The
PpCCA1a and
PpCCA1b genes of the moss
Physcomitrella patens are functional homologs of the
Arabidopsis thaliana circadian clock genes
CCA1/LHY. We made use of disruptant lines for
PpCCA1a and/or
PpCCA1b to elucidate the physiological significance of these genes in the growth of moss protonemal tissue under alternating day/night cycles. Protonemal cells of the double disruptant line, carrying neither of the two genes, grew faster than those of the wild-type plant (WT) in long days (LD), whereas no difference in the growth rate was detected between them in short days (SD). The double disruptant line also showed day length-dependent phenotypic changes in the
PpCCA1b promoter activity: the diurnal profile of bioluminescence from the
PCCA1b::LUC+ reporter strain was more significantly affected in LD than in SD. These observations are the first demonstration of a physiological function of the circadian clock in non-angiosperm land plants, and are consistent with recent findings that the clock controls hypocotyl elongation of
A. thaliana in a photoperiod-dependent manner.
抄録全体を表示