Genome wide expression analysis of react

Spaceflight environments generate reactive oxygen species (ROS) and induce oxidative stress in plants, but the gene expression of the ROS gene network in long-term spaceflight remains underexplored. This study aimed to investigate the molecular responses of Mizuna plants cultivated for 27 days aboard the International Space Station (ISS) using genome-wide mRNA expression analysis (mRNA-Seq). Comparative transcript analysis of space-grown and ground-grown Mizuna revealed significant differences, with 8,258 transcripts up-regulated and 14,170 down-regulated in plants from space. Notably, 20 out of 32 oxidative marker genes showed increases in expression, highlighting the activation of key signaling cascades including MEKK1-MK4-MPK3 and OXI1-MK4-MPK3. Genes such as RbohD and RbohF, associated with ROS production, were also preferentially up-regulated. The findings indicate that oxidative stress and the activation of the ROS gene network are vital responses in Mizuna grown in space. Many altered transcripts were related to stress responses, and some were specifically up-regulated in space-grown Mizuna, supporting the notion that these plants can acclimate to the spaceflight environment by reprogramming their expression of the ROS gene network. This study provides insights crucial for future plant cultivation in space missions.