Double-stranded RNA Mind Controls Rust Fungi with Rebecca Degnan
Alisa Nappa
Right out of a science fiction movie - what if there was a magic spray that could control living organisms to do your bidding? Well, that spray exists, and researchers like Rebecca Degnan are using it for good. Rebecca, from the University of Queensland, is taking a double-stranded RNA spray to control rust fungi that are infecting plants to cure or prevent infection. Tune in to uncover more!
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TRANSCRIPT
Alex 0:00
Alex,
welcome, welcome. You are listening to the mushroom revival podcast. I'm your host, Alex Dorr, and we are absolutely obsessed with the wonderful, wacky, mysterious world of mushrooms and fungi. We bring on guests and experts from all around the globe to geek out with us and go down this mysterious rabbit hole to try to figure out what the heck is going on with these fungal beings. And today we are talking about rust fungi. So Rebecca, tuning in from Brisbane, Australia, how you doing about to geek out about this, this type of fungi that I have no idea about. I don't know a single thing about rust fungi, so I'm excited to dive in with you about this in this episode.
Speaker 1 0:55
Yeah. Thanks so much for having me. I love talking about rust fungi So, and I've already noticed we pronounce fungi differently, so that's fun
Alex 1:03
for people wondering. It's all correct. However you say it, it's all good, yeah. And so are you, yeah? What? What? Tell the audience about your studies with rust fungi and or fungi and what you're up to?
Speaker 1 1:20
Yeah. So my name is BEC, Rebecca degman, and I'm based at the School of Chemistry and Molecular bioscience at the University of Queensland, and I live on jagera and turbo country in mianjin, Brisbane, Australia. I'm a third year PhD candidate, so I'm still in graduate school, as you call it in America, and I'm in the field of molecular plant pathology, and currently I'm working on an RNA based control for a pathogenic fungus that actually threatens a lot of our native plants here in Australia.
Alex 1:55
So I know I've talked to a lot of people who have studied mycology in kind of a traditional university setting, and pathogenic fungi are really big, you know, I think that's we love our plants, and we love our commercial crops, and so any fungus that's pathogenic to those, those plants are widely studied and taught in university settings. And I'm guessing rust fungi is a big candidate in that, in that umbrella. But for you, how did you originally get started with both, you know, mushrooms, mycology, fungi, in in, in general, but also specifically with, with rust fungi?
Speaker 1 2:38
Yeah. So I basically always knew that I wanted to be a scientist, um, like, ever since I was really little. Both my parents are marine biologists, so I was very, yeah, it's really cool. And I was super, you know, lucky to have this really awesome childhood, like, always traveling with them and going to these amazing places and seeing all the experiments they did. And so that was kind of an easy progression. And then, when I first started my undergrad, I, like, basically, was interested in everything, and I kind of tried everything from, like neuroscience to ecology, and I eventually came to kind of mycology and Plant Pathology through, like this love for native plants and conservation of plants, and yeah, soon after I learned about Myrtle rust for the first time and how it was kind of threatening a lot of these really precious species, I was also introduced to my now supervisors and learnt about the work They were doing with RNA based pesticides, bio pesticides, and I thought it was just a really perfect way to, like, combine a love for native plants and also with molecular lab work. And I started doing, like, you know, any kind of fungal biology course that I could find, and like you said, most of them are plant pathology, typically in a kind of traditional academic environment. And yeah, I find, I find myself very fortunate to be in the rare little bit of plant pathology that gets to work on an environmental pathogen and not an agricultural pathogen. And yeah, I'm kind of, I find myself a lot more focused on the fungi side of things and the plant side of things now. And, yeah, fungi are pretty cool. So I'm okay with that.
Alex 4:27
I'm sure your your parents are thrilled that you have took the biology torch and are doing amazing, really cool work. I every Marine Biologist I've ever met is, is pretty cool. So that's, that's awesome. You got two for parents, yeah, and for people who don't know, including myself, what are rust fungi? And why are they important? What classifies a rust fungi? Give us kind of a rust fungi? 101, yeah.
Speaker 1 4:56
So rust fungi are actually really. Really, really large and super diverse group of plant pathogenic fungi. I believe they're the largest group of plant pathogenic fungi, but I'm not 100% sure. And I think, as it stands, there are over 7000 described species, and there's basically a rust fungi pathogen for every group of plant hosts. So you have like, an agricultural rust, like coffee rust, wheat rust and soybean rust. Those are, like, the really big ones that, like, you know, get a lot of attention and funding and things like that. And they, of course, threaten some of our really huge agricultural economies through, like, the yield losses that they cause. So they're actually damaging the plants to the point where you're losing yield of those agricultural crops, and then you have your environmentally or culturally significant rusts, such as Myrtle rust, and an example in North America is white pie and blister rust as well. And these can lead to the destruction of native plant species and even kind of break down whole ecosystems.
Alex 6:02
So I'm curious, because I think identification for macro fungi enthusiasts is a bit easier. Obviously, it's case by case, and there's some macro fungi that you need to do DNA sequencing to really figure out the species. But for rust fungi when you when you're out in the woods, you know, or on a farm or something like that, you said it's kind of plant specific. So if you were in a forest of white pine and you saw some rust fungi on a pine needle or something like that. Could you automatically know that that is the was it white pine blister rust? Yeah, yeah. Like, because it's plant specific, or, or, or, is it a sort of thing that you always kind of have to do a DNA sequencing for? Like, How did someone go about identifying rust fungi
Speaker 1 7:04
so you you are spot on. It's because they are generally host specific. And there are so many different rust that you know some of them are host specific and some of them aren't. But like you said, if you're wandering around in the forest and and you see a pine truth rust on it? Yes, you can be pretty sure what kind of rust it is. With something like wheat. There are a few different rusts that infect wheat in slightly different ways, and there are some rust fungi that have a lot of different hosts. There are also some that have what's called an alternate host. So they have their kind of main host plant, and then they, like, overwinter on a different host plant. But yeah, generally you can identify by the host and then things like the spore morphology are a little bit different too. So you could always go and look under a microscope as well. But yeah, I think with rust fungi, it's a bit less common that you would need to do sequencing and things like that. Yeah,
Alex 8:02
cool. That helps a lot. And so I'm curious what rust fungi actually do to the plant. And I know your the focus of your research is Myrtle rust. And so do they all kind of have, do they all have different interactions with different plants? Like per species, they do different things, like one, maybe, I don't know, it makes all the leaves fall off, or the other one steals nutrients. Or what? What are they actually doing to the plants? Yeah.
