Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan.
JST ERATO Higashiyama Live-Holonics Project, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan.
Sci Rep. 2017 May 3;7(1):1403. doi: 10.1038/s41598-017-01610-w.
Plant cells are covered with rigid cell walls, yet tip-growing cells can elongate by providing new cell wall material to their apical regions. Studies of the mechanical properties of tip-growing plant cells typically involve measurement of the turgor pressure and stiffness of the cells' apical regions. These experiments, however, do not address how living tip-growing cells react when they encounter physical obstacles that are not substantially altered by turgor pressure. To investigate this issue, we constructed microfabricated platforms with a series of artificial gaps as small as 1 μm, and examined the capability of tip-growing plant cells, including pollen tubes, root hairs, and moss protonemata, to penetrate into these gaps. The cells were grown inside microfluidic chambers and guided towards the gaps using microdevices customized for each cell type. All types of tip-growing cells could grow through the microgaps with their organelles intact, even though the gaps were much smaller than the cylindrical cell diameter. Our findings reveal the dramatic physiological and developmental flexibility of tip-growing plant cells. The microfluidic platforms designed in this study provide novel tools for the elucidation of the mechanical properties of tip-growing plant cells in extremely small spaces.
植物细胞被坚硬的细胞壁所覆盖，但顶端生长的细胞可以通过向其顶端区域提供新的细胞壁物质来延长。研究顶端生长植物细胞的机械性能通常涉及测量细胞的膨压和顶端区域的刚度。然而，这些实验并没有解决当活的顶端生长细胞遇到物理障碍物时，它们会如何反应的问题，这些障碍物不会因膨压而发生实质性改变。为了研究这个问题，我们构建了带有一系列人工缝隙的微制造平台，这些缝隙小至 1μm，研究了包括花粉管、根毛和苔藓原丝体在内的顶端生长植物细胞穿透这些缝隙的能力。细胞在微流控室内生长，并使用为每种细胞类型定制的微设备引导它们朝向缝隙。所有类型的顶端生长细胞都可以在细胞器完整的情况下穿过微缝隙，尽管这些缝隙比圆柱状细胞直径小得多。我们的发现揭示了顶端生长植物细胞显著的生理和发育灵活性。本研究设计的微流控平台为阐明极小空间中顶端生长植物细胞的机械性能提供了新的工具。
