Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology (KIT), Kaiserstrasse 2, D-76131 Karlsruhe, Germany.
J Plant Physiol. 2013 Aug 15;170(12):1057-66. doi: 10.1016/j.jplph.2013.03.002. Epub 2013 Mar 30.
Polar transport of auxin has been identified as a central element of pattern formation. To address the underlying cellular mechanisms, we use the tobacco cell line (Nicotiana tabacum L. cv. Bright Yellow 2; BY-2) as model. We showed previously that cell divisions within a cell file are synchronized by polar auxin flow, linked to the organization of actin filaments (AF) which, in turn, is modified via actin-binding proteins (ABPs). From a preparatory study for disturbed division synchrony in cell lines overexpressing different ABPs, we identified the actin depolymerizing factor 2 (ADF2). A cell line overexpressing GFP-NtADF2 was specifically affected in division synchrony. The cell division pattern could be rescued by addition of Phosphatidylinositol 4,5-bisphosphate (PIP2) or by phalloidin. These observations allow to draw first conclusions on the pathway linking auxin signalling via actin reorganization to synchronized cell division placing the regulation of cortical actin turnover by ADF2 into the focus.
生长素的极性运输已被确定为模式形成的核心要素。为了解决潜在的细胞机制问题，我们使用烟草细胞系（Nicotiana tabacum L. cv. Bright Yellow 2；BY-2）作为模型。我们之前曾表明，细胞文件内的细胞分裂通过极性生长素流同步，这与肌动蛋白丝（AF）的组织有关，而肌动蛋白丝又通过肌动蛋白结合蛋白（ABP）进行修饰。在对过表达不同 ABP 的细胞系中分裂同步受到干扰的预备性研究中，我们鉴定出了肌动蛋白解聚因子 2（ADF2）。过表达 GFP-NtADF2 的细胞系在分裂同步性方面受到特别影响。通过添加磷脂酰肌醇 4,5-二磷酸（PIP2）或鬼笔环肽可以挽救细胞分裂模式。这些观察结果使我们能够对连接生长素信号通过肌动蛋白重组到同步细胞分裂的途径得出初步结论，将 ADF2 对皮质肌动蛋白周转率的调节作为重点。
