Ca-TDC1 expression in the leaf and stem of 3-month-old Camptotheca acuminata plantlets. Fresh cross sections of the leaf (A) and primary stem (D) stained with 0.1% toluidine blue to show the anatomical structure. Paraffin-embedded cross sections of leaves (B and C) and primary body of the stem (E and F), treated with Ca-TDC 1 antisense (B and E) and sense (C and F) digoxigenin-labelled probes. The square in the bottom right corner of D indicates a vascular bundle, that is, the part of the stem section shown in E and F. The hybridization signals in the leaf treated with antisense probe (B) are present in some spongy parenchyma cells (arrow), in parenchymatic subepidermal cells (double arrows), and in two epidermal cells (arrowheads). In the stem treated with antisense probe (E), hybridization signals are present in parenchyma cells associated with vascular bundles (arrow). No hybridization signals are present in the sections of leaf (C) and stem (F) treated with sense probe. Abaxial Epidermis (AbE); Adaxial Epidermis (AdE); Palisade Parenchyma (PP); Spongy Parenchyma (SP). (A, B, C, E, F) bar = 50 μm; (D) bar = 100 μm.