植物生物钟的研究进展

Biological Clock and Its Research Progress in Plants

在漫长的进化过程中,植物逐渐建立起了一套能够提前预测环境变化的调控网络——生物钟。它不仅仅是植物内部的分子计时器,更是植物与环境间联系的一座桥梁。通过输入途径将环境中授时因子(光照、温度等)发生变化的信息传递给核心振荡器;而后,生物钟核心基因依据信号通过输出途径调控下游钟控基因,从多个方面保证了植物与环境交互过程中的“利益最大化”和“损失最小化”,增强植物对于环境的适应能力。本文重点描述了生物钟在植物的生长发育和胁迫应答过程中发挥的作用,例如,开花时间、碳水化合物代谢以及下胚轴伸长的控制,高温、干旱等非生物胁迫应答的调控。同时对容易混淆的两对概念:近日节律(circadian rhythms)与昼夜节律(diurnal rhythms)、授时因子时间(zeitgeber time)与近日节律时间(circadian time),通过图示的方式进行了简洁明了的阐述。随着模式植物研究的逐渐深入,作为主要粮食作物的水稻(Oryza sativa),其生物钟基因的鉴定与功能分析也越来越完善。我们在多年生水稻基因表达节律方面也开展了系列研究。水稻生物钟参与环境交互以及水稻生长发育的方式渐渐明了,如抽穗期的调控和盐胁迫应答等,这些研究结果将有助于改善水稻农艺性状,拓展水稻的种植范围,缓解粮食安全问题。

During the long process of evolution,plants have gradually established a set of regulatory network that can predict environmental changes in advance,called the biological clock.It is not only a molecular timer inside the plant,but also a connection between the plant and the environment,which transmits the information of the change of the environmental zeitgeber(light and temperature,etc.)to the core oscillator through the input pathway.Then,the core genes of the biological clock regulate the downstream clock-controlled genes through the output pathway according to the signal,which would ensure the"benefit maximization"and"loss minimization"in the process of interaction between plants and the environment,and enhance the adaptability of plants to the environment.In this paper,we focus on the role of the biological clock in the growth and development of plants and the stress response,such as the control of flowering time,carbohydrate metabolism and hypocotyl elongation,and the regulation of abiotic stress responses such as high temperature and drought.At the same time,two pairs of concepts that are easily confused,namely circadian rhythms and diurnal rhythms,zeitgeber time and circadian time,are concisely and clearly illustrated in the form of diagrams.With the deepening of the research on model plants,the identification and functional analysis of biological clock genes of rice,one staple food crop,is on the way of continual improvement.We have also carried out a series of studies on gene expression rhythms in perennial rice.The ways in which the biological clock participates in environmental interaction and the growth and development of rice are gradually understood,such as the regulation of heading stage and the response to salt stress,which will help to improve the agronomic traits of rice,expanding the planting range of rice,and alleviating the problem of food security.