Centering the Organizing Center in the Arabidopsis thaliana Shoot Apical Meristem by a Combination of Cytokinin Signaling and Self-Organization.
Centering the Organizing Center in the Arabidopsis thaliana Shoot Apical Meristem by a Combination of Cytokinin Signaling and Self-Organization.
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DOI：
10.1371/journal.pone.0147830
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Fleck C
中科院分区：
文献类型：
--
作者：
Adibi M;Yoshida S;Weijers D;Fleck C
植物有能力通过在其一生中维持干细胞群来不断产生新器官。茎尖分生组织（SAM）为干细胞的维持提供了稳定的环境。 SAM 内的所有细胞都会分裂，但边界和模式仍保持不变。实验证据表明，模式形成独立于细胞谱系，因此需要动态的自我调节机制。 WUSCHEL 基因 (WUS) 在 SAM 的组织中发挥着关键作用。这方面的一个重要问题是 WUS 表达如何通过细胞谱系独立的信号机制定位在 SAM 中。在本研究中，我们通过数学模型证明，细胞分裂素 (CK) 受体抑制剂、拟南芥组氨酸激酶 4 (AHK4) 和两种源自细胞顶层的形态发生素的组合，可以合理地解释 SAM 内 WUS 表达的细胞谱系无关的中心化。此外，我们的激光消融和显微外科实验支持这样的假设：SAM 中的图案化发生在 CK 接收和信号传导水平。该模型表明 CK 信号、WUS/CLV 反馈环路和边界信号之间的相互作用可以解释 WUS 表达的定位，并为进一步的实验研究提供方向。
Plants have the ability to continously generate new organs by maintaining populations of stem cells throught their lives. The shoot apical meristem (SAM) provides a stable environment for the maintenance of stem cells. All cells inside the SAM divide, yet boundaries and patterns are maintained. Experimental evidence indicates that patterning is independent of cell lineage, thus a dynamic self-regulatory mechanism is required. A pivotal role in the organization of the SAM is played by the WUSCHEL gene (WUS). An important question in this regard is that how WUS expression is positioned in the SAM via a cell-lineage independent signaling mechanism. In this study we demonstrate via mathematical modeling that a combination of an inhibitor of the Cytokinin (CK) receptor, Arabidopsis histidine kinase 4 (AHK4) and two morphogens originating from the top cell layer, can plausibly account for the cell lineage-independent centering of WUS expression within SAM. Furthermore, our laser ablation and microsurgical experiments support the hypothesis that patterning in SAM occurs at the level of CK reception and signaling. The model suggests that the interplay between CK signaling, WUS/CLV feedback loop and boundary signals can account for positioning of the WUS expression, and provides directions for further experimental investigation.