The impact of space environment on gene expression in Arabidopsis thaliana seedlings

One of the important questions in space biology is the mechanisms underlying plant responses to an outer space environment, i.e., how gene expression is altered in space. In this study, the transcriptome of Arabidopsis thaliana seedlings was analyzed as a part of Germany SIMBOX (science in microgravity box) spaceflight experiment on Shenzhou 8 spacecraft. This experiment involved the following treatments: spaceflight with microgravity (F mu g), spaceflight with 1g centrifugal force (F 1g), and ground 1g control (G 1g). Gene chips were used to screen gene expression differences in Arabidopsis thaliana seedlings among these treatments. Microarray analysis revealed that 621 genes were differentially expressed in samples F mu g vs. G 1g, 249 genes in samples F 1g vs. G 1g, and 368 genes in samples F mu g vs. F 1g. Gene ontology analysis indicated that the genes were involved in metabolism of stress response, gravitropic response, and DNA damage and repair, suggesting that plants adjust these metabolic pathways to space environmental stress, microgravity, and radiation.