Light and temperature receptors and their convergence in plants

Abstract

Light and temperature are two essential environmental cues for plants, helping to optimize plant body architecture and physiology. To sense a broad spectrum of sun radiation spanning from UV-B to far-red wavelength, plants are equipped with a sophisticated array of photoreceptors, including phytochromes, cryptochromes, phototropins, Zeitlupes, and UV-B photoreceptor UVR8. On the contrary, since the thermodynamic effects extensively affect the molecular and supramolecular structures, it is difficult to identify the entry point or initial receptor of temperature. Even so, several putative temperature sensors have been proposed, such as calcium ion channels, H2A.Z, and the thermodynamic change of plasma membrane fluidity. Considering that many processes in plant respond to irradiance and temperature, scientists devote to finding out the converge point of these environmental cues. As a typical example, circadian rhythm is such an integration point, which receives the signal input of both irradiance and temperature. The updating evidence shows, as an important photoreceptor, phytochrome B acts as temperature sensors via a thermodynamic active state revision. These findings suggest that the studies on light and temperature receptors in plants should not be separated. Their extensive convergence during signalling provides a new direction for understanding the stimuli perception mechanisms.