Plants have a metabolic signal that adjusts their circadian clock in the evening to ensure they store enough energy to survive the night, a new study reveals.
The research—involving scientists from the University of York—suggests this signal might provide important information to the plant about the amount of sugar available at dusk and therefore how to adjust metabolism to last the night. Plants use sunlight to make their own sugars from photosynthesis during the day and store them to provide energy during the night.
Seedlings expressing a light emitting firefly gene controlled by the plant's circadian rhythm. Credit: Mike Haydon
The ability to predict sunrise and estimate the duration of the night, and fine-tune metabolism accordingly, is critical for plant survival and to maximize growth. This depends on a biological time-keeper called a circadian clock which is an oscillating gene network which drives rhythms of about 24 hours.
Dr. Mike Haydon, formerly from the Department of Biology, University of York and now based at the University of Melbourne said: "We think this metabolic signal is acting rather like setting an alarm clock before bedtime to ensure the plant's survival.
Superoxide is promoted by sucrose and affects amplitude of circadian rhythms in the evening, PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2020646118