植物在其頂端分生組織中不斷保持著干細(xì)胞,，植物的莖系統(tǒng)和根系統(tǒng)就是從頂端分生組織產(chǎn)生的。在經(jīng)典植物模型擬南芥中,，莖頂端分生組織中的干細(xì)胞命運由植物生長素和細(xì)胞分裂素等激素來控制,。
現(xiàn)在，對這些激素之間的交流所做的一項研究表明,，兩個A-型“擬南芥響應(yīng)調(diào)控因子”基因?qū)?xì)胞分裂素和植物生長素信號進行集成,，并將這些輸入與莖頂端分生組織中的核心調(diào)控機制聯(lián)系起來。這項工作為植物生長素和細(xì)胞分裂素在設(shè)置莖干細(xì)胞小生境中的協(xié)同活動提出了一個機制性框架,，并且突顯了根和莖干細(xì)胞系統(tǒng)在對植物激素響應(yīng)方面的差別,。（生物谷Bioon.net）
生物谷推薦原文出處：
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.
