Abstract
To understand the functions and properties of phytochromes in lower plants, we analyzed phytochrome functions and photomorphogenesis in liverwort Marchantia polymorpha. Most of the life cycle of M. polymorpha is haploid and with a simple body structure, and therefore it can be a unique model plant. We identified a phytochrome gene in M. polymorpha and designated it MpPHY. MpPHY consisted of four exons and three introns, similar to typical phytochrome in higher plants. Southern-blot analysis suggested that M. polymorpha has a single PHY gene, unlike from higher plants that have several PHY genes. We analyzed the properties of MpPHY using an expression system in E. coli, and in M. polymorpha using gene targeting by homologous recombination. In M. polymorpha, it is known that the transition into the reproductive stage is repressed under usual light conditions. We found that M. polymorpha rapidly develops into the reproductive stage under FR rich conditions.
