This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Plants continuously adapt to environmental changes, and temperature is a key signal for growth and flowering. How plant thermometers, or "thermosensors," work at the molecular level is not well understood.
An international team led by Professor Dr. Philip Wigge of the Leibniz Institute for Horticultural Sciences (IGZ), in collaboration with the Max Planck Institute of Molecular Plant Physiology and the Karolinska Institute (Sweden), investigated how the molecular regulator COP1 responds to temperature. At higher temperatures, COP1 changes structure, switching on and activating plant growth.
The paper is published in the journal Cell. COP1 (CONSTITUTIVE PHOTOMORPHOGENESIS 1) is a key regulator in plant signaling. It is involved in regulating growth and development by integrating light and temperature signals.
COP1 binds to and triggers the degradation of other proteins. Using molecular and biophysical methods, the research team now demonstrates in the model plant Arabidopsis thaliana (thale cress) that COP1 regulates its activity through a temperature-responsive mechanism built into the protein itself. The protein adopts two different conformational shapes.
At lower temperatures, it predominantly exists in a closed, less active form. A short region at one end of the COP1 protein contains two consecutive amino acids—valine and proline, abbreviated as VP. This region can bind to a site on COP1, called the WD40 domain, where target proteins would normally attach.
At lower temperatures, this internal interaction keeps COP1 in a closed, less active conformation and acts as a built-in latch. Other proteins, including the growth regulator HY5, have less access to the binding site. As the temperature rises, the internal interaction increasingly loosens and COP1 adopts a more open shape.
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