Metabolome of Cadmium Stressed <i>Gracilaria caudata</i> (Rhodophyta)
Luiza Araujo-Motta,
Cicero Alves-Lima,
Leonardo Zambotti-Vilella,
Pio Colepicolo
Affiliations
Luiza Araujo-Motta
Laboratory of Algal Biochemistry and Molecular Biology, Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, São Paulo 05508-000, SP, Brazil
Cicero Alves-Lima
Group of Ecology, Evolution and Bevaviour, Department of Biological Sciences, College of Letters and Science, University of Wisconsin-Milwaukee, 3209 N Maryland Ave, Milwaukee, WI 53211, USA
Leonardo Zambotti-Vilella
Laboratory of Algal Biochemistry and Molecular Biology, Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, São Paulo 05508-000, SP, Brazil
Pio Colepicolo
Laboratory of Algal Biochemistry and Molecular Biology, Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, São Paulo 05508-000, SP, Brazil
We report here the effects of cadmium on the metabolome of the macroalga Gracilaria caudata. The IC50 of 3 mg/L (12 µM) was obtained after 48 hrs exposure and induced lower photosynthesis efficiency. Threshold concentrations determined by the Brazilian Environmental Council (CONAMA) in marine waters (0.04 mg/L) and effluent discharge (0.2 mg/L) were also tested, and the latter changed photosynthetic efficiency similarly to IC50. A total of 43 metabolites were identified, including monosaccharides, carboxylic acids, and amino acids. By an unsupervised PCA, we identified significative alterations in the metabolome by the IC50. An OPLS-DA analysis showed that Cd2+ exposure caused the variation of 20 metabolites, mainly glyoxylate-related, ascorbate, floridoside and proline. Five metabolic pathways altered by Cd2+ showed an accumulation of amino acids, carbon metabolism intermediates and antioxidant responses to Cd2+. We recommend a review of the toxicity parameters and methods that guide environmental policies on cadmium levels in Brazilian marine waters.
