title: Transcriptomic and metabolomic analysis of copper stress acclimation in Ectocarpus siliculosus highlights signaling and tolerance mechanisms in brown algae.
abstract: BACKGROUND
  Brown algae are sessile macro-organisms of great ecological relevance in coastal ecosystems. They evolved independently from land plants and other multicellular lineages, and therefore hold several original ontogenic and metabolic features. Most brown algae grow along the coastal zone where they face frequent environmental changes, including exposure to toxic levels of heavy metals such as copper (Cu).
  
  
  RESULTS
  We carried out large-scale transcriptomic and metabolomic analyses to decipher the short-term acclimation of the brown algal model E. siliculosus to Cu stress, and compared these data to results known for other abiotic stressors. This comparison demonstrates that Cu induces oxidative stress in E. siliculosus as illustrated by the transcriptomic overlap between Cu and H2O2 treatments. The common response to Cu and H2O2 consisted in the activation of the oxylipin and the repression of inositol signaling pathways, together with the regulation of genes coding for several transcription-associated proteins. Concomitantly, Cu stress specifically activated a set of genes coding for orthologs of ABC transporters, a P1B-type ATPase, ROS detoxification systems such as a vanadium-dependent bromoperoxidase, and induced an increase of free fatty acid contents. Finally we observed, as a common abiotic stress mechanism, the activation of autophagic processes on one hand and the repression of genes involved in nitrogen assimilation on the other hand.
  
  
  CONCLUSIONS
  Comparisons with data from green plants indicate that some processes involved in Cu and oxidative stress response are conserved across these two distant lineages. At the same time the high number of yet uncharacterized brown alga-specific genes induced in response to copper stress underlines the potential to discover new components and molecular interactions unique to these organisms. Of particular interest for future research is the potential cross-talk between reactive oxygen species (ROS)-, myo-inositol-, and oxylipin signaling.
authors.forename: Andrés
authors.initials: A
authors.lastname: Ritter
authors.forename: Simon M
authors.initials: SM
authors.lastname: Dittami
authors.forename: Sophie
authors.initials: S
authors.lastname: Goulitquer
authors.forename: Juan A
authors.initials: JA
authors.lastname: Correa
authors.forename: Catherine
authors.initials: C
authors.lastname: Boyen
authors.forename: Philippe
authors.initials: P
authors.lastname: Potin
authors.affiliation: UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, CS 90074, F-29688 Roscoff cedex, France. tonon@sb-roscoff.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Tonon
mesh_terms: D000064:Acclimatization / Q000187:drug effects / Q000235:genetics*; D020418:Algal Proteins / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D016000:Cluster Analysis; D003300:Copper / Q000633:toxicity*; D016002:Discriminant Analysis; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D020869:Gene Expression Profiling; D006801:Humans; D016018:Least-Squares Analysis; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D055442:Metabolome / Q000187:drug effects* / Q000235:genetics; D055432:Metabolomics; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D054883:Oxylipins / Q000378:metabolism; D000459:Phaeophyceae / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D010788:Photosynthesis / Q000187:drug effects / Q000235:genetics; D010802:Phylogeny; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D059467:Transcriptome / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D020418:Algal Proteins; D000596:Amino Acids; D005227:Fatty Acids; D054883:Oxylipins; D003300:Copper