Speaker 1 8:37
So all rusts are obligate biotrophic fungi, meaning that they need a living host cell to survive, like gain nutrients and reproduce and things like that. So the kind of broad impacts that they would have on a plant are pretty kind of ubiquitous amongst rust fungi. But there are some differences depending on kind of what the host is. So osteoporcinia acidi is the causal agent of metal rust. It's the species of rust fungi that causes the disease that we refer to as metal rust. But I'll just call it metal rust because it's like the name is a bit of a mouthful, but basically what it does is it has this main infectious spore stage that just spreads via the wind, and that will kind of go and land on a leaf, and with the kind of right conditions, it will infect the new growth on a plant. And the signs and symptoms can be like, pretty variable. So anything from the appearance of this kind of Telltale rusty orangey yellow pustule on the leaf and like a little bit of leaf blight, and die back to this kind of really dramatic whole tree malformation and mortality. And I think a lot of people think that, because it just infects new growth, it might only be a problem. Them for seedlings, but we're like, really seeing it bringing down really old established trees as well, which is pretty scary. And, yeah, that's something that that can differ a bit from rust species to rust species. Some don't just infect new growth. And then, of course, if you have a rust that's in its native range, where it's actually co evolved with the species around it. It's not going to be as damaging, and probably not going to be bringing down these, you know, established trees in the same kind of way.
Alex 10:34
Side question, I'm guessing it got his name rust fungi from the appearance of looking like rust, you know, so curious. Okay, yeah,
Speaker 1 10:44
well, so this is, like a fun fact, and I and I think this is true, but one of my professors told me this in undergrad. Apparently, rust, like the metal, rust, got its name from rust fungi. Whoa, okay,
Alex 10:57
it's flit. Whoa, okay. It's cool, nice. I love that, apparently.
Okay, well, I like that story, so we'll run with it
Speaker 1 11:06
exactly. That's what I think, too. Well, I'm,
Alex 11:09
I'm also curious if, are they generally kind of an orange, reddish rust color, and then maybe sometimes they're like a purple or a white or something like that. Or they every rust fungi is that color.
Speaker 1 11:23
So typically they are this kind of, yeah, Rusty orangey yellow color. But there is variation in there. So sometimes you have more brown pustules metal. Rust is actually very yellow compared to a lot of other rusts. Yeah, wheat rust is more of that really typical rust color, yeah, so they kind of fall within that range typically. Yeah, cool. And
Alex 11:50
I was reading in your paper, which is kind of scary, as you were alluding to, is that rust fungi invasion of Australia has already accounted for the extinction of three species and then the predicted extinction of 16 rainforest tree species in a single generation, which is crazy. I had no idea that these rust fungi were that damaging to ecosystems. But where did these rust fungi come from? Like is this? Are the invasive from another country and and these, you know, local species just didn't have the right defense mechanisms yet, and it's like a new thing in the last 510, years, or something like that.
Speaker 1 12:40
Yeah, exactly. So metal rust is native to Central and South America, and it has now spread pretty much all around the world in all the environments, or most of the environments where it would thrive. And it turned up in Australia in 2010 and it's really particularly bad news that it's fed to Australia because metal rust infects plants of the family matesi, and we have close to 2000 species of metesi that are actually endemic to Australia. So yeah, that's pretty that's pretty scary. And so from what I know, we're seeing mostly localized extinctions at the moment. I think no whole species extinctions yet, but definitely, yeah, species that are really being kind of put on the brink. And, yeah, this study that that you're referring to with the predicted extinction of 16 species that was done by some some other researchers at UQ at the University of Queensland. And yeah, they did a bunch of surveys and up down the coast of Australia, and found that 16 species would be extinct within a single generation, and a further 20 would be at risk. And yeah, like I said, we're already really seeing the impacts around us, and because Myrtle West is an invasive pathogen, our endemic trees haven't had the chance to co evolve with it, as they would have in Central and South America. So this kind of just means that Australian matesi are, like totally naive to this pathogen, and they don't have adequate resistance in place to defend themselves or coexist with the pathogen. So that's why the the impacts are so severe here,
Alex 14:30
and from an ecological standpoint, does it have any benefits to the wider ecosystem? Is it? Is it more like species, control of trying to control species? Maybe this is a very like anthropogenic or what's the word like? Maybe I'm trying to put a reason on biology that doesn't exist. But like from. From, you know, like a human framing. Do you? Do you think that rust, fungi exists to kind of as, like a check and balance system in ecosystems?
Speaker 1 15:11
Well, yeah. I mean, it's like you said, I think as humans, we like to have an explanation for everything. I'm definitely like too, but I guess, I guess, like, what it seems like to me is that every organism has its role in its place, and in an environment that it's native to, and where it's yeah, like, co evolving with everything it, it probably does have this effect where it's yeah, like a check and balance. It's a really good way of putting it. I'm definitely not an expert of on what its role is in its native range, but just based on, like, general knowledge of how biological organisms kind of coexist with one another, that it seems like a good bet, yeah,
Alex 15:57
but they love to kill trees, and we love trees, yes, yes. And in the meantime, yeah,
Speaker 1 16:03
I should also mention that, because it's a obligate by a trough and it needs a living host, its goal is actually not to kill its host. So when it is running rampant and killing all of its host. That's actually not good for the fungus either, um, because it wants to be able to, you know, live off its host and and that also kind of explains why in its native environment it's not having the same kind of impacts as it has here, like where something is clearly out of whack.
