Bamboo Industry Institute, Zhejiang A&F University, Hangzhou 311300, PR China; College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, PR China.
College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
Carbohydr Polym. 2024 Sep 1;339:122261. doi: 10.1016/j.carbpol.2024.122261. Epub 2024 May 12.
Understanding the distribution and accessibility of polymers within plant cell walls is crucial for addressing biomass recalcitrance in lignocellulosic materials. In this work, Imaging Fourier Transform Infrared (FTIR) and Raman spectroscopy, coupled with targeted chemical treatments, were employed to investigate cell wall polymer distribution in two bamboo species at both tissue and cell wall levels. Tissue-level Imaging FTIR revealed significant disparities in the distribution and chemical activity of cell wall polymers between the fibrous sheath and fibrous strand. At the cell wall level, Imaging Raman spectroscopy delineated a distinct difference between the secondary wall and intercellular layer, with the latter containing higher levels of lignin, hydroxycinnamic acid (HCA), and xylan, and lower cellulose. Mild acidified sodium chlorite treatment led to partial removal of lignin, HCA, and xylan from the intercellular layer, albeit to a lesser extent than alkaline treatment, indicating susceptibility of these polymers to chemical treatment. In contrast, lignin in the secondary wall exhibited limited reactivity to acidified sodium chlorite but was slightly removed by alkaline treatment, suggesting stable chemical properties with slight alkaline intolerance. These findings provide valuable insights into the inherent design mechanism of plant cells and their efficient utilization.
了解聚合物在植物细胞壁内的分布和可及性对于解决木质纤维素材料中生物质的抗降解性至关重要。在这项工作中，我们采用成像傅里叶变换红外（FTIR）和拉曼光谱技术，并结合靶向化学处理，在组织和细胞壁水平上研究了两种竹种细胞壁聚合物的分布。组织水平的成像 FTIR 揭示了纤维鞘和纤维束之间细胞壁聚合物分布和化学活性的显著差异。在细胞壁水平上，成像拉曼光谱清晰地区分了次生壁和细胞层之间的差异，后者含有更高水平的木质素、羟基肉桂酸（HCA）和木聚糖，以及较低水平的纤维素。温和的酸化亚氯酸钠处理导致细胞层中部分木质素、HCA 和木聚糖被去除，尽管其去除程度小于碱性处理，但这表明这些聚合物对化学处理具有敏感性。相比之下，次生壁中的木质素对酸化亚氯酸钠的反应性有限，但碱性处理略有去除，表明其具有稳定的化学性质，对碱性稍有不耐受。这些发现为植物细胞的固有设计机制及其有效利用提供了有价值的见解。
