Announcer:
Welcome to the Salk Institute’s Where Cures Begin podcast, where scientists talk about breakthrough discoveries with your hosts, Allie Akmal and Brittany Fair.

Brittany Fair:
I’m here today with Dr. Joseph Noel. His research focuses on the chemistry, biochemistry, structural biology, and evolution of metabolism in plants. Most recently, Dr. Noel’s research has concentrated on ways to increase carbon storage in plants, ranging from food crops to fresh water and marine wetlands. Dr. Noel, welcome to Where Cures Begin.

Joseph Noel:
Nice to be here. Thank you, Brittany.

Brittany Fair:
Thank you for coming. Just to start out, do you consider yourself a plant biologist or a chemist?

Joseph Noel:
That’s actually a really hard question. I would just consider myself a scientist. I grew up just loving nature and when I got more formal schooling, became very interested in biology and chemistry. When I was in college, got very interested in biochemistry. When I went on to graduate school, interested in the area of structural biology. So looking at things at a molecular atomic level, I think I would consider myself a scientist. And I’m lucky to be here at the Salk because the Salk, more than any place I’ve ever been in my training, really encourages you to follow your interests rather than pigeonholing yourself into a particular discipline.

Brittany Fair:
And speaking of your interests growing up, how did you become interested in studying plants in the first place?

Joseph Noel:
So the interest in plants started at a very young age. My grandmother and my great grandmother and my great aunts grew up during the Depression, and so they grew a lot of their own food. During World War II, people were encouraged to try to grow as much of their own food as possible so that we had enough from our farms to feed the soldiers. And so when I was young, this was in the late ’60s, early ’70s, they were still planting victory gardens and I grew to love gardening. So I was kind of an unusual kid growing up. I was also an avid composter from a very early age. So I grew up in a small town in Western Pennsylvania, a coal mining town largely of about 1,500 people. Now it’s only about 1,000 people, but I would go around every summer and collect grass clippings from all the neighbors that were mowing their grass, which they were very grateful for because they had to get rid of it.

In the fall I collected the fallen leaves. My grandfather, I would go to the local farms and collect manure. And even one summer, this was actually when I was a little bit older, I was 16, I worked at the local town park during the summer, and my job was just to make sure repairing things, fixing things, mowing the grass, et cetera. And a circus came through one weekend with elephants and camels and they had some giraffes. And so the Monday after the circus left, I went around and scooped up all the manure from the elephants and the camels, et cetera, and composted that as well. And I started out with maybe five or six different kinds of plants. By the end, I had 30 or 40 different kinds of things growing in my garden throughout the year.

And I got well known in the neighborhood. I still have friends of my parents when I go back there that talk about the year the elephant poop was put on my tomatoes and I had the best tomatoes. I don’t know if it was the elephant poop, but incidentally, that’s also where I first discovered suberin or cork.

Brittany Fair:
Oh, interesting.

Joseph Noel:
Yeah, I tried to compost cork from wine bottles. I knew it was a natural substance from plants, and what I noticed it was the one thing I put in my compost bin where I could go back the next year or even a year after, sift the compost, and it would look exactly the same. So that was the first inkling that this cork, which is suberin, resisting decomposition.

Brittany Fair:
And what are you currently studying here at Salk?

Joseph Noel:
For a number of years, we’ve thought about how plant biology, plant biochemistry, genetics, can help reshape crops so that they can survive and still produce sufficient amounts of food in the face of changing climates and growing zones, et cetera. Plants do this miraculous thing of using the energy of the sun, some carbon dioxide out of the atmosphere, and they put together and build molecules that essentially store energy in the form of fossil fuels. When we burn them, we release all that carbon backup into the atmosphere, largely as carbon dioxide.

Plants essentially grow almost over the entire globe and the terrestrial globe, and so that’s the idea behind harnessing plants. To coax plants into pulling more carbon dioxide out of the air and converting some of it into forms that will stay behind in the soils. And in theory, if we can do this and find the right varieties of plants, particularly food crops that can do this very effectively, we can draw down on the CO2 in the atmosphere. So that maybe we can now make a dent in this impending crisis that we’re all going to face, which is climate change.

