Plant Circadian Rhythms

作者：C. Robertson McClung · 发表于：The Plant Cell · 年份：2006 · DOI：10.1105/tpc.106.040980 · 被引用次数：874 · 研究领域：Light effects on plants、Plant Molecular Biology Research、Photosynthetic Processes and Mechanisms

The earth rotates on its axis every 24 h, with the result that any position on the earth's surface alternately faces toward or away from the sun—day and night. That the metabolism, physiology, and behavior of most organisms changes profoundly between day and night is obvious to even the most casual observer. These biological oscillations are apparent as diurnal rhythms. It is less obvious that most organisms have the innate ability to measure time. Indeed, most organisms do not simply respond to sunrise but, rather, anticipate the dawn and adjust their biology accordingly. When deprived of exogenous time cues, many of these diurnal rhythms persist, indicating their generation by an endogenous biological circadian clock. Until recently, the molecular mechanisms by which organisms functioned in this fourth dimension, time, remained mysterious. However, over the last 30 or so years, the powerful approaches of molecular genetics have revealed the molecular underpinnings of a cellular circadian clockwork as complicated and as beautiful as the wonderful chronometers developed in the 18th century. Then, the need to accurately measure time to precisely determine longitude sparked an international competition to claim a prize, the princely sum of 20,000 pounds sterling, offered by the British Crown (Sobel, 1995). Critical Terms Used to Describe Circadian Rhythms. Period is defined as the time to complete one cycle. It is commonly measured from peak to peak but could equally be measure...