Plants’ way of considering the time of the day

Time (Credit: Elisa Bieg/Flickr)

Main Point:

Researchers have found that plants use sugars to consider the time of the day.

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Study Further:


Living beings have 24 hour “body-clock” that is known circadian rhythm. In plants, this body-clock helps them to keep a check on the food in the absence of light. This body-clock helps them to know the timing of sunrise. Moreover, this timing also helps in other important biological processes such as flowering, fragrance emission and leaf movement.

Present Research:

Researchers found that the sugars produced in the plants – Arabidopsis thaliana- via photosynthesis, are used to know the time of the day, i.e. to keep the circadian rhythm. This sugar is used by the plants for growth and function.

“Our research shows that sugar levels within a plant play a vital role in synchronizing circadian rhythms with its surrounding environment. Inhibiting photosynthesis, for example, slowed the plants internal clock by between 2 and 3 hours,” explained Dr Alex Webb, lead researcher at the University of Cambridge.

“The accumulation of sugar within the plant provides a kind of feedback for the circadian cycle in plants — a bit like resetting a stopwatch. We think this might be a way of telling the plant that energy in the form of sugars is available to perform important metabolic tasks. This mirrors research that has previously shown that feeding times can influence the phase of peripheral clocks in animals,” explained Dr Mike Haydon, who performed much of the research and is now at the University of York.

“Thus, photosynthesis has a marked effect on the entrainment and maintenance of robust circadian rhythms in A. thaliana, demonstrating that metabolism has a crucial role in regulation of the circadian clock,” Researchers wrote.


Researchers show how plants tell the time – Eurekalert (

Michael J. Haydon et al. (2013). Photosynthetic entrainment of the Arabidopsis thaliana circadian clock Nature DOI: 10.1038/nature12603

Usman Zafar Paracha

Usman Zafar Paracha is a sort of entrepreneur. He is the author of "Color Atlas of Statistics", and the owner of an Android game "Faily Rocket."