The role of antioxidant response and nonphotochemical quenching of chlorophyll fluorescence in long-term adaptation to Cu-induced stress in Chlamydomonas reinhardtii

Abstract

Abstract The aim of present study was to analyse selected aspects of the mechanism of protection of the photosynthetic apparatus and antioxidant activity in response to excessive copper concentrations in wall-less strains of Chlamydomonas reinhardtii not adapted and adapted for growth in the presence of elevated copper level. The measured parameters were photosynthetic pigment content, prenyllipid antioxidant (α-tocopherol, plastoquinone pool) content, peroxidase activity, and nonphotochemical quenching efficiency. The results obtained suggest that the increased content of tocopherol and plastoquinone, as well as the increased efficiency of nonphotochemical quenching of chlorophyll fluorescence, play a role in the acquisition of tolerance to copper. The role of light in the enhancement of copper toxicity and the role of POX in response to elevated copper have also been shown.