Aspects of biochemical adaptation to the stress of pollutants in micro and macro seaweeds: modulation of cellular antioxidants and expression of defence proteins

• Grant number: 01/13482-6
• Support type: Research Projects - Thematic Grants
• Duration: May 01, 2003 - April 30, 2008
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal researcher: Pio Colepicolo Neto
• Grantee: Pio Colepicolo Neto
• Home Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated grant(s): 06/52285-5 - Richard Savre | Ohio State University - United States, AV.EXT
• Associated scholarship(s): 04/09403-1 - Evaluation of gene expression by microarrays in Gracilaria tenuistipitata subjected to stress by heavy metals, BP.DR

Abstract

The long term objective of this project is to understand the molecular mechanism response, when marine algae are exposed to inorganic and organic pollutants. Organic and metallic contaminants are introduced into the marine environment by direct discharge of industrial and sewage effluents into the sea or by previously contaminated rivers. To investigate adaptive responses to metal-induced oxidative stress, we want to evaluate the antioxidant content and oxidative damage in the unicellular alga Lingulodinium polyedrum in the macro algae Gracilaria tenuistipitata and Kappaphycus alvarenzzi exposed to pollutant. Different antioxidant responses will be verified according to the metal and model of stress applied. Algae acutely and chronically exposed to metals will have the activity of superoxide dismutase, catalase, ascorbate peroxidase and glutathione peroxidase measured and levels of glutathione and the pigments such as peridinin, B-carotene and chlorophyll will also be estimated by HPLC. The induced damage to biomolecules will be estimated by measurements of lipoperoxidation, oxidation of protein and DNA. The cDNA library of metal treated L polyedrum will be prepared and genes related to the oxidative stress, DNA repair and metabolic pathways will be isolated, sequenced and the phylogeny studied. (AU)