Phytochrome and Light Signaling in Marchantia.

Bryophytes, which comprise liverworts, mosses, and hornworts, are one of the earliest diverging lineages of extant land plants and a key plant group for understanding evolutionary aspects of land plant adaptation. Marchantia polymorpha, a liverwort, has recently been established as a model plant species having molecular genetic tractability. In M. polymorpha, phytochrome is encoded by a single-copy gene, MpPHY, with Mpphy regulating various physiological responses through PHYTOCHROME INTERACTING FACTOR (PIF)-mediated transcriptional regulation. The phytochrome signaling system of M. polymorpha, with its single Mpphy and single PIF (MpPIF), is relatively simple compared with other model plants carrying multiple phytochromes and PIFs. Consequently, investigation of phytochrome signaling using M. polymorpha may provide novel insights into fundamental mechanisms and roles of phytochrome during the course of land plant evolution. This chapter provides a number of basic procedures, along with some tips, for designing and performing experiments with M. polymorpha to study phytochrome signaling.