Abstract
In plants, the studies on the circadian clock have been so far concentrated on Arabidopsis thaliana, while there are only few studies on the mechanisms of circadian clocks in other plants. Therefore, it is unknown how similar or diverged are the molecular mechanisms of the circadian clocks in plants. Moreover, in plants the evolution and origin are completely a mystery. For these reasons, we started to study the circadian clock at the molecular level using the moss Physcomitrella patens, which diverged from the higher plants before hundreds million years. In A. thaliana, CCA1/LHY, TOC1(PRR1), PCL1 (LUX)have been so far isolated as clock genes. We found some homologs of these genes in P. patens. We report here results of expression analyses using a bioluminescence reporter and those of functional analyses by gene targeting of PpCCA1a and PpCCA1b, CCA1 homolog-genes in P. patens.
