Talking Biotech 049 -- Watermelon Domestication and Breeding

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Now here's your host, Hi everybody, and welcome to the Talking Biotech podcast, this weekly podcast where we discuss the science and technology around genetic engineering and its associated disciplines, but we also throw in a healthy dose of plant domestication and other talk about the current state of science with respect to crops. And our idea is to allay a lot of the conjured-up fears about science and About farming and about how agriculture is still a wonderful industry in this country that does a lot of wonderful things. And we really do need to celebrate the best, safest food supply in human history. And that's what we try to do here, is to provide information that helps us all be better communicators about what this technology is and what this technology isn't, and understand how to speak about it realistically so that we all can maybe get good agricultural innovation into application as fast as we can. So today's guest is not about genetic engineering at all. It's about watermelons and watermelons and their traditional breeding, their domestication, natural origin, maybe some funny uses and ideas about where this crop came from and why people chose to domesticate it in the first place. We'll talk to Dr. Cecilia McGregor, and she comes to us from University of Georgia where she breeds watermelons. And her work has been well recognized and kind of a leader in the integration of genomics tools into solving questions inside the watermelon crop. So here we go with our interview with Dr. Cecilia McGregor.

Today on Talking Biotech, we think about fruits and a very popular fruit that everybody seems to like, yet nobody really knows much about its history or about its genetics. genetic improvement. It's not a real popular topic, and maybe we can change that. So we go today to Athens, not Greece, but Georgia, and University of Georgia to talk to Associate Professor Cecilia McGregor. Welcome to the podcast, Dr. McGregor.

Hi, thank you.

So let's, um, so your program deals with watermelons and genetic improvement of watermelons and And really just kind of breeding for today's breeders or for today's growers. So, but let's turn back the page a little bit. Where did this thing come from? Where did it originate?

Yes, that's a kind of a thorny issue because there's different schools of thought at the moment. So for a very long time, we knew that watermelon was generally from Africa, but where exactly in Africa It's been a long and winding road. For a long time, we thought that it was from Southern Africa, then more Northern Africa. The latest information is based on some genomic data, but also some archaeological data. Currently, the thought is that it's either from Western Africa or maybe Eastern Africa. So we've gone through quite a few iterations. The thing is, we don't— at the moment, we still don't really know for sure where The sweet, like dessert type watermelon we eat are from.

Okay, and could it be possible that there were multiple centers of origin based upon where people were population centers identified a common need and a common basal species that's there in the wild that maybe this thing was domesticated in different places for the same reason?

It's possible. However, watermelon, it has an extremely narrow genetic base. And I know everybody in breeding always says, oh, my crop has a very narrow genetic base. It's something we're all very proud of, it seems.

For sure.

But actually, from genomic data, we know that watermelon has an even narrower genetic base than something like maize or corn or soybean or rice. So Whether there's several places where it was domesticated is very unclear at the moment.

Okay, and just for the listener, when we talk about a narrow genetic base, what we're saying is, is that there's not a lot of variability that's happening inside the modern domesticated varieties, that we think that these came from a very narrow number, a very limited number of ancestral selections that have contributed to the modern germplasm. Is that the best way to say that?

Yes, you know, when we look at watermelon, we think, oh, look at all this variation, these striped ones and solid color and red, you know, for the rind color. And when we look at the flesh, oh, there's red flesh and orange flesh, and it looks like, oh, look at all this variation. But those kind of traits are controlled by a few genes, so it doesn't really give us a good overview of the overall amount of genetic variation that we see.

Yes, and we'll come back to that in a little bit because I think that's a really interesting aspect of watermelons that we don't really appreciate. But let's talk a little bit about its, its venture, its journey from Africa to where we see it today. There's a lot of artwork if you go back into antiquity and you look at pictures where people frequently would have a fruit plate or some fruit in the picture. Sometimes you see something on there that looks kind of like watermelon. And did this move through Europe, or how did it get to where we see it today?

Yes, so we know that watermelon was in Egypt thousands of years ago. There's actually watermelon seed, 5 total watermelon seeds that was found in Tutankhamun's grave. So we know it moves through Egypt, and then Once again, we're not 100% sure. Either it went directly to Europe from there, or maybe it went first to Asia and then came to Europe. So it's a little bit unclear, but we know that a lot of watermelon was grown by the 1500s in Europe, and especially in Spain, which, you know, watermelon likes warm weather. So in those regions that had warm weather, we see a lot of paintings and artwork of watermelon. It's not quite clear from that artwork always which species it is and which type it is, but it looks somewhat like the watermelon we recognize today.

And maybe that's a good next question is, you know, what is this thing that we're calling a watermelon? Is it really a combination of different melon types that all have similar characteristics, or is it really just one Well, yes, that once again, that's a little bit convoluted at the moment.

What do we call species in watermelon? Just last year there was basically a reclassification of how we think of the species in watermelon. Most of what we eat is one species, although if we look at some of the watermelon that are eaten in some other parts of the world, like in Africa, By the new classification, there are some other species that are eaten there, but what we think of in the United States or in Europe as what we are eating, it's one species currently called Citrillus lennatus.