Alex 16:38
Interesting, yeah, is there any I'm guessing it's stealing nutrients from the plant,
Speaker 1 16:46
yeah, yeah. So it takes all in all the nutrients it needs to grow and reproduce from the host plant cell. Yeah? And
Alex 16:54
it's defined as a parasite, because it's giving absolutely nothing in return that we know of.
Speaker 1 16:59
Yeah, yeah, yeah. It's, um, it doesn't contribute anything to the well being of the plant. It is putting its own toxins and everything into the plant to kind of aid in its infection. But yeah, it's not contributing anything useful.
Alex 17:17
I did, I
Unknown Speaker 17:19
think it
Alex 17:20
was a TED talk or something years ago, talking about how we should redefine the word parasite, because it's actually giving these plants a RE, like hardened evolution to where, you know, it's like, I think there was a there was This, I think it was a study or a story that I that I heard about many, many years ago, about people making this very in this very large, enclosed, like, ecosystem, and the trees started falling over, and they're like, Well, why? Like, we have the right nutrients, the soil is good. Like, why are the trees falling over, and they figured out because they didn't have any like fans in there, and the only thing that they're missing is like wind. And plants need wind to like. They need their stems and everything to shake in order to like, grow their roots wider. And because they didn't have the stress of wind. Their roots were just really narrow and flimsy, because they're like, Oh yeah, we're good. We don't have any stresses in our in our life. And then they fell over. So this, this researcher, I It's been so many years, but he was arguing, like, the benefit of parasites, because it and, you know, viruses and infections and all these things, because it actually helps our evolution, because we grow to be stronger as as organisms. So could be a potential benefit on, like a grand scheme of things. But in the meantime, I'm curious about, like the the current treatment of these rust fungi, specifically in Australia, and probably beyond, is going to try this name tridiminal, triadminal, which is a fungicide. And I'm curious, what are the negative side effects of this fungi fungicide?
Speaker 1 19:21
Yeah, so I will preface by saying this is not my area of expertise, but just based on what I know about fungicide use to control metal rust and you know, other similar rust fungi, it basically for metal rust can be quite effective, at least in the short term, but there is always that risk of develop developing resistance. And there are like guidelines in place to manage this risk, but basically you have to be really careful not to be overusing it. And because my rust is an environmental pathogen. Like. So it's out in, you know, forests and natural ecosystems, and not in a agricultural setting, the fungicides are, yeah, they're not applied at the same frequency and rate as you would see within agricultural pathogens. And so things like fungicide resistance should be naturally slower to develop in this kind of patho system. But yeah, there are, of course, drawbacks to the use of fungicides, like you have to continuously apply them. They don't tend to be, like, a really long term option or or they can be, you know, expensive because you have introduced continual application. There are also the environmental drawbacks of fungicides. So potentially, with broad spectrum fungicides, you have potential off target effects, so maybe killing beneficial microbes or insects or plants that are in the environment just around your whatever you're targeting. And you also have problems with things like runoff, which is a really big problem in Australia and in Queensland, because if we're spraying plants up on the like East Coast, and then they're running off into the Great Bay reef. So yeah, there's downsides to fungicides, for sure. They also take a really long time to be developed, so if you develop resistance. The production time for a new fungicide is like 15 years or something, and it's very expensive, so we really kind of need to slowly move away where we can. And yeah,
Alex 21:38
so the focus of your research is using this double stranded RNA spray. And I'm curious what that does. What? What is that?
Speaker 1 21:55
Yeah, so that's a good place to start. So basically, we wanted to develop this as an alternative to these fungicides. We wanted an option that is going to basically utilize a lot of the same infrastructure, so it's not going to be a big change in practice, or there won't be big kind of implementation costs, but it's going to be environmentally friendly. It's not going to have any impacts on off target organisms. It's cheaper and faster to produce and yeah, really species specific, so only going to be targeting the myrtle rust, which is the major downfall of a lot of the current, um, fungicide options that exist. So, yeah, basically, uh, maybe we'll go back to explain what RNA is and, um, kind of go, I
Alex 22:52
love that. Yeah. I remember it from like, my middle school biology class. So it's been a it's been a while. Um,
Speaker 1 23:00
yeah, yeah, no, it's, I think that's probably where most people are coming from, too, and and even, even me, like in the world of biology, every day, I really forget that basic fundamental biology. So it's actually good to remember myself, but probably more people are familiar with DNA, which is deoxyribonucleic acid, and basically that's like the genetic blueprint that kind of contains all the instructions for building and maintaining a living organism. And most frequently, RNA, or ribonucleic acid, is regarded as like this messenger that actually carries instructions from the DNA to the cell's protein making machinery. So a really important messenger molecule molecule, but typically it occurs in this single stranded form. So DNA is usually double stranded and RNA is usually single stranded. And when a living organism senses double stranded RNA like invading its genome, defense pathway is triggered, and this pathway is known as the RNA interference pathway, and that's what we're kind of taking advantage of with our double stranded RNA based spray. So in terms of actually making the spray and what it is and what it's doing. We basically design these, this double stranded RNA spray, which is just literally a mix of double stranded RNA and water. We designed it to target genes that the fungus needs to survive. So we just choose these genes based on the literature what we know about the biology of the pathogen and war effect of these as essential genes. So we then, I don't know how much you want me to go into detail with, like the synthesis process. Do it up. Yeah, go. I think, I think it's really cool, but yeah, I don't know. Just stop me if it's too much. Of, go off, go on. So basically, we've got our essential genes. We've, like, decided, okay, these are the essential genes the fungus needs, and if we can silence those genes, then the fungus won't be able to survive. So we design these little they're kind of like molecular bookmarks called primers. And what those do is they find and mark these specific genes in Myrtle rust, and then we can cut out those genes and make lots of copies, like heaps of copies, through a process called PCR, which people might be more familiar with now post covid. But at this stage we have, like, heaps and heaps of little chunks of these genes in a single stranded form, and we basically just do a reaction that synthesizes a matching complementary strand, and that turns it into a double stranded RNA molecule. And then we can just purify that molecule, mix it with some water, and it's ready to be sprayed. So because we've designed these dsrnas to perfectly match those essential genes, once they're sprayed onto the plant and taken up into the fungus, the that RNA interference pathway will look for transcripts that encode those essential genes, and it actually destroys them, and that leads to inhibition of infection by Myrtle rust. So you basically can, like, trick the fungus into its own demise through its own genome defense pathway.
