Maria Rodriguez
Welcome to Longitude Sound Bytes where we bring innovative insights from around the world directly to you.
Hi, my name is Maria Rodriguez. I’m a Longitude fellow and a graduate student at Rice University studying Geology. We are exploring the approaches of individuals to contemplation, experimentation, and communication in scientific and creative fields.
For this episode, I had the opportunity to speak with Dr. Graham Peers. Dr. Peers is a professor of biology at Colorado State University, where he studies effects of photosynthesis on plants, algae, and cyanobacteria.
We start a conversation on how he found himself in the amazing world of biology. Enjoy listening…

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Maria
If you could tell us about your journey into the field of biology and what initially sparked your interest, and then led you to specialize into studying photosynthesis.

Graham Peers
So, I think it depends on who you ask. I thought my travels here were a little random. And I just kind of picked up interesting things as I go along. But if you asked my mom, she’ll say that when I was a little kid, I was like walking around picking up algae on the beach and messing around with things that I called the green slimes, like, you know, in in lakes and things like that all the time. So, she thinks I always had a predilection towards being interested in algae and photosynthesis and green things the whole time. But, you know, I think I came about it in in a kind of a slow way. I wasn’t too sure what I wanted to do and science initially, and because I wasn’t too sure, I was looking for things that were more kind of like general where I didn’t just have to specialize in biology or chemistry or something like that. And so, I got attracted to the oceanography program at the University of British Columbia, which is where I did my undergraduate. And yeah, it was interesting, because you know, for the first three years, you basically just took a little spattering of biology courses. And in my case, I chose biological oceanography. So, a lot of biology courses, you know, some geology, some chemistry, some physics, I think it was really cool. It just gave me a different perspective on things from my friends who took like just marine biology or just botany or something like that. I kind of stayed in the oceanography realm through my PhD. And then I kind of found that I was more interested with the individual organisms and more interested in how they actually got by living just on light and CO2 and inorganic nutrients. And so, I started to read more and more about that in my spare time. And I’ve just started to get absolutely fascinated by photosynthesis. I think it’s the most utterly amazing thing that happens on Earth. Literally, making something out of nothing is just fantastic to me. And learning about the complexity of how plants versus algae versus cyanobacteria do it is something that still totally fascinates me.

Maria
That’s awesome. That’s really amazing! Are you as fascinated with moss as I am? Because anytime I go hiking, I just go, and I touch all the beautiful soft moss.

Graham
Yeah, moss are super cool! I have friends who work on photosynthesis in moss, but I personally never got into it. They grow a little too slowly for my taste. I am kind of an impatient scientist so I like to try and find things out fast.

Maria
Oh, what would grow faster? Cyanobacteria or just like plants itself?

Graham
Oh, yeah. Cyanobacteria. The plants that a lot of people use for Molecular Biology of photosynthesis, one of them is related to like mustard greens. It’s called the Arabidopsis, and it can go through a full life cycle in less than two months.

Maria
Oh, wow. Very quick.

Graham
Yeah, you planted it immediately germinates and then within a month that flowers and then you can collect the seeds again, and keep going.

Maria
Wow, that is very fast. Can you summarize the project you’re working on in lay terms regarding space biology and lunar agricultural research and share its potential significance?

