Ca-TDC2 expression in the leaf Camptotheca acuminata plantlets subjected to drought-stress. Paraffin-embedded cross sections of leaves treated with Ca-TDC 2 antisense (A) and sense (B) digoxigenin-labelled probes. The hybridization signals are present in some palisade parenchyma cells (arrows). Abaxial Epidermis (AbE); Adaxial Epidermis (AdE); Palisade Parenchyma (PP); Spongy Parenchyma (SP). (A, B) bar = 50 μm; (D) bar = 100 μm.