A Giant Leap for Plant Science: Growing Plants on the Moon

The AO Editors

Compared to those grown in lunar regolith, seedlings grown in terrestrial volcanic soil were the largest and healthiest. Apollo 11 seedlings were the most stunted and exhibited a genetic profile indicative of stress, whereas those grown in Apollo 12 and 17 soil were small and healthy.

Image Credit: Paul et al., 2022.

The Space Plants Lab at the University of Florida in Gainesville has made an important discovery in space biology. They successfully grew plants in extraterrestrial soil for the first time. The team reported in a recent paper published in Communications Biology that a dozen Arabidopsis thaliana plants germinated and grew in just a few teaspoons of lunar regolith. This dusty material covers most of the Moon.

Rob Ferl, who co-directs the laboratory with Anna-Lisa Paul, was surprised by the germination of the plants because lunar regolith is sharp and angular, and it was unanticipated that plants would grow in it. The team was also surprised by the growth patterns of the plants, as they appeared stunted and stressed compared to plants grown in soil. Additional genetic analysis revealed that the plant's adaptation to the environment required the activation of distinct genes.

There have been few biological studies of lunar regolith because plants alter the soil as they grow and could contaminate the samples. Nevertheless, this experiment suggests that regolith could be used to grow food on the Moon and demonstrates how plants can shape extraterrestrial soil, enabling future missions to the Moon or Mars to search for signs of vegetation.

As the Artemis Program prepares to return humans to the Moon, the timing of this discovery is crucial. The authors of the paper believe that a greater understanding of plant growth in space is essential to the success of the Artemis Program. In addition, the Moon could serve as a hub or launching pad for extended space missions, making it paramount to understand how to grow plants in lunar soil.

Full and Paul designed a small-scale experiment to plant seeds in lunar soil, add water, nutrients, and light, and record the results to answer these questions. The researchers could only borrow a small amount of Apollo-era dirt from NASA, so they had to carefully plan their experiment. Using plastic plates with wells the size of a thimble, they filled each well with approximately one gram of lunar soil, a nutrient solution, and a few Arabidopsis seeds.

As Arabidopsis is widely utilized in plant science and its genetic code has been completely mapped, growing it in lunar soil allowed researchers to gain insight into the soil's effect on plant gene expression. As a control group, the team also grew Arabidopsis in non-lunar soils, such as terrestrial substances and simulated Martian soils. To their astonishment, nearly all the seeds planted in lunar soil germinated. Over time, the researchers observed differences between the plants grown in lunar soil and the control group.

This ground-breaking discovery made by the University of Florida has paved the way for future space missions and created new opportunities for growing plants beyond Earth. It will be exciting to see what discoveries space biologists make in the coming years.