Designer Plants on Mars
Take the cold tolerance of bacteria that thrive in arctic ice, add the ultraviolet resistance of tomato plants growing high in the Andes mountains, and combine with an ordinary plant. What do you get? A tough plant "pioneer" that can grow in Martian soil.
Like customizing a car, NASA-funded scientists are designing plants that can survive the harsh conditions on Mars. These plants could provide oxygen, fresh food, and even medicine to astronauts while living off their waste. They would also improve morale as a lush, green connection to Earth in a barren and alien world.
Image above: Project logo: "Redesigning Life for Mars". Credit: North Carolina State University
The research is being sponsored by the NASA Institute for Advanced Concepts (NIAC), which investigates revolutionary ideas that could greatly advance NASA's missions in the future. The proposals push the limits of known science and technology, and thus are not expected to be realized for at least decade or more.
The plants would probably be housed in a greenhouse on a Martian base, because no known forms of life can survive direct exposure to the Martian surface, with its extremely cold, thin air and sterilizing radiation. Even then, conditions in a Martian greenhouse would be beyond what ordinary plants could stand. During the day, the plants would have to endure high levels of solar ultraviolet radiation, because the thin Martian atmosphere has no ozone to block it like the Earth's atmosphere does. At night, temperatures would drop well below freezing. Also, the Martian soil is poor in the mineral nutrients necessary for plants to thrive.
"Our idea is to enable plants to survive on Mars by adding features from microscopic organisms called extremophiles that live in the most inhospitable environments on Earth," said Dr. Wendy Boss of North Carolina State University. Boss and her colleague, Dr. Amy Grunden, also of North Carolina State, head the research team working on this project.
The team uses the techniques of gene splicing to remove useful genes from extremophiles and add them to plants. (A gene is a molecular instruction that specifies a feature for an organism, such as eye color, height, the ability to digest certain foods or resist toxins, etc.)
Image above: Plant seedlings that have been transformed with the "superoxide reductase" gene. Not all seedlings take up the new gene, so the seedlings are placed on material that only allows the transformed plants to grow (large green seedling in the middle of the left image). In the image on the right, the transformed seedling glows because the product of the new gene (a protein) has been tagged with a molecule from a species of jellyfish that glows when exposed to special light. Researchers use this procedure to determine where the new gene is functioning in the transformed plant. Image credit: North Carolina State University Click here for a 150 k print-resolution version of this image (jpg format)
The current NIAC funding pays for "proof of concept" work that demonstrates the feasibility of the team's idea and identifies the technical challenges that must be overcome for Martian plants to become a reality.
To prove their concept, the team took a gene from "Pyrococcus furiosus," a microbe that lives in the scalding water issuing from deep sea vents, and inserted it into a tobacco cells. The gene, "superoxide reductase," removes toxic oxygen atoms and molecules that are generated in organisms under stress. The gene was successfully incorporated into the tobacco cells and functioned without harming them.
The team plans to transform plants with genes for cold tolerance as the next step in their research. They also used their NIAC concept as an educational experience, giving undergraduate students at North Carolina State the challenge of selecting features from existing organisms that would be useful for Martian plants and designing ecosystems for Martian greenhouses.
"The features we are incorporating in Martian plants, like cold and drought tolerance, will also help crops bear severe weather here on Earth, so this work has practical application," said Grunden.
"This type of long-term research, with an uncertain path to success, is only possible with an organization like NIAC that doesn't mind taking a chance for the possibility of an incredible breakthrough," added Grunden.
NIAC was created in 1998 to solicit revolutionary concepts from people and organizations outside NASA. The Universities Space Research Association operates NIAC for NASA.
More about NIAC
More about desiging plants for Mars (pdf presentation)
NASA Goddard Space Flight Center