title: High light stress triggers distinct proteomic responses in the marine diatom Thalassiosira pseudonana.
abstract: Diatoms are able to acclimate to frequent and large light fluctuations in the surface ocean waters. However, the molecular mechanisms underlying these acclimation responses of diaotms remain elusive.
  
  
  
  In this study, we investigated the mechanism of high light protection in marine diatom Thalassiosira pseudonana using comparative proteomics in combination with biochemical analyses. Cells treated under high light (800 μmol photons m-2s-1) for 10 h were subjected to proteomic analysis. We observed that 143 proteins were differentially expressed under high light treatment. Light-harvesting complex proteins, ROS scavenging systems, photorespiration, lipid metabolism and some specific proteins might be involved in light protection and acclimation of diatoms. Non-photochemical quenching (NPQ) and relative electron transport rate could respond rapidly to varying light intensities. High-light treatment also resulted in increased diadinoxanthin + diatoxanthin content, decreased Fv/Fm, increased triacylglycerol and altered fatty acid composition. Under HL stress, levels of C14:0 and C16:0 increased while C20:5ω3 decreased.
  
  
  
  We demonstrate that T. pseudonana has efficient photoprotective mechanisms to deal with HL stress. De novo synthesis of Ddx/Dtx and lipid accumulation contribute to utilization of the excess energy. Our data will provide new clues for in-depth study of photoprotective mechanisms in diatoms.
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.|School of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China.
authors.forename: Hong-Po
authors.initials: HP
authors.lastname: Dong
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
authors.forename: Yue-Lei
authors.initials: YL
authors.lastname: Dong
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Cui
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Balamurugan
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China. lusonghui1963@163.com.
authors.forename: Song-Hui
authors.initials: SH
authors.lastname: Lu
authors.affiliation: Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
mesh_terms: D059001:Aquatic Organisms; D002851:Chromatography, High Pressure Liquid; D019295:Computational Biology / Q000379:methods; D017377:Diatoms / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D050356:Lipid Metabolism; D010455:Peptides / Q000378:metabolism; D010788:Photosynthesis; D010860:Pigments, Biological; D020543:Proteome; D040901:Proteomics; D013312:Stress, Physiological
chemical_list: D005227:Fatty Acids; D010455:Peptides; D010860:Pigments, Biological; D020543:Proteome
keywords: Light protection; Quantitative proteomics; Thalassiosira pseudonana; iTRAQ labeling