In angiosperms, a negative feedback pathway involving CLAVATA3 (CLV3) peptide and WUSCHEL transcription factor maintains the stem-cell population in the shoot apical meristem and is central for continued shoot growth and organogenesis. An intriguing question is how this cell-signalling system was established during the evolution of land plants. On the basis of two recent studies on CLV3/ESR-related (CLE) genes, this paper proposes a model for the evolution of meristem zonation. The model suggests that a stem-cell-limiting CLV3 pathway is derived from stem-cell-promoting CLE pathways conserved in land pants by gene duplication in the angiosperm lineage. The model can be examined in the future by genomic and developmental studies on diverse plant species.

在被子植物中，涉及 CLAVATA3 (CLV3) 肽和 WUSCHEL 转录因子的负反馈途径维持茎尖分生组织中的干细胞群，并且对于茎的持续生长和器官发生至关重要。一个有趣的问题是，这种细胞信号系统是如何在陆地植物的进化过程中建立起来的。本文在最近两项关于CLV3/ESR相关( CLE )基因的研究基础上，提出了分生组织分区演化的模型。该模型表明，通过被子植物谱系中的基因复制，限制干细胞的 CLV3 途径源自陆地裤中保存的促进干细胞的 CLE 途径。该模型可以在未来通过对不同植物物种的基因组和发育研究进行检查。