Graham
Yeah, so we’ve got two projects right now that we work on associated to thinking about plants and space. The first one is partnership with a private company that builds instruments that measure gases and the composition of the air in real time. It turns out, you know, other than just making oxygen and consuming CO2, plants also are interacting with the atmosphere in all sorts of ways. And they also make a hormone. We think about things in hormones in humans as being things like testosterone or estrogen, and they’re in our bloodstream. But it turns out there are plant hormones that are gases, as well. And so, if you’re a plant and you can’t move around, how is it that you can communicate with your neighbors? It turns out that they make this gas called ethylene. And ethylene, if you look it up really quickly, you’ll see that ethylene is like a gas that most people have familiarity with, but never knew what it was. And it’s the thing that makes bananas ripen quickly. So, bananas are throwing off all this ethylene, all the time. And if you put a green banana, and next to a really ripe banana, that ripe banana is making ethylene, and it will signal the green banana to start ripening really quickly. And it turns out, plants make this also all the time when they’re stressed out. And so, what we’re trying to do or what NASA wants us to do is can we develop this instrumentation so that folks on the International Space Station or people on spacecraft or even on the moon, don’t have to be continuously watching their plants? So instead of saying, Okay, going every day watering them trying to figure out what their physiology is, can we be continuously measuring things like the amount of ethylene in the air, and when it reaches a certain point, we could say, oh, there’s something wrong with the plants. Let’s go check on them see what’s wrong, right, because an astronaut has a lot of things to do every day, and gardening? Well, you know, it’s important to eat, you know, it’s something that if they don’t have to spend a lot of their time looking at their plants, that could be better for them. So that’s the first project that we’re working on. And that one’s been really fun. The instrument works, we know we can measure ethylene. But now we’re going to see if we can actually measure when plants get stressed.

The second project that we’re working on right now is trying to figure out if we can improve the growth of plants on lunar soil or lunar regolith, so it’s not really soil because soil here on earth has a lot of organic constituents, dead plants, worm poop, you know, all that kind of stuff. But on the lunar surface, because there’s never been any life on the moon, it’s completely inorganic. It’s just ground rock pretty much. And the chemical composition of that rock or this regolith is very different from what we see on Earth. So even though there’s a little bit of shared geologic history between the Moon and Earth, the metal composition of the regolith, and the rocks on the moon are very different from what we see in the ground up rocks that we see on Earth. And so, it turns out that there are metals, particularly this metal called chromium, which is quite abundant on the Moon, and we don’t see very much of it naturally on Earth. So, our idea that we had when we were comparing the makeup of rocks on the moon and rocks on the earth were, okay, we think that one of the reasons that plants don’t grow well on lunar regolith, is because of the really high concentrations of chromium, because chromium is super toxic. So basically, our proposal was like, Okay, we think it’s issues with chromium. So how can we try to remove the chromium from the regolith such that plants would want to grow on it again. And we came up with an idea of using a cyanobacteria that is very insensitive to the chromium. So, at concentrations of chromium where you get poison for plants, the cyanobacteria don’t care. They can grow on them. They can take up that chromium. They don’t really mind. So, what this ends up being is a kind of a bio accumulation study. Can we get the cyanobacteria to grow on the regolith, suck up the chromium, and then use the regolith that’s been cured of chromium now and grow plants on?

Maria
Wow, that’s super interesting. Have you all tried experiments that plants do grow on this lunar regolith, it but they’re just like really stressed out? Or do they just not grow at all?

Graham
Yeah, so here’s the deal. This is the this is the kicker. Because it’s so hard to get that lunar regolith, you know, it’s not just at your corner store, you’ve got to go a fair distance to get that. So there really hadn’t been very many experiments done on the genuine thing, the actual article, but NASA scientists working with private companies tried to develop fake regolith or what’s called Regolith Simulant. And, and plants will grow on that simulant. You know, they’re not the happiest. You have to give them a little bit more nutrients, literally, you can just give them a little bit of a miracle grow, and that’ll help. You know, they grow okay, not great. There are a lot of people have been working on that, but finally NASA said, Okay, we’re going to release a little bit of the real stuff. Okay, and we’re gonna take a little bit and I’m talking, you know, the amount of regolith would be amount of the amount of dirt that you can like, put on your little fingernail. So, you know, they were growing plants, that mustard I told you about earlier, they were growing that. They germinated the seeds on the actual regolith, and the plants hated it. They’re like, Nope, we don’t like this at all. They were extremely stressed. They didn’t reach the end of their lifecycle. That made everyone’s kind of ears perk up, because we said, okay, there’s a difference between the real stuff and what we’ve been trying to use for the last 20 years to imitate growing plants on the moon. What we found was one of the major differences between the actual regolith and what we see in the simulant is that chromium. So, believe it or not, we only found that out, scientists only published that, last year. So, this is a pretty new finding. So, of course, NASA really wants to make sure that we can try and fix that.