Alex 26:34
This is probably one of the most insane things that I've ever heard in a very long time. That's crazy. That's awesome. That's so it's really crazy. Wow. Okay, so I'm gonna try to put it in, like, really dumb down layman's terms, and let me know if I'm on the right track, because I think I understand it. But So basically, DNA is, like, I've heard this analogy before where it's kind of like the blueprints of a building. Like, you know, you have your all your architecture blueprints for for this building, and then you have the RNA, which is kind of like the general architect. That's like telling all the workers, you know, it's looking at the blueprint and then telling all the workers, like, all right, this is how we build the building go, you know, build the foundation, and build the walls here, and then. So basically, what the spray is doing is you are basically, like, switching out the the general, uh, architect person that's getting orders, and you're like, yeah, yeah, instead of concrete for the foundation of the building, let's just use, like, wet paper. Like, that's, you know, is that, like, am I kind of on track with that dumb
Speaker 1 27:43
analogy? That's actually great, yeah, okay, great. That's totally
Alex 27:48
it. That's how I help I create these, like, dumb visualizations to learn things. So I'm glad I actually, I'm
Unknown Speaker 27:55
gonna use it that's awesome.
Alex 27:57
Yeah, you gotta give me all the, all the academic credit, oh yeah, yeah, 100% Yeah, yeah. Just, just, just put me as like a contributor for your next paper, and we'll be get Yeah, we'll be solid, yeah. Sweet. So, how does one make that spray?
Speaker 1 28:17
Yeah? So that's basically the the synthesis process that I just described. So we, at the moment, do all of that ourselves in the lab, because it's, as you can imagine, pretty small scale. At the moment, we're kind of just doing glass house trials and lab trials and things like that. So yeah, it's all in vitro synthesis in the lab at the moment, but it can also be scaled up. So you can actually order this double stranded RNA from from companies who have these much more large scale pipelines, and they're like a microbial based pipeline, so in some cases, they're actually growing the double stranded RNA and like Agrobacterium, or there's different ways of doing it. But, yeah, you can also order the double stranded RNA from these kind of in bulk companies as well.
Alex 29:08
So I don't know if you know how they do it, but I'm, I'm just trying to wrap my head around this synthesis, or even, like, the microbial production. Are they like, growing the rust fungi in like a big bioreactor, like a big vat, like liquid broth, and then somehow, like going in to the RNA and just swapping out instructions, like, how, how do you do
Speaker 1 29:35
so, in terms of in the lab, like the way that I do it, you can't actually grow rust fungi in, like, any kind of culture, because they need a host. Yeah, goodbye trough, yeah. So it's right, super annoying thing to work on. Okay, fun little challenge. But so basically, what I do is I actually just like, like, go around to the trees, you know, around here, that are infected, and I get, like, a big paper bag. Bag, and I just stand there like an idiot, like with the paper bag, shaking the spores off. And then I freeze them at minus 80, and you can extract the RNA from them, and then kind of do that whole synthesis process that I described. But in terms of in these large scale production facilities, I'm not too vast, but I know that one approach is, yeah, to grow the double stranded RNAs in Agrobacterium. So Agrobacterium is like a commonly used bacteria for a lot of kind of traditional molecular biology techniques, because it's very basically, you can just put anything in it, and then it will just multiply. So people use it a lot for cloning and things like that. But if you design your double stranded RNA, and you just get that into the Agrobacterium, and then you just grow up your Agrobacterium on a plate, and then, like suddenly, you have heaps of it, and then you can just purify it back out of the Agrobacterium again. Yeah.
Alex 31:03
My brain just went down, like a very dark rabbit hole about, I just watched this movie about Teflon and and, like the it's a really good movie. I was trying to Google what that the name of it was, yeah. But it was a really good movie about Teflon, and, like, the manufacturers of Teflon, and how they knowingly were making this really toxic substance, and they knew it was super cancerous for people, but they just did it anyways. Wow. And it just made me think, like, oh my god, there's like crazy companies like making wild chemicals that alter people, um, intentionally, and they just, like, don't care. And went down this rabbit hole, like, kind of a conspiracy theory of, like, how easy would it be for like, the government or something, to make a double stranded RNA to spray for humans to just, like, just, you know, be like, Oh yeah, we want a mass group of people to do XYZ. Like, let's just spray stuff to make them do whatever we want.
Speaker 1 32:11
To ease your concerns, that would take a lot of RNA, it would take a lot, like, what it would to bring down a human I like, yeah, you already have to use quite a lot to get, like, a tiny little rust ball, so it's a kind of inconceivable amount
Alex 32:32
that'll that will make me sleep better at night. Thank you. But, and
Speaker 1 32:35
I don't think anyone is doing that, I think there would be way easier ways to control a group.
