Laboratoire de Biochimie et Physiologie Moléculaire des Plantes (INRA, CNRS, Montpellier SupAgro, Université Montpellier 2), 34060 Montpellier Cedex 2, France.
Laboratoire de Biochimie et Physiologie Moléculaire des Plantes (INRA, CNRS, Montpellier SupAgro, Université Montpellier 2), 34060 Montpellier Cedex 2, France.
Plant Sci. 2014 Jul;224:112-9. doi: 10.1016/j.plantsci.2014.03.015. Epub 2014 Mar 22.
Carbon assimilation, a key determinant of plant biomass production, is under circadian regulation. Light and temperature are major inputs of the plant clock that control various daily rhythms. Such rhythms confer adaptive advantages to the organisms by adjusting their metabolism in anticipation of environmental fluctuations. The relationship between the circadian clock and nutrition extends far beyond the regulation of carbon assimilation as mineral nutrition, and specially iron homeostasis, is regulated through this mechanism. Conversely, iron status was identified as a new and important input regulating the central oscillator, raising the question of the nature of the Fe-dependent signal that modulates the period of the circadian clock. Several lines of evidence strongly suggest that fully developed and functional chloroplasts as well as early light signalling events, involving phytochromes, are essential to couple the clock to Fe responses. Nevertheless, the exact nature of the signal, which most probably involves unknown or not yet fully characterized elements of the chloroplast-to-nucleus retrograde signalling pathway, remains to be identified. Finally, this regulation may also involves epigenetic components.
碳同化作用是植物生物量生产的关键决定因素，它受到昼夜节律的调节。光和温度是植物生物钟的主要输入，控制着各种日常节律。这种节律通过调整代谢来适应环境波动，为生物体带来了适应性优势。生物钟与营养之间的关系远远超出了碳同化作用的调节范围，因为矿物质营养，特别是铁的动态平衡，是通过这种机制来调节的。相反，铁的状态被确定为调节中央振荡器的一个新的重要输入，这就提出了一个问题，即调节生物钟周期的铁依赖性信号的性质是什么。有几条证据强烈表明，完全发育和功能正常的叶绿体以及早期的光信号事件，涉及到光敏色素，对于将时钟与铁反应联系起来是必不可少的。然而，信号的确切性质，很可能涉及到叶绿体到细胞核逆行信号通路中未知的或尚未完全表征的元素，仍有待确定。最后，这种调节也可能涉及到表观遗传成分。
