* Publication: Current Biology, March 2022

* Authors: Keisuke Hitosugi-Kawamura and colleagues

* Institution: Nagoya University, Japan

Background

The circadian clock is a biological rhythm that regulates many physiological and behavioral processes in animals and plants. In humans, the circadian clock helps us to sleep at night and wake up in the morning. In plants, the circadian clock regulates processes such as photosynthesis, flowering, and seed germination.

The circadian clock is controlled by a set of genes called clock genes. Clock genes encode proteins that regulate the expression of other genes in a 24-hour cycle. In animals, the main clock gene is called the Clock gene. In plants, the main clock gene is called the Circadian Clock Associated 1 (CCA1) gene.

Results

In a new study, scientists have identified a new clock gene in green algae. The gene, called the Morning Expressed (MEX1) gene, is expressed in a 24-hour cycle and regulates the expression of other genes involved in the circadian clock.

The scientists found that the MEX1 gene is essential for the circadian clock in green algae. When the MEX1 gene was disrupted, the algae's circadian clock was disrupted and the algae could not grow properly.

Significance

The discovery of the MEX1 gene provides new insights into how the circadian clock works in plants. This knowledge could be used to improve crop yields by engineering plants with a more efficient circadian clock.