Citrillus lennatus, that's the one that we're consuming?

Yes, by the new classification, I should say. If you read some of the scientific literature, it's called all kinds of different things, but I All kinds of different species names, or— but that's, I think, what we settled on now.

Yeah, I noticed that in preparation for today is that it doesn't seem like scientists are in consensus about what this thing is or how to call it. And, you know, maybe that's a job for genomics tools going forward. But one other really interesting thing that I didn't realize, and I kind of heard from one of your former students who we hired, Recently. And the question is, is that, you know, I always thought watermelon, this is this, you know, red, fleshy, wonderful fruit that we eat. But it turns out that in many parts of the world or many areas, they use this for not so much the flesh but for the seeds. Could you tell us more about that?

Yes, the consumption of watermelon seed is actually very popular. So, what we mainly think of normally is something called igusi seed. Now, once again, if you look at the literature, oftentimes it doesn't include just watermelon seed, but generally it refers to a certain species of watermelon, a different species from the one that we eat for the red dessert flesh. And yes, it has kind of a fleshy pericarp or outside. The seed looks a little bit different. It looks nearly more like a pumpkin seed than a watermelon seed. And the watermelons, they are grown, it's mainly in West Africa, just for seed. The flesh is not really edible. It's like a white hard flesh. After the seed is harvested, they might feed the flesh for animal feed, but it's not for human consumption generally. And the seeds are harvested all by hand normally and then dried out outside and then Sometimes just the seed is cracked open and the kernel inside is eaten, or it can be ground into a kind of flour that is often used, you know, in porridges and stews. It's very high in protein and high oil content. But, you know, it's not just in West Africa where seeds are eaten. In countries like China and India, a huge amount of watermelon seeds A lot of watermelons are grown for seed consumption. It's not this Igusi type, it's kind of the more red flesh type, the dessert type, but they're grown for seed. To give you an idea, China grows more watermelon just for seed than the entire US watermelon production. So it's a big business, it's a big part of watermelon production is actually seed production.

Yeah, that's pretty interesting. And the other thought about that is I know that I was just kind of looking through some papers. There was something called an iguicy trait. And what is that?

Yes, it's a seed trait. It's this kind of nearly pumpkin-type seed trait. Genetically, it's pretty interesting because it has kind of a fleshy pericarp on the outside of the seed. When you harvest it, it looks like kind of a gelatinous material that sticks to the seed when you harvest it. And once the seed is dried, it basically looks like a pumpkin seed. Those seeds are very high in oil content and very high in protein. And so in West Africa, those type of seeds are very popular for eating.

So we talk about the dessert watermelon, this thing that we all enjoy, and then we talk about the use of seeds in the diet. What are some other uses for watermelons that you've seen throughout the world?

Yeah, so I'm originally from South Africa, and a lot of the watermelons that grow there grow in semi-desert areas all the way up to Namibia, Botswana, where we have the Kalahari Desert. And in that region, traditionally, the San people, the hunter-gatherers in that region, they used watermelon as a source of water to cross the desert. So it's this what we call the citron-type watermelon. They're not sweet. They're kind of small and hard. However, what they do is they collect the fruit, cut off the top of it, and then just kind of mush it up with a stick or something, and that is a huge source of water to carry across. It's easy to carry across the desert as a water source. And it's not just for humans, it's also for animals. Where I come from, you see watermelons eaten all the time. Especially by porcupines. Apparently porcupines really, really like watermelon.

I've seen pictures where, or video, where they're throwing watermelons into the mouths of hippopotamuses. Whole watermelons and they just crush them like they're popcorn. When did watermelons really first show up in the United States or in North America?

So watermelons, they came with the Spanish but also with the slave trade because of course in West Africa a lot of watermelon was already grown. The first documentation was probably in, I think, like 1576. So they've been around for a long time. Apparently Thomas Jefferson was a big lover of watermelon.

Well, that's pretty cool. And what about, so in terms of breeding and modern breeding, what have breeders really been focusing on in terms of traits? I mean, I guess we could look at what's in the store and get that answer, But are there specific traits that modern breeders are really trying to pursue?

Yes, so watermelon, it really depends on which countries you are talking about. Here in the United States, the biggest invention in watermelon breeding really has been the seedless watermelon over the last 20 years or so. Seedless watermelon is not consumed so much in other countries, but in the US that was a a very big breakthrough. It actually complicates breeding quite a bit to breed for seedless watermelon, and it really changed how we have to do production for seedless watermelon.

And maybe we could talk a little bit about that, because people automatically assume, well, seedless watermelon must be a GMO, this must be something dangerous, but it really is a much more elegant solution. Would you want to try to break that down for us a little bit, like exactly how they come up with this seedless watermelon type?

Yes, so basically what we do is we double the chromosome number of regular watermelon, and then we cross that doubled watermelon with the regular watermelon. Basically what happens is you have an uneven chromosome number, and those watermelons that the growers grow, they have this uneven chromosome number. They have 3 of each chromosome. And it means that they don't produce seed. They still need pollination, and that's where the big change for the growers comes in, because they still have to grow some regular seeded watermelons as a pollen source. But basically it's that uneven chromosome number that leads to the seed basically aborting, and so you don't have any seed in your fruit. You can sometimes still see the seed coats, those little white things.

