Molecular identification, differential expression and protective roles of iron/manganese superoxide dismutases in the green algae Closterium ehrenbergii against metal stress.

Molecular identification, differential expression and protective roles of iron/manganese superoxide dismutases in the green algae Closterium ehrenbergii against metal stress. Eur J Protistol. 2020 Mar 04;74:125689 Authors: Wang H, Ki JS Abstract The green microalgae Closterium ehrenbergii is an ideal organism for ecotoxicology assessments; however, its toxicogenomics has been insufficiently examined. Here, we identified three iron/manganese superoxide dismutase (SOD) genes (designated as CeFeSOD1, CeFeSOD2, and CeMnSOD) from C. ehrenbergii and examined their expressional patterns for four metals (iron, manganese, copper, and nickel). These genes encoded 362, 224, and 245 amino acids, respectively; signal-peptide analysis showed that they were differentially located in chloroplasts, cytosol, or mitochondria. Real-time PCRs revealed differential expression patterns according to metal and doses. Interestingly, CeSODs displayed no noticeable changes to treatment with their corresponding cofactor metals, iron or manganese, even at high doses. However, they were obviously up-regulated under toxic metal (copper and nickel) exposure, exhibiting approximately 10.8- and 4.4-fold increases, respectively. Copper (0.2 mg/L) dramatically stimulated intracellular reactive oxygen species (ROS) formation, increased SOD activity, and reduced photosynthetic efficiency in C. ehrenbergii. These results suggest that CeFeSODs and CeMnSOD might be involved ...
Source: European Journal of Protistology - Category: Microbiology Authors: Tags: Eur J Protistol Source Type: research