Analyses and localization of pectin-like carbohydrates in cell wall and mucilage of the green alga Netrium digitus
Analyses and localization of pectin-like carbohydrates in cell wall and mucilage of the green alga Netrium digitus
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DOI：
10.1007/s00709-009-0040-0
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发表时间：
2010-07-01
期刊：
影响因子：
2.9
通讯作者：
Luetz-Meindl, Ursula
中科院分区：
文献类型：
--
作者：
Eder, Magdalena;Luetz-Meindl, Ursula
栖息在酸性沼泽池塘中的单细胞、形状简单的鼓藻（Netrium digitus）以两个阶段生长。在分裂之前，细胞在其中心区域伸长，而在第二个阶段，发生极尖生长。电子显微镜显示鼓藻被一层形态均匀且无孔的细胞壁所包围。免疫细胞化学和生化分析有助于深入了解细胞壁的物理特性，进而了解其对极端环境的适应情况。针对不同酯化程度的果胶表位的单克隆抗体JIM5和JIM7优先标记鼓藻中正在生长的细胞壁区域。相反，2F4只有在实验性去酯化后才能标记细胞壁。电子能量损失谱揭示了果胶的钙结合能力，并间接证明了其酯化程度。一种针对鼓藻黏液的抗体不仅对黏液具有特异性，而且在透射电子显微镜和斑点印迹中还能识别细胞壁成分。这些结果表明鼓藻中黏液和细胞壁之间存在平滑过渡。
The unicellular, simply shaped desmid Netrium digitus inhabiting acid bog ponds grows in two phases. Prior to division, the cell elongates at its central zone, whereas in a second phase, polar tip growth occurs. Electron microscopy demonstrates that Netrium is surrounded by a morphologically homogeneous cell wall, which lacks pores. Immunocytochemical and biochemical analyses give insight into physical wall properties and, thus, into adaptation to the extreme environment. The monoclonal antibodies JIM5 and JIM7 directed against pectic epitopes with different degrees of esterification label preferentially growing wall zones in Netrium. In contrast, 2F4 marks the cell wall only after experimental de-esterification. Electron energy loss spectroscopy reveals Ca-binding capacities of pectins and gives indirect evidence for the degree of their esterification. An antibody raised against Netrium mucilage is not only specific to mucilage but also recognizes wall components in transmission electron microscopy and dot blots. These results indicate a smooth transition between mucilage and the cell wall in Netrium.