Sure, sure.

But yeah, that's basically how it's done. It's actually quite laborious. What I explained now takes 10, 15 years.

And I can see why that makes the breeding a challenge, because you're breeding a female and a male parent essentially that each have specific traits that upon combination are beneficial. But you're also— when we talk about this on the podcast now and then, is this idea of polyploidy, that as a breeder or as someone in genetic improvement, you can take a diploid organism, so one set of chromosomes from mom, one set from dad, and you can use certain chemicals that cause this to double. And that's a kind of a long process we can talk about another time, but that would give you maybe the mother, the female parent of the watermelon.

Mm-hmm.

And now you use maybe a diploid male, or, you know, here you got a female with 4 sets of chromosomes, a male with 2 sets of chromosomes, and upon pollination, the next generation will have 3 chromosomes of each chromosome. That makes it, in some species, a block, that that embryo is not viable and can't develop, so the seed doesn't develop. Is that pretty much— did I encapsulate that correctly?

Yes, that's Yes, that's pretty much exactly what happens. One of the biggest problems we run into is that the female has to be the tetraploid, the one with the double chromosome number, and those plants normally have very low fertility. So you don't get a lot of seed from an individual female plant, which makes the seed for these seedless watermelons more expensive to produce. And it really complicates breeding because you have to have basically 2 2 separate breeding programs, one for the diploid and one for the tetraploid.

Oh, I see. That's really interesting. So the other side of that coin too is that you have— these are inbred lines, like the females are inbred and the males are inbred, and— or you're— how— what's the genetic composition of the parent plants?

Yes, they are. They're both inbred lines. So it's an F1 hybrid, just like you would think about a traditional F1 hybrid. The problem is, it's a little bit like tissue culture. Certain cultivars are much easier to double the chromosome numbers, or certain genotypes are much easier to double the chromosome numbers than others. And so, as it always works out in science, the ones you want in the end is not the ones that are easy to do.

Yes, that's right. It's always the good ones you want that are the difficult ones. That's, that's, yeah, that's— well, what about other traits though? I mean, it seems that we are in a time when we're seeing 2 things happening in fruits and vegetables. One is that people want improvements in what they already know, so maybe a seedless, you know, red flesh dessert watermelon. But we also see these kind of niches opening for something new and unusual, especially with respect to sensory qualities like flavors or colors? And what kind of options are being pursued by watermelon breeders currently to fill those niches?

Yes, so of course we are all used to the red-fleshed watermelon, and now and then in the stores you see yellow-fleshed watermelon, but you can have white flesh, orange flesh. So that's definitely something, especially for the smaller growers, farmers markets, they really like, you know, the new and different colors. Also the same with rind patterns. A very well-known watermelon cultivar or heirloom watermelon cultivar is Moon and Stars. It has these spots on the rind. And so those type of interesting rind patterns, especially for like farmers markets, are very important. If you look in the store now, You know, all the watermelons kind of look very similar. They're kind of the same size. Where we used to get very large, picnic-sized watermelons, now they've become smaller, more for, you know, maybe 2 or 3 people rather than very large families. So all those kind of traits. We also have the very small watermelons now, which is more what is called personal size. So all of those type of traits are important for consumers, and there are breeding efforts for most of those traits.

Yeah, I know that here at University of Florida, we've traditionally had some sort of a melon breeding program that, or, you know, at least something in cucurbits or something, and that was always traditionally something happening here in the state. Probably in the 1990s, '90s or so that, that ended or slowed down. And we had a tremendous germplasm here at base, like lots of different varieties and interesting old stuff. And 2 big— or was something like 54 boxes of varieties of seeds. And that probably most of them were not viable by the last couple of years. And eventually we lost the whole collection.

Oh no. Yeah, I was just gonna ask you to ship those boxes to me.

You know, it would have been a cool move. Because there was stuff in there that I wanted to trial with organic growers and others locally who might be able to find something interesting that would work well in that production system. Maybe not suitable for, for, you know, major cultivation, but certainly maybe a small niche crop with some cool colors and patterns and maybe some funny resistance to nematodes or insects could have been a real score for local small growers. And I was really disappointed to lose that because I thought, oh, we got something cool here. But so it is. But what do you— what's happening? I know that you work with more genomics and kind of the molecular breeding side of things. What kind of work are you doing and what are some of the traits that you're chasing with genomics tools?

Yes, it was really interesting. You know, when I first started working at the University of Georgia, I wasn't really tied to a specific crop, and I kind of could decide which crop I wanted to work on. And I chose watermelon, well, I'm from Southern Africa, and actually the wild watermelons grow on the— where I grew up. But also, it has a relatively small genome, and at that stage, not a lot has been done. So when I started, we didn't have a genome sequence, really no QTL has been mapped, even though it's a diploid small genome. known crop. So we started with a lot of the, what you would think, basic traits like fruit shape and size, those kind of, you know, what I would call relatively easy traits, and seed traits. Like, for instance, the Igusi locus, we talked about the Igusi trait, so we mapped that Igusi seed trait. So as we've moved forward, now we work more on disease resistance. We still work on a lot of the other traits, but disease resistance is really important, especially in Georgia with the high humidity. Fungal diseases like gummy stem blight and also Fusarium are big problems. So we've kind of moved, although we still do some of the fruit traits, we do a lot of the disease resistance traits.

