Department of Cell Biology, Centre for Organismal Studies Heidelberg, Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.
Plant Biology Laboratory, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
Development. 2021 Nov 1;148(21). doi: 10.1242/dev.199504. Epub 2021 Nov 5.
Plant brassinosteroid hormones (BRs) regulate growth in part through altering the properties of the cell wall, the extracellular matrix of plant cells. Conversely, feedback signalling from the wall connects the state of cell wall homeostasis to the BR receptor complex and modulates BR activity. Here, we report that both pectin-triggered cell wall signalling and impaired BR signalling result in altered cell wall orientation in the Arabidopsis root meristem. Furthermore, both depletion of endogenous BRs and exogenous supply of BRs triggered these defects. Cell wall signalling-induced alterations in the orientation of newly placed walls appear to occur late during cytokinesis, after initial positioning of the cortical division zone. Tissue-specific perturbations of BR signalling revealed that the cellular malfunction is unrelated to previously described whole organ growth defects. Thus, tissue type separates the pleiotropic effects of cell wall/BR signals and highlights their importance during cell wall placement.
植物油菜素甾体激素（BRs）通过改变细胞壁的特性来调节生长，细胞壁是植物细胞的细胞外基质。相反，来自细胞壁的反馈信号将细胞壁动态平衡的状态连接到 BR 受体复合物，并调节 BR 活性。在这里，我们报告说果胶触发的细胞壁信号和受损的 BR 信号都会导致拟南芥根分生组织中细胞壁方向的改变。此外，内源 BR 的耗竭和外源 BR 的供应都会引发这些缺陷。细胞壁信号诱导的新放置细胞壁方向的改变似乎发生在胞质分裂后期，在皮质分裂区的初始定位之后。BR 信号的组织特异性扰动表明，细胞功能障碍与先前描述的整个器官生长缺陷无关。因此，组织类型将细胞壁/BR 信号的多效性影响分开，并强调了它们在细胞壁放置过程中的重要性。
