Branched Pectic Galactan in Phloem-Sieve-Element Cell Walls: Implications for Cell Mechanics.
Branched Pectic Galactan in Phloem-Sieve-Element Cell Walls: Implications for Cell Mechanics.
复制标题
韧皮部筛元件细胞壁中的分支果胶半乳聚糖：对细胞力学的影响。
DOI：
10.1104/pp.17.01568
复制
发表时间：
2018
期刊：
影响因子：
7.4
通讯作者：
Knox,JPa
中科院分区：
文献类型：
--
作者：
Torode,ThomasA;O'Neill,Rachel;Marcus,SusanE;Cornuault,Valérie;Pose,Sara;Lauder,RebeccaP;Kračun,StjepanK;Rydahl,MajaGro;Andersen,MathiasCF;Willats,WilliamGT;Braybrook,SiobhanA;Townsend,BelindaJ;Clausen,MadsH;Knox,JPa
植物生物学中的一个主要问题涉及细胞类型的特化和功能分化。这是在细胞壁网络所施加的限制的背景下，细胞壁网络既粘附细胞又有助于发育器官的形式和功能。在这里，我们报告的聚糖表位，是特定的韧皮部筛网元件细胞壁在几个系统中的识别。命名为LM 26的单克隆抗体与拟南芥（Arabidopsis thaliana）、米芥（Misericusxaparteus）和特别是甜菜（Beta vulgaris）根的茎中的韧皮部筛元件的细胞壁结合，其中韧皮部鉴定是研究Suc的韧皮部卸载的重要因素。使用合成寡糖的微阵列，LM 26表位已被鉴定为β-1，4-半乳聚糖的β-1，6-半乳糖基取代，需要三个以上的骨架残基以优化识别。这种分支半乳聚糖结构先前已在大蒜（Allium sativum）鳞茎中鉴定，其中LM 26表位遍布大多数细胞壁，包括韧皮部细胞的细胞壁。大蒜鳞茎细胞壁材料已被用于确认与细胞壁果胶鼠李半乳糖醛酸-I多糖的LM 26表位的协会。在草茎的韧皮部组织中，LM 26表位具有与LM 5线性β-1，4-半乳聚糖表位的互补模式，其仅在伴随细胞壁中检测到。对M.通过原子力显微镜对茎和叶进行的分析表明，韧皮部筛单元细胞壁具有比伴随细胞壁更低的压痕模量（指示更高的弹性）。
A major question in plant biology concerns the specification and functional differentiation of cell types. This is in the context of constraints imposed by networks of cell walls that both adhere cells and contribute to the form and function of developing organs. Here, we report the identification of a glycan epitope that is specific to phloem sieve element cell walls in several systems. A monoclonal antibody, designated LM26, binds to the cell wall of phloem sieve elements in stems of Arabidopsis (Arabidopsis thaliana),Miscanthusxgiganteus, and notably sugar beet (Beta vulgaris) roots where phloem identification is an important factor for the study of phloem unloading of Suc. Using microarrays of synthetic oligosaccharides, the LM26 epitope has been identified as a β-1,6-galactosyl substitution of β-1,4-galactan requiring more than three backbone residues for optimized recognition. This branched galactan structure has previously been identified in garlic (Allium sativum) bulbs in which the LM26 epitope is widespread throughout most cell walls including those of phloem cells. Garlic bulb cell wall material has been used to confirm the association of the LM26 epitope with cell wall pectic rhamnogalacturonan-I polysaccharides. In the phloem tissues of grass stems, the LM26 epitope has a complementary pattern to that of the LM5 linear β-1,4-galactan epitope, which is detected only in companion cell walls. Mechanical probing of transverse sections ofM. xgiganteusstems and leaves by atomic force microscopy indicates that phloem sieve element cell walls have a lower indentation modulus (indicative of higher elasticity) than companion cell walls.