植物在其顶端分生组织中不断保持着干细胞，植物的茎系统和根系统就是从顶端分生组织产生的。在经典植物模型拟南芥中，茎顶端分生组织中的干细胞命运由植物生长素和细胞分裂素等激素来控制。
现在，对这些激素之间的交流所做的一项研究表明，两个A-型“拟南芥响应调控因子”基因对细胞分裂素和植物生长素信号进行集成，并将这些输入与茎顶端分生组织中的核心调控机制联系起来。这项工作为植物生长素和细胞分裂素在设置茎干细胞小生境中的协同活动提出了一个机制性框架，并且突显了根和茎干细胞系统在对植物激素响应方面的差别。（生物谷Bioon.net）
生物谷推荐原文出处：
Nature doi:10.1038/nature09126
Hormonal control of the shoot stem-cell niche
Zhong Zhao,Stig U. Andersen,Karin Ljung,Karel Dolezal,Andrej Miotk,Sebastian J. Schultheiss& Jan U. Lohmann
The classic phytohormones cytokinin and auxin play essential roles in the maintenance of stem-cell systems embedded in shoot and root meristems, and exhibit complex functional interactions1, 2, 3, 4. Here we show that the activity of both hormones directly converges on the promoters of two A-type ARABIDOPSIS RESPONSE REGULATOR (ARR) genes, ARR7 and ARR15, which are negative regulators of cytokinin signalling5 and have important meristematic functions3. Whereas ARR7 and ARR15 expression in the shoot apical meristem (SAM) is induced by cytokinin, auxin has a negative effect, which is, at least in part, mediated by the AUXIN RESPONSE FACTOR5/MONOPTEROS (MP) transcription factor6. Our results provide a mechanistic framework for hormonal control of the apical stem-cell niche and demonstrate how root and shoot stem-cell systems differ in their response to phytohormones.
