As an undergrad studying ecology and evolutionary biology, Lizzie Lombardi found herself as one of the few āplantā people on a team of ĄÖ²„“«Ć½ Boulder engineering students who were tasked with a lofty mission: build a robotic system that could garden in space.
The aerospace engineering team was participating inĢżĢżacademic innovation challenge, known as XHab, to develop the best practices for growing fresh produce during deep space missions. The goal is both to sustain astronauts and to buoy their morale during long months of isolation.
As her teammates fretted over how to build a robotic system that could plant seeds, monitor growth, harvest the plantsāand then repeat that cycle indefinitelyāLombardi began to wonder about the plants themselves. Could they grow a plant that would meet the particular nutritional needs of an astronaut taking extended jaunts in space?
At first Lombardi, unsure of how sheād go about answering the question, assumed it would remain simply something to ponder. But with the encouragement of her advisor, she sought out professors in theĢżĢżwho had the expertise to help her design an experiment as part of an Honors Thesis that would deliver some concrete answers.
Ģż
Lombardiās research was recently published in the journalĢż. With the mentorship of professors Barbara Demmig-Adams and Williams Adams, both of the Department of Ecology and Evolutionary Biology, and the day-to-day coaching of postdoctoral researcher Christopher Cohu, Lombardi was able to show that using a specific technique to grow plants in spaceāexposing them to bright pulses of light several times a dayācan increase the amount of eye-protecting nutrients the plants produce.
āAt first I didnāt even consider the possibility that I was ready to do primary research for an Honors ThesisāI wasnāt sure that was in the cards for me,ā Lombardi said. āIt was challenging, but I loved it. I still do research and Iām increasingly sure that I will continue to pursue new frontiers in plant ecophysiology in the future.ā
The spark and the know-how
When Lizzie first approached Demmig-Adams with her idea of trying to grow plants in space that would be as nutritious as possible, Demmig-Adams thought the proposition sounded a little outlandish.
āI said, āLizzie, Iām a plant functional biologist; I donāt know anything about astronauts,āā she said. āAt first I was going to say, āNo. Thatās not going to happen.ā But Iām glad I took a second look at it.ā
The second look led to a partnership unique to universities that allow novice researchers and experienced experts in their fields to work side-by-side in the same labs. The students may provide the spark of an entirely new idea; the professors can provide the grounded-in-reality know-how.
āFaculty need to recognize the merit of a studentās off-the-wall idea and students need to listen to the experts,ā Demmig-Adams said. āLizzie was the impetus for this project, but she couldnāt do it on her own. But I never would have thought about this without her.ā
More stress equals more antioxidants
The foundational knowledge that Demmig-Adams brought to the project was the fact that plants grown to optimize growth do not produce as many antioxidants as plants exposed to some stress. Because research into space gardening tends to focus on producing as much biomass as quickly as possible, Demmig-Adams knew that the plants might lose some of their nutritional value. Ģż
Lombardi and the rest of the research team decided to focus their study on an antioxidant long studied by Demmig-Adams called zeaxanthin, a carotenoid known to protect various aspects of human health, particularly eye health. Demmig-Adams had just written a review on the function of zeaxanthin in increasing the acuity of human vision and protecting against cataracts and age-related blindness. Her review also highlighted the fact that human are unable to produce zeaxanthin themselves and must consume it with their diet.
In space, astronauts are exposed to an onslaught of eye-damaging radiation, and eating foods that contain zeaxanthin could be a key strategy for protecting their eyes.
Plants produce zeaxanthin on Earth when their leaves absorb more sunlight than they can use, which often happens when the plants are stressedāperhaps by exposure to drought, or excessive heat or cold. In the 1980s, Demmig-Adams discovered that zeaxanthin safely removes the excess light to keep the sunlight from damaging the plantās own biochemical pathways. But unstressed plants, like the ones that would be grown in space under conditions that promote maximal plant growth, would not accumulate much zeaxanthin in their leaves.
āOur eyes are a lot like a leafāthey are both about collecting light,ā Demmig-Adams said. āWe need the same protection to keep us safe from damage by intense light.ā
A great opportunity
Demmig-Adams and Adams began to wonder if their past research in Australia might offer a solution to growing plants packed with zeaxanthin in space. In the 1990s, the pair had studied plants on the floor of a eucalypt forest in Australia. The plants were often shaded by taller trees but were occasionally hit by a shaft of intense light that pierced the canopy. Though the stream of light was usually short-lived, it was enough to cause the plants to begin producing antioxidants. Ģż
Based on those findings, the research team tested to see if the plants they were studying as a model for possible cultivation in space could be intentionally exposed to several bright pulses each day to get a similar effect. The pulses were short enough that they didnāt interfere with the otherwise optimal growing conditions, but the team found they were long enough to cause accumulation of zeaxanthin.
The research project helped Lombardi get a job in a lab on campus after graduation, and she plans to pursue an advance degree to continue on with research as a career in the future.
āI was really lucky that I had advisors who were so constructive and open-minded,ā she said. āIt was difficult, but I learned so much and cannot express how appreciative I am for the opportunity.ā
- See more at:
