Journal article
Induction of domoic acid production in diatoms—Types of grazers and diatoms are important
University of Copenhagen1
Natural History Museum of Denmark2
Alfred Wegener Institute - Helmholtz Centre for Polar and Marine Research3
Helmholtz Institute for Functional Marine Biodiversity4
The Danish Environmental Protection Agency5
Northwest Agriculture and Forestry University6
National Institute of Aquatic Resources, Technical University of Denmark7
Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark8
University of Gothenburg9
Section for Oceans and Arctic, National Institute of Aquatic Resources, Technical University of Denmark10
...and 0 moreGrazers can induce toxin (domoic acid, DA) production in diatoms. The toxic response has been observed in two species of Pseudo-nitzschia and was induced by Calanus copepods. In this study, interactions between diatoms and copepods were further explored using different species of diatoms and copepods.
All herbivorous copepods induced toxin production, whereas exposure to carnivorous copepods did not. In line with this, increasing the number of herbivorous copepods resulted in even higher toxin production. The induced response is thus only elicited by copepods that pose a real threat to the responding cells, which supports that the induced toxin production in diatoms evolved as an inducible defense The cellular toxin content in Pseudo-nitzschia was positively correlated to the concentration of a group of specific polar lipids called copepodamides that are excreted by the copepods.
This suggests that copepodamides are the chemical cues responsible for triggering the toxin production. Carnivorous copepods were found to produce less or no copepodamides. Among the diatoms exposed to grazing herbivorous copepods, only two of six species of Pseudo-nitzschia and none of the Nitzschia or Fragilariopsis strains responded by producing DA, indicating that not all Pseudo-nitzschia species/strains are able to produce DA, and that different diatom species might have different strategies for coping with grazing pressure.
Growth rate was negatively correlated to cellular domoic acid content indicating an allocation cost associated with toxin production. Long-term grazing experiments showed higher mortality rates of grazers fed toxic diatoms, supporting the hypothesis that DA production is an induced defense mechanism.
Language: | English |
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Year: | 2018 |
Pages: | 64-73 |
ISSN: | 18781470 and 15689883 |
Types: | Journal article |
DOI: | 10.1016/j.hal.2018.06.005 |
ORCIDs: | 0000-0002-2035-1997 , 0000-0001-6213-6657 and Nielsen, Torkel Gissel |
Co-evolution Copepod Cost Defensive response Diatom Domoic acid Gazing Induction Pseudo-nitzschia Toxin production Trade-off
Animals Biological Coevolution Copepoda Diatoms Grazing Herbivory Kainic Acid domoic acid