‘Space screws up biology:’ UW botanist grows plants in NASA space station

UW botanist, team prepare to send up their third experiment with NASA later this year

By Cadence Bambenek | February 16, 2016

Taking his research and questions to space, a University of Wisconsin faculty member now works closely with NASA to study how environmental stress affects plants.

Botany professor Simon Gilroy and his lab have been studying environmental stress on earth, but in 2014 they sent 1,002 seeds up to the International Space Station (ISS) to study the affects of outer space. Once there, the seeds grew for eight days in Biological Research in Canisters (BRICs) before being chemically preserved and brought back to Gilroy’s earth-based lab for comparison with control seeds.

An open BRIC canister showing 5 PDFU and the HOBO data logger in the corner spot.
An open BRIC canister showing 5 PDFU and the HOBO data logger in the corner spot, courtesy of Gilroy’s Lab.

Gilroy and his team then sent their seeds to UW’s Biotechnology Center to map the plant genome’s more than 30,000 data points.

Comparing the space plants with the control group will help scientists to create a fingerprint, Gilroy said, which can be used to understand the impact of microgravity and radioactivity on seedling growth.

Understanding how the physical force of how gravity works, or rather, doesn’t work in space, is helping scientists on campus and at NASA learn more about growing seeds in space, Gilroy said.

“In the absence of convection in space, liquids and gases behave differently,” Gilroy said.

Imagine lighting a candle. Upon taking a match and igniting the braided cotton wick, a shapely teardrop appears as radiation works to pull the flame outwards, and convection draws the little light to a point, reaching for the ceiling. This is the work of the lighter gases, hydrogen and carbon dioxide, tugging the flame up as they rise.

But, light a candle in space and in the absence of gravity, the force of radiation would reign dominant, reducing the flame to a simple, round ball of light. This is known as a diffusion limited flame, according to Gilroy.

If fire becomes round in space, water becomes sticky. When gravity isn’t around to draw the liquid down through the soil to the roots of the plant, keeping the plants hydrated proves difficult.

Watering the seedlings requires feeding them directly through syringes to the petri dishes cradling the specimens, Gilroy said. But because of water’s sticky properties, the experimental space plants seem to experience something known as “flooding stress,” a response similar to drowning, Gilroy explained.

“Space screws up biology,” Gilroy said.

The actuator tool used by astronauts to inject liquids into the petri dish compartment of the PDFU.
The actuator tool used by  astronauts to inject liquids into the petri dish compartment of the PDFU, courtesy of Gilroy’s Lab.

But it’s not just plant biology, Gilroy said, that takes a toll in space. It can also be very tough on people, both physically and psychologically. Gilroy detailed how caring for plants in space can improve mental state, recalling one astronaut, Don Pettit, who created a blog for the vegetable he grew in outer space: The Space Zucchini.

Gilroy’s lab is set to send their third experiment to space at the end of this year or early 2017 from the Kennedy Space Center in Florida. Building on the complexity of the last experiment, the next batch of seeds will spend 12 days growing in space under artificial light, Sarah Swanson, who runs the lab’s logistics, said.

Just as Gilroy attributes his passion for botany to the great professors during his time in university studying zoology at Cambridge, he is serving as a mentor to students of his own.

Postdoctoral research associate  Richard Barker made his way to UW from the United Kingdom to fill a research position in the Biotechnology Center, arriving in Madison on the crest of a wave of the new technique known as RNA sequencing. Working with this technique helped Barker develop the skills to analyze the patterns found in genome sequences that led him to Gilroy’s lab.

“His enthusiasm is intoxicating,” Barker said. “It’s a great environment to work in and students have really succeed under Gilroy’s direction.”

In fact, Gilroy was just named one of UW’s postdoctoral mentors of the year and one of his former students, Gioia Massa, is heading NASA’s endeavor to find the best ways to grow plants and produce oxygen in space for long-distance travel.

Both Gilroy and Barker agree that it’s amazing to be in a lab at UW doing what used to be science fiction.