Brittany Fair:
And this sounds like a potentially very effective plan, but why can’t we just plant more plants?

Joseph Noel:
So we can. Plants in general help, but we’ve reached now a tipping point where we don’t have very much time. So we need to do something more quickly than can be done over 100 or 200 or 300 years. We’re talking about a couple of decades before we reach a tipping point. And so I think the real key behind this is to think about plants in two ways. One is where do they put carbon if they can pull it out of the atmosphere and change it? And one way they do that is in their root system. And so we’re very fortunate at the institute now because we have one of the world’s best scientists, Wolfgang Busch, who’s a root biologist and works on the genetics of root development.

So one thing we would like to do is to find engineer plants, find natural varieties that have more extensive, deeper root systems. And the roots are made up largely of carbon. And then what we want to do is a portion of the carbon that’s in the roots, we want it to remain in the soil and we want to coax the plant to make a little bit more of those substances so that each plant that you would grow, particularly if it’s a crop, every year actually leaves behind more carbon in the soil than it re-releases when it decomposes.

Brittany Fair:
What are those substances?

Joseph Noel:
So they have some fancy names, but they’re actually pretty easy for most people to understand. It’s fancy name is suberin, but it’s cork. And obviously the plants that decompose and are used as food, that carbon dioxide is returned to the atmosphere when they’re eaten. So those substances also allow plants to resist drought, as well as flooding and diseases in the soil. But we don’t have very much time, and that’s why we’re using these modern methods in biology and genetics to speed that process up so that crops can actually become not only the food we eat, but a way of mitigating the issues associated with too much carbon dioxide in the atmosphere.

Brittany Fair:
And do you think this project will succeed?

Joseph Noel:
I hope it succeeds. I’m very optimistic. I would have said, 10 years ago, five years ago even, I was very pessimistic about whether we could make a dent in climate change. And then I got to go travel a bit and meet with various groups that span the political spectrum from the right to the left, but all knew that this is occurring, we’re putting too much carbon dioxide in the atmosphere, but all approaching it, maybe for different reasons, but recognizing it’s a problem and that it has to be solved. And with the speed at which science is evolving and improving in technology, I’m very optimistic that we can get there with the right people.

I think a big success of the Harnessing Plants Initiative would be that more scientists, plant scientists worldwide, recognize that plants can make a dent, not only in feeding people, but also in this issue of climate change. So I think even if we just get the word out and get people excited about this and to test our hypothesis, we may be wrong. And most of the time in science, you are wrong or at least your hypothesis has proven would be wrong, but the more people that test things, the quicker we’ll be able to reach the solution. And over the last few years now that we’ve been engaged in this initiative at Salk, it’s really gaining traction beyond just the walls of the Salk, not only with the lay public, but with other scientists. So I’m actually very optimistic.

Brittany Fair:
And there’s a second arm of HPI, right? That involves coastal plants. Can you tell me about that?

Joseph Noel:
Yeah, so this is my pet project. So the initiative really began by thinking about what substances in plants resist decomposition. And as I started to learn more about how those molecules were made, things like suberin or cork, it turns out the more I did research, the more I learned that plants that grow in environments where their feet are wet, so either in a wetland or where there’s periodic flooding or whatever, one of the ways they adapt to that really stressful situation. So it turns out when you flood a plant, the oxygen that the roots need to breathe is restricted, but one way the plants adapt to that is they, in many cases, they make more suberin and more cork in their roots. So the more I studied it, the more I thought, “Well, why not also shouldn’t we be studying wetland plants?” But the more I learned about it, it turns out that wetlands globally, whether it’s freshwater or marine or in between brackish conditions, they can trap per unit area up to a hundred times more carbon than the terrestrial earth.

