Revealing the Circadian Clock: How Plants Control the Day!

Revealing the Circadian Clock: How Plants Control the Day!

An international study into the functioning of light-sensitive proteins known as cryptochromes was recently published. The research was led by Professor Dr. Lars-Oliver Essen from the Philipps University of Marburg. The National Taiwan University (NTU) and other international scientists were actively involved in the study. The aim of the comprehensive research work is to expand the understanding of the day-night rhythm and the biological clock in living beings.

The results show that cryptochromes play a key role in regulating circadian rhythms and light-dependent processes in plants, animals and other organisms. Loud uni-marburg.de Light is converted into chemical signals, which is crucial for the internal clock of many living beings. This conversion occurs through complex light reactions.

Mechanisms of light perception

The study revealed the sequence of reactions triggered by exposure to light. In particular, two central mechanisms were identified: the “N395/FAD switch,” which activates the protonation route (TPP) and stabilizes the radical pair, and the “D321/Y373 switch,” which destabilizes the helix and initiates the signaling state. These processes are essential for controlling the complex biological rhythms that organisms need to behave in harmony with their environment.

Previous studies have shown that cryptochromes are of great importance not only in animals, but also in plants. These flavin-containing photoreceptors are structurally similar to photolyases, which repair UV-damaged DNA, and are found in many organisms from archaea to bacteria to plants and animals. Their functions range from regulating processes such as germination and flowering to adapting to lighting conditions, highlighting the role of the circadian clock.

The plant circadian clock is an internal timekeeping system that adapts physiological processes to the light-dark cycle. This clock helps plants prepare for regular changes in their environment, such as day and night and seasons. It influences essential processes, including photosynthesis and metabolism, and is synchronized by light signals perceived by various light receptors. These mechanisms allow plants to regulate their genes according to the time of day and adapt their development ( plantresearch.de ).

Importance of research

The results of this study have far-reaching implications. They could explain how cryptochromes allow birds to use magnetic fields for navigation and offer new approaches to treating circadian rhythm-related diseases. This includes greater insight into the functioning of the circadian clock, which plays a central role not only in plants but in many living organisms.

The research was partially supported by the German Research Foundation (DFG) and funding organizations from Taiwan, Japan and the USA. State-of-the-art X-ray free electron lasers (XFEL), available in only a few locations worldwide, were used to create the high-resolution snapshots that were crucial to the investigations. This highlights how innovative technologies can drive scientific progress in the study of biological clocks.

This remarkable advance in science was published in the journal Science Advances and is available at DOI 10.1126/sciadv.adu7247 be retrieved.