Scientists Grow the First Plants in Lunar “Soil”

Seedlings grown in terrestrial volcanic soil (leftmost images, JSC1A) were the largest and healthiest compared to those grown in lunar regolith. Apollo 11 seedlings were the most stunted and displayed a stressed genetic profile, while those grown in Apollo 12 and 17 soil were healthy and small. Credit: Paul et al., 2022.

In a small lab-grown garden, the first seeds planted in lunar soil have sprouted. A team of researchers led by Anna-Lisa Paul at the University of Florida developed these experiments using a well-studied plant named thale cress. The lunar “soil” consists of regolith, a fine and powdery layer of debris that blankets the Moon. This regolith is similar to terrestrial regolith but lacks the organic compounds that support life. Seeds were planted in twelve pots containing regolith from the Apollo 11, 12, and 17 missions. Sixteen pots were filled with terrestrial volcanic soil as a control, and all plants were grown under LED lights. Seeds began to sprout after two days, and for the first six days, all sprouts appeared identical.

After 16 days, the healthiest plants grown in lunar soil were small, while the sickliest plants displayed purple pigmentation, a sign of plant stress. None of the seedlings grew as well as those cultivated in terrestrial soil. The team also examined gene expression and found that all lunar plants exhibited stress responses similar to those of terrestrial plants struggling to grow in soil rich in metals, salts, and reactive oxygen compounds. Moreover, seedlings grown in Apollo 11 samples, which were exposed on the lunar surface the longest, expressed genes associated with nutrient starvation and toxicity. This suggests that prolonged regolith exposure on the lunar surface leads to an enrichment in impact glass and metallic iron derived from impactors, making it more toxic for plant growth. These findings show that lunar habitats should be sited in regions with relatively young regolith. NASA’s upcoming Artemis mission provides a new incentive to explore the possibilities for lunar agriculture to support long-term missions. This work paves the way to better understand the habitability of lunar regolith and for the development of genetically modified plants that can survive in harsh regolith. READ MORE