These authors contributed equally to this work as first authors.
Diurnal oscillations of metabolite abundances and gene analysis provide new insights into central metabolic processes of the brown alga Ectocarpus siliculosus
Article first published online: 29 JUL 2010
© CNRS (2010). Journal compilation © New Phytologist Trust (2010)
Special Issue: Featured papers on ‘The Ectocarpus genome sequence’
Volume 188, Issue 1, pages 98–110, October 2010
How to Cite
Gravot, A., Dittami, S. M., Rousvoal, S., Lugan, R., Eggert, A., Collén, J., Boyen, C., Bouchereau, A. and Tonon, T. (2010), Diurnal oscillations of metabolite abundances and gene analysis provide new insights into central metabolic processes of the brown alga Ectocarpus siliculosus. New Phytologist, 188: 98–110. doi: 10.1111/j.1469-8137.2010.03400.x
- Issue published online: 2 SEP 2010
- Article first published online: 29 JUL 2010
- Received: 30 April 2010, Accepted: 17 June 2010
- brown algae (Phaeophyceae);
- carbon-concentrating mechanisms;
- Ectocarpus siliculosus;
- metabolite profiling;
- nyctemeral cycle;
- transcriptomic profiling;
- γ-aminobutyric acid (GABA)
- •Knowledge about primary metabolic processes is essential for the understanding of the physiology and ecology of seaweeds. The Ectocarpus siliculosus genome now facilitates integrative studies of the molecular basis of primary metabolism in this brown alga.
- •Metabolite profiling was performed across two light–dark cycles and under different CO2 and O2 concentrations, together with genome and targeted gene expression analysis.
- •Except for mannitol, E. siliculosus cells contain low levels of polyols, organic acids and carbohydrates. Amino acid profiles were similar to those of C3-type plants, including glycine/serine accumulation under photorespiration-enhancing conditions. γ-Aminobutyric acid was only detected in traces.
- •Changes in the concentrations of glycine and serine, genome annotation and targeted expression analysis together suggest the presence of a classical photorespiratory glycolate pathway in E. siliculosus rather than a malate synthase pathway as in diatoms. Several metabolic and transcriptional features do not clearly fit with the hypothesis of an alanine/aspartate-based inducible C4-like metabolism in E. siliculosus. We propose a model in which the accumulation of alanine could be used to store organic carbon and nitrogen during the light period. We finally discuss a possible link between low γ-aminobutyric acid contents and the absence of glutamate decarboxylase genes in the Ectocarpus genome.