Expanding frontiers: harnessing plant biology for space exploration and planetary sustainability

: Plants are critical for sustaining human life and planetary health. However, their potential to enable humans to survive and thrive beyond Earth remains unrealized. This Viewpoint presents a collective vision outlining priorities associated with plant science to support a new frontier of human existence. These priorities are drawn from the International Space Life Sciences Working Group (ISLSWG) Plants for Space Exploration and Earth Applications workshop, held at the European Low Gravity Research Association (ELGRA) conference in September 2024. First, we highlight transformative advances gained from using the 'laboratory of space' in understanding how plants respond to gravity and other stressors. Second, we introduce a new crop Bioregenerative Life Support System (BLSS) readiness level (BRL) framework - extending the existing Crop Readiness Level (CRL) - to assist in overcoming challenges to establish resilient, sustainable crop production. Materializing the vision of plants as enablers of space exploration will require innovative approaches, including predictive modeling, synthetic biology, robust Earth-based analogue systems, and reliable space-based instruments to monitor biological processes. Success relies upon a unified international community to promote sharing of resources, facilities, expertise, and data to accelerate progress. Ultimately, this work will both advance human space exploration and provide solutions to enhance sustainable plant production on Earth.