Yeah, that would seem to be a good move because if you can limit the inputs for watermelon farmers, you make it more attractive.

Yes, and certain diseases like Fusarium wilt, farmers used to use methyl bromide as a fumigant. However, that's been phased out now because of the environmental concerns, and so they really don't have an option, you know, much option for anything to use for Fusarium wilt. So that's definitely a big challenge now.

Okay.

And is gummy stem blight, is that Botrytis ferrea?

It used to be Didymella. It's been reclassified now as some word I cannot even pronounce.

Okay, well.

Yeah, so it turned out to be 3 different species now instead of what we thought of was one species. So over the last few years that has also become a lot more complicated than what we originally thought.

I see.

So just for the listener, you know, methyl bromide was this stuff that we used to use as a soil fumigant. You could actually sterilize the soil with this chemical and it worked great. It killed weed seeds, killed fungus, killed bacteria, killed nematodes, and your plants can move into a clean environment with very little challenge from pests and pathogens. and competition. The big problem is, is that it ate a hole in the ozone, and since 2003 that's been phased out and almost not available anywhere now, at least in the States. So we've had to resort to more genome— genetic-based strategies to confer resistance. Since you can't use chemicals, use the plant's own immune system to be able to fight back. And this is where efforts like Dr. McGregor's with genomics have accelerated those opportunities. So just to fill in the listener on that, where do you see the future of watermelon breeding going next?

Well, so at least in the US, there's been a big move toward fresh-cut fruit. So instead of buying a whole watermelon, the consumer buys fruit that has already been cut. And so flesh firmness, for instance, to make the flesh firmer, there's been a lot of effort into that, and we're seeing big improvements in that kind of post-harvest preservation of watermelon so that it looks more attractive to the consumer after it's been cut. So that's a big move, I think, as people want more convenient fruit and vegetables.

Yeah, that's a really important consideration because— and again, for the listener, when we're cutting fruits and vegetables, we are damaging the item. And so different fruits and vegetables perform differently after you harm them with respect to issues like water-soaked lesions and things like we see in watermelon where it gets kind of weird and wet. And to be able to find cultivars or varieties that can withstand withstand that injury and don't show those kinds of post-harvest decay traits is a really big step forward. And exciting to hear that that's where that's going next. So in conclusion, you know, watermelons, I think about, I associate with things like picnics or parties or whatever. What are some of the cool things you can do with a watermelon?

Yeah, so the great thing about working with watermelon, it's basically Endless amusement. You just have to look at the internet and see what you can do with watermelon. Anything from watermelon seed spitting contests to, you know, growing the biggest watermelon, which is actually something like 350 pounds, I think is the record for the biggest watermelon. Carving watermelons is very, very popular, and you can make Really interesting carvings. And my favorite is what we call watermelon roulette, which is where you put rubber bands across a watermelon until it explodes. And basically the person that puts the last rubber band on gets totally drenched in watermelon juice. I wouldn't advise you to do that inside. Better outside, maybe where you can jump in the pool afterwards and wear safety Glasses.

You guys in Georgia know how to have a good time. Well, that's, that's all really good. I, I always liked watermelons. Like, I've seen people do the thing where they punch a hole in and stick a bottle of vodka in it and, you know, turn the whole watermelon into trouble.

Yeah, yeah, to me that is ruining both the vodka and the watermelon.

Yeah, it is one of those things where 1 plus 1 equals, you know, 0.5.

I know, yeah, very good.

It's those things, some things are best left separate. Well, I really appreciate you taking the time with us today. I know I'll never look at a watermelon the same way again going forward. Thank you for joining us and best wishes in all your work, and we'll watch for your products.

Yeah, thanks a lot. Thanks for having me.

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And the thorn in the side of agriculture misinformation. Now back to the Talking Biotech podcast, already in progress.

