The extremotolerant desert moss Syntrichia caninervis is a promising pioneer plant for colonizing extraterrestrial environments.

ABSTRACT

Many plans to establish human settlements on other planets focus on adapting crops to growth in controlled environments. However, these settlements will also require pioneer plants that can grow in the soils and harsh conditions found in extraterrestrial environments, such as those on Mars. Here, we report the extraordinary environmental resilience of Syntrichia caninervis, a desert moss that thrives in various extreme environments. S. caninervis has remarkable desiccation tolerance; even after losing >98% of its cellular water content, it can recover photosynthetic and physiological activities within seconds after rehydration. Intact plants can tolerate ultra-low temperatures and regenerate even after being stored in a freezer at -80°C for 5 years or in liquid nitrogen for 1 month. S. caninervis also has super-resistance to gamma irradiation and can survive and maintain vitality in simulated Mars conditions; i.e., when simultaneously exposed to an anoxic atmosphere, extreme desiccation, low temperatures, and intense UV radiation. Our study shows that S. caninervis is among the most stress tolerant organisms. This work provides fundamental insights into the multi-stress tolerance of the desert moss S. caninervis, a promising candidate pioneer plant for colonizing extraterrestrial environments, laying the foundation for building biologically sustainable human habitats beyond Earth.