Changes in Plastid and Mitochondria Protein Expression in Arabidopsis Thaliana Callus on Board Chinese Spacecraft SZ-8

Abstract

Microgravity represents an adverse abiotic environment, which causes rearrangements in cellular organelles and changes in the energy metabolism of cells. Plastids and mitochondria are two subcellular energy organelles that are responsible for major metabolic processes, including photosynthesis, oxidative phosphorylation, s-oxidation, and the tricarboxylic acid cycle. In our previous study performed on board the Chinese spacecraft SZ-8, we evaluated the global changes exerted by microgravity on the proteome of Arabidopsis thaliana cell cultures by comparing the microgravity-exposed samples with the controls either under 1 g centrifugation in space or 1 g ground conditions. Here, we report additional data from this space experiment that highlights the plastid and mitochondria proteins that responded to space flight conditions. We observed that 43 plastidial proteins and 50 mitochondrial proteins changed their abundances under microgravity in space. The major changes in both plastids and mitochondria involved proteins that functions in a suite of redox antioxidant and metabolic pathways. These results suggested that these antioxidant and metabolic changes in plastids and mitochondria could be important components of the adaptive strategy in plants subjected to microgravity in space.