Figure 3.

In situ localization of PtPAL1, PtPAL2, and Pt4CL2 mRNAs and histochemical detection of CTs in developing aspen leaves. Sections (10-μm thickness) were hybridized with DIG-labeled antisense PAL1 (A, C, and E), PAL2 (B), or 4CL2 (D and F) RNA probes, or stained with toluidine blue (TB) for the detection of total phenolics (H and J). Sections (75-μm thickness) were stained with DMACA (G) or vanillin-HCl (I) for the detection of CTs. Shown are third leaf midvein and lamina (A, B, C, D, G and H) and 10th leaf lamina (E, F, I and J). Scale bar = 200 μm (A and B) or 50 μm (C–J). e, Epidermis; h, hypodermis; pa, palisade; sp, spongy mesophyll; xy, xylem.