The biological clock of plants

'A Nobel Prize for the biological clock has long been overdue,' says Dorothee Staiger. What is so remarkable is that the prize has been granted to basic research - that is, to studies on fundamental concepts in nature.

Whereas the American colleagues have been analysing the biological clock in animals, Staiger's 'RNA Biology and Molecular Physiology' research group has been studying biological rhythms in plants. 'At the time when Hall, Rosbash, and Young were discovering the first clock protein, we discovered another protein in plants that works in a similar way,' reports Staiger. 'The difference is that it does not work completely independently; it depends on the central biological clock. Hence, we have called it an auxiliary clock. This was the first auxiliary clock to be identified on the molecular level.'

Staiger's research group has now discovered a new regulatory process of this special protein. The group had to optimize methods of modern systems biology for their use in plants. The researchers Dr. Katja Meyer and Dr. Tino Köster carried out a sort of census in the plants and isolated all messenger RNAs binding to the 'auxiliary clock' protein.

Martin Lewinski from Staiger's research group together with Professor Dr. Ivo Große's team at the Institute of Computer Science of the Martin Luther University Halle-Wittenberg then used bioinformatics procedures to determine how this auxiliary clock protein and these messenger RNAs interact. Afterwards, Staiger's team studied how the auxiliary clock regulates these messenger RNAs by extracting messenger RNAs from the plants and analysing them every two hours over a period of several days.

'Binding the auxiliary clock protein to the messenger RNAs is important, because it helps to keep the biological clock running,' says Staiger.