背景回顾：Spatiotemporal patterns of gene expression are instrumental to morphogenesis. A stable pattern interface, often between reciprocal-inhibiting morphogens, must be robustly maintained after initial patterning cues diminish, organ growth, or organ geometry changes. In plants, floral and leaf primordia obtain the adaxial-abaxial pattern at the shoot apical meristem periphery. 

提出问题：However, it is unknown how the pattern is maintained after primordia have left the shoot apex. 

主要发现：Here, through a combination of computational simulations, time-lapse imaging, and genetic analysis, we propose a model in which auxin simultaneously promotes both adaxial and abaxial domains of expression. Furthermore, we identified multilevel feedback regulation of auxin signaling to refine the spatiotemporal patterns. 

结论：Our results demonstrate that coactivation by auxin determines and stabilizes antagonistic adaxial-abaxial patterning during aerial organ formation.

 摘 要 

基因表达的时空模式在形态建成中起重要作用。一个稳固的模式界面，通常介于相互抑制的发生因子间，必需在最初的模式建成信号衰弱、器官生长或者器官几何特征改变之后，能够被稳健的维持。在植物中，花和叶原基在茎尖分生组织周边时获得了近–远轴模式。但是，目前还不清楚在原基离开茎尖之后，这种近–远轴模式是如何被维持的。本文中，作者通过计算模拟、延时成像以及遗传分析，提出了一个生长素同时促进近–远轴域表达的模型。此外，作者鉴定了生长素信号转导的多层次反馈调节，从而建立起时空模式。本文的研究结果揭示了在植物地上组织器官形成时，生长素介导的共激活决定且稳定了本身具有拮抗性的近–远轴模式建成。

 焦雨铃