Hey, thanks, Vern, really appreciate you chiming in for us today. I wanted to, uh, last night I was working on the podcast and assembling the discussion with Dr. MacGregor, and at the same time I didn't realize that I had a little time to kill here, a little extra time to do something else with the podcast. So I decided I would solicit questions via the web and said, you know, send me your questions, send me, and I'll try to answer them. Figure get 5 more minutes on the podcast, that would be good. And however, I got a lot of questions. So be careful of what you wish for, or to do it in In Vern Blazek's voice, be careful of what you wish for. I don't do a great impression of the guy, but anyway, let's take a look at the first one. Comes to us from— and the best part, I didn't look at these ahead of time. I mean, I looked at them so that I would know they were there, but I didn't read them. So here we go. First one comes from Tom. Tom says, I'm writing regarding your call for questions. Okay, I've chosen to write this here as I want to ensure it's framed properly and Precisely as I can. To give a bit of context, I'm an agricultural engineer student in Australia, not Austria, so there's a small cultural difference between farming practice but no less misinformation and hysteria on GMOs. So do you think there is a middle ground between GMO and organic? For example, could you envision— envisage improved environmental, social, food security outcomes GMO seeds and what are termed organic farming systems. You know, I'm certainly of that thought. I mean, it makes the most sense if we're talking about what is the most sustainable approach. We want to use every tool we can. And so whether you're talking about the basic biology of organic systems in terms of, let's say, intercropping and cover crops and all the neat things that you could do. At the same time, the cultural practices you could use and the basic philosophy of use less and reuse, which was really the original idea before it became a marketing campaign, we could use transgenic crops, the best genetic tools, in the best production scenario. So for me, those things go hand in hand. I don't, I don't think that's a big issue. The other question you leave us with here are Do you think that farming in such a way would help appease some in the anti-GMO lobby's arguments? I don't think so. I think that there— a lot of this has a very religious connotation to it. It is about food. People have very strong opinions that are emotional, and you can't sway them just with facts alone. So I don't think a lot of folks will really get excited about this. Yesterday someone was trashing me for— they said, you know, what was it, that I was, you know, supporting big companies, and this is why organic growers are against transgenic technology. And I said, no, how can that be true? You know, it's— don't condemn a technology because you don't like a company. It's kind of short-sighted. And lots of people who use insulin probably think this is a pretty solid technology. And the last question he ties up with here is, do you think that it may also assist in encouraging the uptake of GMOs in developing nations? In developing nations, you know, they're going to do what they're going to do based upon their leadership, and the demands of a population are only heard as leaders begin to step up. And the B.T. Brinjal that I spoke of last week is an outstanding example of how How leadership, which the agricultural minister, her name escapes me, very strong political leader and someone who wanted to do the right thing for her people and her country's environment. Okay, so let's go over to Facebook here. You'll hear the little clicks of the mouse as I try to move this around and get this in a way I can look at it. One more, one second. This is kind of fun to do. I, you know, try to move this so I can actually see it. Okay, Andrew says, when addressing genetic engineering, is it better to use the term GE crops, GMOs, or transgenic crops? I understand that GMO is not a scientifically recognized term, yet many people use it in such daily conversation. Do you see a strong stigma behind the acronym GMO as opposed to other terms? And yes, that's absolutely true. GMO, genetically modified organism, is is a really imprecise term scientifically. And I spoke about this this week. It's not the way scientists talk. We don't say— we don't write a paper and say that the GMO plant— we say the transgenic plant, or the genetically— you know, we don't even use genetically engineered. We say transgenic. And this is really important because it is the way that we communicate this that really defines how well The technology is accepted. And to accept what really is a derogatory kind of a smear term, GMO, that's been painted very negatively, doesn't give us the proper context to communicate this effectively. And as my grad student Chris says, would you rather drive across an engineered bridge or a modified bridge? You know, so using the term genetic engineering is my preference. And really speaks to the precision, the thought, the planning, the analysis, and continued monitoring that we do when we engineer crops. The next question comes from Jeff. How much wood could a woodchuck chuck if it had access to woodchucking technology? And it's a really, really great question because many people are aware that woodchucks are chucking wood, hence the clever name, you know, they How much would they do? And they always would do more with technology because wood chucking technology today is much different than your grandfather's wood chucking technology back when. And although we've seen a lot of foreign competition in the wood chucking space, it still is important that American wood chuckers are competitive in wood chucking space. So there you go. Thank you. And Let's see, Joshua, you say, I had an interesting argument that genetic engineering isn't a plant breeding method because it doesn't involve actual, you know, breeding plant or animal sex. What would be your response? And I agree. A lot of folks have been saying this lately, that's just another breeding technique. No, plant breeding is a very specific discipline and has one major central idea, and that is that you're exchanging gametes between 2 organisms. There's, you know, a little something going on there, a little plant sex. You know, you're rubbing pistils and stigmas, you know, bumping— we in the discipline call it pistil and stigma bumping. We're— the folks who are plant breeders take this very seriously because it is an art as much, if not more, than a science. And being able to make those kinds of predictions and educated guesses and deep analysis of plants before you cross them is really important. And I don't think that it's fair to plant breeding to call genetic engineering a breeding method. It is a genetic improvement method, and I think that that's the word, the phraseology we need to adopt. And it took me a long time to stumble onto that, that these are genetic improvement methods, whether you're talking about plant breeding, mutation breeding, Polyploid induction, like in watermelons, or genetic engineering. Excuse me. You know that it's live. Okay, genetic engineering. Let's go down. I once heard that GM— about a GM cress that was being developed potentially to turn a different shade to help farmers locate landmines. Whatever happened to that? Thanks if you can answer. Yeah, sure, that's an easy one, Jessica. See what I did? Yeah, Jessica, um, they're talking about Arabidopsis thaliana, the model plant, which is also known as mouse-ear cress. And years ago, a number of scientists were playing with plants as biological sensors, and they still do. Plants have exquisite systems to sense and respond to changes in their immediate environment. So whether you're talking about light, water, or maybe some sort of a byproduct of a