(A) to (C): Histochemical localization of GUS activity in leaf sections of transgenic F. bidentis plants transformed with constructs ppcA-PRFt-DR(+)Ft(A), ppcA-PRFp-DR(+)Ft (B) or ppcA-PRFtΔIntron-DR(+)Ft (C). Incubation times were 6 h (A, C) and 20 h (B). (D): GUS activities in leaves of transgenic F. bidentis plants. The numbers of independent transgenic plants tested (N) are indicated at the top of each column. Median values (black lines) of GUS activities are expressed in nanomoles of the reaction product 4-methylumbelliferone (MU) generated per milligram of protein per minute.