Scientists clock on to how sunlight shapes daily rhythms

November 22, 2010

Fresh insight into how biological clocks adjust to having less sunlight in the winter could help us better understand the impact of jet lag and shift work.

Scientists studying the daily activity cycle in plants – known as circadian rhythms – have discovered a finely tuned process that enables the plant's genes to respond to the times of dawn and dusk each day, as well as the length of daylight in between.

This system helps the plant to reset its internal clock every day in response to seasonal changes in daylight, which helps the plant control the timing of key activities such as growth and flowering.

The findings shed light on how living things, including people, respond to patterns of daylight, and how our bodies respond when our daily rhythms are interrupted, for example by global travel or unsociable working hours.

Circadian rhythms – which are found in most living things – influence many biological functions that vary throughout the day. In people, these include sleepiness, body temperature, blood pressure, and physical strength.

Researchers at the University of Edinburgh used mathematical models to show how much the plants' rhythms accounted for dawn and dusk as well as day length.

The study, published in Molecular Systems Biology, was carried out with the Universities of Warwick and Central Lancashire and the Hungarian Academy of Sciences. It was funded by the Biotechnology and Biological Sciences Research Council and the Engineering and Physical Sciences Research Council.

Professor Andrew Millar of the University of Edinburgh's School of Biological Sciences, who led the study, said: "Our results give us valuable information on how plants – and people – respond to changing lengths of day. It could give a new way to understand how to cope when our daily rhythms of light and dark are interrupted."

Explore further: Separating morning and evening in the circadian clock of mammals

Related Stories

Circadian clock controls plant growth hormone

August 13, 2007

The plant growth hormone auxin is controlled by circadian rhythms within the plant, UC Davis researchers have found. The discovery explains how plants can time their growth to take advantage of resources such as light and ...

Clockwork plants

March 25, 2009

(PhysOrg.com) -- How do plants tell the time and the passing of the seasons? Plant scientists are enlisting the help of engineers in their quest to uncover the rhythms of circadian clocks.

Scientists show that plants have measure of the shortest day

December 23, 2009

(PhysOrg.com) -- It is not only people who feel the effects of short winter days - new research by the University of Edinburgh and the University of Warwick has shed light on how plants calculate their own winter solstice.

Internal body clock controls fat metabolism, study shows

November 15, 2010

UC Irvine researchers have discovered that circadian rhythms – the internal body clock – regulate fat metabolism. This helps explain why people burn fat more efficiently at certain times of day and could lead to ...

Recommended for you

Genomes uncover life's early history

August 24, 2015

A University of Manchester scientist is part of a team which has carried out one of the biggest ever analyses of genomes on life of all forms.

Rare nautilus sighted for the first time in three decades

August 25, 2015

In early August, biologist Peter Ward returned from the South Pacific with news that he encountered an old friend, one he hadn't seen in over three decades. The University of Washington professor had seen what he considers ...

Why a mutant rice called Big Grain1 yields such big grains

August 24, 2015

(Phys.org)—Rice is one of the most important staple crops grown by humans—very possibly the most important in history. With 4.3 billion inhabitants, Asia is home to 60 percent of the world's population, so it's unsurprising ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.