Dr. Robert Ferl: Zero-gravity ops in crops
How do plants grow in space? Dr. Robert Ferl, a molecular and space biologist who has spent his career studying how biology adapts to strange environments through gene expression in plants, offers insights on how these studies can affect agriculture not only on Earth, but also in space.
The following is an edited transcript of Kara Keeton’s interview with Dr. Robert Ferl. Click below to hear the full audio.
Kara: I'm excited to have with me today Dr. Robert Ferl. You have many titles, sir. You are a professor, a molecular biologist, director of the Interdisciplinary Center for Biotechnology Research at the University of Florida — but my favorite that I heard today was space biologist, I believe, so that's what I think I want to call you today.
Robert: That's perfect. Believe me, of all those things that you've mentioned, being a space biologist is the most enjoyable.
Kara: Well, it is definitely an exciting field, I would say. I guess I would want to start with what inspired you to go down the road of, of course, molecular biology, and how did that evolve into your role as a space biologist?
Robert: Well, thanks for asking the question, because that's really sort of a fun one and easy one to start out with. It's worth going over because very few people would actually start out — although I think, maybe, these days, perhaps they would — but certainly in my era, you wouldn't start out saying, "I want to grow up to be a space biologist." I've always been interested in space. I'm a child of the Apollo era, and I'm inspired by space, plain and simple. As a scientist, however, I became a biologist during the era of the expansive growth in molecular biology. I got my degree as the first genes were being sequenced and as we were beginning to understand the role of genetics in adaptation and, in particular, the notion that, as you go into a new environment, you have to express genes to allow you to adapt to that environment.
I happened to be working on plants that were adapting to being flooded. That was about the same time as the space shuttle was taking some of the first real plant experiments to space. Some of those plants that came back from space looked like they were under stresses that were similar to what we were studying by studying flooding. And then the two things that sort of underscore my history came together: the question of how biology adapts to strange and useful environments through gene expression and my long-time history with the fascination of the space program.
Kara: And so, as you started down this road of research, how did you begin working with NASA and working on projects with them and researching gene expression in these plants that are sent to space?
Robert: NASA, for all the things that it does, is actually very good at thinking broadly. Also, the people that are involved in, basically, the defense industry have long recognized that long-term interest in maintaining bases or people or other things in distantly deployed locations involves life support in one way or another. So NASA, along with the Air Force, as early as the late 1950s recognized that there were very good reasons for wanting to understand not only biological adaptation to spaceflight and vehicular environment but also that we needed to have organisms with which to understand what happens to terrestrial biology when it leaves the surface of the Earth or when it's in a human-rated vehicle.
NASA actually has — and, at that time especially, during the space shuttle era, when there was a lot of science in space going on — put out calls for proposals to understand what happens to organisms that go into space. We raised our hands and said, "Hey, we're plant molecular biologists. You guys are interested in plants. We've got these new tools to bring to bear on the questions that you guys want to know about adaptation to space."
Kara: And in this early research, what did you start seeing develop with these plants that were sent to space? Was there anything that happened that was a surprise or unexpected, or has it pretty much turned out as you thought it would be as you would go through the research trials?
Robert: The first thing I have to say is that, as a biologist, I'm just utterly astounded that plants, when they grow in space, look like regular plants. Are you kidding me? These things have spent every one of their evolutionary generations on the surface of the Earth, with a full gravity vector pulling on their roots and pushing on their shoots, and everything in my biological training tells me that plants orient themselves to the Earth based on gravity.
Moreover, all those decisions about whether to sprout your leaves or continue your shoot, all of those are decisions that are made in the presence of gravity. So, am I surprised when plants germinate from a seed and grow normally, as long as you give them directional light? Yeah, that's, to me, pretty surprising.
Kara: That is amazing. I did not realize they would do that. So, the root structure is the same? It doesn't just go in one direction that fills out, as a traditional root would?
Robert: Yup. The longer answer to your question is — so to me, personally, that's sort of a surprise, that plants undergo their normal development pretty much the same in space as they do on the Earth; not exactly the same, but pretty much the same. Plants do interpret spaceflight as a novel environment, however, so it's not like they are exactly the same as they are in the Earth. In fact, it takes this differential expression of several hundred genes to allow plants to live in spaceflight compared to living on the ground, but again, think about what these plants are doing and think about the experiment you're doing.
