The Arabidopsis Receptor Kinase IRK Is Polarized and Represses Specific Cell Divisions in Roots

First author: Roya Campos; Affiliations: University of California, Riverside (加州大学河滨分校): Riverside, USA

Corresponding author: Jaimie M. Van Norman

Development of multicellular organisms requires coordination of cell division and differentiation across tissues. In plants, directional signaling, and implicitly cell polarity, is proposed to participate in this coordination; however, mechanistic links between intercellular signaling, cell polarity, and cellular organization remain unclear. Here, we investigate the localization and function of INFLORESCENCE AND ROOT APICES RECEPTOR KINASE (IRK) in root development. We find that IRK-GFP localizes to the outer plasma membrane domain in endodermal cells (内胚层细胞) but localizes to different domains in other cell types. Our results suggest that IRK localization is informed locally by adjacent cell types. irk mutants have excess cell divisions in the ground tissue (基本组织) stem cells and endodermis, indicating IRK functions to maintain tissue organization through inhibition of specific cell divisions. We predict that IRK perceives a directional cue that negatively regulates these cell divisions, thus linking intercellular signaling and cell polarity with the control of oriented cell divisions during development.

多细胞生物的发育需要不同组织之间细胞分裂与分化的协调。在植物中，具有方向性的信号转导与隐含地细胞极性被认为参与了这类的协调，然而胞间信号转导、细胞极性以及细胞层面组织之间的关联还不清楚。本文中，作者研究了植物IRK基因在根发育中的定位与功能。作者发现IRK-GFP定位于内胚层细胞的外侧质膜结构域上，但在其它类型的细胞中则定位于不同的结构域。本文的研究显示IRK的区域化定位是由相邻细胞的类型所决定的。irk突变体的基本组织干细胞和内胚层细胞的细胞分裂过多，说明IRK通过抑制特定类型细胞的分裂来维持植物组织的有序化。作者预测IRK会感知一个定向的信号，负调控这些细胞的分裂，因此将植物发育过程中对于细胞分裂方向性的控制与胞间信号转导及细胞极性联系到一起。

通讯：Jaimie M. Van Norman (https://iigb.ucr.edu/vannorman/)

个人简介：2008-2014年，杜克大学，博士后。

研究方向：植物细胞和发育生物学。

doi: https://doi.org/10.1016/j.devcel.2019.12.001

Journal: Developmental Cell

Published date: December 26, 2019