Space explorers need to be space farmers: What we know and what we need to know about plant growth in space

Space exploration will require life support systems, in which plants can provide nutrients, oxygen, moisture, and psychological well-being and eliminate wastes. In alien environments, plants must adapt to a different gravity force, even the zero gravity of spaceflight. Under these conditions, essential cellular and molecular features related to plant development are altered and changes in gene expression occur. In lunar gravity, the effects are comparable to microgravity, while the gravity of Mars produces milder alterations. Nevertheless, it has been possible to develop and reproduce plants in space. Current research seeks to identify signals replacing gravity for driving plant growth, such as light. Counteracting gravitational stress will help in enabling agriculture in extraterrestrial habitats.