The Circadian Clock in Arabidopsis Roots Is a Simplified Slave Version of the Clock in Shoots
The Circadian Clock in Arabidopsis Roots Is a Simplified Slave Version of the Clock in Shoots
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DOI：
10.1126/science.1161403
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发表时间：
2008-12-19
期刊：
影响因子：
56.9
通讯作者：
Nimmo, Hugh G.
中科院分区：
文献类型：
--
作者：
James, Allan B.;Monreal, Jose A.;Nimmo, Hugh G.
真核生物中的昼夜节律振荡器由几个连锁的反馈环组成，通过这些反馈环控制时钟基因的表达。通常认为，所有植物细胞都含有基本上相同的、细胞自主的多循环时钟。在这里，我们表明，在成熟的拟南芥植物的根的昼夜节律时钟明显不同于在地上部，根的时钟是由地上部的光合作用相关的信号同步的。植物生物钟的两个反馈环在根中是分离的，因为两个关键的时钟成分，转录因子CCA1和LHY，能够抑制基因在茎中的表达，但不能在根中抑制基因表达。因此，植物时钟是器官特有的，但不是器官自主的。
The circadian oscillator in eukaryotes consists of several interlocking feedback loops through which the expression of clock genes is controlled. It is generally assumed that all plant cells contain essentially identical and cell- autonomous multiloop clocks. Here, we show that the circadian clock in the roots of mature Arabidopsis plants differs markedly from that in the shoots and that the root clock is synchronized by a photosynthesis- related signal from the shoot. Two of the feedback loops of the plant circadian clock are disengaged in roots, because two key clock components, the transcription factors CCA1 and LHY, are able to inhibit gene expression in shoots but not in roots. Thus, the plant clock is organ- specific but not organ- autonomous.