Root stem cell niche (SCN) consists of a quiescent center (QC) and surrounding stem cells. Disrupted symplastic communication leads to loss of stemness in the whole SCN. Several SCN regulators were reported to move between cells for SCN maintenance. However, single mutant of these regulators is insufficient to abolish QC stemness despite the high differentiation rate in surrounding stem cells. To dissect the mechanism behind such distinct stemness in SCN, we combined the mis‐expression strategy with pWOX5:icals3m system in which QC is symplastically isolated. We found the starch accumulation in QC could be synergistically repressed by WUSCHEL‐RELATED HOMEOBOX 5 (WOX5), SHORT‐ROOT (SHR), SCARCROW (SCR), and PLETHORA (PLT). Like PLTs, other core regulators also exhibited dimorphic functions by inhibiting differentiation at a higher dose while promoting cell division at a low protein level. Being located in the center of the intersected expression zones, QC cells receive the highest level of core regulators, forming the most robust stemness within SCN. WUSCHEL‐RELATED HOMEOBOX 5 was sufficient to activate PLT1/2 expression, contributing to the QC‐enriched PLTs. Our results provide experimental evidence supporting the long‐standing hypothesis that the combination of spatial expression, synergistic function and dosage effect of core regulators result in spatially distinct stemness in SCN.

中文翻译：

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转录调节子的相交功能区在根尖分生组织的干细胞生态位内形成干性模式。

根干细胞生态位（SCN）由一个静态中心（QC）和周围的干细胞组成。破坏性的共生性交流导致整个SCN失去干性。据报道，有几种SCN调节剂在细胞之间移动以进行SCN维护。然而，尽管周围干细胞的分化率很高，但这些调节子的单个突变体仍不足以消除QC干性。为了剖析SCN中这种独特的词干背后的机制，我们将错误表达策略与pWOX5：icals3m相结合QC被共生隔离的系统。我们发现，与WUSCHEL相关的HOMEOBOX 5（WOX5），SHORT-ROOT（SHR），SCARCROW（SCR）和PLETHORA（PLT）可以协同抑制QC中的淀粉积累。像PLT一样，其他核心调节因子也通过在高剂量下抑制分化同时在低蛋白水平下促进细胞分裂而表现出双态功能。QC细胞位于相交的表达区的中心，接受最高水平的核心调节因子，在SCN内形成最坚固的茎。与WUSCHEL相关的HOMEOBOX 5足以激活PLT1 / 2表达，从而为富含QC的PLT做出了贡献。我们的结果提供了实验证据，支持长期以来的假设，即空间表达，