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The effects of lead and copper on the cellular architecture and metabolism of the red alga Gracilaria domingensis.

Authors :
Gouveia C
Kreusch M
Schmidt ÉC
Felix MR
Osorio LK
Pereira DT
dos Santos R
Ouriques LC
Martins Rde P
Latini A
Ramlov F
Carvalho TJ
Chow F
Maraschin M
Bouzon ZL
Source :
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada [Microsc Microanal] 2013 Jun; Vol. 19 (3), pp. 513-24. Date of Electronic Publication: 2013 Apr 03.
Publication Year :
2013

Abstract

The effect of lead and copper on apical segments of Gracilaria domingensis was examined. Over a period of 7 days, the segments were cultivated with concentrations of 5 and 10 ppm under laboratory conditions. The samples were processed for light, confocal, and electron microscopy, as well as histochemistry, to evaluate growth rates, mitochondrial activity, protein levels, chlorophyll a, phycobiliproteins, and carotenoids. After 7 days of exposure to lead and copper, growth rates were slower than control, and biomass loss was observed on copper-treated plants. Ultrastructural damage was primarily observed in the internal organization of chloroplasts and cell wall thickness. X-ray microanalysis detected lead in the cell wall, while copper was detected in both the cytoplasm and cell wall. Moreover, lead and copper exposure led to photodamage of photosynthetic pigments and, consequently, changes in photosynthesis. However, protein content and glutathione reductase activity decreased only in the copper treatments. In both treatments, decreased mitochondrial NADH dehydrogenase activity was observed. Taken together, the present study demonstrates that (1) heavy metals such as lead and copper negatively affect various morphological, physiological, and biochemical processes in G. domingensis and (2) copper is more toxic than lead in G. domingensis.

Details

Language :
English
ISSN :
1435-8115
Volume :
19
Issue :
3
Database :
MEDLINE
Journal :
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada
Publication Type :
Academic Journal
Accession number :
23551883
Full Text :
https://doi.org/10.1017/S1431927613000317