Monophyly of primary photosynthetic eukaryotes: green plants, red algae, and glaucophytes.
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.
Rodríguez-Ezpeleta
Naiara
N
Canadian Institute for Advanced Research, Centre Robert Cedergren, Département de Biochimie, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, Québec, H3T 1J4, Canada.
Brinkmann
Henner
H
Burey
Suzanne C
SC
Roure
Béatrice
B
Burger
Gertraud
G
Löffelhardt
Wolfgang
W
Bohnert
Hans J
HJ
Philippe
Hervé
H
Lang
B Franz
BF
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
D018076:DNA, Complementary