So it turns out they’re amazing carbon sequestration ecosystems. Unfortunately, they’re also in areas of the globe that are under high economic pressure for human development. And so we’ve destroyed a lot of these. So these are ecosystems that over hundreds of years have been storing carbon. And so we’ve actually now with collaborators that work in the Mississippi River Delta, have looked at the carbon deposits in these wetlands systems, and you can drill down two, three, four feet, and these sediments are really dark, very carbon-rich sediments, and you can actually date the carbon there. And we’re talking about centuries old carbon.

Brittany Fair:
Oh, wow.

Joseph Noel:
And so they store a lot. But unfortunately, when you destroy the ecosystem, when the plants that are growing there go away, all that carbon that’s been stored for up to 100, 200, 300 years is rapidly metabolized. So oxygen now can actually flow in and then bacteria start using it quickly. And there are a number of cases that have already been documented in these wetland systems whereby removing the plant life, you have what’s called a carbon bomb. And so all this carbon that had been stored for up to several centuries is rapidly metabolized and gets released as methane and carbon dioxide in the atmosphere.

So without those plants, you lose the ecosystem, you lose the ability to trap the carbon because the plant roots that are growing there are really critical factors in trapping all that carbon. But two, once you remove it, the carbon that was there gets released. And so we have the potential to really add to our problem in ways that we really aren’t fully accounting for yet in climate models.

Brittany Fair:
What can nonscientists do to support their local wetland ecosystems?

Joseph Noel:
Yeah, this is something that I’m only learning about even here in the San Diego area, we’re now interacting with a number of groups involved in restoration of wetlands. And actually, California in general is doing actually a very nice job at this. When I first moved here in 1994, some of the lagoons along the coast were either filled with non-native species or there was heavy duty human development, and we’re going back now and reclaiming those, replanting them. In fact, we at Salk with our work that we’re doing, we’re now sequencing the genomes of these wetland plant species. So these are plants that no one’s ever looked at from that perspective. So we’re reading the book of life in each of these different species, and what we hope to understand is when people are doing restoration, that we can better inform what are the best varieties to put back when you’re doing a restoration effort to recover these lost ecosystems so that the chance of success for that restoration is much higher?

In that process, what we’re finding is that we’re working a lot with what I call citizen scientists. So just people in the public that are interested in these ecosystems in this volunteer their time. So I think people can get involved in a variety of different ways, but even just being a voice for preserving these ecosystems is really important.

Brittany Fair:
And I have to ask, now you live here in San Diego, which is very close to one of the top zoos in the US. Do you ever call them?

Joseph Noel:
They actually have a fantastic group of scientists right next to the wild animal park in what they call the Beckman Center, that are doing things very much like we’re interested in doing.

Brittany Fair:
Interesting.

Joseph Noel:
Yeah, so they’re working, for instance, on the endangered white rhino, but also on endangered plant species. One of the first things you want to do is read the genomes because it’s the genome that is the code book for how you put together these various forms of life. And so next Wednesday, we’re going on a field trip with a group of scientists from the San Diego Zoo that are interested in some of the wetlands here in San Diego County to just take a look at what these wetlands look like, what are the endangered wetland plant species in these environments? Are there species there that we also now have in our collection of plants that we’ve collected from various places around the US? I see over the next several months, really formulating a very solid, collaborative working relationship with folks from the San Diego Zoo.

Brittany Fair:
And you’re no longer collecting elephant you know?

Joseph Noel:
I am not. I don’t have a comp… So I now live in a small house more in urban setting in the heart of the city, but prior to that, in my first two houses that I owned here in San Diego, I had an edible landscape and I was an avid composter. So I’m no longer collecting elephant poop, but that doesn’t mean that I won’t do it in the future. So very well in the future-

Brittany Fair:
Will you have [crosstalk] set up and…

Joseph Noel:
Exactly. I have an unlimited supply that it would appear of not only elephant poop, a diversity of feces from various wild animals.

Brittany Fair:
I wonder which one would provide the most luscious garden.

