title: Evolution of galactoglycerolipid biosynthetic pathways--from cyanobacteria to primary plastids and from primary to secondary plastids.
abstract: Photosynthetic membranes have a unique lipid composition that has been remarkably well conserved from cyanobacteria to chloroplasts. These membranes are characterized by a very high content in galactoglycerolipids, i.e., mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively). Galactoglycerolipids make up the bulk of the lipid matrix in which photosynthetic complexes are embedded. They are also known to fulfill specific functions, such as stabilizing photosystems, being a source of polyunsaturated fatty acids for various purposes and, in some eukaryotes, being exported to other subcellular compartments. The conservation of MGDG and DGDG suggests that selection pressures might have conserved the enzymes involved in their biosynthesis, but this does not appear to be the case. Important evolutionary transitions comprise primary endosymbiosis (from a symbiotic cyanobacterium to a primary chloroplast) and secondary endosymbiosis (from a symbiotic unicellular algal eukaryote to a secondary plastid). In this review, we compare biosynthetic pathways based on available molecular and biochemical data, highlighting enzymatic reactions that have been conserved and others that have diverged or been lost, as well as the emergence of parallel and alternative biosynthetic systems originating from other metabolic pathways. Questions for future research are highlighted.
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Petroutsos
authors.affiliation: ApicoLipid Group, Laboratoire Adapation et Pathogenie des Microorganismes, CNRS, Univ. Grenoble Alpes, UMR 5163, Institut Jean Roget, F-38042 Grenoble, France.
authors.forename: Souad
authors.initials: S
authors.lastname: Amiar
authors.affiliation: Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure, CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, 75005 Paris, France.
authors.forename: Heni
authors.initials: H
authors.lastname: Abida
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Lina-Juana
authors.initials: LJ
authors.lastname: Dolch
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bastien
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Rébeillé
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Juliette
authors.initials: J
authors.lastname: Jouhet
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Falconet
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France.
authors.forename: Maryse A
authors.initials: MA
authors.lastname: Block
authors.affiliation: Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia.
authors.forename: Geoffrey I
authors.initials: GI
authors.lastname: McFadden
authors.affiliation: Environmental and Evolutionary Genomics Section, Institut de Biologie de l'École Normale Supérieure, CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, 75005 Paris, France.
authors.forename: Chris
authors.initials: C
authors.lastname: Bowler
authors.affiliation: ApicoLipid Group, Laboratoire Adapation et Pathogenie des Microorganismes, CNRS, Univ. Grenoble Alpes, UMR 5163, Institut Jean Roget, F-38042 Grenoble, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Botté
authors.affiliation: Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Univ. Grenoble Alpes, UMR 5168, Institut de Recherches en Sciences et Technologies pour le Vivant, CEA Grenoble, F-38054 Grenoble, France. Electronic address: eric.marechal@cea.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Maréchal
mesh_terms: D000818:Animals; D000458:Cyanobacteria / Q000166:cytology / Q000378:metabolism*; D019143:Evolution, Molecular; D038983:Galactolipids / Q000096:biosynthesis*; D006801:Humans; D018087:Plastids / Q000378:metabolism*
chemical_list: D038983:Galactolipids
keywords: Chloroplast; Digalactosyldiacylglycerol; Galactolipids; Monogalactosyldiacylglycerol; Plastid; Secondary endosymbiosis