University of Massachusetts Dartmouth, Dartmouth, Massachusetts 02747, USA.
Mol Reprod Dev. 2010 Sep;77(9):751-8. doi: 10.1002/mrd.21199.
The establishment of polarity is a fundamental property of most cells. In tip-growing plant and in fucoid algal cells, polarization specifies a growth pole, the center of localized secretion of new plasma membrane and cell wall material, generating a protrusion with a dome-shaped apex. Although much progress has been made concerning the cellular machinery required to execute tip growth, less is known regarding the signaling mechanisms involved in selecting the growth site and regulating vectorial cell division and expansion. Fucoid algal zygotes use extrinsic cues to orient their growth axes and are thus well-suited for studies of de novo selection of an axis. This process has been investigated largely by both pharmacological and immuno-localization studies. In tip growing plant cells, polarity is often predetermined, as in the formation of root hairs or moss protonema branches. More focus has been on genomic and genetic studies to reveal the molecules involved in expressing a growth axis. Here we review the common roles of the cytoskeleton and signal transduction pathways in the formation of a developmental axis in fucoid algal cells and the control of tip growth in higher plant cells.
极性的建立是大多数细胞的基本特性。在顶端生长的植物和褐藻细胞中，极化指定了一个生长极，即新质膜和细胞壁物质局部分泌的中心，产生一个具有圆顶状尖端的突起。尽管在执行顶端生长所需的细胞机制方面已经取得了很大进展，但对于参与选择生长部位和调节定向细胞分裂和扩展的信号机制知之甚少。褐藻受精卵利用外在线索来确定其生长轴，因此非常适合研究新轴的选择。这个过程主要通过药理学和免疫定位研究来研究。在顶端生长的植物细胞中，极性通常是预先确定的，例如在根毛或苔藓原丝体分支的形成中。更多的关注集中在基因组和遗传研究上，以揭示参与表达生长轴的分子。在这里，我们综述了细胞骨架和信号转导途径在褐藻细胞发育轴形成和高等植物细胞顶端生长控制中的共同作用。
