Decentralized circadian clocks process thermal and photoperiodic cues in specific tissues.
Decentralized circadian clocks process thermal and photoperiodic cues in specific tissues.
复制标题
分散的生物钟处理特定组织中的热和光周期线索。
DOI：
10.1038/nplants.2015.163
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发表时间：
2015
期刊：
影响因子：
18
通讯作者：
M.
中科院分区：
文献类型：
--
作者：
Shimizu;H.;Katayama;K.;Koto;T.;Torii;K.;Araki;T.;Endo;M.
生物钟通过调节生理反应来增加生物体的适应性1。在哺乳动物中，视交叉上核（SCN）中的生物钟控制着日常行为节奏2。类似地，在拟南芥中，已经出现了组织特异性昼夜节律钟功能，并且已经证明了脉管系统时钟对于光周期开花的重要性3-5。然而，目前尚不清楚血管时钟是否调节大多数生理反应，如哺乳动物中的SCN，以及其他环境信号是否也由血管时钟处理。在这里，我们研究了不同光周期和温度下的开花和细胞伸长的组织特异性生物钟调节的参与。我们发现，在维管韧皮部伴随细胞的生物钟是必不可少的光周期开花调节，相比之下，表皮环境温度依赖的细胞伸长有着至关重要的影响。因此，每个组织中的生物钟之间有明确的角色分配。我们的研究结果表明，与哺乳动物更集中的生物钟不同，植物生物钟是分散的，每个组织都专门处理个体环境线索并调节个体生理反应。我们的新概念框架将成为破译每个组织中生物钟功能的起点，这将有助于更好地理解环境信号的生物钟处理如何受到持续气候变化的影响。
The circadian clock increases organisms' fitness by regulating physiological responses 1. In mammals, the circadian clock in the suprachiasmatic nucleus (SCN) governs daily behavioural rhythms 2. Similarly, in Arabidopsis, tissue-specific circadian clock functions have emerged, and the importance of the vasculature clock for photoperiodic flowering has been demonstrated 3–5. However, it remains unclear if the vasculature clock regulates the majority of physiological responses, like the SCN in mammals, and if other environmental signals are also processed by the vasculature clock. Here, we studied the involvement of tissue-specific circadian clock regulation of flowering and cell elongation under different photoperiods and temperatures. We found that the circadian clock in vascular phloem companion cells is essential for photoperiodic flowering regulation; by contrast, the epidermis has a crucial impact on ambient temperature-dependent cell elongation. Thus, there are clear assignments of roles among circadian clocks in each tissue. Our results reveal that, unlike the more centralized circadian clock in mammals, the plant circadian clock is decentralized, where each tissue specifically processes individual environmental cues and regulates individual physiological responses. Our new conceptual framework will be a starting point for deciphering circadian clock functions in each tissue, which will lead to a better understanding of how circadian clock processing of environmental signals may be affected by ongoing climate change 6.