Professor Chris Wolverton’s Work to Sprout on International Space Station
As a ninth-grader in suburban Cincinnati, Chris Wolverton landed what was, at the time, his dream job. The local garden center didn’t just sell plants; it made them. This early opportunity to experiment with propagation — creating new plants from parts of other plants — helped set Wolverton on his path toward becoming a botanist. On top of that, he was raised by a mother who spent her free time in the yard, her hands in the earth. And, “I had a fabulous 10th-grade biology teacher,” Wolverton recalls.
So by the time he set foot on the Miami University campus as an undergrad, he had an uncommonly clear idea of where he was headed. A lot of botanists settle on that particular slice of science propelled by other primary interests — cell biology, for instance. For Wolverton, the plants came first. “It was purely, genuinely about the plant stuff,” he says.
“I didn’t grow up on a farm or anything, but plants always seemed cool, and it just seemed like they didn’t get a lot of attention.’’
Now, Wolverton’s plants — well, the seeds that will grow into plants — are on the verge of leaving Earth on a rocket bound for space. The OWU professor of botany and microbiology has secured a coveted spot for his research on a flight to the International Space Station. For somebody who studies the interplay between plants and gravity, this is a great big deal.
Wolverton’s project, which is tentatively scheduled to launch at the end of 2017, was one of 16 selected to fly this round. Fewer than a third of the applicants were awarded grants.
Most people probably never consider gravity’s role in plant development. But Wolverton is practically giddy about this opportunity to study the effects of weightlessness. He marvels at what might unfold when the same thread-thin roots he investigates on Earth grow in space, free of the inescapable pull here.
Wolverton and his team, which includes several current OWU students, hope to answer two primary questions: How much gravitational force does it take for cells within the root tips to respond? And how does it differ in plants that have been bred free of starch-filled bodies normally found in the roots? Scientists know these bodies play an important role, but the specifics of that remain a mystery.
The vital relationship between plants’ roots and the pull of gravity — called gravitropism — is, on its own, scientifically interesting. But the work is about much more than scratching the itch of curiosity. It could have implications for crop productivity for farmers. It could answer questions about plants’ ability to survive when stressed by drought, how they regulate nutrients drawn from the soil, and how much fruit erupts from their blossoms.
The seedlings that are at the heart of the story are called Arabidopsis thaliana. The small, flowering weed is the fruit fly of botany, the plant scientists most often study and manipulate to learn more about all plant life. It’s a member of the same family (Brassicaceae) that includes cabbage and radishes.
Wolverton will send some genetically altered Arabidopsis seeds (which are 30 percent as responsive to Earth’s gravitational pull) and some wild seeds. They’ll be mounted at NASA’s Ames Research Center in California — 14 at a time — on rectangular membranes about the size of two postage stamps. Then, they’ll go into seed cassettes (each about the size of a large Lego block) that have holes that allow moisture in. The cassettes eventually will be placed inside LED-lit boxes in a unit aboard the space station.
There, they’ll grow for almost four days on a centrifuge that will replicate the Earth’s pull, just shy of 1 G. During that time, the roots should grow about the length of a staple.
After that, the crew aboard the space station will drop the gravitational pull so that Wolverton can study what happens to the roots at zero gravity and at increments between zero gravity and 1 G. They’ll get pictures during the flight, and frozen seedlings will come back for further study.
“We want to know: What is the minimum amount it takes to trigger these cells to know which way is down?” he says.
“It’s a bit like, ‘Can you hear me now? Can you hear me now?’ ’’
In his lab at Ohio Wesleyan, Wolverton and his students have advanced understanding of how the root architecture develops in relation to gravity — basically by tipping tiny plants on their sides and gathering data on what is happening at a cellular level as the roots twist and turn and exploring how he can manipulate that.
Wolverton is working to determine the genetic switches that control the plants’ response to moisture, nutrients, and other elements within the soil. One of the primary focuses is the role of auxin, a plant hormone that pools in the tip of the root.
