Laboratory of Plant Cell Growth Mechanisms, Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky str., 2/31, 420111, Kazan, Russia.
The Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky str., 2/31, 420111, Kazan, Russia.
Planta. 2022 Apr 21;255(5):108. doi: 10.1007/s00425-022-03887-2.
In cells of growing rye roots, xyloglucans and homogalacturonans demonstrate developmental stage specificity, while different xylans have tissue specificity. Mannans, arabinans and galactans are also detected within the protoplast. Mannans form films on sections of fresh material. The primary cell walls of plants represent supramolecular exocellular structures that are mainly composed of polysaccharides. Cell wall properties and architecture differ between species and across tissues within a species. We revised the distribution of cell wall polysaccharides and their dynamics during elongation growth and histogenesis in rye roots using nonfixed material and the spectrum of antibodies. Rye is a member of the Poaceae family and thus has so-called type II primary cell walls, which are supposed to be low in pectins and xyloglucans and instead have arabinoxylans and mixed-linkage glucans. However, rye cell walls at the earliest stages of cell development were enriched with the epitopes of xyloglucans and homogalacturonans. Mixed-linkage glucan, which is often considered an elongation growth-specific polysaccharide in plants with type II cell walls, did not display such dynamics in rye roots. The cessation of elongation growth and even the emergence of root hairs were not accompanied by the disappearance of mixed-linkage glucans from cell walls. The diversity of xylan motifs recognized by different antibodies was minimal in the meristem zone of rye roots, but this diversity increased and showed tissue specificity during root growth. Antibodies specific for xyloglucans, galactans, arabinans and mannans bound the cell content. When rye root cells were cut, the epitopes of xyloglucans, galactans and arabinans remained within the cell content, while mannans developed net-like or film-like structures on the surface of sections.
在生长的黑麦根细胞中，木葡聚糖和同质半乳糖醛酸聚糖表现出发育阶段特异性，而不同的木聚糖具有组织特异性。甘露聚糖、阿拉伯聚糖和半乳糖聚糖也存在于原生质体中。甘露聚糖在新鲜材料的切片上形成薄膜。植物的初生细胞壁代表主要由多糖组成的超分子细胞外结构。细胞壁特性和结构在物种间以及同一物种内的组织间存在差异。我们使用非固定材料和一系列抗体修订了黑麦根伸长生长和组织发生过程中细胞壁多糖的分布及其动态。黑麦是禾本科的一员，因此具有所谓的 II 型初生细胞壁，其果胶和木葡聚糖含量较低，而阿拉伯木聚糖和混合链葡聚糖含量较高。然而，在细胞发育的最早阶段，黑麦细胞壁富含木葡聚糖和同质半乳糖醛酸聚糖的表位。混合链葡聚糖通常被认为是 II 型细胞壁植物伸长生长特异性多糖，但在黑麦根中没有表现出这种动态。伸长生长的停止，甚至根毛的出现，都没有导致细胞壁中混合链葡聚糖的消失。不同抗体识别的木聚糖基序的多样性在黑麦根的分生组织区最小，但在根生长过程中增加并表现出组织特异性。针对木葡聚糖、半乳糖聚糖、阿拉伯聚糖和甘露聚糖的特异性抗体结合了细胞内容物。当黑麦根细胞被切割时，木葡聚糖、半乳糖聚糖和阿拉伯聚糖的表位仍保留在细胞内容物中，而甘露聚糖在切片表面形成网状或薄膜状结构。
