%A %T The Lignin Topochemistry of Daemonorops margaritae (Hance) Becc. by Molecular Spectroscopic Imaging %0 Journal Article %D 2017 %J SPECTROSCOPY AND SPECTRAL ANALYSIS %R 10.3964/j.issn.1000-0593(2017)10-3138-07 %P 3138-3144 %V 37 %N 10 %U {https://www.gpxygpfx.com/CN/abstract/article_9425.shtml} %8 2017-10-01 %X The topochemistry of lignin in commercial rattan (Daemonorops margaritae (Hance)) cell wall was investigated by combining fluorescence confocal laser scanning microscopy and confocal Raman microscopy at cellular and sub-cellular level. Confocal fluorescence images indicated that within the stem tissues of rattan higher fluorescence intensity and thus higher lignin concentration was visualized in proto-, meta-xylem vessel, parenchyma between vascular bundles and the cell corner middle lamella regions of fiber. More importantly, linear unmixing images based on the difference of fluorescence spectra revealed that the Rattan fiber secondary wall was divided into alternations alternating broad and narrow layers and the lignin concentration was higher in the narrow layers. Comparing the average Raman spectra extracted from the D. margaritae (Hance), P. heterocycla cv pubescens, M. sinensis, P. tomentosa and P. bungeana Zucc. secondary wall indicated that rattan fiber wall had a comparable molecular structure as hardwood poplar. Raman images by calculating the lignin band at 1 598 cm-1further confirmed the heterogeneous distribution of lignin at cellular level. It was found that the cell corner middle lamella of fiber had the highest lignin concentration followed by the narrow layer, and had the fewest in the broad layer, which was in accordance with the topochemical features of bamboo fiber. Meanwhile, Raman spectra analysis confirmed that other than the variation in lignin concentration between the broad and narrow layers, they also displayed differences in ratio of lignin structure units. Specifically, the ratio of G lignin to S lignin was 0.19 and 0.14 in the narrow and broad layers, respectively. The present results will provide a theoretical instruction for rattan cell wall biosynthesis and the origin of cell wall reaction stress.