A research group led by Manabu Sugimoto, an associate professor at the Institute of Resources and Plant Sciences, Okayama University, found that rice seeds stored offboard at the International Space Station (ISS) have a lower germination rate due to the length of the storage period, and germination in the seeds. It was revealed that the stored mRNA involved in the disease was reduced.
When human beings stay and work in space for a long time, it is necessary to store and cultivate seeds in space for food self-sufficiency.Seeds are stored on the ground under low temperature and low humidity conditions, but there are restrictions on the electricity and building materials that can be used in space, and seed storage facilities are required to be as simple as possible.However, there is little information on the effects of cosmic rays, electromagnetic fields, microgravity, and other space environments that are completely different from the Earth on the viability of seeds, and the factors involved in the viability of seeds in the space environment and the level of protection are Not sure if it is needed.
With the cooperation of the National Institute of Agrobiological Sciences (currently National Institute of Agrobiological Sciences), the research group stores rice seeds offboard the ISS and comprehensively analyzes their viability and expressed genes. Was done.Rice "Nihonbare" seeds were placed in a metal cylinder, placed outside the ISS, left for 13 or 20 months, and then transported to the ground.As a result, the 13-month outboard storage seeds germinated on the 3rd day after water absorption and the germination rate was 48%, whereas the 20-month outboard storage seeds germinated on the 5th day and the germination rate was 7%. there were.
As a result, it was confirmed that the germination rate of rice seeds decreased and germination was delayed due to the length of the storage period outside the ISS.As a result of analysis of seeds, germinated seeds, gene sequences of juvenile buds and roots, and gene abundance, almost no mutations were found in either rice gene, but in 20-month outboard storage seeds, storage-type mRNA involved in germination. It was revealed that the amount was reduced, and that the damage of the stored mRNA by the space environment was involved in the viability of the seeds.
The results of this research are useful for understanding possible problems with seeds stored in the space environment and essential conditions for seed storage, and are expected to contribute to human space development in the future.
