Development of Equipment that Uses Far-Red Light to Impose Seed Dormancy in Arabidopsis for Spaceflight

Abstract

Abstract In order to use plants as part of a bioregenerative life support system capable of sustaining long-term human habitation in space, it is critical to understand how plants adapt to the stresses associated with extended growth in spaceflight. Optimally, dormant seeds would be germinated on orbit to divorce the effects of spaceflight from the one-time stresses of launch. At an operational level, it is also important to develop experiment protocols that are flexible in timing so they can adapt to crew schedules and unexpected flight-related delays. Arabidopsis thaliana is widely used for investigating the molecular responses of plants to spaceflight. Here we describe the development of a far-red light seed treatment device that suppresses germination of Arabidopsis seeds for periods of ≥12 weeks. Germination can then be induced when the seeds encounter red light, such as transfer to the illumination from on orbit plant growth hardware. This device allows for up to twelve 10×10 cm square Petri dishes containing seeds on nutrient gel to be irradiated simultaneously. The far-red device is contained within a light-proof fabric tent allowing the user to wrap the Petri dishes in aluminum foil in the dark, preventing room lights from reversing the far-red treatment. Long-term storage of the wrapped plates is accomplished using foil storage bags. The throughput of this device facilitates robust, high-replicate biological experiment design, while providing the long-term pre-experiment storage required for maximum mission flexibility.