Molecular modulations and influence of acclimation of Ni on acute Ni toxicity in Plectonema boryanum

Abstract

AbstractObjective:In this study, metal induced accumulation of antioxidants, proline and phenol were proposed during acclimation, to provide defense, protection and resistance against oxidative stress on Ni acclimated cyanobacterium.Methods:was used as a test organism in the present study and the experiments were performed in two sets (1) cells differentially exposed to Ni (2) cells acclimated with Ni and then further exposed to Ni in the plant tissue culture laboratory.Results:Dose-dependent formation of peroxide in Ni-treated cells increased the activity of superoxide dismutase (SOD) and also enhanced accumulations of non-enzymatic antioxidants such as proline and total phenols at low concentrations of Ni. Down regulation of most of the polypeptides at 20 μM of Ni demonstrated the severe toxicity of the metal while a slight up-regulation of peptide depicted its role in metal tolerance. Ni acclimated cells also showed reduction in peroxide and an increase in proline and total phenol after exposure to 4 μM of Ni.Conclusion:Our results for the first time demonstrated that accumulation of phenol and proline during the acclimation process could provide tolerance to the cyanobacterium from deleterious effects of the metal stress if it is further exposed to the same metal.