Subcellular Dynamics, Cell Morphogenesis, and Organ Formation in Plants

植物的亚细胞动力学、细胞形态发生和器官形成

• 批准号: RGPIN-2015-05938
• 负责人: Ambrose, Chris
• 金额: $ 2.55万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=590734
• 关键词: Subcellular; Dynamics; Cell; Morphogenesis; Organ

Plants grow and respond to their surroundings through coordinated patterns of cell division and cell expansion. For example, in a root, cell division is restricted to the tip, forming an apical meristem that produces layers of cells. Behind the tip is the elongation zone, where cells cease dividing and begin expanding lengthwise to form the mature root. Since plant cells are surrounded and supported by cell walls, all cell division and expansion depends on cell wall structure and composition. Strands of cellulose called cellulose microfibrils (CMFs) form a meshwork that determines the direction of cell expansion. For example, in the root elongation zone, CMFs line up in parallel hoops that restrict lateral cell expansion and favor elongation. In contrast, dividing meristematic cells have mixed CMF orientations that prevent elongation. CMF orientation is controlled by the orientation of microtubules (MTs), which form a network of cables that line the cell membrane. MTs guide the linear movement of cellulose-synthesizing enzymes in the membrane that extrude CMFs into the adjacent cell wall. As with CMFs, MTs switch from mixed to organized patterns upon entry into cell expansion.

植物生长并通过细胞分裂和细胞扩张的协调模式对周围环境做出反应。例如，在根中，细胞分裂仅限于顶端，形成产生细胞层的顶端分生组织。在根尖后面是伸长区，细胞停止分裂，开始纵向扩展，形成成熟的根。由于植物细胞由细胞壁包围和支撑，所有细胞分裂和扩展都取决于细胞壁的结构和组成。纤维素微纤维（CMF）形成的纤维素链决定了细胞扩张的方向。例如，在根伸长区，CMF以平行的箍排列，限制了细胞的侧向扩张并有利于伸长。相反，分裂的分生组织细胞具有防止伸长的混合CMF取向。CMF的方向是由微管（MT）的方向控制的，微管形成了一个排列在细胞膜上的电缆网络。MT引导纤维素合成酶在膜中的线性运动，将CMF挤出到相邻的细胞壁中。与CMF一样，MT在进入细胞扩增时从混合模式切换到有组织模式。