Molecular and Computational Biology, University of Southern California, Los Angeles, USA.
J Integr Plant Biol. 2011 Jun;53(6):446-54. doi: 10.1111/j.1744-7909.2011.01045.x.
The plant meristems possess unique features that involve maintaining the stem cell populations while providing cells for continued development. Although both the primary shoot apical meristem (SAM) and the root apical meristem (RAM) are specified during embryogenesis, post-embryonic tissue proliferation is required for their full establishment and maintenance throughout a plants' life. The phytohormone cytokinin (CK) interacts with other systemic signals and is a key regulator of meristem size and functions. The SAM and the RAM respond to CK stimulations in different manners: CK promotes tissue proliferation in the SAM through pathways dominated by homeobox transcription factors, including the class I KNOX genes, STIP, and WUS; and curiously, it favors proliferation at low levels and differentiation at a slightly higher concentration in the RAM instead. Here we review the current understanding of the molecular mechanisms underlying CK actions in regulating meristematic tissue proliferation.
植物分生组织具有独特的特征，涉及维持干细胞群体，同时为持续发育提供细胞。虽然初生茎尖分生组织（SAM）和根端分生组织（RAM）在胚胎发生过程中被指定，但它们的完全建立和维持需要胚胎后组织增殖。植物激素细胞分裂素（CK）与其他系统信号相互作用，是分生组织大小和功能的关键调节剂。SAM 和 RAM 以不同的方式对 CK 刺激作出反应：CK 通过以同源盒转录因子为主导的途径促进 SAM 中的组织增殖，包括 I 类 KNOX 基因、STIP 和 WUS；有趣的是，它在 RAM 中较低水平促进增殖，在稍高浓度下促进分化。在这里，我们回顾了目前对 CK 作用于调节分生组织组织增殖的分子机制的理解。