Joseph Noel:
Well, that was the interest. So actually when I first started composting that, that was one of the reasons why I collected different things. I think I recognized then even though I didn’t have the scientific breadth of knowledge that I have now, I knew at that point that it was best to have a diversity of things. And so I was so excited when I had the opportunity to collect, not horse or cow manure, which there were a lot of horses and cows around where I grew up, but now these exotic animals. So you never know. I did have fantastic tomatoes. And my neighbor that I growing up with still lives there, he’s an older gentleman in my parents’ age. Every time I’m visiting family back there, my sister or my brother, he still brings up, “I still remember your tomatoes and your peppers and the elephant poop that you’ve spread all over your garden.”

Brittany Fair:
And speaking of San Diego gardens, is there a type of plant that you would recommend to people that’s easy to grow, hard to kill, will do well here?

Joseph Noel:
So one thing about the San Diego environment, you can grow anything. So the first house I had, I had lots of tropical fruits, guavas, bananas. At one point I had, I think, 14 different varieties of bananas. You can grow just about anything. And things thrive here. The issue of course is water, but with a little bit of water, you can grow almost anything. My second house was a low water use place, but I also wanted it to also be an edible landscape. So I grew a lot of cacti. Actually, when I was younger as well, I collected succulents and cacti. They take very little water. They like our environment here.

So anything in the prickly pear family does very well here. You just have to find a pad off of one of the cacti that are growing all over San Diego, stick it in the ground and it grows quite effectively. And incidentally, you can eat it. So a lot of prickly pears, they produce a very tasty, nutritious fruit, and the pads are also edible. So cacti are a very interesting group of plants that do well here. Don’t take a lot of water, don’t take a lot of fertilizer, hard to kill, but also in many cases, they produce something that’s edible. I always like to grow something that you can eat.

Brittany Fair:
I’m going to ask you a hard question.

Joseph Noel:
Yeah.

Brittany Fair:
If you were no longer allowed to be a scientist for some reason, what job would you have? What would you do?

Joseph Noel:
There was one other hobby that growing up I really enjoyed. I wouldn’t be doing it at my age now, but it was playing American football. That’s why I’m wearing my Pittsburgh Steelers shirt here. I’m a very rabid American football fan, particularly the Pittsburgh Steelers. And so I played football since I was very young and that was one dream. If I wasn’t a scientist, I would have been a football player. Obviously, I’d be retired by now and then probably a fly fishing guide on some really great rivers in the West or where I grew up as well.

So one thing, where I grew up, we had some very famous trout streams. And so I enjoy fly fishing because there’s a biology component too to it as well. I really enjoyed, wasn’t so much catching the fish, looking at all the insect life in the stream and then picking the appropriate fly or nymph that mimic that biological system and catching fish. So yeah, if I wasn’t a scientist right now, I would have been a professional football player until the age of 35, and then I would retire and be a fly fishing guide on trout streams.

Brittany Fair:
Well, that sounds very relaxing.

Joseph Noel:
Yeah, it is. And again, it’s a way… I grew up in a rural part of the country being out in nature, and so it’s another way of reconnecting with nature.

Brittany Fair:
Makes sense. And a big question to end on, but what do you think the future holds for plants on earth?

Joseph Noel:
Future for plants I think is fantastic. Humans and other warm blooded animals, if we don’t solve the climate crisis, not so good. Plants will be here long after we’re gone. They were here, photosynthesis first emerged on the earth around 3 billion years ago. They’re probably one of the most adaptable living things on the planet. But in general, plants will be here probably long after humans and other animals have gone extinct.

Brittany Fair:
Well, thank you so much for joining us today, Dr. Noel.

Joseph Noel:
Thank you, Brittany.

Announcer:
Join us next time for more cutting edge Salk science. At Salk, world renowned scientists work together to explore big, bold ideas from cancer to Alzheimer’s, aging to climate change. Where Cures Begin is a production of the Salk Institute’s Office of Communications. To learn more about the research discussed today, visit salk.edu/podcast.