volatile compound emitted by explosives, plants can sense and then respond to it. And the way that they respond to it is, is we can kind of manipulate that a little bit. We can— let's say a plant senses a certain kind of molecule. It can then have a series of internal signaling steps that move from the outside of the plant cell to the nucleus and say turn on these genes in response to that molecule that I've sensed? Well, what we do in science is we can use what are called reporter genes. And so these are reporters, which mean that when we stimulate a given pathway, we see that reporter come on, and usually they're visible. And a lot of times with plants, what people will do is hook up something that is in what they call the phenylpropanoid pathway, which is a the pathway that allows us to make a series of plant products, one of which are anthocyanins, so those dark purple colors. So it would be entirely feasible to have a plant that when detecting a certain something in the, in the environment would turn dark purple. They do this already in response to UV light, which is already a downstream output of the phenylpropanoid pathway, so activation of the phenylpropanoid pathway. So there's a lot of neat things you can do to have these reporters that tell the plant— that where the plant can tell you, hey, there's something here that you need to know about. Really interesting technology. I don't know that there's been a whole lot out about that in terms of final products, but then again, I'm not really walking in landmine areas very much. Can my husband come work for you? Also, what changes What changes could we look for in GE plants on the political level if Trump or Clinton wins? Oh, great. Sure, your husband can come anytime. No problem. I mean, you know, I hope— I mean, the fact that you're trying to pass him off on me, I hope he's— I hope you like him. Yeah, well, our lab is always accepting people as volunteers and folks to do work, and I don't know that I turn away too many people. And I know I drive nuts the people in my lab because, you know, someone shows up and says, I really want to do science. And I got to say, you know, how can I turn someone away? You know, and it means a lot of work for all of us because I don't have a lot of time as an engineer— engineer— as an administrator, and as a, you know, working full-time science, full-time administration, and on the road a lot with communication and, you know, doing the podcast really takes the time. But have him contact me if he's in the area. I'd love to do that. Also, what change can we look for about GE plants on a political level if Trump or Clinton wins? I don't think you'll see any difference. I mean, it is what it is. Both candidates, just about all the candidates, no president's going to create a whole lot of change on their own, mostly because Well, don't get me started. I think that there's something that we've sorely lacked for generations in the U.S. is really strong leadership from the executive office. I think that there's a lot of folks who are good at expressing their political party's bidding, you know, doing the work of the party rather than of the people. And I think we always can do better. It would be great to have some leadership who who is able to have a put on some blinders with respect to ideology and do what's best for everybody. My whole story, I always um I always have a hard time pushing an election button. I'm always voting for the lesser of two evils, and that's not always good. Megan, I'd love to hear more about your research and how different wavelengths of light affect plant growth, volatiles, etc. Yeah, that's really cool. Well, listen next week because Because I'll talk a bit about that. It's our 50th episode and I'll interview— well, no, I won't interview me. Vern Blaszczak will be doing the podcast from Tillamook, Oregon, and I will be interviewed about some of this stuff. But in short, we use light as a regulator of growth, a non-chemical treatment that we can apply that manipulates the way a plant grows and behaves. And much like the question about the landmines, we're basically just taking a set of genetics inside that plant and expressing them in different ways based upon environmental inputs. So in other words, plants being stuck to the ground have to be able to sense the environment and respond accordingly. And in this case, we can treat the plant with blue light, or blue plus green, and blue plus green and then some red after the lights go out. Give them a little dose of red. We can give different combinations of light treatments. We call it plant whispering. That allow us to generate interesting outcomes and control things like flavor, color, shelf life. A lot of interesting stuff going on there, so we'll talk about that more soon. How can we better communicate that GMOs and GE crops are safe to science deniers? And I think, Walter, the trick on this one's easy. And I've been talking about this a lot. You will never convince these folks with facts. You have to talk to them about— hit them in the values. Get on the same page and say, are children in the developing world important to you? Are profits from farming important for you? Is care for the environment important to you? And they say, yes, yes, yes. And you say, yes, it's me too. Now that we're on that page, let me show you how the BT eggplant is changing the lives for farmers in Bangladesh. And then you refer them to Talking Biotech podcast number 48. And, and if you, um, talk to them about these kinds of— and what the buzzword is now is shared values or common concerns or areas where we all can relate— that's the inroads to start to get people to put away their, um, their kind of religious fervor about the technology, the anti-side of the technology, and connect to them about the good things we could do if we were all on the same page. What is Pineberry strawberry? All the seed catalogs claim— oh no, is the Pineberry strawberry all that the seed catalog company says it is? Yeah, and Pineberry is a white strawberry. We did a little bit I don't remember much about it, but it has a rather unique flavor profile which is very rich in what they call esters. So you have a lot of the pineapple and kind of banana smells. It's a soft berry that doesn't work well in production. It's not the most prolific plant in the world, and a good one to grow in the garden if you like some small sweet berries. Maybe there's a way we can Introduce the pineberry into regular strawberry eventually, but that's a long-term breeding opportunity. Gary— wow, there's a lot of questions. Well, we'll be back tomorrow with more questions for the podcast. What are some of the more common examples of biotech applications in both in and out of agriculture? And this is a good question because people fail to realize that Some of its most obvious and frequent applications are in medicine. Again, we talk about insulin, which since the early 1980s has provided a source of— recombinant insulin has been a source of relief from the symptoms of diabetes without having to harvest insulin from pancreases of slaughtered animals. Really good stuff. So this is, um, this is where we are. That's a really good example, the use of cheese enzymes, which we talked about here on the podcast back with Levi Gaty and Coven Synapathy. That's a good one to listen to too. Those are really good examples to kind of soften the interface of people's experience with the technology. Let's see, Michael. How long do How long do you think it will take before people stop being afraid of GM technology? And I think that you're seeing a real turning point, and I think it's because you're seeing such a strong reaction to the fact that people really are starting to see that, you know, the sky isn't falling, and that all the predictions that these people made back in, you know, 1985 have never come true.

