The Role of Copper in the Oxidative Stress Response of Chlamydomonas reinhardtii to heat shock

Abstract

In response to stress, cells produce reactive oxygen species (ROS) such as superoxide O2-, peroxide H2O2 and hydroxyl radical HO- which cause molecular damage in the form of DNA breaks, lipid peroxidation and protein carbonylation. ROS are also important in cell signaling and to induce differential gene expression, metabolic changes and thus adaptation to different environmental conditions. The hypothesis of this project is that the ROS response is a common denominator of different environmental challenges, including radiation and microgravity, during spaceflight. Algae, such as the unicellular green alga Chlamydomonas reinhardtii, grown in spaceflight are exposed to stress. The goal of this work was to characterize the response of C. reinhardtii to stress by examining biochemical and gene expression changes using heat shock. The heat shocked (42°C) C. reinhardtii exhibited a selective regulation of ion transporters, and an increase in ROS in cells and supernatant. Such results provide new insights about the intracellular response to stress and its possible mediation during spaceflight.