Methods for On-Orbit Germination of Arabidopsis thaliana for Proteomic Analysis

Large-scale omics approaches make excellent choices for research aboard the International Space Station (ISS) because they provide large amounts of data that can be continually mined even after the original research has been completed. A proteomic approach can provide information about which proteins are produced, degraded, or post-translationally modified, potentially shedding light on cellular strategies that cannot be discerned from transcriptomic data. To collect sufficient tissue from a Biological Research In Canisters (BRIC)-grown experiment on the ISS for proteomic analysis, several modifications were made to existing protocols. Approximately 800–1000 seeds were housed in each Petri Dish Fixation Units (PDFU). These were germinated up to 120 h after planting by transferring the BRIC from cold stasis to room temperature. Growth continued for only 72 h after germination to allow sufficient tissue for extraction, and to minimize the impact of ethylene and crowding stress. Seedlings were then exposed to RNAlater®. Results indicate that RNAlater® - treated Arabidopsis seedlings yield an equal amount of protein to those flash-frozen in liquid nitrogen.