The relationship between sulfur metabolism and tolerance of hexavalent chromium in Scenedesmus acutus (Spheropleales): Role of ATP sulfurylase
| Autor: | Anna Torelli, Corrado Zanni, Alessio Sardella, Isabel Mercatali, Gessica Gorbi, Matteo Marieschi |
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| Rok vydání: | 2019 |
| Předmět: |
Chromium
Time Factors Health Toxicology and Mutagenesis Sulfur metabolism chemistry.chemical_element 010501 environmental sciences Aquatic Science 01 natural sciences Gene Expression Regulation Enzymologic 03 medical and health sciences chemistry.chemical_compound Biomass Cysteine RNA Messenger Hexavalent chromium 030304 developmental biology 0105 earth and related environmental sciences 0303 health sciences Chromate conversion coating Metabolism Glutathione Sulfur Sulfate Adenylyltransferase chemistry Biochemistry Water Pollutants Chemical Scenedesmus |
| Zdroj: | Aquatic Toxicology. 216:105320 |
| ISSN: | 0166-445X |
| DOI: | 10.1016/j.aquatox.2019.105320 |
| Popis: | Sulfur availability and the end products of its metabolism, cysteine, glutathione and phytochelatins, play an important role in heavy metal tolerance, chromium included. Sulfate and chromate not only compete for the transporters but also for assimilation enzymes and chromium tolerance in various organisms has been associated to differences in this pathway. We investigated the mechanisms of Cr(VI)-tolerance increase induced by S-starvation focusing on the role of ATP sulfurylase (ATS) in two strains of Scenedesmus acutus with different chromium sensitivity. S-starvation enhances the defence potential by increasing sulfate uptake/assimilation and decreasing chromium uptake, thus suggesting a change in the transport system. We isolated two isoforms of the enzyme, SaATS1 and SaATS2, with different sensitivity to sulfur availability, and analysed them in S-sufficient and S-replete condition both in standard and in chromium supplemented medium. SaATS2 expression is different in the two strains and presumably marks a different sulfur perception/exploitation in the Cr-tolerant. Its induction and silencing are compatible with a role in the transient tolerance increase induced by S-starvation. This enzyme can however hardly be responsible for the large cysteine production of the Cr-tolerant strain after starvation, suggesting that cytosolic rather than chloroplastic cysteine production is differently regulated in the two strains. |
| Databáze: | OpenAIRE |
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