Figure 3. HSQC NMR spectrum of “Cellulolytic Enzyme Lignin” (CEL, Chang et al. 1975. Holzforschung, 29:153-159.) isolated from the stem wood of wildtype P. trichocarpa. Contour colors correspond with the lignin inter-unit linkages shown. Linkages were quantified by 13C and HSQC and compared with those from 4CL down-regulated P. trichocarpa. Values (wildtype; transgenic) are quantity/100 monomeric lignin units. Y and Z were quantified based on the NMR spectra of crude milled-wood-lignins from the wildtype and transgenic.
