•This research comes at a time when the Artemis Program plans to return humans to the Moon.
•This work is the first step toward one-day growing plants for food and oxygen on the Moon or during space missions.
Scientists have for the first time grown plants in soil from the Moon.
The research, which was published in the journal Communications Biology showed that plants can successfully sprout and grow in moon soil.
The study conducted by the University of Florida researcher also investigated how plants respond biologically to moon soil which is radically different from earth soil.
This research comes at a time when the Artemis Program plans to return humans to the Moon.
This work is the first step toward one-day growing plants for food and oxygen on the Moon or during space missions.
"Artemis will require a better understanding of how to grow plants in space," said Rob Ferl, one of the study's authors and a distinguished professor of horticultural sciences at the UF Institute of Food and Agricultural Sciences.
Anna-Lisa Paul, also one of the study's authors said that even in the early day of lunar exploration, plants played an important role in the research.
"Plants were only dusted with the lunar regolith(soil) and were never actually grown in it," Paul said.
Paul and Ferl are internationally recognized experts in the study of plants in space.
"For future, longer space missions, we may use the Moon as a hub or launching pad. It makes sense that we would want to use the soil that is already there to grow plants," Ferl said.
"So, what happens when you grow plants in lunar soil, something that is totally outside of a plant's evolutionary experience? What would plants do in a lunar greenhouse? Could we have lunar farmers?"
To begin to answer these questions, Ferl and Paul planted seeds in lunar soil, add water, nutrients, and light, and record the results.
These video clips show the researchers working with the lunar soil, planting thale cress (Arabidopsis thaliana) seeds and the resulting plants. Credit: Tyler Jones, UF/IFAS.
The scientists only had 12 grams of moon soil to do this experiment.
On loan from NASA, this soil was collected during the Apollo 11, 12 and 17 missions to the Moon.
Paul and Ferl applied three times over the course of 11 years for a chance to work with the moon soil.
To grow their tiny lunar garden, the researchers used thimble-sized wells in plastic plates normally used to culture cells.
Each well functioned as a pot. Once they filled each "pot" with approximately a gram of moon soil, the scientists moistened the soil with a nutrient solution and added a few seeds from the Arabidopsis plant.
Growing Arabidopsis in the lunar soil allowed the researchers more insight into how the soil affected the plants, down to the level of gene expression.
The plants grown in these non-moon soils were the experiment's control group.
Before the experiment, the researchers weren't sure if the seeds planted in the lunar soils would sprout. But nearly all of them did.
"We were amazed. We did not predict that," Paul said.
"That told us that the lunar soils didn't interrupt the hormones and signals involved in plant germination."
However, as time went on, the researchers observed differences between the plants grown in moon soil and the control group.
For example, some of the plants grown in the moon soils were smaller, grew more slowly, or were more varied in size than their counterparts.
These were all physical signs that the plants were working to cope with the chemical and structural make-up of the Moon's soil, Paul explained.
How plants respond to lunar soil may be linked to where the soil was collected, said Ferl and Paul, who collaborated on the study with Stephen Elardo, an assistant professor of geology at UF.
For instance, the researchers found that the plants with the most signs of stress were those grown in what lunar geologists call mature lunar soil.
These mature soils are those exposed to more cosmic wind, which alters their makeup. On the other hand, plants grown in comparatively less mature soils fared better.
Growing plants in lunar soils may also change the soils themselves, Elardo said.
"The Moon is a very, very dry place. How will minerals in the lunar soil respond to having a plant grown in them, with the added water and nutrients? Will adding water make the mineralogy more hospitable to plants?" Elardo said.
Follow-up studies will build on these questions and more.
For now, the scientists are celebrating having taken the first steps toward growing plants on the Moon.
"We wanted to do this experiment because, for years, we were asking this question: Would plants grow in lunar soil," Ferl said. "The answer, it turns out, is yes."