Alex 32:41
True, true, yeah, subliminal messaging and other things, yeah? But yeah, would be a cool, you know, like movie idea or something. I mean,
Speaker 1 32:53
that's true, that's true. That would be cool, yeah, yeah. That's
Alex 32:57
really crazy. But you said in your paper, and you know, we were just talking about this large scale microbial production, how the cost used to be around 12,500 USD dollars per gram, in like 2008 and then through this large scale microbial production process. It's as little as $1 per gram in 2023 so were they? Were before? Were they doing kind of that, that small scale synthesis that you're kind of doing currently in your lab, and then now they develop this new microbial pipeline technology,
Speaker 1 33:43
yeah. So I think the decrease in cost just kind of comes down to a few different factors. One of them is definitely, like a change in in process and and again, I don't, yeah, I'm not really an expert on this. I'm just kind of going off, like the quotes that we've seen and things like that. But yeah, it's definitely like this combination of kind of advancements and in tech and like streamlining a lot of these processes, of streamlining the synthesis and purification methods. I think the microbial based pipeline would definitely be a part of that, because the in vitro synthesis, where you have to pay for enzymes and everything, is a lot more expensive. I think a big part of it too is probably that there's a lot more research funding and investment going towards these kind of technologies. So a lot of countries are really interested in investing in RNA technology after kind of realizing some of its potential uses during the covid 19 pandemic, and to Australia, for example, has really invested in RNA technology, which is awesome, and I think you know, that makes a lot of these things more possible too. There's also a lot more competition, just more companies producing this kind of. Thing. And I think the most important factor is probably scale. So if I wanted to buy one or two grams of double stranded RNA, it's not going to be that cheap. It's going to be probably still pretty expensive. But if I'm if everything is scaled up, then that cost per unit is way lower. So if I'm talking about doing, like, a massive field trial, and I need to, like, get heaps of double stranded RNA, then it's going to be the numbers we're seeing are really like, yeah, as low as this kind of $1 program, Mark,
Alex 35:33
yeah. I've heard the same thing with DNA sequencing, that new technologies have come out where, you know, I can't remember how much it used to be, I think it was like $100 per test, and now it's like less than 10 cents per test. So I think, I mean, this is so exciting to hear, like in multiple fields of science, but also like related to mycology, these, these really influential technologies are becoming extremely affordable for scientists and researchers, and now people are doing DNA sequencing at home, and are doing like, really cool research that was once, you know, you only it was only kind of reserved for, what is the term, like, the porcelain castle or something like that? Have you heard that? Or, like, there's like, a term for, like, uh, kind of, like, academic elite that I can't remember the the name for, yeah, right, something, something, some phrase like that. Um, so that's much
Speaker 1 36:38
more accessible now, yeah, yeah, it's really cool, yeah. And it's like, you can get a whole, your whole human genome done for, like, I think it's like 1000 bucks. It's, which is insane. That's a lot of genes. So, yeah, it's, it's definitely, I think it all, like you said, it all is kind of part of that just general progression of science and molecular techniques as we move further into the future. Yeah,
Alex 37:06
complete side tangent to go in a full 180 right right now. But I do want to get into the biology of rust fungi and how it's changed through this RNA. But have you studied marine fungi ever?
Speaker 1 37:28
I haven't, but it's like one of the things I'm considering doing for a postdoc. I Yeah, I'm interested in it, but I've never, I've never studied it. No, so I but do you have a fun fact?
Alex 37:44
Only that I think you should, because your parents study marine biology, and that would be a fun crossover.
Unknown Speaker 37:50
That would be a cool question. I
Alex 37:52
it's one of the rarest things that I come across people studying, and we have one person come on the podcast to talk about marine fungi, and it blew my mind, and it left me having this feeling that, yeah, more people should definitely go into it. And then I also just brought on someone from Japan. I'm gonna butcher his name, so apologies, but I think it's Kai hiroma, if I'm pronouncing that correctly. But he was studying root molds that were parasitic to plants and doing genetic engineering to turn them from a parasite into a symbiont, wow, and turn them from actually damaging the plant into being beneficial to the plant, and I thought that was really cool. And I'll connect you to after this podcast, because I think it would be a really cool potential collaboration, or at least information exchange. You know, get the mycorrhizal roots connected between you two. Sounds unreal.
Unknown Speaker 38:57
That's so cool. Thank you. Those
Alex 38:58
were little SCI tangent, but in your study, you said you looked at the leaves that were sprayed with the double stranded RNA spray and saw inhibited germination and stunted germ tube development and germinated spores. I know we just talked about how the spray was obviously changing the biology of the fungus, but is it changing the biology of the plant at all? Like, is it helping boost the defenses, or is it just focusing on the rust fungi?
Speaker 1 39:34
Yeah. So of course, we don't always know everything that's going on, but from what we do know in this part of the system, and part of the system is just, you know, the pathogen interacting with the plant. So in this system, the double stranded RNA is not doing anything in the plant. So, like, yeah, we spray it onto the surface of the leaf, and it basically just sits on the surface of the leaf until the fungal spores start germinating. And then. We know that it's taken up into the germinating spores, and that's where everything kind of happens. There are some pada systems where the plant will take up the double stranded RNA, and it's like pre processed in the plant, and then it's trafficked in a different form, in little packaged into little vesicles into the fungus. So in in the case of metacie, it's like very hard to get double stranded RNA into the plant, because they have this really thick, waxy cuticle. But it's different in every system. Yeah,
Alex 40:33
Hmm, interesting. Yeah, that. That's cool, that the plant would uptake it and kind of deliver it as needed. That's really awesome. I still can't get over this concept. I'm gonna tell so many people about this episode. Like, you know what I just learned this? Yeah, every once in a while, get an episode that I'm like, What the hell that's crazy. That's so cool. Like, I can't I love the feeling of being humbled, of like, looking around and even this computer screen, I'm like, How the hell did humans come up with this and then this research? I'm like, how who came up with this? Like, this is, this is so wild. How smart humans can be. Some types, sometimes we're pretty Yes, dumb. But this, this, I congratulate you for doing research on this is awesome.
