Integrative analysis of metabolite and transcript abundance during the short-term response to saline and oxidative stress in the brown alga Ectocarpus siliculosus

Simon M Dittami, Antoine Gravot, David Renault, Sophie Goulitquer, Anja Eggert, Alain Bouchereau, Catherine Boyen, Thierry Tonon

Research output: Contribution to journalArticlepeer-review


The model brown alga Ectocarpus siliculosus undergoes extensive transcriptomic changes in response to abiotic stress, many of them related to primary metabolism and particularly to amino acid biosynthesis and degradation. In this study we seek to improve our knowledge of the mechanisms underlying the stress tolerance of this alga, in particular with regard to compatible osmolytes, by examining the effects of these changes on metabolite concentrations. We performed extensive metabolic profiling (urea, amino acids, sugars, polyols, organic acids, fatty acids) of Ectocarpus samples subjected to short-term hyposaline, hypersaline and oxidative stress, and integrated the results with previously published transcriptomic data. The most pronounced changes in metabolite concentrations occurred under hypersaline stress: both mannitol and proline were accumulated, but their low final concentrations indicate that, in this stress condition, both compounds are not likely to significantly contribute to osmoregulation at the level of the entire cell. Urea and trehalose were not detected in any of our samples. We also observed a shift in fatty acid composition from n-3 to n-6 fatty acids under high salinities, and demonstrated the salt stress-induced accumulation of small amounts of γ-aminobutyric acid (GABA). GABA could be synthesized in E. siliculosus through a salt stress-induced putrescine-degradation pathway.

Original languageEnglish
Pages (from-to)629-42
Number of pages14
JournalPlant, Cell and Environment
Issue number4
Publication statusPublished - Apr 2011


  • Amino Acids/metabolism
  • Fatty Acids/metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation/genetics
  • Mannitol/metabolism
  • Metabolome
  • Oxidative Stress/genetics
  • Phaeophyta/drug effects
  • Sodium Chloride/pharmacology
  • Stress, Physiological/genetics
  • Transcription, Genetic
  • Urea/metabolism
  • Water-Electrolyte Balance
  • gamma-Aminobutyric Acid/metabolism

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