As Wolverton contemplates the upcoming months and the opportunity to see how his experiments fare, he’s experiencing his share of nervous energy. There’s a lot to do to get this right. NASA has questions. And Wolverton has a lot of his own questions that he wants answered, and reanswered.
When he applied for the grant in 2014, he knew it wasn’t a slam dunk. But, “I thought it was clever.”
As the months passed, “I was checking the site every week, and I’d pretty much given up hope. I started to think it wasn’t clever enough.”
In early 2015, word came. He remembers his disbelief as he digested news that NASA would give him $520,000 for three years plus a rare spot on the space station for his project.
The Pull of Gravity
That kid back in southwestern Ohio? He didn’t care much about space travel. He wasn’t a boy who dreamed of becoming an astronaut or begged his parents to take him to the planetarium on the weekend. For him, it’s always been about the plants.
Back in 1994, as an undergrad at Miami, Wolverton managed to find his way to Portland, Ore., to attend the annual meeting of the American Society of Plant Physiologists.
“I was listening to all these talks I could barely understand,” he says. So he went for a walk. As he wandered alone through an exhibition hall filled with 1,000 or more scientific posters, he encountered some science that stopped him. The researchers employed a computer to take pictures of roots as they grew.
This was 1994. People were still getting accustomed to email. The marriage of computer and camera was something that could grab a 21-year-old botany major’s attention. As it turned out, the researchers behind it were from home, or close to it. Mike Evans, a now-retired plant biology professor from Ohio State University, led the work.
Wolverton and Evans got to talking and kept talking. After he graduated from Miami, Wolverton headed to Ohio State for graduate work in Evans’ lab. “We watched for really subtle changes in the root architecture — movement at the top, or the bottom, or both. You can answer some questions about gravity just by looking carefully,” Wolverton says.
He’s continued to write new chapters in that body of research, which he brought with him to Ohio Wesleyan. And it’s hit a point where his questions can’t be answered on this planet. Opportunities to conduct an experiment aboard the International Space Station are to scientists interested in gravity what working with Meryl Streep is to an actor.
“It’s a huge opportunity. Space flight and crew time aboard the International Space Station are rare commodities,” says Sarah Wyatt, a professor of environmental and plant biology from Ohio University whose work went to space in 2014.
She counts herself among those eager to learn the answers to the scientific questions Wolverton is posing. “For someone working on gravity, the only real control experiment is to have no gravity, and that can’t happen on Earth,” she says. “Many of the questions we would like to ask … can’t be answered on Earth.”
Wyatt is aware that watching her research go into space might have been a once-in-a-lifetime experience. Her project evaluated what proteins were expressed in the cells of the plants in microgravity, the first analysis of this type.
“I think it’s fantastic that Chris is getting this chance,” she says.
Wolverton, 44, who lives in Delaware with his wife Jenn and their 13-year-old daughter Lindsay and 9-year-old son Jack, is a dedicated researcher. But toiling in a lab without the opportunity to interact with budding scientists was never going to suit him. That’s what brought him to Ohio Wesleyan.
The school’s size and the priorities set by leadership allow him the opportunity to run a robust research program while maintaining an active class schedule, something that can be difficult at larger research centers, Wolverton says.
He first came to Ohio Wesleyan in the summer of 2001 as an Ohio State doctoral student filling in for a professor who had left for another opportunity. “There were maybe seven, eight students, and I just loved it. I just fell in love with the place and the commitment to both time in the classroom and research.”
Wolverton was walking the hallways with researchers whose work was appearing in prominent journals, including Science, and who interacted with students daily.
“So I put my hat in the ring, and I got the job.”
Nathan Madonich ’16, who graduated with a degree in botany, says he’s grateful for Wolverton’s teaching style (hands on, inclusive) and enthusiastic support of his students’ pursuits.
Madonich, 22, spent the summer after his freshman year working on research in Wolverton’s lab and, with the support of his professor, applied for and secured a research internship at Cornell University the next two summers.