Speaker 1 41:21
Yeah, it's a when I when I first learned about it, this whole kind of pathway in this whole concept, I was also totally dumbfounded. Like the fact that this pathway exists in almost all living things is just unreal. And of course, it would exist in most living things because it's such a cool pathway. So of course, like in terms, in an evolutionary sense, we would have held on to it, like, it's pretty awesome. Yeah.
Alex 41:46
So do you just need to spray this once, or do you need to come back every three months? Or what? How often does one need to spray and then what? Ideally, I'm guessing this is just in I don't know if this has been done kind of on a mass scale ever, but are they spraying this from like an airplane? Are they going around with like a backpack sprayer and spraying each plant or, yeah,
Speaker 1 42:15
yeah. So, because it's not actually doing any gene editing or genetic modification. It's not considered GM at all, because it doesn't actually change the biology of the fungus. It's just a transient, like a temporary silencing kind of thing. So it's not a once once off treatment, you would need to do multiple sprays, like you would with a typical fungicide. So we've shown that you can spray it both preventatively and curatively. So we sprayed it onto infected plants that were had already been experiencing like a severe infection, and they actually recovered really, really beautifully. So you can apply it at different points in the infection cycle. But the problem with double stranded RNA, so single stranded RNA is, like, super unstable. I mean, it's everywhere, all around us, but it's just, like, degrades, like, basically instantly. Double stranded RNA is a little bit more stable, just cuts in that double stranded form. But if it's, you know, sitting on the leaf surface, it will be degraded by rain and UV and enzymes on the leaf surface. So it only lasts about 10 days on the leaf surface. But the cool thing is that there are lots of people working on like carriers for this double stranded RNA that improve its stability for much longer periods of time. Um, so the one that my lab group is working on, which was, uh, kind of CO developed by one of my supervisors, is called Bio clay. And basically you complex a double stranded RNA with literally, like a clay molecule, um, and it's like, there's nothing weird or scary about it. It's literally just clay, and it naturally just binds because it's positive and negatively charged. And you spray that onto the leaf surface, and it kind of promotes this slow release of the double stranded RNA, and it also improves its stability. So yeah, the idea would be that once we can optimize all these things. We can get it to like, a point where you're just needing to spray, yeah, maybe every few months or so. It would be something similar to a fungicide. At the moment, I think it's at about like 40 days or something, that they can get this, this stability of the double stranded RNA with the clay. But we're just only starting these trials with the metal rust. So they've done this in other patho systems and in some other patho systems, like with viruses, they have much larger scale field trials, but at least in my group, nothing on the mass scale yet. But there was just the first double stranded RNA. A based treatment was actually registered in the United States for Colorado potato beetle, so that has been through all the large scale trials and will soon be actually beetle. Yeah,
Alex 45:14
yeah. Well, used for animals. Well, this conspiracy theory is growing bit by bit.
Unknown Speaker 45:25
It's a pest beetle.
Alex 45:26
It's still an animal. It's still an animal.
Unknown Speaker 45:29
It is very small.
Alex 45:31
It is small. It's very small. But, yeah, you know, wow, I gonna have some wild dreams tonight, I'll tell
Unknown Speaker 45:41
you. Yeah, no, fair enough.
Alex 45:41
I know that's a huge problem in Colorado. So that's, that's great, yeah,
Speaker 1 45:46
yeah, no, it's really, it's really cool. And the that whole pipeline took, I think it was 11 years, so it's significantly faster than, and that was from like conception of the idea to like registered. So yeah, significantly faster than, like, a typical insecticide or fungicide. Yeah, cool.
Alex 46:07
And, you know, I asked this to everyone that that comes on the show, but I'm curious, what would you say is the hardest part of your research, and it could be like, one day, you know, where all your files got deleted, and you're like, you know, I gotta restart everything and or it could be just kind of like a daily thing, you know, like, I like, I hate using that piece of equipment, and it's like, so hard, or whatever. But yeah, what would you say is the hardest
Speaker 1 46:39
part? Yeah, so I it's an interesting question, I think, because I really, really like what I do, and I find the day to day pretty fun. So I think my hardest part is much more like larger scale. But I think the hardest part is that metal rust is predominantly an environment pathogen, not an agricultural one, and most of the funding in plant pathology and plant biosecurity is directed to agricultural pests and pathogens. So it can be really difficult to kind of get that funding that we need when you can't easily point to, like, a tangible financial loss in industry, and like, on an even more big picture scale, plant pathology is a really relatively small field, like, you know, relative to something like medical research, and it can be really difficult to, like, actually get your research out there. Like, our reach is just a lot smaller, and the journals we publish in don't have the same impact as those in kind of medical research or similar. So, of course, like medical research and agricultural research is, like crucial. It's obviously so important. But I think the thing that I find really hard is that if our ecosystems all collapse, we're kind of screwed anyway. So I feel like we should be prioritizing that a bit more too, but that's not often a shared sentiment, yeah.
