It’s a little plant stem, a giant leap for plant science.
The first seeds sown in the lunar dirt sprouted in a small garden grown in a laboratory. This small crop, planted in samples returned by Apollo missions, gives hope that one day astronauts will be able to grow their own food on the moon.
But plants planted in lunar dirt they grew slower and were thinner than others grown in volcanic material from Earth, researchers reported on May 12 Biology of communications. This finding suggests that farming on the moon would take much more than a green thumb.
“Ah! It’s so cool! “Said Richard Barker, an astrobot at the University of Wisconsin-Madison, about the experiment.
“Since these samples came back, there have been botanists who wanted to know what would happen if you grew plants in them,” said Barker, who was not involved in the study. “But everyone knows that these precious specimens … are priceless, so you can understand why [NASA was] he doesn’t want to let them go. “
Now NASA’s upcoming plans to send astronauts back to the moon as part of it Artemis program proposed a new impetus to explore this precious dirt and explore how lunar resources could sustain long-term missions (SN: 15.07.19).
The dirt or regolith that covers the moon is actually the gardener’s worst nightmare. This fine razor-sharp powder is filled with metallic iron, not the oxidized kind that tastes good to plants (SN: 15.09.20). It is also full of small pieces of glass forged from cosmic rocks measuring the moon. What is no it is full of nitrogen, phosphorus or many other plants that need to grow. So, although scientists have become quite good at convincing plants to grow into fake lunar dust made from earthy materials, no one knew if newborn plants could put their delicate roots into the real thing.
To find out, three researchers from the University of Florida at Gainesville conducted experiments with thallus watercress (Arabidopsis thaliana). This well-studied plant is from the same family as mustard and can only grow in a small lump of material. This was crucial because the researchers had little of the moon to orbit.
The team planted seeds in small pots, each containing about a gram of dirt. Four pots were filled with samples returned from Apollo 11, another four with samples from Apollo 12 and the last four with dirt from Apollo 17. Another 16 pots were filled with terrestrial volcanic material used in past experiments to mimic lunar dirt. All were grown under LED lamps in the laboratory and soaked in nutrient broth.
“Nothing really compared to when we first saw the seedlings sprouting in the lunar regolith,” said Anna-Lisa Paul, a plant molecular biologist. “It was an exciting experience to be able to say that we are seeing the first terrestrial organisms to grow into extraterrestrial material at all. And it was amazing. It’s just amazing. “
The plants grew in all pots with lunar dirt, but none grew as well as those grown in earth. “The healthiest were just smaller,” says Paul. The sickest plants grown on the moon were small and had purple pigmentation, a red flag for plant stress. The plants grown in Apollo 11 samples that were exposed to the lunar surface for the longest time were the most stunted.
Paul and colleagues also inspected the genes in their mini-alien Eden. “Seeing what genes turn on and off in response to stress shows you what tools plants take out of their metabolic toolbox to deal with that stress,” she said. All plants grown in lunar dirt took out genetic tools that are commonly found in plants struggling with stress from salt, metals or reactive oxygen species (SN: 9/8/21).
Apollo 11 seedlings have the most stressed genetic profile, offering more evidence that regolith exposed to the moon’s surface longer – and therefore dotted with more impact glass and metallic iron – is more toxic to plants.
Future space explorers could choose the appropriate location for their lunar habitat. Maybe lunar dirt can also be modified in some way to make it more comfortable for plants. Or plants can be genetically modified to feel more comfortable in foreign soil. “We can also choose plants that do better,” says Paul. “Perhaps spinach plants, which are very resistant to salt, will have no problem growing in lunar regolith.
Barker is not worried about the challenges promised by this first attempt at lunar gardening. “There are many, many steps and pieces of technology that need to be developed before humanity can really engage in lunar agriculture,” he said. “But having this particular set of data is really important for those of us who believe it’s possible and important.”
