethanol washes and photographed at different zoom levels (1X, 4X and 10X) under a light microscope. (a) eight-week-old plantlets; (b) four-week-old plantlets.