Alex 48:03
And unfortunately, I feel like, for most people in power, you could say that they're like, Oh, we already have a we already have a fungicide, you know, like, we already have a solution. And, yeah, I've had a lot of conversations, like, especially revolving around micro remediation of so many companies are not incentivized for environmental cleanup, or, like, the negative effects of their products on the environment. There's no penalty, there's no tax. And if they're brought to court, a lot of times, they just get away with it, or pay, like a very, very small fee. And so a lot of times these, like really toxic, quote, unquote solutions, are picked because they're cheaper, they're easier, XYZ. And a lot of these environmental, we more friendly solutions that are great, they're just, yeah, unfortunately, not picked a lot of times, which can make it really hard, like as a human with a heart and soul that cares about the environment, you know, yeah, yeah. But so I also asked this question all the time, if you had unlimited funds, and people were totally psyched about this and just gave you a blank check, and you had the biggest team ever, of all the experts in the world, all the best equipment, all the large scale microbial, you know, pipeline production, pipelines, any resources you need. What would you do and why?
Speaker 1 49:35
Yeah, it's also a tricky question, because it's actually impossible to imagine. But I think, and I often say this, like when I give talks at conferences and stuff, but what I would really love to see is, like an integration of all the work that's being done to manage Myrtle rust. So we have, like so many amazing researchers in Australia and also internationally, who are kind of coming out this problem from. Every angle. So there's like work involving tissue culture, germpus and collection, indigenous management, on country, cryopreservation, seed banking, double stranded RNA resistance, Gene analysis, like so many different things, that's really just a few. And I think what we're really missing is, like this large scale, long term project that can integrate all of these approaches and actually follow them through to implementation. I think, like we often get insights like quite buried into what we're doing that we like, forget to look around us. And I'm definitely 100% to blame for doing this too. But yeah, I think if we were to kind of work across those like traditional confines of a field, and have more collaboration and investment in that collaboration for a really long term project, I think that's where we could really actually solve a problem like this? Yeah, so that would be amazing. Besides, to dream
Alex 51:07
you say you love your day to day, which is awesome to hear. What would you say is your favorite part of doing this work, like, what gets you out of the bed in the morning? And you're like, so I get to do this thing. Or, on the flip side, if you have, like, one moment where maybe you won an award, or, like, you figured out this crazy thing, or, you know, it could be like one day, or on the day to day, however you want to answer.
Speaker 1 51:33
So I think, like one day that I really loved, just in terms of like, like feeling like a scientist was I just, like, had this cool idea one day, and it was just like a hypothesis for, like, why double stranded RNA is so effective in this system. And I won't go into it because spit, you know, takes a while to explain. But for me, it was like such a cool moment, because I really felt like a scientist who, like, have their own ideas and everything, but yeah, in terms of, like, what gets me out of bed, I think I just, I yeah, that kind of subtropical rainforest that surrounds Brisbane, Where I live, is, is a super special place. It's like, such a biodiversity rich environment. And, yeah, it's, it's very special. And it feels rewarding to be kind of doing, doing my bit in protecting it, hopefully doing some good. I think, yeah, I
Alex 52:37
had no idea you had rainforest in Australia. Yeah,
Speaker 1 52:40
we have so much rainforest. So you have tropical rainforest up up north, some of the oldest rainforest in the world, actually. And then we have subtropical rainforest down here in Brisbane, and it's actually, like, heaps of it. Yeah, it's some really high rainfall areas. And, yeah,
Alex 52:58
it's incredible. Yeah, just google image. Yeah, this is beautiful. I I'm dying to go. I've been to Australia and New Zealand when I was a little little kid, and I loved it, but we mostly stayed by the beach in Australia, yeah, learned how to surf there, which is awesome, but cool, yeah, wow. This is gorgeous,
Speaker 1 53:18
like the Daintree Rainforest, yeah, is, is one of the oldest rainforests. I don't, I don't know exactly how old, but it's, like, like, totally ancient. And it's, um, what is this? Just amazing
Alex 53:32
with this horn, the horn on his head. I just looked up Daintree Rainforest, and there's, like, all these. It looks massive with like a blue neck, and like a big horn on his head. It looks like a dinosaur. Wait, I want to see a name for it. This is wild.
Unknown Speaker 53:51
There are some crazy creatures around
Alex 53:53
here, cassowary. Oh, cassowary.
Unknown Speaker 53:56
Oh, yeah. Cassowaries are, yeah, crazy. I've never
Alex 53:59
seen one before. This is people should Google that. If you're listening to this, this is a wild animal. This looks huge.
Speaker 1 54:06
They're huge. They're they're really, like, they're bigger than most people. And they're, you have, like, they're a bit scary.
Alex 54:12
Oh, my God, it's the size of a person. Oh, my God, this is massive. Whoa. If I saw a picture of this, like, not in this setting, I would have assumed this was a dinosaur, like, generated picture, like AI, like dinosaur image of it, bird, yeah, they're cool. Pretty crazy, yeah. Well, that's awesome. Well, Australia has the craziest species of everything. Was it the most poisonous species per square foot on the planet? I don't know everything is going to kill you in Australia. No, no, no.
Speaker 1 54:45
About America. It's really funny. I have this conversation with my friends a lot, but we all feel that way about America. Where, like, just for America, yeah? Humans kill a lot of people in America. Yeah, yeah. We're all very scared of bears too. Like bears sound terrifying. Um,
Alex 55:00
polar bears will, yeah, polar black polar bears and grizzlies. Black bears are fine. They're Yes, okay, okay, yeah, they're more scared of you, like grizzly bears the step up. They'll definitely kill you. And then polar bears will, like, hunt you. Like, they'll, they'll, like, keep going after Yeah, they're very, very scary. But you get, I think I saw this video that was like, oh, there's, there's only, I'm just making up the numbers. Like, there's 20 poisonous snakes that will kill you, or venomous snakes that will kill you, and like 16 of them are in Australia, or something like that. Like, it was a crazy statistic that,
Speaker 1 55:40
yeah, no, there are. I would be surprised if we only had 16 I, yeah, I It's really funny. Like, as a kid, you're like, taught like, what to do if you get a venomous snake bite, like, so everyone knows like, exactly what to do. Yeah, what do you what do you do? You basically, like, have to stay really still. Yeah, get, like, a tourniquet. Stay really still, turning it around, like the area that got bit in, so that it doesn't travel up to your heart. And then you have to try and kind of slow down your heart rate so not be stressed. You have to try and call for help without moving. So, like, obviously, if you have a phone that's best, or, like, scream is good, but just don't run somewhere. And then you really just have to kind of sit and wait and stay as still as possible and keep that area that's been bitten like as far away from your heart as possible. Wow. So the venom doesn't get too hot, but even with like, a brown snake, which is one of the most venomous, I think you have like, four hours, so plenty of time. Yes, you're sweet. Yeah, sweet. Make
Alex 56:43
some memories. And yeah, you got four hours. You're good.
