International Advanced Energy Science Research and Education Center, Graduate School of Energy Science, Kyoto University, Yoshida-Honmachi Kyoto 606-8501, Japan.
Plant Cell Manipulation Laboratory, Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, 5562 Nanatsukacho, Shobara, Hiroshima 727-0023, Japan.
J Agric Food Chem. 2020 Sep 16;68(37):9896-9905. doi: 10.1021/acs.jafc.0c02258. Epub 2020 Aug 31.
A 6.2 m high immature bamboo () was divided into seven fractions. The bamboo cell walls and lignin samples from young to old were characterized by H-C correlation heteronuclear single-quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy both qualitatively and semiquantitatively. Mature bamboo and bamboo shoot samples were used as comparison references. HSQC-NMR analysis proved that cellulose and arabinoxylan have already deposited in bamboo shoot, and cellulose amount increased during growth. Lignin side chain linkage formation started from β-ether (β--4), then phenylcoumaran (β-5), and finally resinol (β-β). Ferulic acid and -coumaric acid (CA) were formed at the earlier stages in the immature bamboo, and the CA proportion decreased throughout the lignification process. We propose that the bamboo lignification process is distinct from both woody and other herbaceous plants, where syringyl units deposited at the early stage and polymerized with the β--4 linkage. Then guaiacyl units formed gradually, and finally, -hydroxyphenyl units formed.
一株 6.2 米高的未成熟毛竹（）被分为七个部分。通过 H-C 相关异核单量子相干（HSQC）核磁共振（NMR）光谱技术，对从幼龄到老龄的竹细胞壁和木质素样本进行了定性和半定量分析。成熟的竹子和竹笋样本被用作比较参考。HSQC-NMR 分析证明，纤维素和阿拉伯木聚糖已经在竹笋中沉积，并且在生长过程中纤维素的含量增加。木质素侧链连接的形成始于β-醚（β--4），然后是苯基肉桂醇（β-5），最后是松柏醇（β-β）。阿魏酸和咖啡酸（CA）在未成熟的毛竹早期形成，并且随着木质化过程，CA 的比例逐渐降低。我们提出，竹子的木质化过程与木本植物和其他草本植物明显不同，其中在早期阶段沉积了愈创木基单元，并与β--4 键聚合。然后逐渐形成松柏基单元，最后形成对羟基苯基单元。
