CLEs are small non-cell autonomous signalling peptides that regulate cell division rate and orientation in a variety of developmental contexts. Recent years have generated a huge amount of research on CLE function across land plants, characterising their role across the whole plant; they control stem cell division in the shoot, root and cambial meristems, balance developmental investment into symbiosis, regulate leaf development, pattern stomata and control axillary branching. They have even been co-opted by parasitic nematodes to mediate infection. This review synthesises these recent findings and embeds them in an evolutionary context, outlining the likely evolution of the CLE signalling pathway. I use this framework to infer common mechanistic themes and pose key future questions for the field.

CLE 是小的非细胞自主信号肽，可在各种发育环境中调节细胞分裂率和方向。近年来，对陆生植物的 CLE 功能进行了大量研究，描述了它们在整个植物中的作用；它们控制茎、根和形成层分生组织中的干细胞分裂，平衡对共生的发育投资，调节叶片发育，模式气孔和控制腋生分枝。它们甚至被寄生线虫利用来介导感染。这篇综述综合了这些最近的发现，并将它们嵌入到进化背景中，概述了 CLE 信号通路的可能进化。我使用这个框架来推断常见的机械主题，并为该领域提出关键的未来问题。