Sciennce News -- Date: May 17, 2022 University of Florida as a source
Summary: For the first time, scientists have grown plants on lunar soil. They used dirt from the Apollo 11 and 12 flights, as well as the Apollo 17 expedition.
The researchers sought to see if plants could thrive in lunar soil and, if so, how they would react to the strange environment, even down to gene expression.
Plants have been grown on lunar soil for the first time in human history, marking a watershed moment in lunar and space exploration.
University of Florida researchers demonstrated that plants can sprout and flourish on lunar soil in a recent report published in the journal Communications Biology. Their research also looked into how plants react biologically to the dirt on the Moon, known as lunar regolith, which is very different from soil on Earth.
This research is a first step toward one day growing plants on the Moon or during space missions for food and oxygen. This research comes at a time when the Artemis Program is planning 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 in the UF Institute of Food and Agricultural Sciences (UF/IFAS).
Plants were significant even in the early days of lunar exploration, according to Anna-Lisa Paul, a research professor of horticultural sciences at UF/IFAS and one of the study's authors.
"Plants helped establish that the soil samples brought back from the moon did not harbor pathogens or other unknown components that would harm terrestrial life, but those plants were only dusted with the lunar regolith and were never actually grown in it," Paul said.
Paul and Ferl are world-renowned experts in the field of plant research in space. They've sent experiments on space shuttles, to the International Space Station, and on suborbital missions through the UF Space Plants Lab.
"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's 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?"
Ferl and Paul devised a deceptively easy experiment to begin answering these questions: plant seeds in lunar soil, add water, nutrients, and light, and record the outcomes.
The problem was that the scientists only had 12 grams of lunar dirt to work with, which was only a few teaspoons. This soil was gathered during the Apollo 11, 12, and 17 flights to the Moon and is on loan from NASA. Over the course of 11 years, Paul and Ferl applied three times for a chance to work with lunar regolith.
Paul and Ferl had to devise a small scale, carefully coordinated experiment due to the little amount of dirt and its enormous historical and scientific value. The researchers used thimble-sized wells in plastic plates normally used to culture cells to produce their tiny lunar garden. Each well served as a container. The scientists hydrated the soil with a fertilizer solution and added a few seeds from the Arabidopsis plant after filling each "pot" with around a gram of lunar soil.
Because its genetic code has been thoroughly mapped, Arabidopsis is widely used in plant science. Growing Arabidopsis in lunar soil gave researchers a better understanding of how the soil influenced the plants, right down to gene expression.
Arabidopsis was also planted in JSC-1A, a terrestrial substance that replicates true lunar soil, as well as simulated Martian soils and terrestrial soils from harsh conditions, as a point of comparison. The experiment's control group consisted of plants grown in non-lunar soils.
The researchers were unsure whether the seeds put in the lunar soils would sprout prior to the experiment. However, almost 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, the researchers noticed variations between the plants growing in lunar soil and the control group as time went on. Plants planted in lunar soils, for example, were smaller, grew more slowly, and had a wider range of sizes than their terrestrial counterparts.
Paul said that these were all physical evidence that the plants were attempting to adapt with the Moon's soil's chemical and structural make-up. This was confirmed when the researchers looked at the gene expression patterns of the plants.
"At the genetic level, the plants were pulling out the tools typically used to cope with stressors, such as salt and metals or oxidative stress, so we can infer that the plants perceive the lunar soil environment as stressful," Paul said. "Ultimately, we would like to use the gene expression data to help address how we can ameliorate the stress responses to the level where plants -- particularly crops -- are able to grow in lunar soil with very little impact to their health."
Ferl and Paul, who worked on the project with Stephen Elardo, an assistant professor of geology at UF, believe that how plants respond to lunar soil is tied to where it was collected.
For example, the researchers discovered that plants growing in what lunar geologists refer to as mature lunar soil showed the most evidence of stress. These mature soils are ones that have been exposed to more cosmic wind, which has changed their composition. Plants cultivated on less mature soils, on the other hand, performed better.
Elardo believes that growing plants in lunar soils could alter the soils themselves.
"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 research will address these and other issues. For the time being, the researchers are congratulating themselves for taking the initial 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."
Materials provided by University of Florida. Original written by Samantha Murray. Note: Content may be edited for style and length.
Paul, AL., Elardo, S.M. & Ferl, R. Plants grown in Apollo lunar regolith present stress-associated transcriptomes that inform prospects for lunar exploration. Commun Biol, 2022 DOI: 10.1038/s42003-022-03334-8
Cite This Page:
University of Florida. "A first: Scientists grow plants in soil from the Moon." ScienceDaily. ScienceDaily, 12 May 2022.
Wnctimes by Marjorie Farrington