According to a new study conducted by researchers at York University in the U.S., plants adjust their biological clock in the evening to ensure they have enough energy to survive throughout the night. Experts have identified a metabolic signal that plants use to regulate what can be described as a "bedtime alarm."
Researchers believe that this newly identified metabolic signal informs the plant about the amount of sugar available at dusk, allowing it to adjust its metabolism to survive through night hours without sunlight. Plants use sunlight to produce sugar through photosynthesis, storing the sugar for energy during the night. It is crucial for plants to anticipate the duration of these dark hours so they do not run out of energy. The prediction of sunrise and estimation of night length depends on the plant's biological clock, a 24-hour cycle.
Dr. Mike Haydon stated, "We believe that this metabolic signal acts as a substitute for a bedtime alarm in the plant to ensure its survival. Plants need to coordinate photosynthetic metabolism with their daily environment and adapt their biological clock to correspond with carbon availability."
To investigate how sugars affect the biological clock, researchers altered the sugar supply of some seedlings and measured their gene expression. They focused on a set of genes regulated by a supercompound linked to metabolic activity. They found that most of these genes are activated in the evening, including those regulating the biological clock. When experts inhibited the production of this supercompound, the evening effects of sugar on circadian clock genes were also blocked.
Professor Ian Graham remarked, "Discerning between the effects of light and sugars in photosensitive cells is challenging, as our data suggest a new role for the superoxide-like chemical as a rhythmic signal related to sugar that operates in the evening and affects daily gene expression and development."