You are comparing plants that are above the surface of the Earth, hurtling around the Earth at 17,000 miles per hour, and you're comparing those plants to plants that are sitting at Kennedy Space Center in a container that is programmed to the same environment as the space shuttle or the space station, except that it's not moving, and there's gravity here, but not there. It's not a perfect comparison, but it's a pretty good comparison. Under those conditions, there's only a couple of hundred genes that it takes to live in space, so the adaptation that does occur is profound, and it's interesting, but it's not insurmountable.
Kara: Talking about the difference in having a sample in space versus here on Earth, as you have developed the research process, are there challenges you've had to meet when you were taking something up in space? Is it still just like a lab up there? To me, thinking about it, you would have to have special equipment; maybe you have to approach it differently. Walk through that and the challenges you all have faced as you've worked on projects like this, and the successes, the failures, and what you've learned from this through the years.
Robert: Being a scientist that interacts with the spaceflight program does indeed present challenges, and many of them are procedural, as you indicated. Chief among them: as biologists, we move liquids around the laboratory all the time. We pipette them. We pour them. We move them around. We freeze them. We add things to them, and we mix stuff up. Every one of those things is a challenge when there's no gravity around. In fact, working with the people that train the astronauts, working with the astronauts themselves to understand how to do processes that are important to us while they are in zero-gravity, was an interesting and evolutionary process in itself.
During the space shuttle era, there were only a few laboratory capabilities in the space shuttle, in the space station. There are workstations that, for all intents and purposes, look a lot like the laboratory bench for any graduate student to use. In fact, we get these wonderful videos from the astronauts working at that bench in orbit, and you'd be hard-pressed to know they were in space until somebody else floats by, and then you know that they are, in fact, in zero-gravity. In fact, I find it hilarious that, when we get these videos back, we always orient them so that the person's head is up and their feet are down, but that has absolutely no relevance to what's going on.
The first big thing is liquid handling. Second thing is storage of frozen samples, return of those samples to Earth — how do you get them back into your lab, how do you do the ground control so that you can compare them into space? There are a lot of procedural things, but we, the collective, we have gotten pretty good at it over the last 20 years.
Kara: While you yourself have not gone to space to have that experience, you have been a field researcher in some pretty unique locations. Tell me a little bit about Antarctica, the Arctic, and parabolic flights. You've had the opportunity to do your field research in areas that most people would never imagine doing research.
Robert: One of the things that is absolutely truthful about this area of research is that it can be, if you so desire, extraordinarily experiential. In other words, you can roll up your sleeves and stand there with an astronaut and train them how to do what it is you do. In order to be able to do that well, you might want to train yourself in a micro-gravity environment, and you might want to train yourself in the other environments that astronauts have to work in, such as airplanes, fighter jets — the other kinds of things that encumber you with the experience of being in a spaceflight environment but that don't actually take you to space. All those things are available to you as a scientist, and they're very valuable in terms of making sure that the communication between you and the astronaut and the actual experiment are good communications.
The first kind of experience that I'll mention is that which enables you to better prepare experiments for the microgravity environment. That is the kind of experience that allows us to study what goes on in the vehicles that we build to move us around in space. We have yet to have a similar kind of habitat sitting on the surface of the moon or sitting on the surface of Mars. Nonetheless, we want to prepare ourselves, our experiments and our agriculture to be there when humans are there on those planetary surfaces. That brings us to talking about the High Canadian Arctic or Antarctica as a place to go.
