Role of iron in gene expression and in the modulation of copper uptake in a freshwater alga: Insights on Cu and Fe assimilation pathways.

Kochoni, Émeric; Doose, Caroline; Gonzalez, Patrice et Fortin, Claude ORCID: https://orcid.org/0000-0002-2479-1869 (2022). Role of iron in gene expression and in the modulation of copper uptake in a freshwater alga: Insights on Cu and Fe assimilation pathways. Environmental Pollution , vol. 305 . p. 119311. DOI: 10.1016/j.envpol.2022.119311.

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Résumé

Metal uptake and toxicity can generally be related to its aqueous speciation and to the presence of competitive ions as described by the biotic ligand model. Beyond these simple chemical interactions at the surface of aquatic organisms, several internal biological feedback mechanisms can also modulate metal uptake. This is particularly important for essential elements for which specific transport systems were developed over the course of evolution. Based on the results of short-term Cu²⁺ uptake experiments and on the analysis of the expression of certain genes involved in Cu and Fe homeostasis, we studied the effects of Fe³⁺ on Cu²⁺ uptake by the freshwater green alga Chlamydomonas reinhardtii. We observed a significant increase in Cu²⁺ uptake rate in algal cells acclimated to a low Fe³⁺ medium up to 4.7 times greater compared to non-acclimated algal cells. The overexpression of the ferroxidase FOX1 and permease FTR1 genes suggests an activation of the high affinity Fe³⁺ assimilation system, which could constitute a plausible explanation for the increase in Cu²⁺ uptake rate in acclimatized algae. We show that Fe availability can have a significant impact on Cu uptake. Our observations reinforce the importance of considering physiological factors to better predict metal bioavailability.

Type de document:	Article
Mots-clés libres:	metals; transport; effects; algae; biotic ligand model; transcriptomics
Centre:	Centre Eau Terre Environnement
Date de dépôt:	13 juin 2022 18:08
Dernière modification:	16 avr. 2024 04:00
URI:	https://espace.inrs.ca/id/eprint/12624

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