The mammalian-type thioredoxin reductase 1 confers a high-light tolerance to the reinhardtii

Reactive oxygen species (ROS) can both act as a poison causing cell death and important signaling molecules among various organisms. Photosynthetic organisms inevitably produce ROS, making the appropriate elimination of ROS an essential strategy for survival. Interestingly, the unicellular green alga Chlamydomonas reinhardtii expresses a mammalian form of thioredoxin reductase, TR1, which functions as a ROS scavenger in animal cells. To investigate the properties of TR1 in C. reinhardtii, we generated TR1 knockout strains using CRISPR/Cas9-based genome editing. We found a reduced tolerance to high-light and ROS stresses in the TR1 knockout strains compared to the parental strain. In addition, the regulation of phototactic orientation, known to be regulated by ROS, was affected in the knockout strains. These results suggest that TR1 contributes to a ROS-scavenging pathway in C. reinhardtii. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study found that TR1 functions as a pathway for scavenging ROS in Chlamydomonas reinhardtii. Knocking out TR1 reduced tolerance to high-light and ROS stresses, as well as affected the regulation of phototactic orientation.