Li Man-Wah, Lam Hon-Ming
Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
Front Genet. 2020 Sep 30;11:571188. doi: 10.3389/fgene.2020.571188. eCollection 2020.
Agricultural production is greatly dependent on daylength, which is determined by latitude. Living organisms align their physiology to daylength through the circadian clock, which is made up of input sensors, core and peripheral clock components, and output. The light/dark cycle is the major input signal, moderated by temperature fluctuations and metabolic changes. The core clock in plants functions mainly through a number of transcription feedback loops. It is known that the circadian clock is not essential for survival. However, alterations in the clock components can lead to substantial changes in physiology. Thus, these clock components have become the targets of artificial selection for crop improvement during domestication. Soybean was domesticated around 5,000 years ago. Although the circadian clock itself is not of particular interest to soybean breeders, specific alleles of the circadian clock components that affect agronomic traits, such as plant architecture, sensitivity to light/dark cycle, flowering time, maturation time, and yield, are. Consequently, compared to their wild relatives, cultivated soybeans have been bred to be more adaptive and productive at different latitudes and habitats for acreage expansion, even though the selection processes were made without any prior knowledge of the circadian clock. Now with the advances in comparative genomics, known modifications in the circadian clock component genes in cultivated soybean have been found, supporting the hypothesis that modifications of the clock are important for crop improvement. In this review, we will summarize the known modifications in soybean circadian clock components as a result of domestication and improvement. In addition to the well-studied effects on developmental timing, we will also discuss the potential of circadian clock modifications for improving other aspects of soybean productivity.
农业生产极大地依赖于由纬度决定的日照长度。生物体通过生物钟使自身生理机能与日照长度保持一致，生物钟由输入传感器、核心和外周时钟组件以及输出部分组成。光/暗周期是主要的输入信号，受温度波动和代谢变化的调节。植物中的核心时钟主要通过一些转录反馈环发挥作用。已知生物钟对于生存并非必不可少。然而，时钟组件的改变会导致生理机能发生重大变化。因此，在驯化过程中，这些时钟组件已成为人工选择以改良作物的目标。大豆大约在5000年前被驯化。虽然生物钟本身对大豆育种者来说并不特别感兴趣，但影响农艺性状（如植株形态、对光/暗周期的敏感性、开花时间、成熟时间和产量）的生物钟组件的特定等位基因却备受关注。因此，与它们的野生近缘种相比，栽培大豆经过培育，在不同纬度和栖息地具有更强的适应性和更高的生产力，从而扩大了种植面积，尽管在选择过程中对生物钟并无任何先验知识。如今，随着比较基因组学的发展，已发现栽培大豆中生物钟组件基因的已知修饰，这支持了生物钟修饰对作物改良很重要这一假设。在这篇综述中，我们将总结驯化和改良导致的大豆生物钟组件的已知修饰。除了对发育时间的深入研究影响外，我们还将讨论生物钟修饰在提高大豆生产力其他方面的潜力。
