COMPARATIVE-STUDY OF LIGNINS PRODUCED BY THE TEA-PLANT AND BY TEA-PLANT DERIVED CALLUS TISSUES

The main degradation products of lignin in the tea-plant stems and lea ves are represented by vanillin, syringic aldehyde and syringic acid, along with many unidentified compounds absent in the degradation produ cts of standard spruce lignin. In the stem lignin guaiacyl structures dominate (81.5%) and the leaf lignin is richer in syringyl structures (56.6%). Lignins of dark grown (heterotrophic) leaf- and stem-derived callus tissues consist of not only guaicyl and syringyl structures (va nillin, vanillic acid, syringic aldehyde, and syringic acid) but also of p-hydroxyphenyl structures (p-hydroxybenzaldehyde and p-hydroxybenz oic acid). Lignins of light grown (photomixotrophic) callus tissues ar e represented by guaiacyl and syringyl structures (vanillin, and syrin gic acid) only. This means that tissue culture conditions contribute m ore to lignin composition than the origin of the callus tissue.