拟南芥茎尖干细胞调控机制的研究进展

Research Progresses of the Regulatory Mechanism of the Shoot Apical Stem Cell in Arabidopsis

植物茎尖干细胞是位于植物顶端一团具有无限增殖能力的细胞,它是植物整个地上部分发育的源泉.干细胞分裂产生的子细胞一部分用来保持自我更替,另一部分形成器官原基,进而使其处于一种动态平衡状态,来维持植物甚至可长达千年的生长周期.现代分子生物学与遗传学表明这种动态平衡的维持受到来自干细胞微环境的各种因素的精确调控.其中起核心作用的是由WUSCHEL(WUS)基因与CLAVATA(CLV)基因之间形成的负反馈调节环,而其他生物学因素如细胞分裂素、可以移动的小RNAs和表观遗传作用等最终都作用于这一负反馈调节环,另外与WUS-CLV信号通路相平行的SHOOTMERISTEMLESS(STM)信号通路在干细胞维持中也发挥着积极的作用.在此主要综述了模式植物拟南芥(Arabidopsis thaliana)茎尖干细胞维持分子机制的最新研究进展.

The shoot apical stem cell is a pool of pluripotent cell in the apex of the plant, which is the source of the whole parts above the ground.The stem cell divides to produce two daughter cells. One can renew itself,and the other can form the organ promordia for proliferation.At last the stem cell stablizes in homeostasis, which can maintain plant development even up to a thousand years. Modern molecular biology and genetics have indicated that the homeostasis is regulated exactly by various factors from stem cell niche.The key pathway among the network is the negative feedback loop between the WUSCHEL （WUS） gene and the CLAVATA （CLV） gene.Other biological factors,such as cytokinin, the moved small RNAs and the epigenetics effects,play a role on this loop eventually.Besides, the SHOOTMERISTEMLESS （STM） signaling pathway, which is parallel to the WUS-CLV loop, plays a positive role in stem cell maintenance. This article mainly reviewed the latest research progresses on the molecular mechanism of stem cell maintenance in model plant Arabidopsis.