title: Monophyly of primary photosynthetic eukaryotes: green plants, red algae, and glaucophytes.
abstract: Between 1 and 1.5 billion years ago, eukaryotic organisms acquired the ability to convert light into chemical energy through endosymbiosis with a Cyanobacterium (e.g.,). This event gave rise to "primary" plastids, which are present in green plants, red algae, and glaucophytes ("Plantae" sensu Cavalier-Smith). The widely accepted view that primary plastids arose only once implies two predictions: (1) all plastids form a monophyletic group, as do (2) primary photosynthetic eukaryotes. Nonetheless, unequivocal support for both predictions is lacking (e.g.,). In this report, we present two phylogenomic analyses, with 50 genes from 16 plastid and 15 cyanobacterial genomes and with 143 nuclear genes from 34 eukaryotic species, respectively. The nuclear dataset includes new sequences from glaucophytes, the less-studied group of primary photosynthetic eukaryotes. We find significant support for both predictions. Taken together, our analyses provide the first strong support for a single endosymbiotic event that gave rise to primary photosynthetic eukaryotes, the Plantae. Because our dataset does not cover the entire eukaryotic diversity (but only four of six major groups in), further testing of the monophyly of Plantae should include representatives from eukaryotic lineages for which currently insufficient sequence information is available.
authors.affiliation: Canadian Institute for Advanced Research, Centre Robert Cedergren, Département de Biochimie, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, Québec, H3T 1J4, Canada.
authors.forename: Naiara
authors.initials: N
authors.lastname: Rodríguez-Ezpeleta
authors.forename: Henner
authors.initials: H
authors.lastname: Brinkmann
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Burey
authors.forename: Béatrice
authors.initials: B
authors.lastname: Roure
authors.forename: Gertraud
authors.initials: G
authors.lastname: Burger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Löffelhardt
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Bohnert
authors.forename: Hervé
authors.initials: H
authors.lastname: Philippe
authors.forename: B Franz
authors.initials: BF
authors.lastname: Lang
mesh_terms: D001499:Bayes Theorem; D000460:Chlorophyta / Q000235:genetics*; D016000:Cluster Analysis; D019295:Computational Biology; D000458:Cyanobacteria / Q000235:genetics; D044424:Cyanophora / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D010944:Plants / Q000235:genetics*; D018087:Plastids / Q000235:genetics*; D000461:Rhodophyta / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary