College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
Plant Physiol. 2023 Aug 31;193(1):70-82. doi: 10.1093/plphys/kiad309.
Distinct from animals, plants maintain organogenesis from specialized tissues termed meristems throughout life. In the shoot apex, the shoot apical meristem (SAM) produces all aerial organs, such as leaves, from its periphery. For this, the SAM needs to precisely balance stem cell renewal and differentiation, which is achieved through dynamic zonation of the SAM, and cell signaling within functional domains is key for SAM functions. The WUSCHEL-CLAVATA feedback loop plays a key role in SAM homeostasis, and recent studies have uncovered new components, expanding our understanding of the spatial expression and signaling mechanism. Advances in polar auxin transport and signaling have contributed to knowledge of the multifaceted roles of auxin in the SAM and organogenesis. Finally, single-cell techniques have expanded our understanding of the cellular functions within the shoot apex at single-cell resolution. In this review, we summarize the most up-to-date understanding of cell signaling in the SAM and focus on the multiple levels of regulation of SAM formation and maintenance.
与动物不同，植物通过被称为分生组织的专门组织来维持器官发生。在芽尖中，茎尖分生组织（SAM）从其外围产生所有的气生器官，如叶子。为此，SAM 需要精确地平衡干细胞更新和分化，这是通过 SAM 的动态分区以及功能域内的细胞信号传导来实现的。WUSCHEL-CLAVATA 反馈环在 SAM 稳态中起着关键作用，最近的研究揭示了新的成分，扩展了我们对 SAM 中空间表达和信号传导机制的理解。极性生长素运输和信号转导的进展有助于了解生长素在 SAM 和器官发生中的多方面作用。最后，单细胞技术提高了我们对单个细胞分辨率下芽尖内细胞功能的理解。在这篇综述中，我们总结了对 SAM 中细胞信号转导的最新理解，并重点介绍了 SAM 形成和维持的多个调节层次。
