Figure 3.

Quantification of gray levels in light microscopy autoradiographs of pine developing secondary xylem. Dissected cambium and associated tissue samples were fed [³H]Phe and various inhibitors for 4 h. To inhibit the phenylpropanoid pathway, AIP and AOPP were used as inhibitors of PAL, and PA was used as an inhibitor of C4H. Cycloheximide (CH) was used to block translation and inhibit the incorporation of Phe into proteins. Gray levels, where 0 is black and 1,024 is white, were inverted and scaled to mean white background to give positive mean ± se values.