Right.

And in addition, people are starting to see that things they care about have been affected by the lack of technological deployment. So in other words, the solutions we didn't take. And that's what frustrates me as a scientist. We spend a lot of time and a lot of public money to come up with solutions that we don't implement. And these things die in the lab. And to see them move to the field would be tremendous. And I think some of the things like papaya, eggplant, the citrus situation here where we have a dying citrus crop— here's a case where maybe these kinds of technologies could be very important in assisting the public in understanding that this is good technology that can help us.

Hey, Kevin.

Can you give us examples of how genetic engineering can precisely place a trait in a desired DNA string? That's a whole episode. I mean, right now we're not good at this in plants. You can't do it at all. You don't have much choice about where a gene lands when it's inserted. So what the companies do is do thousands of insertion events and sequence them all and find the one that's in the least invasive space. Now in yeast, you can do something called homologous recombination, where the ends of a gene find a match in the genome, and you can replace— essentially replace a gene with another gene. Going forward, there's some thinking that this can be done well with CRISPR, and so you may be seeing some kinds of homologous recombination tactics being done in plants. Sometime, my guess is within 5 years, but that would be great. So there you go. Also, where can I hear the podcast? Walter, go on iTunes and look under, um, uh, whatever, Talking Biotech. Also, you can go on the talkingbiotechpodcast.com website. And the irony is, is how did you expect me to answer your question if you don't know where to hear it? All right, so where can I hear your podcast? All right, so it so what I'll do is I'm gonna I'm going to go out and do some smoke signals. I'm going to drop a drop you an email and maybe put one in the mailbox today with your name on it to send that information to you so you can hear your answer here. So there you go. It has a number of replies. These are all on my Facebook. Page, by the way. So if you want to go see more, oh, people put the post up. That's very nice. But you can hear the podcast on Stitcher, on iTunes, on all the other ones. I don't even know what they are. And I think the last question on Facebook is: How much harder is it to? Oh no, here, Scott. Sorry. Is anyone working on incorporating defensive proteins from Chinese ash trees into North American species? The emerald ash borer. Emerald ash borer will wipe us out and we can't treat trees. Seems like a no-brainer. Yeah, Scott, this is really gnarly. Emerald ash borer is a tremendous problem causing all kinds of grief in ash, and as they call it, it's, it's not a cigarette-associated bug, it's ash trees, not ashes. And if you go back to Steve Strauss's podcast On this series, he talks a little bit about that, and I believe you can use BT as a way to stop emerald ash borer, and that does seem to have some effect. There's some other remedies as well, and I would like to have a guest on regarding this, so thank you for reminding me. The other opportunity certainly is breeding, but breeding trees takes an awfully long time. So hopefully we'll see some solutions, but ash is one One of many trees that are under assault, whether it was the American chestnut, which was wiped out by chestnut blight back in the late 19th century. That's, I think, episode 10 here we talk about that, or many of the other challenges to trees between climate, between humans, between critters. It's going to be a challenge, and genetic engineering should likely be a good part of the solution. Last one. From Facebook. How much harder is it to change the minds of borderline anti-science people when groups of science communicators act like bullies by insulting them? Why would you ask such a dumb question though? You know, I agree 100%. We need to be on our best behavior, and I'm really disappointed, or frequently disappointed, by folks who are in the alleged science-friendly community who take to the tactics of those who are harassing us, and there's no room for it. I got emails a few weeks ago saying, you know, help us spread the word to spam this page and get it taken off of Facebook. No, don't do that. You know, don't do the things they do. Obviously they're wrong, and let's just do what's right. We know we have evidence on our side, and we can very easily turn people and, and change the middle by showing that we are going to take the high road. So what I would recommend is instead of being a science communicator who becomes— who takes on the harassment and starts acting like a bully online, do the opposite. Be super kind, and then, you know, just— and then make sure people are seeing you being super This is how you can maybe get around this. It has to be a question of us as science communicators taking the highest high road, showing people that this is science, that we're not going to play in the mud. And gosh, I used to be the best at playing in the mud. I used to love it. You know, I was down slugging and giving insults and being difficult. It didn't win the people we were trying— it didn't change the the people who are difficult, and it certainly pushed away the middle. Let them be difficult. Let the critics, you know, let them be the ones who are playing dirty. Let's take the high road. And I think that's the way that we're going to be more positively viewed by the folks in the middle and help us spread our message. And let's see. Okay. Okay, so that's it for Facebook. Let's go to Tweeter—

Twitter.

