Bioabsorption of cadmium, copper and lead by the red macroalga Gelidium floridanum: Physiological responses and ultrastructure features

• Published in: Ecotoxicology and environmental safety 2014-07, Vol.105, p.80-89
• Main Authors: dos Santos, Rodrigo W., Schmidt, Éder C., de L Felix, Marthiellen R., Polo, Luz K., Kreusch, Marianne, Pereira, Debora T., Costa, Giulia B., Simioni, Carmen, Chow, Fungyi, Ramlov, Fernanda, Maraschin, Marcelo, Bouzon, Zenilda L.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Cadmium; Cell Respiration - drug effects; Chloroplasts; Copper; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Fundamental and applied biological sciences. Psychology; Gelidium floridanum; Lead; Metals, Heavy - metabolism; Metals, Heavy - toxicity; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Photosynthesis - drug effects; Pigments, Biological - metabolism; Rhodophyta - drug effects; Rhodophyta - growth & development; Rhodophyta - metabolism; Rhodophyta - ultrastructure; Ultrastructure; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2014.02.021

Heavy metals, such as lead, copper, cadmium, zinc, and nickel, are among the most common pollutants found in both industrial and urban effluents. High concentrations of these metals cause severe toxic effects, especially to organisms living in the aquatic ecosystem. Cadmium (Cd), lead (Pb) and copper (Cu) are the heavy metals most frequently implicated as environmental contaminants, and they have been shown to affect development, growth, photosynthesis and respiration, and morphological cell organization in seaweeds. This paper aimed to evaluate the effects of 50μM and 100μM of Cd, Pb and Cu on growth rates, photosynthetic pigments, biochemical parameters and ultrastructure in Gelidium floridanum. To accomplish this, apical segments of G. floridanum were individually exposed to the respective heavy metals over a period of 7 days. Plants exposed to Cd, Cu and Pb showed discoloration of thallus pigmentation, chloroplast alteration, especially degeneration of thylakoids, and decrease in photosynthetic pigments, such as chlorophyll a and phycobiliproteins, in samples treated with Cd and Cu. Moreover, cell wall thickness and the volume of plastoglobuli increased. X-ray microanalysis detected Cd, Cu and Pb absorption in the cell wall. The results indicate that Cd, Pb and Cu negatively affect metabolic performance and cell ultrastructure in G. floridanum and that Cu was more toxic than either Pb or Cd. •Heavy metals promote increased cell wall Gelidium floridanum.•Copper and lead induce increased synthesis of carotenoids.•Copper is more toxic than lead and copper for Gelidium floridanum.