Cellular distribution of coniferin in differentiating xylem of Chamaecyparis obtusa as revealed by Raman microscopy
Cellular distribution of coniferin in differentiating xylem of Chamaecyparis obtusa as revealed by Raman microscopy
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DOI：
10.1515/hf.2010.015
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发表时间：
2010-01-01
期刊：
影响因子：
2.4
通讯作者：
Takabe, Keiji
中科院分区：
文献类型：
--
作者：
Morikawa, Yohei;Yoshinaga, Arata;Takabe, Keiji
利用拉曼显微镜分析了松柏素在日本扁柏木质部分化过程中的细胞分布。从分化的木质部收集小块，冷冻，用滑动切片机在其表面上切割，然后冷冻干燥。扫描电镜观察表明，从S-1层形成开始到S-2层形成阶段，管胞腔中有大量针状沉积物。管胞腔沉积物的拉曼光谱与松柏素的拉曼光谱相似。松柏素的存在下，从分化木质部的水提取物中证实了基质辅助激光解吸/电离飞行时间质谱和H-1-和C-13-核磁共振谱。从用水洗涤和在乙醇中脱水之前和之后的样品中获取的差分拉曼光谱表明，在S-2层形成阶段期间以及在S-3层形成之后，发育中的次生壁含有松柏素。而在S-2层形成阶段，在细胞角中板层中检测到松柏素，其差示光谱与S-3层形成后的松柏素差示光谱不同。该阶段的差示光谱与通过“zulauf”方法（本体聚合）制备的松柏醇脱氢聚合物的差示光谱相似。这些结果表明，游离木质素低聚物的类型散装聚合物可能存在于细胞角的中间层在S-3层形成阶段，并可以从样品在洗涤和脱水过程中除去。结果可以被解释的方式，没有这样的低聚物存在于次生壁在同一阶段，由于末端添加的单木酚（类似于“zutropf”聚合）。
Cellular distribution of coniferin in differentiating xylem of Japanese cypress (Chamaecyparis obtusa) was analyzed by Raman microscopy. Small blocks were collected from differentiating xylem, frozen, cut on their surface with a sliding microtome, and then freeze-dried. Scanning electron microscopy showed numerous needle-like deposits in the tracheid lumina from the beginning of the S-1 layer formation to the S-2 layer-forming stage. The Raman spectrum of the deposits in the tracheid lumen was similar to that of coniferin. The presence of coniferin in a water extract from differentiating xylem was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy and H-1- and C-13-nuclear magnetic resonance spectra. Differential Raman spectra taken from samples before and after washing with water and dehydration in an ethanol showed that developing secondary walls contained coniferin during the S-2 layer-forming stage and also after S-3 layer formation. In contrast, coniferin was detected in the cell corner middle lamella during the S-2 layer-forming stage, and the differential spectra were different from that of coniferin after S-3 layer formation. The differential spectrum in this stage was similar to that of a dehydrogenation polymer of coniferyl alcohol prepared by the "zulauf" method (bulk polymerization). These results suggest that free lignin oligomers of the type bulk polymerizate might exist in the cell corner middle lamella during the S-3 layer-forming stage and can be removed from specimens during washing and dehydration. The results can be interpreted in a way that no such oligomer exists in the secondary wall during the same stage owing to endwise addition of monolignols (in analogy to a "zutropf" polymerization).