Then his graduation coincided with a rare opportunity: Wolverton had money in his NASA grant to hire a research technician. “Working with him has been a blast,” Madonich says. “This is not something everyone gets to do. This couldn’t have happened to a better guy.”
Current students also are working with Wolverton, helping shepherd his science to space. Allyson Wojnoski ’18, a French and biology major from Connecticut, says working with him has opened doors for her, including the opportunity to present her own research at OWU’s Summer Science Research Symposium and the American Society for Gravitational and Space Research meeting in Cleveland in October.
Wojnoski says she was set on going from undergrad studies straight to medical school prior to studying under Wolverton, but now is considering exploring more research before that. In addition to sparking an interest in plant biology, the experience also has likely given her a competitive edge when it comes to future job opportunities, Wojnoski says.
Troy Jones ’18 has been inspired to pursue a career in plant physiology by working alongside his favorite professor. “It has been an amazing opportunity to work with Dr. Wolverton,” he says.
Wolverton’s enthusiasm rubs off easily on undergraduate botany students, Jones says, and he gives them freedom to meaningfully contribute to the science. “He is able to teach complex ideas in a way that makes them manageable,” says Jones, who is from Detroit and is triple majoring in botany, environmental studies, and classics.
Sowing Seeds for Space
The days in Wolverton’s lab are filled with the kind of detail-driven preparation necessary for a rare shot at conducting an experiment in outer space. There aren’t any do-overs. If the seeds don’t grow or the lighting doesn’t work like they hope, it could be a bust.
“We have been doing a lot of verification tests. For instance, NASA was interested in seeing how long our seeds would be viable,” Madonich says. “We found that they can be pretty reliable even up to a year after they’ve been glued on membranes and are ready to go.
“We’re also working to become comfortable with the flight hardware that will actually go on the International Space Station so there are no glitches.”
If he’s nervous about anything, it’s that the plants won’t respond to their light source in the way he and Wolverton expect.
“Another thing that’s always tricky is the germination rate and how viable these seeds will be. There’s always this worry in the back of my mind that the seeds won’t germinate,” Madonich says.
Wolverton, who will take the seeds first to California to NASA’s Ames Research Center, then to the launch site, either Florida’s Kennedy Space Center in Cape Canaveral or Wallops Flight Facility in Virginia, agrees. “The biggest issue would be some sort of biological failure,” he says.
They’re sending a lot of seeds, though, and an outright experimental failure seems doubtful, Madonich and Wolverton say. And the lead-up to a trip to space is all about ensuring things go off as planned, which means lots of reassurances will happen between now and then.
“At one point, I pictured that I would drop some seeds in the mail and NASA would plant them and water them, and I would get the data back,” Wolverton says, laughing.
Marianne Steele, a project manager at the Ames Research Center who is working with Wolverton, says his work could provide important insights into human life as well. “One of the things NASA wants to do is to go to the moon and Mars and beyond. When we do that we’re not going to have gravity, and one of the important questions from a science perspective, as well as an exploration perspective, is what happens … to human immunity, and muscle, and bone.”
Basic plant science can help NASA piece together information with applications that go far beyond the tiny seedlings aboard the space station, Steele says. “Plants are not human, and yet, they have a lot of similar molecular mechanisms going on. And they are a lot easier to take a look at than humans are.”
Beyond fostering a better understanding of what can be accomplished in zero gravity — and in different levels of gravity below what we experience on Earth — NASA is interested in promoting work that has the potential to improve life on Earth, Steele says.
“That’s part of the whole process of selection,” she says. “This is taxpayer money and we have to be responsible in using that money for Earth benefits as well as for exploration.”
Wolverton says applications in the field are probably a decade or more off, but the information he and other scientists are gathering about the interplay between plants and gravity could have far-reaching implications. “It doesn’t get much better than this in my field, to have this opportunity,” he says.
“It sort of feels like this is what I came here to do.”
Misti Crane is a freelance writer in Columbus, Ohio.