title: Phytochrome diversity in green plants and the origin of canonical plant phytochromes.
abstract: Phytochromes are red/far-red photoreceptors that play essential roles in diverse plant morphogenetic and physiological responses to light. Despite their functional significance, phytochrome diversity and evolution across photosynthetic eukaryotes remain poorly understood. Using newly available transcriptomic and genomic data we show that canonical plant phytochromes originated in a common ancestor of streptophytes (charophyte algae and land plants). Phytochromes in charophyte algae are structurally diverse, including canonical and non-canonical forms, whereas in land plants, phytochrome structure is highly conserved. Liverworts, hornworts and Selaginella apparently possess a single phytochrome, whereas independent gene duplications occurred within mosses, lycopods, ferns and seed plants, leading to diverse phytochrome families in these clades. Surprisingly, the phytochrome portions of algal and land plant neochromes, a chimera of phytochrome and phototropin, appear to share a common origin. Our results reveal novel phytochrome clades and establish the basis for understanding phytochrome functional evolution in land plants and their algal relatives.
authors.affiliation: Department of Biology, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Fay-Wei
authors.initials: FW
authors.lastname: Li
authors.affiliation: Botany Department, Cologne Biocenter, University of Cologne, 50674 Cologne, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Melkonian
authors.affiliation: University Herbarium and Department of Integrative Biology, University of California, Berkeley, California 94720, USA.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Rothfels
authors.affiliation: Royal Botanic Gardens Edinburgh, Edinburgh EH3 5LR, UK.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Villarreal
authors.affiliation: New York Botanical Garden, Bronx, New York 10458, USA.
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Stevenson
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
authors.forename: Sean W
authors.initials: SW
authors.lastname: Graham
authors.affiliation: 1] Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 [2] Department of Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 2E1 [3] BGI-Shenzhen, Shenzhen 518083, China.
authors.forename: Gane Ka-Shu
authors.initials: GK
authors.lastname: Wong
authors.affiliation: Department of Biology, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Pryer
authors.affiliation: Harvard University Herbaria, Cambridge, Massachusetts 02138, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Mathews
mesh_terms: D049936:Anthocerotophyta / Q000235:genetics; D001483:Base Sequence; D044002:Bryophyta / Q000235:genetics; D057946:Charophyceae / Q000235:genetics*; D019143:Evolution, Molecular; D029624:Ferns / Q000235:genetics; D014644:Genetic Variation; D035926:Hepatophyta / Q000235:genetics; D032502:Lycopodium / Q000235:genetics; D008969:Molecular Sequence Data; D010834:Phytochrome / Q000235:genetics*; D032503:Selaginellaceae / Q000235:genetics; D057948:Viridiplantae / Q000235:genetics*
chemical_list: D010834:Phytochrome