And, um, oh, never mind, I got the wrong one here. The first one is, are you kidding me? But that was in something else. Okay, so here we are in questions from Twitter. The first one comes from— sorry, yeah, this is high quality, isn't it? The first one is, um, what do you think of antibiotics Treat citrus greening in Florida, or it says in FA, but Florida, possible resistance, etc. Yes, so what this is in reference to is that there have been some limited applications of antibiotics to trees in an attempt to slow down the progression of citrus greening disease. And what it looks like is, at least in some limited cases, you can reverse reverse the symptomology which is caused from bacteria that are, that are infecting this tree's vasculature. And it seems like it works a bit, at least to turn it around. It's hard to tell because you can't do easy long-term studies in trees. But of course, people are concerned about things like resistance. People are concerned about things like, you know, allergies and all that. But this is old-school antibiotics that aren't used much in human health and used in a rather limited way at the right time of the season where it won't be present in fruit. You know, you know the drill. Certainly the industry is aware of the hazards of such types of— or the potential difficulties with such types of applications and the things you need to be aware of and do And so all of this has been reasonably well thought out, and I don't see that it would be problematic. I certainly do believe you will have resistance because that's what bacteria do, but we're talking about getting farmers through a couple years. You know, you've got citrus farmers who have these groves hanging on a thread, and if we can get them 4 or 5 years, the next generation of trees maybe genetically engineered trees, maybe new treatments, or maybe all the above will be at their fingertips to help solve the problem. Right now, uh, it's, it's pretty tough, and we need something just to build that bridge. And a little, little dose of old-school antibiotics to give a tree a break, uh, doesn't seem like too invasive of a treatment to me, and I, I fully endorse it, and I feel pretty good about what's happening. Chad, No, not Chad. He didn't ask me a question. He commented on someone else's. Ah, Bill. Would you rather face 3 horse-sized ducks or 3 duck-sized horses? Oh geez, that's a no-brainer. You always— you never want to fight a bird. And, you know, in my— you know, birds, you know, ducks especially, masters of the earth, masters of the sky, masters of the water. You're pretty much screwed, especially if you take them on in their domain. So, you know, three horse-sized ducks. I don't want to take on three duck-sized ducks. I mean, those things are bastards. I mean, I don't know if you've ever had the opportunity to step too close to a mother duck or a mother goose—the bird, not the book—with Offspring. Well, mother has offspring, and, you know, they get a little— they get a little weird on you. In my mind, you always face the mammal. Mammal on mammal is usually your better bet. When you're in the domain of the fish, you're in the domain of the shark, in the domain of the duck, you're gonna probably face a pretty formidable challenge. If you do find yourself in a situation where you're fighting a duck. The conventional wisdom is you have to go for that long goofy neck. It's a decent target. There's some soft spots on there that if you are— and people don't know that I am formally trained in duck fighting— there are some places that a well-placed blow can actually disable a duck pretty quickly. And so, but you have to— it's hard to get to. So you got to get past that beak. You have to You have to use some sort of misdirection with maybe one hand or maybe a kick to one side, but then usually some sort of knife hand move to the throat of the duck is usually the best way to dispatch them. Okay, there you go. How do biotech startups compare with digital tech startups? Can biotech learn from digital tech entrepreneurship? I don't know. You got me on that one. I don't know much about about any of that stuff. You know, maybe even might be able to get to do a startup sometime. Good things coming there. And I think that wraps up our question and answer session on the Talking Biotech podcast. So thank you very much for all your questions. Thank me for all the answers. I really appreciate everybody getting so excited to ask the things that they are curious about. So I'll wrap that up today. Thank you very much to Cecilia McGregor. Dr. McGregor is an associate professor at the University of Georgia, and thank her very much for joining me today with what was a really fun talk about watermelons. For everybody else, write a review on iTunes if you don't mind. We're moving up really well. I think we were last in the high 60s in science and technology as in terms of podcast popularity and ratings. Which is pretty good. So thank you very much for listening to the Talking Biotech Podcast, and we'll talk to you next week.

Thank you for listening to the Talking Biotech Podcast. Please send your suggestions for guests, comments, or questions to talkingbiotech@gmail.com. Please write a review on iTunes and recommend this podcast to a friend. More downloads and reviews raise the visibility of this podcast And help us reach a wider audience with science.

Nothing. Oh, Doctor, I'm so— No, no, be of good cheer. If science teaches us anything, it teaches us to accept our failures as well as our successes with quiet dignity. And Grace. Son of a bitch! Bastard! I'll get you for this! What did you do to me? What did you do to me? Stop it! You'll kill him! I don't want to live! I do not want to live!

Quiet dignity and grace.