Abstract
The moss Physcomitrella patens is the plant chosen to understand the evolution of land plants. To extend our recent studies on two-component systems and circadian clock in the flowering plant Arabidopsis thaliana, we have addressed these issues in P. patens from the evolutionary viewpoint. Here, we focused on a set of transcription factors, which are well known to play crucial roles at the downstream of photoreceptors in photomorphogenesis of A. thalians. Namely, they are HY5 (bZIP type)-, BBX (B-box-CCT type)-, PIF (bHLH type)-family. Are they evolutionarily conserved in P. patens? Are their physiological roles something to do with light-signaling? To gain insights into these questions, the following points are reported. These transcription factors are highly conserved in P. patens. Their corresponding cDNAs were introduced into A. thaliana to see how they function in the heterologous host in terms of photomorphogenesis. Characterization of PpHY5a PpHY5b double deletion mutant of P. patens was carried out. These results are discussed in the context of evolution of light-signaling in land plants.