Another thing that NASA and other space agencies have been very, very good at is developing a series of analog environments for the various parts of deep-space exploration. I've already mentioned that parabolic aircrafts have microgravity experiences in preparation for going into space. There are also stations at remote, hard-to-get-to analog environments that, in one way or another, simulate what it might be like to be operational on the moon or Mars. In High Canadian Arctic, we were a part of what's called the Haughton Mars Project, which, on the largest uninhabited island in the Canadian Arctic, Devon Island, there's a large impact crater that has no plants growing out, essentially, no plants growing out, no animals, except for the wandering bears and a few other things living there. It's a true polar desert that has a large meteor crater on it, and situated on the edge of that crater is maybe where you would put the greenhouse and the habitat that you were going to build on the moon or Mars. It's the Haughton Mars Project where the SETI Institute and others from around the world go to do experiments, to do operational exercises of what it's like to live and work around a crater, one that's got no other life, essentially, nearby. It's dusty. The rocks are sharp. It's all the kinds of things that you would want to simulate there. In that greenhouse there, we worked with the Canadian Space Agency to understand remote operations, to understand the difficulties of growing plants in a place where there are no humans yet and you would want to robotically get the plants to grow so that, when you got there, the plants would be there. Also, we worked with them to understand the movement of data back and forth between a remote greenhouse and home.
Similarly, with the German Space Agency, we worked most recently in Antarctica at a different kind of analog and remote location: an ice shelf where there's absolutely no dirt, where there are no humans or animals within miles and miles and miles, and the terrain and the weather are extreme. At that particular station — that's the Neumayer III German Ice Station — we worked with the German Space Agency to build a space station-sized greenhouse that is used to produce food for the overwintering crew there at the Neumayer Station on the ice. That is a very different kind of environment than the Arctic, but the two of them combined give us two different views of what it would be like to perch a greenhouse, a plant production unit and an agricultural production unit at a challenging and interesting environment, where it can actually make a difference to the people that are living there.
Kara: When you talk about very different environments, when you are growing plants in these extreme conditions, does it impact the growth of the plant, being in these extreme conditions, or are you building facilities that control the environment, and after, where you don't see those different gene expressions as much?
Robert: That's really one of the fundamental questions of all analog studies. It would be best, of course, if we could go to the surface of Mars and put a unit there and study it there. We can't. We can't go to the moon yet either, but what we can do is create enough of an analog environment that teaches us about one or two components of what goes on in each of those places. Each of those places tested very different kinds of aspects of the question that you posed, but both of them together give us much more information than we ever would have had if we didn't do those kinds of studies.
Kara: With advances in technology, are you seeing new ways to approach the challenge of growing in space and growing plants in those extreme conditions? Does that help with these challenges?
Robert: Oh, absolutely. One of the things that's most important to recognize is that, by looking at those conditions, and by looking at what it would look like to grow plants in space, we come up with, collectively, a good definition of the really driving questions and limitations.
Let me back up just a little bit and say it would be great if the spaceships that we build to go to Mars, where we've got to spend, like, a year in transit, it'd be great if those spun in a way so that there's artificial gravity, and all the engineering and all the biology issues would go away. So, what you would have is you just have our normal plants, our typical plants, and our normal water movements being cared for by creating enough of an Earth-like environment that we didn't have to worry about the fact that they were in space. We can't do that. Nobody knows how to build a big, spinning spaceship yet to create gravity.
Two, we don't quite know what it would be like to have a growth chamber or growth greenhouse on the moon or Mars, but what we do is we come up with as much engineering as we can to ask how would we mitigate the questions and problems that we would face there. The Arctic and Antarctic greenhouses actually took two different approaches. In the Arctic, we used sunlight in a regular, sort of more traditional greenhouse approach. In the Antarctic, the German Space Agency built a thing that is entirely driven by LED and internal lighting. Therefore, they're asking two very different questions, two very different approaches about how you might design, how you might engineer, enough of a habitat to make it Earth-like enough to get what you needed to get out of it. Underneath all of those things, or as a part of all those things, we are working with them to understand the physiology and gene expression that goes on as the plants adapt to each of those environments.
Kara: Have any of the results of the research on gene expression in different environments played into concerns or issues that we currently face in horticulture production here on Earth? Have you found answers, or has it helped in other areas here on Earth?
Robert: One of the more interesting things that currently characterizes the gene expression patterns of plants in space, compared to plants on the ground, is that plants in space seem to be remodeling their cells’ walls. If you think about it, that makes some sense, because they don't need to be as strong, because they're not growing and being moved by gravitational forces, and in that modeling of their cell walls and, then, that remodeling of their cell walls, they're expressing genes that sometimes — and, in many cases, often — are associated in our terrestrial vernacular with pathogen attack. In other words, some of the enzymes and some of the signaling molecules that are expressed when something eats away at your cell walls — pathogens — are some of the same characters that are remodeling cell walls in orbit.
