WUSCHEL acts as an auxin response rheostat to maintain apical stem cells in Arabidopsis

First author: Yanfei Ma; Affiliations: Heidelberg University (海德堡大学): Heidelberg, Germany

Corresponding author: Jan U. Lohmann

To maintain the balance between long-term stem cell self-renewal and differentiation, dynamic signals need to be translated into spatially precise and temporally stable gene expression states. In the apical plant stem cell system, local accumulation of the small, highly mobile phytohormone auxin triggers differentiation while at the same time, pluripotent stem cells are maintained throughout the entire life-cycle. We find that stem cells are resistant to auxin mediated differentiation, but require low levels of signaling for their maintenance. We demonstrate that the WUSCHEL transcription factor confers this behavior by rheostatically controlling the auxin signaling and response pathway. Finally, we show that WUSCHEL acts via regulation of histone acetylation at target loci, including those with functions in the auxin pathway. Our results reveal an important mechanism that allows cells to differentially translate a potent and highly dynamic developmental signal into stable cell behavior with high spatial precision and temporal robustness.

为了维持长期的干细胞自身更新与分化之间的平衡，动态信号需要被转化为精确且稳定的时空基因表达状态。在顶端植物干细胞系统中，小的、高度可移动的植物激素生长素的局部积累会诱导分化，而与此同时，多能干细胞在整个植物生命周期中都会得到维持。作者发现干细胞对于生长素介导的细胞分化具有抗性，但是需要低水平的生长素信号来维持干细胞的活性。作者揭示了转录因子WUSCHEL通过“变阻性”控制生长素信号转导和响应途径赋予了干细胞这种特性。最终，作者的研究显示WUSCHEL通过调控包括能够控制生长素通路在内的靶位点上的组蛋白乙酰化来发挥作用。本文的研究结果揭示了一个重要的分子机制，植物通过该机制能够差异地将一个有效且高度动态的发育信号转化为稳定的细胞行为，同时保证空间上的精确性和时间上的稳定性。

通讯：Jan U. Lohmann (https://www.cos.uni-heidelberg.de/index.php/j.lohmann?l=_e)

研究方向：植物茎尖分生组织中的干细胞起始与维持；局部转录信号如何与系统范围内的激素信号整合在一起，调控干细胞行为与整个植物的生长状态同步；植物如何感知并传递环境信号以调控茎尖分生组织活性。

doi: https://doi.org/10.1038/s41467-019-13074-9

Journal: Nature Communications

Published date: November 08, 2019