Plant and animal circadian rhythms, 24-hour cycles that regulate many physiological and metabolic functions, are ultimately influenced by the same thing: light. Scientists are now beginning to realize that plants and animals may also share some of the mechanisms for receiving and processing that light so that the day/night cycles in both organisms are optimized. Two reports in the Nov. 20 issue of Science --one by researchers from The Scripps Research Institute in La Jolla, Calif. (D.E. Somers et al., Science, 282:1488-90), and one by University of North Carolina, Chapel Hill, and Northwestern University researchers (R.J. Thresher et al., Science, 282:1491-4)--identify light-sensitive molecules called photoreceptors that act as intermediaries between environmental cues and the machinery of the circadian clock.
The first paper outlines the roles of plant photoreceptors in the Arabidopsis thaliana that detect blue and red light, the two wavelengths plants primarily absorb; the second investigates the role of ...