Maria
Super interesting. Wow. And so just from my understanding of plants, just from what you had mentioned, when they are stressed in this type of environment, similar to your first project, do they emit that ethylene?

Graham
Yeah, you know what, there have been some studies on other plants and different metals that show that these plant stress hormones are produced during metal toxicity. I will be totally honest with you. I’ve never thought of combining the two projects until you mentioned it. That’s awesome.

Maria
Just to see if they’re stressed out. Yeah, I wasn’t sure.

Graham
Yeah, we have a whole bunch of other ways of measuring plant stress. So like a doctor might measure your blood pressure, right? And say, Okay, well, your blood pressure is really high, your heart is racing, you’ve got this. And then you also have this stress hormone called cortisol. Right? So, a doctor can measure all those things and say you’re stressed. We have different techniques for measuring stress in plants. That’s actually looking at light emission from plants. So, we think about plants actually using light for photosynthesis, but it turns out, they also emit really low amounts of almost infrared light. And the amount of that light that gets produced gets increased when they get stressed. So that’s how we kind of independent measure stress in the lab. Yeah.

Maria
Very interesting. Very cool.

Graham
All the plants outside are glowing. You just can’t see it.

Maria
They’re glowing with infrared light. Wow.

Graham
Yeah, they’re fluorescent red during the day. Yeah. If you have the right instruments, you can measure that.

Maria
Can I ask how did you come to be involved with this project?

Graham
Yes. So, the first one, I was invited by the company and another person who has worked with the company before. They were looking for someone who had more expertise in photosynthesis, so they contacted me. This other project, the Chromium project, is working with a scientist at the NASA Ames lab, A-M-E-S. And I worked with the scientist there during his PhD. We worked together on algae on things that were completely unrelated to what we’re going to be working on for this chromium project. We enjoyed working together and we were trying to find different projects to work together on and this idea cropped up. And so, we decided to put it forward and we’re lucky enough to get it funded.

Maria
Real cool. Your research involves a multidisciplinary approach sounds like, and it combines genetics, physiology, plant biology. So how do you navigate the intersections between these different fields? And what have been some of the key insights gained from this inter disciplinary collaboration?

Graham
Yeah, yeah. How do you navigate it? Oh, man, I don’t know if I have a good blueprint for that, you know. I’ve always enjoyed thinking about different aspects of science. I don’t like to be siloed or just focus on one thing. And I think that came out of that oceanography degree that I told you about earlier, where I took a lot of different things. I like learning about a whole bunch of different things too. You know, I’m not the best at math, I will fully admit that. And so eventually, I kind of reach a point where I have difficulties and often at that point, if it’s something that I’m really interested in, and I think could be a powerful tool, I’ll try and find a collaborator to help with. Because everybody can’t be an expert in everything. It’s just not possible. And so, when I reach the kind of limits of my abilities, then I asked for other people’s help and I’ve never had any problem doing that, in my career, at least. And so, what happens then is that, you know, as you start to interact with people that don’t have a similar background to you, you start to learn additional things and new doors of knowledge open up to you. So, you start to poke around in a different area. Because I think most of us, you know, most active level scientists are still very curious, right? We, we like to find out new things still, even if they weren’t in our previous understanding of how the world worked. And so, I try to take advantage of that as I go along, and combine new things I, I try to look at what’s new in different fields. So, I actually read like the medical literature sometimes just to find out, Oh, what are people doing in this world that maybe I could learn something from, to apply to plants even? I think it’s important to be very open minded to that. And it can be frustrating, right? Because people use different terminologies or you know, you’re unfamiliar with certain methodologies. But if you have a little bit of patience with yourself, you can expand into those regions and start to learn more. Yeah, and so, the intersectionality, you know, it can be a challenge, but it’s also really exciting. It’s important to find new folks to work with who you enjoy working with and can learn from, and that’s really how you push the field forward.

Maria
I definitely agree. Coming from a geology background, I completely agree with that. Because geology is one of the most like interdisciplinary type of fields. We work with all types of geosciences, like climate scientists, soil scientists, like in our department here. Yeah, our field is super collaborative and just coming from that oceanography background, I could see that for sure.

