FTIR difference spectra for MWLs and CWRs. Difference spectra were obtained by subtracting the absorption spectrum of wild type from the spectrum of the mutant: peaks (above the origin) represent stronger absorption in the mutant, troughs are stronger in the wild type. Assignments of absorption bands (10, 32) are 1, 1665–1680 cm−1: carbonyl group (C=O) conjugated to aromatic ring; 2, 1595 cm−1: aromatic ring with C=O stretching; 3, 1510 cm−1: aromatic ring with C—O stretching; 4, 1270 cm−1: C—O stretching, aromatic (methoxyl); 5, 1040 cm−1: dialkyl ether linkages (between cinnamyl alcohol subunits). CWR spectrum is the average from four pairwise comparisons of cad-n1 and wild-type plants.