Structural and functional compartmentalization in pollen tubes
Structural and functional compartmentalization in pollen tubes
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DOI：
10.1093/jxb/erl122
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发表时间：
2007-01-01
影响因子：
6.9
通讯作者：
Wu, Hen-Ming
中科院分区：
文献类型：
--
作者：
Cheung, Alice Y.;Wu, Hen-Ming
真核细胞的功能是通过细胞质中的协同活动和细胞核和其他膜结合细胞器中的功能来实现的。此外，细胞质和核质中充满了专门用于不同代谢和生化过程的大分子系综。花粉管是植物细胞中具有显著生长极性的特殊细胞。管生长仅限于尖端，并由极化的细胞质组织支持。伸长花粉管的顶端区域是一个专门由运输小泡占据的区域，以支持顶端细胞快速扩张所需的分泌和内吞活性。较大的细胞器主要分布在远侧的细胞质中。在细胞器划分的基础是一个精心制作的肌动蛋白细胞骨架，具有独特的结构和动力学特性的尖端，在亚顶端区域，并在细胞质subtending it.Cytoplasmic域的差异离子条件和空间限制的定位分子在花粉管中也可能是重要的调节极性细胞的生长过程。花粉管中的极化细胞组织驱动着一个非常有效的细胞生长过程，该过程对细胞外信号（包括方向性信号）做出反应。它可能是细胞质结构的扩增框架，支持其他植物细胞类型的生长，涉及相当多的微妙和短暂的差异细胞扩增。
Eukaryotic cellular functions are achieved by concerted activities in the cytosol and functions compartmentalized in the nucleus and other membrane-bound organelles. Moreover, the cytosol and nucleoplasm are populated with mega molecular ensembles that are specialized for different metabolic and biochemical processes. Pollen tubes are unique plant cells with a dramatic growth polarity. Tube growth is restricted to the tip and is supported by a polarized cytoplasmic organization. The apical region of elongating pollen tubes is a domain occupied exclusively by transport vesicles to support the secretion and endocytic activity needed for the rapid cell expansion at the apex. Larger organelles are predominantly segregated to the cytoplasm distal to the subapical region. Underlying the organelle compartmentalization is an elaborate actin cytoskeleton with distinct structural and dynamics properties at the tip, in the subapical region, and in the cytoplasm subtending it. Cytoplasmic domains with differential ionic conditions and spatially restricted localization of molecules in pollen tubes may also be important for regulating the polar cell growth process. The polarized cellular organization in pollen tubes drives an extremely efficient cell growth process that is responsive to extracellular signals, including directional cues. It may be an amplified framework of the cytoplasmic architecture that supports growth in other plant cell types that involves considerably more subtle and transient differential cell expansion.