Scientists Discover Circadian Clock Controls Cell Cycle in Plants

From the beating of the heart to the rhythms of flowering plants, biological rhythms are everywhere in nature. These are determined by the oscillations in the activity of proteins, present in cells, which mark the rhythms of the processes they control. The two main cellular oscillators are the circadian clock and the cell cycle. The circadian clock generates the oscillations of biological processes in coordination with the day and night cycle and its associated changes in light and temperature. In turn, the cell cycle controls cell division and growth.

A research team from the Centre for Research in Agricultural Genomics (CRAG), led by Paloma Mas, has shown, for the first time in plants, that the circadian clock controls the speed of the cell cycle and, consequently, regulates cell division and growth in synchronization with the day and night cycles.

The research team used modified Arabidopsis thaliana plants in which the circadian clock goes slower due to an increased and constant accumulation of TOC1 protein, an essential component of the plant circadian clock. It was observed that their leaves were smaller than normal, and the number of cells in the leaves that overexpress TOC1 were fewer. This suggests that by modifying the circadian clock, the cell division pace was also modified. In addition, the CRAG research team observed the opposite effect when the amount of TOC1 was decreased. The researchers conclude that the circadian clock sets the pace of the cell cycle.

For more details, read the news article in the CRAG website.