Green plants produce carbohydrate as an energy for all organisms by photosynthesis. It is therefore considered that plant cultivation is necessary for life support not only on Earth but also in space. To inhabit the space for a long duration, human needs to be closed in the life support system in which plants provide them with foods and a stress-relief circumstance. During evolution, on the other hand, plants developed various strategies to survive terrestrial environment on Earth because of their sessile nature. Plant responses to gravity and lights are examples of such strategy to avoid or mitigate stressful environment they come across. Now, space environment is available for biological studies to understand how plants respond to gravity and how plants are influenced by microgravity and/or space radiation. We extend such studies to understand the effects of space environment on plant growth and development in the seed-to-seed or the generation-to-generation experiments. To explore the deeper space or inhabit planets such as the moon or Mars, we next need to establish a sustainable recycling-oriented life support system with plant cultivation and environmental control facilities. Here, we show our research scenario of the space-utilizing plant science to achieve such objective, which is important to efficiently cultivate plants and develop the life support system in space. We believe our approach, in cooperation with various communities of the related fields, enables us to further reveal the biological systems required for not only colonizing to space but also conserving or improving the living Earth.
