title: Phylogenetic viewpoints on regulation of light harvesting and electron transport in eukaryotic photosynthetic organisms.
abstract: The comparative study of photosynthetic regulation in the thylakoid membrane of different phylogenetic groups can yield valuable insights into mechanisms, genetic requirements and redundancy of regulatory processes. This review offers a brief summary on the current understanding of light harvesting and photosynthetic electron transport regulation in different photosynthetic eukaryotes, with a special focus on the comparison between higher plants and unicellular algae of secondary endosymbiotic origin. The foundations of thylakoid structure, light harvesting, reversible protein phosphorylation and PSI-mediated cyclic electron transport are traced not only from green algae to vascular plants but also at the branching point between the "green" and the "red" lineage of photosynthetic organisms. This approach was particularly valuable in revealing processes that (1) are highly conserved between phylogenetic groups, (2) serve a common physiological role but nevertheless originate in divergent genetic backgrounds or (3) are missing in one phylogenetic branch despite their unequivocal importance in another, necessitating a search for alternative regulatory mechanisms and interactions.
authors.affiliation: Molecular Plant Biology, University of Turku, Tykistökatu 6A, Turku, Finland. irigro@utu.fi
authors.forename: Irina
authors.initials: I
authors.lastname: Grouneva
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Gollan
authors.forename: Saijaliisa
authors.initials: S
authors.lastname: Kangasjärvi
authors.forename: Marjaana
authors.initials: M
authors.lastname: Suorsa
authors.forename: Mikko
authors.initials: M
authors.lastname: Tikkanen
authors.forename: Eva-Mari
authors.initials: EM
authors.lastname: Aro
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D060365:Chloroplast Proteins / Q000145:classification / Q000378:metabolism; D017377:Diatoms / Q000201:enzymology / Q000378:metabolism; D004579:Electron Transport; D019143:Evolution, Molecular; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D010766:Phosphorylation; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010802:Phylogeny; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D020524:Thylakoids / Q000201:enzymology / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D017346:Protein Serine-Threonine Kinases; C497212:STN7 protein, Arabidopsis