TY - JOUR
T1 - Histochemical study on heterogeneity of lignin in Eucalyptus species II. The distribution of lignins and polyphenols in the walls of various cell types
AU - Watanabe, Yoko
AU - Kojima, Yasuo
AU - Ona, Toshihiro
AU - Asada, Takayuki
AU - Sano, Yuzou
AU - Fukazawa, Kazumi
AU - Funada, Ryo
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2004
Y1 - 2004
N2 - We examined the effects of polyphenols on the analysis of lignin by histochemical methods, namely, the Mäule color reaction coupled with microspectrophotometry and ultraviolet microspectrophotometry, in wood of Eucalyptus camaldulensis and E. globulus. Thin sections and wood meals were extracted with solutions of alkali at different concentrations. The amounts of alkali-soluble extractives increased with increasing concentrations of NaOH. By contrast, there was no clear correlation between amounts of Klason lignin and the concentration of NaOH. The visible-light absorption spectra of cell walls of all woody tissues from both species changed after alkali extraction. In particular, the spectra of cell walls of vessel elements changed considerably, even when only a dilute solution of alkali was used. Ultraviolet absorption spectra did not show clear changes after extraction with alkali. These results indicate that polyphenols in cell walls affect the results of histochemical analysis. Therefore, a preliminary extraction with alkali, namely, extraction with a 1% solution of NaOH, is needed to assess the precise distribution of lignins in the cell walls of Eucalyptus wood by histochemical methods. The cell walls of wood fibers of Eucalyptus camaldulensis contained both guaiacyl and syringyl units and those of vessel walls contained mostly guaiacyl units. However, the cell walls of wood fibers in Eucalyptus globulus contained mainly syringyl units, while those of vessel elements contained both guaiacyl and syringyl units. Syringyl-type polyphenols, which have spectra similar to those of syringyl-type lignins, were found in the cell walls of wood fibers and vessel elements and in cell corners among wood fibers in both species of Eucalyptus.
AB - We examined the effects of polyphenols on the analysis of lignin by histochemical methods, namely, the Mäule color reaction coupled with microspectrophotometry and ultraviolet microspectrophotometry, in wood of Eucalyptus camaldulensis and E. globulus. Thin sections and wood meals were extracted with solutions of alkali at different concentrations. The amounts of alkali-soluble extractives increased with increasing concentrations of NaOH. By contrast, there was no clear correlation between amounts of Klason lignin and the concentration of NaOH. The visible-light absorption spectra of cell walls of all woody tissues from both species changed after alkali extraction. In particular, the spectra of cell walls of vessel elements changed considerably, even when only a dilute solution of alkali was used. Ultraviolet absorption spectra did not show clear changes after extraction with alkali. These results indicate that polyphenols in cell walls affect the results of histochemical analysis. Therefore, a preliminary extraction with alkali, namely, extraction with a 1% solution of NaOH, is needed to assess the precise distribution of lignins in the cell walls of Eucalyptus wood by histochemical methods. The cell walls of wood fibers of Eucalyptus camaldulensis contained both guaiacyl and syringyl units and those of vessel walls contained mostly guaiacyl units. However, the cell walls of wood fibers in Eucalyptus globulus contained mainly syringyl units, while those of vessel elements contained both guaiacyl and syringyl units. Syringyl-type polyphenols, which have spectra similar to those of syringyl-type lignins, were found in the cell walls of wood fibers and vessel elements and in cell corners among wood fibers in both species of Eucalyptus.
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U2 - 10.1163/22941932-90000366
DO - 10.1163/22941932-90000366
M3 - Article
AN - SCOPUS:4444320528
VL - 25
SP - 283
EP - 295
JO - IAWA Journal
JF - IAWA Journal
SN - 0928-1541
IS - 3
ER -