A Self-Activation Loop Maintains Meristematic Cell Fate for Branching
A Self-Activation Loop Maintains Meristematic Cell Fate for Branching
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DOI：
10.1016/j.cub.2020.03.031
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发表时间：
2020-05-18
期刊：
影响因子：
9.2
通讯作者：
Jiao, Yuling
中科院分区：
文献类型：
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作者：
Cao, Xiuwei;Wang, Jin;Jiao, Yuling
在植物和动物中，自我更新的干细胞群在许多发育环境中发挥着重要作用。植物与大多数动物的不同之处在于，它们保留了启动新的生长和发育周期的能力，这依赖于分支分生组织的建立和活动。在种子植物中，分支是由含有干细胞的腋生分生组织实现的，它是由最初从茎尖分生组织分离出来的叶腋分生组织细胞群产生的。目前尚不清楚分生细胞的命运是如何维持的。本研究表明，拟南芥HOMEOBOX GENE1 （ATH1）可维持分生组织标记基因SHOOT MERISTEMLESS （STM）在叶腋的表达，从而维持分生组织细胞的命运。此外，ATH1蛋白与STM蛋白相互作用形成STM自激活环。遗传和生化数据表明，ATH1锚定STM，激活STM以及其他腋窝分生组织调节基因。这种自动调节允许STM基因座保持表观遗传活性。综上所述，我们的研究结果提供了一个引人注目的例子，即在器官发生过程中，自我激活环保持了干细胞生态位重建所需的灵活性。
In plants and animals, self-renewing stem cell populations play fundamental roles in many developmental contexts. Plants differ from most animals in their retained ability to initiate new cycles of growth and development, which relies on the establishment and activity of branch meristems. In seed plants, branching is achieved by stem-cell-containing axillary meristems, which are initiated from a leaf axil meristematic cell population originally detached from the shoot apical meristem. It remains unclear how the meristematic cell fate is maintained. Here, we show that ARABIDOPSIS THALIANA HOMEOBOX GENE1 (ATH1) maintains the meristem marker gene SHOOT MERISTEMLESS (STM) expression in the leaf axil to enable meristematic cell fate maintenance. Furthermore, ATH1 protein interacts with STM protein to form a STM self-activation loop. Genetic and biochemical data suggest that ATH1 anchors STM to activate STM as well as other axillary meristem regulatory genes. This auto-regulation allows the STM locus to remain epigenetically active. Taken together, our findings provide a striking example of a self-activation loop that maintains the flexibility required for stem cell niche re-establishment during organogenesis.