Plant and animal stem cells receive signals from their surrounding cells to stay undifferentiated. In the Arabidopsis root, the quiescent center (QC) acts as a stem cell organizer, signaling to the neighboring stem cells. WOX5 is a central transcription factor regulating QC function. However, due to the scarcity of QC cells, WOX5 functions in the QC are largely unexplored at a genomic scale. Here, we unveil the transcriptional and epigenetic landscapes of the QC and the role of WOX5 within them. We find that WOX5 functions both as a transcriptional repressor and activator, affecting histone modifications and chromatin accessibility. Our data expand on known WOX5 functions, such as the regulation of differentiation, cell division, and auxin biosynthesis. We also uncover unexpected WOX5-regulated pathways involved in nitrate transport and the regulation of basal expression levels of genes associated with mature root tissues. These data suggest a role for QC cells as reserve stem cells and primed cells for prospective progenitor fates. Taken together, these findings offer insights into the role of WOX5 at the QC and provide a basis for further analyses to advance our understanding of the nature of plant stem cell organizers.

中文翻译：

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破译 WOX5 在根干细胞组织者中的分子逻辑。


植物和动物干细胞接收来自周围细胞的信号以保持未分化状态。在拟南芥根中，静止中心 （QC） 充当干细胞组织者，向邻近的干细胞发出信号。WOX5 是一种调节 QC 功能的关键转录因子。然而，由于 QC 细胞的稀缺性，WOX5 在 QC 中的功能在很大程度上尚未在基因组规模上得到探索。在这里，我们揭示了 QC 的转录和表观遗传景观以及 WOX5 在其中的作用。我们发现 WOX5 既作为转录抑制因子又作为激活因子发挥作用，影响组蛋白修饰和染色质可及性。我们的数据扩展了已知的 WOX5 功能，例如分化、细胞分裂和生长素生物合成的调节。我们还发现了意想不到的 WOX5 调节途径，这些途径涉及硝酸盐转运和与成熟根组织相关的基因的基础表达水平的调节。这些数据表明 QC 细胞作为潜在祖细胞命运的储备干细胞和引物细胞的作用。综上所述，这些发现为 WOX5 在 QC 中的作用提供了见解，并为进一步分析提供了基础，以促进我们对植物干细胞组织者性质的理解。