Unknown Speaker 56:46
But like, if you get to a hospital within four hours, you'll then you're good, yeah, they
Alex 56:50
have probably, yeah, probably you have a good you have better chance. Yeah, yes, yeah. Remember where I was travel is somewhere in the Amazon, I'm guessing Peru, but I was with someone who was telling me a story about it was either them, it was many years ago, but it was either them or a family member or someone in their community. They were on a boat with their their son, and their son, like, picks up a venomous snake that was super deadly, my gosh. And they were way out there, like, super far out there. And I think they said it would probably take them like, eight hours to get to a hospital to do something, yeah, and it was one of those snakes that it was like, it will kill you in four so the son got bit on his hand, and the dad processed it in like a split second and took his machete and cut off his son's hand. Because he's like, I either you lose your hand or you'll die, like, there's no way I can get you to a hospital. And that was just like, the craziest story of, like, That's so crazy, and he knew to do it. Like he knew, like he premeditated that. Like, if, if that happens, like you either amputate or you're dead, yeah, because there's no way we get to a hospital. Crazy it might go live in a place where that is, like a worry, or something that you have to think about and do anyways, we're not going on like a crazy tangent right now for going back to rust fungi. Yeah, I am curious. So people who like are psyched about this, this episode, maybe don't know much about rust fungi like myself. Do you have any good resources where people can learn? Maybe good books, videos, online courses, things like that. Yeah.
Speaker 1 58:43
So if you don't mind a bit of reading one of my supervisors, his name is Alistair McTaggart. He actually has a really great blog called spores for all, and His current research actually focuses on magic mushroom. So he's kind of changed fields a bit, but he's also a rust fungi expert, so there's a lot of stuff on there about rust fungi, and he just has a really fun way of writing, so it's really enjoyable to read. And in terms of, like, more video stuff, if you're this is more specific to Myrtle rust, because that's kind of what I know the resources for. But so landcare research, New Zealand has this really amazing webinar series called Beyond Middle West. And every month they have like, a different speaker, and it's all on YouTube, or you can, like, sign up and watch it live as well. And then my, my top recommendation would be these two films that have been made by various groups in Australia. So the first one is called Myrtle rust, the silent killer. They're short films, very short. You're not signing up for like a two hour movie, don't worry. And that one is made in collaboration with the Queensland Government and the Australian network of plant conservation and the. Chiller Aboriginal Corporation, and the second is called Roots of resilience, which is made with the Australian Government and First Nations communities in Australia and New Zealand and also the Queensland and New South Wales Government. So those two short films are like, Yeah, I just think they're so well done. They really kind of encapsulate what the impacts of Myrtle rust are on the environment and what that means for First Nations peoples in Australia, and just our, yeah, our general kind of way of living in Australia too. So those are really beautiful, and I would really recommend to them.
Alex 1:00:40
Love it. Thank you. And where can people follow your work? So
Speaker 1 1:00:45
I'm, I'm not the best poster.
Alex 1:00:51
You just, yeah, it's great.
Speaker 1 1:00:54
But yeah, I'm on LinkedIn. Just my name Rebecca Degnan, or I also have a Twitter X account at Beck underscore Degnan, yes, and I'm I'm really not best when I try. So yes, you're welcome to follow me on there. Love
Alex 1:01:11
it. Well, it's been such a pleasure. You absolutely blew my mind. And I know you have a meeting right now that I'm making you late for with all my yapping about prehistoric birds and conspiracy theories and venomous snakes and all this stuff, but thank you so much for coming on. It's been awesome and great work. This is world changing, and I think it's such fascinating stuff. So thank you so much.
Speaker 1 1:01:37
Thanks so much for having me. It's been so much fun. Yeah, likewise.
Alex 1:01:41
And thank you for everyone for tuning in and shrooming in for another episode wherever in the world that you are tuning in from, we could not do this without you. So thank you so much. If you want to support the show, leaving a review goes a really long way. If you want to help out financially or monetarily. We don't have a Patreon or any way that you can donate directly. But we do have a mother brand called mushroom revival, where you have a whole line of organic functional mushroom products, from gummies to tinctures, capsules, powders, all super delicious, all organic, all really high quality, with QR codes, with lab results fully transparent. We have a special discount code for listeners, and that is pod treat. And plug it in. We change it all the time, so you get a surprise discount if you don't want to spend any money. We have a giveaway going on, and we pick a winner once a month to win some goodies. And we also have a bunch of free products or free resources on the website as well. We have some free ebooks that you can download. We have a whole blog that we write a bunch of blogs about all different things about mushrooms and fungi, from ecology to magic mushrooms to cooking with mushrooms, you name it. And also, you can get my newest book, The Little Book of mushrooms on there, as well as pretty much any bookstore in the US that you go to. And thank you as well. And you know, in line with this podcast, we want to connect people with the power of mushrooms. And so please spread the word if you if you found a fun fact in this episode, please tell your friends, tell your family, tell the random person at the grocery store, and keep getting people inspired and excited about mushrooms. And as always, mush, love and may the spores be with you. You
Transcribed by https://otter.ai
