Kazan Institute of Biochemistry and Biophysics, Kazan Scientific Center, Russian Academy of Sciences, 420111 Kazan, Russia.
Biochemistry (Mosc). 2013 Jul;78(7):836-53. doi: 10.1134/S0006297913070146.
Plant polysaccharides comprise the major portion of organic matter in the biosphere. The cell wall built on the basis of polysaccharides is the key feature of a plant organism largely determining its biology. All together, around 10 types of polysaccharide backbones, which can be decorated by different substituents giving rise to endless diversity of carbohydrate structures, are present in cell walls of higher plants. Each of the numerous cell types present in plants has cell wall with specific parameters, the features of which mostly arise from the structure of polymeric components. The structure of polysaccharides is not directly encoded by the genome and has variability in many parameters (molecular weight, length, and location of side chains, presence of modifying groups, etc.). The extent of such variability is limited by the "functional fitting" of the polymer, which is largely based on spatial organization of the polysaccharide and its ability to form supramolecular complexes of an appropriate type. Consequently, the carrier of the functional specificity is not the certain molecular structure but the certain type of the molecules having a certain degree of heterogeneity. This review summarizes the data on structural features of plant cell wall polysaccharides, considers formation of supramolecular complexes, gives examples of tissue- and stage-specific polysaccharides and functionally significant carbohydrate-carbohydrate interactions in plant cell wall, and presents approaches to analyze the spatial structure of polysaccharides and their complexes.
植物多糖构成了生物圈中有机质的主要部分。基于多糖构建的细胞壁是植物生物的关键特征，在很大程度上决定了其生物学特性。在高等植物的细胞壁中，总共存在大约 10 种多糖骨架，这些骨架可以通过不同的取代基进行修饰，从而产生无数种碳水化合物结构的多样性。植物中存在的众多细胞类型中的每一种都具有具有特定参数的细胞壁，其特征主要源自聚合成分的结构。多糖的结构不是由基因组直接编码的，其在许多参数上具有可变性（分子量、长度和侧链位置、存在修饰基团等）。这种可变性的程度受到聚合物“功能适配”的限制，这在很大程度上基于多糖的空间组织及其形成适当类型的超分子复合物的能力。因此，功能特异性的载体不是特定的分子结构，而是具有一定异质性的特定类型的分子。本综述总结了植物细胞壁多糖结构特征的数据，考虑了超分子复合物的形成，给出了组织和阶段特异性多糖以及植物细胞壁中功能重要的碳水化合物-碳水化合物相互作用的例子，并提出了分析多糖及其复合物的空间结构的方法。