They're not under pathogen attack in orbit. Don't get me wrong, but what that's teaching us is that not everything that we are associating with pathogen attack on Earth is necessarily a result of a pathogen attack, but it clues us into the pathways that are activated when you want to remodel your cell wall, whether it's because you no longer have gravity or because there's a pathogen nearby, or any of the other reasons that we don't yet understand.
One of the nice things about taking plants into space is that it takes them to an environment that is truly novel. In other words, they have no preconceived notions in their little plant heads. They have no preconceived notions about how they should behave. So, what they're doing is they're reaching into their toolbox, and they're doing what their biochemistry tells them to do to live without gravity or to live in a spaceflight vehicle. That allows us, as scientists, to probe the edge of the pathways and responses that we study all the time here on Earth: salt stress, pathogen stress, too much light, too little light, cold, heat. All of those things that are boxed off nice and carefully for us here on Earth are now more richly informed by what we see in spaceflight, because we're seeing activations of pathways that, in a sense, don't really make sense, but it's the plant's interpretation of its environment.
What this does for us as scientists is it says, “Okay, we now know how a plant will think, how it will behave biochemically, if presented with a very novel, very new and potentially stressful environment.” Climate change, for example, comes to mind. We are informing plant biologists what the full toolbox looks like and what plants do when they run up against the edges of that toolbox with respect to the known ways to respond to their environment.
Kara: That is just amazing to me, and I think it just really opens the door, that there's so much out there still to learn with gene expression, the molecular biology of plants, as you continue your research. What do you hope to see research develop or go, or where do you hope to be 20 years down the road with progress?
Robert: There are a couple of things in your question that I'd like to tug on. The first thing is that we're at a place that's talking about innovation and grand ideas. One of the things that we are currently limited in, for the most part, in our thinking about how we are going to feed the people that live on Mars or the people that are going to live in space for a long period of time is that we're going to feed them with the plants that we currently know about, that we currently have. We have never sat down as a society or as a group, or even as a brainstorming cadre of scientists, and said, “Okay, plants don't need to have this in space. They don't need to have that on Mars. Let's design, breed or select something that looks totally different.”
We come to think about, just because the crops that we have, we have, doesn't mean that we've always had them. We haven't. We've built them. We really need to build some novel, new ones, and they need to be very special. They need to be very special, not only because they need to be really efficient, but they also need to be, maybe, able to produce nutraceuticals and other things that we need that astronauts have. Maybe they're there to produce plastics and other things so that 3D printers can make what the colonists need. There's a whole series of deeply innovative thinking that can go on there, and so, in 20 years, I think what's going to be in space — and probably here on the ground as well — are plants that we haven't thought of yet, that we haven't imagined yet, but that the next generation of scientists will be capable not only of imagining but selecting and building them so that space will not be a strange place to those plants, such that they will produce much more efficiently and much more effectively with a lot less waste and a lot less input than we currently use.
Getting back to something that I've mentioned a little bit earlier, agriculturalists are always, always good stewards of the environment and of the community. If you shrink that environment and you shrink that community down to a half a dozen people whose life absolutely depends on a good agricultural system that doesn't waste a lot of molecules, you get to have some really interesting thinking going on so that you can address those problems, address those opportunities, in ways that can really be fun. When I look back to your question, when I look out into the future, I think we're going to understand, physiologically, what happens when plants are in space. I think we're going to understand how to move water better. I think we're going to have better engineering for solving the technical issues of growing our food, but we're also going to be solving some of the biological questions and coming up with absolutely wonderful new varieties that will do things that are going to be really cool.
Kara: I also believe that “space biologists” will be a regular term in the near future.
Robert: Very good.
Kara: Thank you so much for joining me today.
Robert: It's been my pleasure. Thanks for having me.
Kara: That was Dr. Robert Ferl, space biologist and professor at the University of Florida.