John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Curr Biol. 2013 Sep 9;23(17):R807-11. doi: 10.1016/j.cub.2013.07.027.
Plants have to cope with constantly changing conditions and need to respond to environmental stresses and seasonal changes in temperature and photoperiod. Alignment of their development with particular seasons requires memory mechanisms and an ability to integrate noisy temperature signals over long time scales. An increasingly well understood example of how seasonal changes influence development is vernalization, the acceleration of flowering by prolonged cold. Vernalization has been dissected in Arabidopsis thaliana and shown to involve a Polycomb-based epigenetic memory system. This minireview summarizes our current understanding of this mechanism and its modulation through adaptation. A key concept that has emerged is that cell-autonomous switching between epigenetic states can provide the basis for quantitative accumulation of environmental memory.
植物必须应对不断变化的环境条件，需要对环境压力以及温度和光周期的季节性变化做出响应。使它们的发育与特定季节保持一致需要记忆机制和在长时间尺度上整合嘈杂温度信号的能力。季节性变化如何影响发育的一个越来越被理解的例子是春化作用，即通过延长低温来加速开花。春化作用在拟南芥中已经被剖析，并显示涉及到一个基于 Polycomb 的表观遗传记忆系统。这篇综述总结了我们目前对这一机制及其通过适应进行调节的理解。一个出现的关键概念是，表观遗传状态的细胞自主转换可以为环境记忆的定量积累提供基础。
