Domoic acid: The synergy of iron, copper, and the toxicity of diatoms

  title={Domoic acid: The synergy of iron, copper, and the toxicity of diatoms},
  author={Mark L. Wells and Charles G. Trick and William P. Cochlan and Margaret P. Hughes and Vera L. Trainer},
  journal={Limnology and Oceanography},
Diatom blooms generated by the alleviation of iron limitation in high nitrate–low chlorophyll (HNLC) regions of the oceans often are composed of pennate diatoms of the genus Pseudo‐nitzschia, many of which periodically produce the potent neurotoxin domoic acid. We show that toxigenic diatoms have an inducible high‐affinity iron uptake capability that enables them to grow efficiently on iron complexed by strong organic ligands in seawater. This low‐iron adaptive strategy requires copper and… 

Dissolved Domoic Acid Does Not Improve Growth Rates and Iron Content in Iron-Stressed Pseudo-Nitzschia subcurvata

Many regions of Antarctica are classified as high nutrient low chlorophyll (HNLC) areas. In these, iron availability is limiting primary productivity and subsequent carbon export. Domoic acid (DA)

Iron enrichment stimulates toxic diatom production in high-nitrate, low-chlorophyll areas

It is demonstrated that the sparse oceanic Pseudonitzschia community at the high-nitrate, low-chlorophyll Ocean Station PAPA produces approximately 200 pg DA L−1 in response to iron addition, that DA alters phytoplankton community structure to benefit Pseud ontzschia, and that oceanic cell isolates are toxic.

Variability in the production of organic ligands, by Synechococcus PCC 7002, under different iron scenarios

Several Fe-uptake mechanisms suggest the importance of the presence of certain organic ligands in phytoplankton exudates. Here, it has been studied how Synechococcus (strain PCC 7002) acclimates to

Iron acquisition and allocation in stramenopile algae.

  • J. Raven
  • Environmental Science
    Journal of experimental botany
  • 2013
Genomic studies show that pennate, but not centric, diatoms have the iron storage protein ferritin, and essentially all of the iron in the cells can be accounted for by the iron occurring in catalytic proteins, however, stramenopiles can store iron.

Iron uptake by the ichthyotoxic Chattonella marina (Raphidophyceae): impact of superoxide generation 1

The results suggest that superoxide can participate in the C. marina iron‐uptake process when iron is complexed to weak ligands, such as citrate, but plays only a minor role whenIron is bound to a strong ligand, and it thus appears that facilitation of iron acquisition is not the sole purpose of superoxide production by these organisms.

Iron and copper limitations differently affect growth rates and photosynthetic and physiological parameters of the marine diatom Pseudo‐nitzschia delicatissima

In this species, the Cu demand for Fe acquisition may be low relative to other cellular Cu pools or this species may not use Cu to uptake Fe, and this species produced no DA during these experiments.

Domoic Acid Improves the Competitive Ability of Pseudo-nitzschia delicatissima against the Diatom Skeletonema marinoi

It is found that domoic acid had a slight negative effect on growth of the diatom Skeletonema marinoi when it was grown in monocultures and that iron is likely to be involved.

Iron requirements of the pennate diatom Pseudo‐nitzschia: Comparison of oceanic (high‐nitrate, low‐chlorophyll waters) and coastal species

The ability of oceanic Pseudo-nitzschia species to exhibit an extensive growth response to iron enrichment events may be a result of their extraordinary capacity to accumulate and potentially store large amounts of intracellular iron when iron concentrations are high, yet substantially reduce their iron requirements to sustain fast growth rates well after externalIron concentrations are depleted.

Competition among marine phytoplankton for different chelated iron species

Competition between prokaryotes and eukaryotes for organically-bound iron may depend on the chemical nature of available iron complexes, with consequences for ecological niche separation, plankton community size-structure and carbon export in low-iron waters.

Iron‐limited growth of cyanobacteria: Multiple siderophore production is a common response

Investigation of the frequency of siderophore production in iron-deficient culture of freshwater and marine cyanobacteria and the effects of extracellular iron chelators on iron uptake in a coccoid marine species confirm that iron chelate production is prevalent amongfreshwater and marine species and that some of these ironChelators function as siders.

Production of extracellular Cu complexing ligands by eucaryotic phytoplankton in response to Cu stress

This survey shows that there are many biological sources of copper binding ligands, but that procaryotes such as cyanobacteria are more plausible sources of class 1 ligands in the open ocean than eucaryotes.

Controlling iron availability to phytoplankton in iron-replete coastal waters

Production of strong, extracellular Cu chelators by marine cyanobacteria in response to Cu stress

It is suggested that cyanobacteria modify Cu chemistry in seawater, creating conditions more favorable for growth, as well as a tight linear correlation between chelator and Cu concentration.

Manipulating iron availability in nearshore waters

Results of size-fractionated shipboard culture experiments using the fungal siderophore desferriferrioxime B (DFB) to regulate iron availability in coastal upwelling waters demonstrate that DFB can be used to manipulate biologically accessible iron to determine how iron affects algal community structure and carbon cycling in ironreplete waters.

Effects of iron, manganese, copper, and zinc enrichments on productivity and biomass in the subarctic Pacific

Natural plankton populations from subarctic Pacific surface waters were incubated in 7-d experiments with added concentrations of Fe, Mn, Cu, and Zn. Small additions of metals (0.89 nM Fe, 1.8 nM Mn,