Plants form new organs from pluripotent stem cells throughout their lives and under changing environmental conditions. In the Arabidopsis root meristem, a pool of stem cells surrounding a stem cell organizer, named Quiescent Center (QC), gives rise to the specific root tissues. Among them, the columella stem cell niche that gives rise to the gravity-sensing columella cells has been used as a model system to study stem cell regulation at the young seedling stage. However, little is known about the changes of the stem cell niche during later development.

Here, we report that the columella stem cell niche undergoes pronounced histological and molecular reorganization as the plant progresses towards the adult stage. Commonly-used reporters for cellular states undergo re-patterning after an initial juvenile meristem phase. Furthermore, the responsiveness to the plant hormone abscisic acid, an integrator of stress response, strongly decreases. Many ageing effects are reminiscent of the loss-of-function phenotype of the central stem cell regulator WOX5 and can be explained by gradually decreasing WOX5 expression levels during ageing. Our results show that the architecture and central regulatory components of the root stem cell niche are already highly dynamic within the first weeks of development.

植物在其整个生命周期和不断变化的环境条件下从多能干细胞形成新器官。在拟南芥根分生组织中，干细胞组织者周围的干细胞池称为静止中心 (QC)，产生特定的根组织。其中，产生重力感应小柱细胞的小柱干细胞生态位已被用作研究幼苗期干细胞调控的模型系统。然而，人们对后期发育过程中干细胞生态位的变化知之甚少。

在这里，我们报告说，随着植物向成虫阶段发展，小柱干细胞生态位经历了明显的组织学和分子重组。细胞状态的常用报告基因在初始幼年分生组织阶段后进行重新模式化。此外，对植物激素脱落酸（一种胁迫反应的整合因子）的反应强烈降低。许多衰老效应让人想起中央干细胞调节剂 WOX5 的功能丧失表型，可以通过衰老过程中 WOX5 表达水平逐渐降低来解释。我们的结果表明，根干细胞生态位的结构和中央调节组件在发育的最初几周内就已经是高度动态的。