Graham
Oh, yeah. I tell most of my students who are interested in studying evolution and microbes, I say, one of the most important things you could take is a geology course. Because the biological world, when we think about it, working on our life spans, the exertions that are exerted on the biological world are on geologic timescales, and understand how we got to life on earth as it is right now without understanding geology.

Maria
Awesome. So, you mentioned students, of course, and I know you’re not teaching this semester, but what do you find most rewarding about working with students, and do you have a favorite class you teach?

Graham
Can I start with my favorite class?

Maria
Yes.

Graham
Okay, so I actually just started a new class that I gave last semester for the first time. It’s an upper-level seminar and it’s all about death.

Maria
Okay!

Graham
Yeah, so I think as biologists, we spend all of our time teaching things about life. How life comes about, about reproduction, and we really don’t teach or think much about the end of life. And that’s one constant of all life forms, all life forms die at some point. And so, the concept behind the course was to remove ourselves from the human experience. So, I didn’t want to think about humans. I didn’t want to think about the metaphysical aspects, you know, of why are we here, etc, but instead to look at how other forms of life experience death. Just to expand, so really, you’re still thinking about biology, right? But you’re, you’re approaching it from a different angle and thinking about the diversity. So, for instance, we read scientific manuscripts and looked at data about organisms. This one organism in particular, there is a jellyfish that is immortal. Any as it gets towards the end of its adult lifecycle, it turns back into a juvenile again. And it goes back and forth. And they’ve done this cycle hundreds of times. So why? how does that happen? That completely is unusual, right? That changes our thinking about life cycles, etc. Another thing we learned about is some of the molecular biology associated with really long-lived trees, things like Gingko trees, or Giant Sequoias and things like that. Those organisms live for so long. And they don’t have the markers of aging that we see in animal systems and other plant systems. They’re just not doing the same thing as everything else like that. And they’re not related to each other. They’re very distantly related to one another, like Ginkgo’s and Sequoias are different groups of plants entirely. And they have all these relatives that can’t do it, but somehow, they’ve gotten to a position where they can have extremely long 1000s of year lifespans. How does that happen? So, there’s two examples of kind of how we think about things differently. So, it’s fascinating. It’s really intriguing to me. And the students, I think, really kind of get a broad idea of the diversity of what’s out there. Much more so than just taking a botany and zoology course. So that’s my favorite course right now.

Maria
So, for my own edification, which jellyfish is this, that is, quote, unquote, immortal that Phoenix’s into its new life?

Graham
Yeah, oh, I can’t remember the species name right now, it doesn’t really have a popular name. It’s very rare. I would have to look up and send it to you. I don’t have it at my immediate recall.

Maria
I’ll keep a lookout. Oh, my gosh, wow.

Graham
Yeah, it’s super cool.

Maria
Yeah, for that first part, what do you find the most rewarding about working with students?

Graham
Yeah. So, the best part about working with students is honestly seeing students become independent and they’re their own thinkers. It is, by far the most amazing thing. Just to put this into perspective, I have two of my most memorable students when I first became a professor here, these two students, they’re both in one class of mine, they both are applying for and getting interviews for professorships this year. And that is the most rewarding thing, I think that I’ve ever experienced as an instructor. To see people go from learning about science, practicing with science, to being experts in their field and wonderful teachers on their own, it’s just phenomenal. And so that’s the really, the most rewarding thing is to see a student, you know, essentially struggle a little bit with new information, struggle with how their worldviews change, but gain their own tools, they had their own experiences, to be able to say, I can do this, like, I am able now to take new information, put it into perspective, and go in a new direction with it.

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Maria
We hope you enjoyed hearing about the interesting facets of photosynthetic biology and the innovative ideas that come out of biological research. If you are as curious as I was about the immortal jelly fish Dr. Peers mentioned, it turns out, it is called Turritopsis dohrnii, a very small animal about 4.5 millimetres wide and tall, making it smaller than the average fingernail!

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