Scientists from the University of Florida have grown plants on the soil of the Moon, a first in human history and a milestone in lunar and space exploration.
In a new paper published in the journal “Communications Biology,” researchers from the University of Florida show that plants can successfully sprout and grow in lunar soil. Their study also investigated how plants respond biologically to lunar soil, also known as lunar regolith, which is radically different from soil found on Earth.
This work is a first step toward one day growing plants for food and oxygen on the Moon or during space missions. More immediately, this research comes as the Artemis Program plans to return humans to the Moon.
“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 (UF/IFAS).
Even in the early days of lunar exploration, plants played an important role, said Anna-Lisa Paul, also one of the study’s authors and a research professor of horticultural sciences at UF/IFAS.
“The plants helped establish that soil samples brought back from the Moon harbored no pathogens or other unknown components that could harm life on Earth, but those plants were just dusted with lunar regolith and never actually grown on it,” Paul said. .
Paul and Ferl are internationally recognized experts in the study of plants in space. Through UF’s Space Plant Laboratory, they have sent experiments on space shuttles, to the International Space Station, and on suborbital flights.
“For future longer space missions, we may use the Moon as a hub or launch pad. It makes sense that we want to use the soil that is already there to grow plants,” Ferl said. “So what happens when plants are grown on 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 designed a seemingly simple experiment: plant seeds in lunar soil, add water, nutrients, and light, and record the results.
How the experiment was carried out
The complication: Scientists only had 12 grams – just a few teaspoons – of lunar soil to conduct the experiment. On loan from NASA, this soil was collected during the Apollo 11, 12, and 17 missions to the Moon. Paul and Ferl showed up three times over 11 years for the opportunity to work with lunar regolith.
The small amount of soil, not to mention its incalculable historical and scientific importance, meant that Paul and Ferl had to design a carefully choreographed, small-scale experiment. To grow their tiny lunar garden, the researchers used thimble-sized wells in plastic dishes that are normally used to grow cells. Each well functioned as a flower pot. Once they filled each “pot” with about a gram of lunar soil, the scientists moistened the soil with a nutrient solution and added a few seeds of the Arabidopsis plant.
Arabidopsis is widely used in plant science because its genetic code has been fully mapped. Growing Arabidopsis in lunar soil allowed the researchers to better understand how the soil affected plants, down to the level of gene expression.
As points of comparison, the researchers also planted Arabidopsis in JSC-1A, a terrestrial substance that mimics real lunar soil, as well as in simulated Martian soils and terrestrial soils from extreme environments. Plants grown on these non-lunar soils were the control group for the experiment.
Before the experiment, the researchers weren’t sure whether seeds planted in lunar soils would sprout. But almost all of them did. “We were surprised. We hadn’t anticipated it,” Paul said. “That told us that lunar soils did not disrupt the hormones and signals involved in plant germination.”
However, over time, the researchers observed differences between the plants grown in lunar soil and the control group. For example, some of the plants grown on lunar soils were smaller, grew more slowly, or were more varied in size than their counterparts.
How the plants responded
These were all physical signs that plants were working to cope with the chemical and structural makeup of the lunar soil, Paul explained. This was further confirmed when the researchers analyzed the gene expression patterns of the plants.
“At the genetic level, plants used the typical tools to cope with stress factors, such as salt and metals or oxidative stress, so we can deduce that plants perceive the lunar soil environment as stressful,” he said. Paul. “Ultimately, we’d like to use gene expression data to help address how we can enhance stress responses to the level where plants – particularly crops – are able to grow on lunar soil with very little impact to the environment.” your health”.