Tissue-wide Mechanical Forces Influence the Polarity of Stomatal Stem Cells in Arabidopsis
Tissue-wide Mechanical Forces Influence the Polarity of Stomatal Stem Cells in Arabidopsis
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DOI：
10.1016/j.cub.2017.01.059
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发表时间：
2017-03-20
期刊：
影响因子：
9.2
通讯作者：
Bergmann, Dominique C.
中科院分区：
文献类型：
--
作者：
Bringmann, Martin;Bergmann, Dominique C.
机械信息是单细胞和多细胞系统中细胞极性的重要贡献者[1-3]。在果蝇翅膀等平面组织中，随着细胞分裂和重组，细胞极性在生长过程中重新定向[4]。在另一个平面组织中，拟南芥叶表皮[5]，气孔干细胞（分生组织样母细胞[MMC]）的极化，不对称分裂是多种细胞类型（包括气孔）的产生和图案化的基础。关键转录因子、极化因子[6]和肽信号[7]的活性解释了一些局部气孔！从一些线性相关细胞的行为中出现的模式[6，8-11]。在这里，我们表明，除了局部作用信号，组织范围内的机械力可以作为组织线索，他们这样做是通过影响个别MMC的极性。如果组织中的机械应力环境通过拉伸或细胞消融而改变，则细胞极性会相应改变。反过来，极性预测细胞和组织生长的方向，导致穿孔细胞之间的机械冲突增加。这种生长、定向分裂和细胞特化之间的相互作用可能有助于气孔的特征性图案形成。在生长的叶子中的保卫细胞。
Mechanical information is an important contributor to cell polarity in uni- and multicellular systems [1-3]. In planar tissues like the Drosophila wing, cell polarity reorients during growth as cells divide and reorganize [4]. In another planar tissue, the Arabidopsis leaf epidermis [5], polarized, asymmetric divisions of stomatal stem cells (meristemoid mother cells [MMCs]) are fundamental for the generation and patterning of multiple cell types, including stomata. The activity of key transcription factors, polarizing factors [6], and peptide signals [7] explains some local stomata! patterns emerging from the behavior of a few lineally related cells [6, 8-11]. Here we demonstrate that, in addition to locally acting signals, tissue-wide mechanical forces can act as organizing cues, and that they do so by influencing the polarity of individual MMCs. If the mechanical stress environment in the tissue is altered through stretching or cell ablations, cellular polarity changes in response. In turn, polarity predicts the orientation of cellular and tissue outgrowth, leading to increased mechanical conflicts between neigh-boring cells. This interplay among growth, oriented divisions, and cell specification could contribute to the characteristic patterning of stomata! guard cells in the context of a growing leaf.