Weird things we do to food plants (other than genetic engineering)

Mutant carrot. Photo credit: Joebeone

Here’s an embarrassing confession: when I was eight, the cartoon Attack of the Killer Tomatoes gave me nightmares. Seriously, what could be scarier than giant mutant tomatoes with teeth? (Don’t answer that.)

I’ve been thinking about these killer tomatoes a lot recently in the context of GMOs. Genetically modified organisms probably do seem about as unnatural and just as frightening (if less overt) as these tomatoes. It is scientists playing God. It is taking genes from one organism and sticking them into another. It is definitely unnatural.

But is it significantly more unnatural than other things we do to food plants?

I wanted to talk about some of the other weird s*** humans do to plants in this post, because I think there are a lot of misconceptions about how we develop crops. Unless you survive strictly off foraging, we all eat mutant plants every day. (That is, if you eat fruits and vegetables, which I hope you do.) Virtually all of our food plants are mutants, clones, or freaks, and about as far from their natural state as they can get through intense human meddling. Here are a handful of the ways we grow and eat mutants.

Corn: pretty much unrecognizable from its wild grass ancestor. Photo credit: photofarmer

Cherishing Mutants

Plants don’t evolve to be edible. (Quite the opposite, generally.) Many, in their unmodified state, are toxic, unproductive, hard to get, or just plain unappetizing. If you take a look at the wild ancestors of things like corn or tomatoes, you will almost certainly come to the conclusion that our ancestors must have been damn hungry to eat that. Corn is a great example. It started off as a wild grass with 5-10 extremely hard kernels per spike. Now, we don’t know the whole story, but we guess that when our ancestors found a mutant plant with softer kernels, they saved them to grow more mutant corn plants, maybe bred them with each other. This particular mutation is bad for the plant (soft kernels = seeds are all eaten by predators), but good for humans. Lots of crosses and some more chance mutations later, we have corn. Mutations, which are the raw material of genetic diversity — and which result in novel proteins — still happen. So does cross-breeding. Kevin Folta, a plant geneticist at the University of Florida, estimates that between 10,000 and 300,000 genes are affected when we breed plants the traditional way. We definitely don’t eat what our ancestors ate, and in a lot of ways, that’s a good thing.

Mutagenesis: plant breeding through radiation damage. Photo credit: ssoosay

Making Mutants (MOARRR MUTANTS!)

Right. So mutation is the rough material of genetic diversity, but we can’t control where and what kind of mutations will occur in nature. If we’re trying to get a new a trait into a plant, we can a) damage its DNA through chemicals or radiation and hope that some of the resulting mutants will have good traits; b) insert the gene in through genetic engineering; or c) try to get it through traditional breeding. Believe it or not, we’ve been using the first (mutagenesis) for the past 80 years. Wiki notes that, between 1930-2007, more than 2540 mutagenic plant varieties have been released. These mutants are fairly common in our food supply and include varieties of grapefruit, pear, sweet potato, rice, peppermint, citrus, and yam. No label required. Yay for DNA damage!

A grafted tree. Photo credit: Jbcurio

Attack of the Clones

Not to take down a childhood hero or anything, but Johnny Appleseed probably left behind a lot of apple trees that produced gnarly inedible apples. Apples don’t breed true from seed (since they are not self-pollinated, a Golden Delicious tree will only pass on half its genetic data to its seeds), so in order to get an orchard growing, all the same type of apple, you need clones. Every Honeycrisp apple tree in the world is genetically identical.

One of the really weird things we do in order to clone trees is to take a branch, cut a slice in an existing, related plant, and bind them up until they grow together. This is an age old technique known as grafting. You can end up with at tree that bears several types of fruit! They’re called ‘fruit salad trees.‘ In the photo, you can still see where one tree started and the other left off, yet they’re part of the same tree. Sort of. These guys are the real frankentrees, in my opinion.

Seedless watermelon…nope, definitely not natural. Photo credit: stevendepolo

Polyploidy

Would you be insulted if I called you a diploid? I’m one, too. So is your mother. So is my cat. It just means that we have two copies of each of our chromosomes (23 pairs in humans, for a total of 46 — get this, the adder’s tongue fern has 1440!).  Some organisms have just one copy of each chromosome, like bacteria, where others can have four, six, or even more. When something has more than two copies of each chromosome, it’s a polyploid.

Humans have figured out how to induce polyploidy in plants by treating them with a certain chemical (colchicine). We’re not just adding a couple of genes — we’re adding a whole extra genome. (You’ll remember that even one extra copy of one chromosome in humans — 3 copies of chromosome 21 — causes Down syndrome.) And in fact, polyploidy is how we get things like seedless watermelon and seedless bananas. (I know, right? A seeded banana??) First we treat them to get tetraploid plants, which are crossed with regular diploid plants to produce sterile (seedless) offspring. Think about that the next time you eat a banana without spitting out seeds.

***

Bottom line: humans do lots of weird things to plants, most of which have the potential to result in harmful, toxic, or allergenic foods. We don’t have long term safety tests for most of the foods we eat, including things like hot dogs, goji berries, and root beer (one component, natural sassafras flavor, was found to be carcinogenic fairly recently). Given that almost all of these techniques (except cloning, of course), result in much greater genetic changes than genetic engineering, I think it makes sense to be, if anything, more worried about mutagenesis and polypoidy than genetic engineering.

…Or, if you’re lazy and have a family history of heart disease and cancer anyway, you could be like me and eat lots of fruits and veggies and not worry too much about the other stuff. Just an option.

On a side note, I’m back in school, and my brain is inundated — and I mean polyatomic ions are coming out my ears — with chemistry and biology at the moment. I’m hoping to pursue a graduate degree in botany or plant bio once I’ve beefed up my wussy language arts background. Having this blog has made me realize that it’s time to get out of my house and brain and start doing something about the many problems we face. It’s starting not to be enough for me to sit behind my computer and fret over the miniscule impact of forgetting to bring my reusable bulk bin bags. I want to be doing something. I’m not an activist — I don’t like ideology or emotions — so science it is. I hope you’ll wish me luck and forgive me my erratic postings in the months to come. Peace.

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30 responses to this post.

  1. Now I know why every time my mother took me to dog ‘n suds as a child and gave me root beer I’d get sick! Congratulations on going back to school, I thought about it several times, but after the first degree which did nothing for me I decided to not further my education that way, at least for now as I have learned to never say never.

    Your post also reminded me of the many mutants we have tried to create by crossing insects. (here is where I think of the movie The Fly) between gmo’s and now the cloning of plants and animals, I don’t want to think too much of what will be out there to eat in the future. I mean are you ready to eat a cloned pig? I’m not but then again I don’t like meat.

    Reply

    • Hi Lois!

      Cloned pigs, cattle, and sheep are already in our food supply and have been for some years. Apparently they clone the animals that produce the best quality of milk or meat. I’m looking this up, and there is (not surprisingly) a labeling controversy about eating cloned animals. I don’t eat meat, so it’s not something I have to consider, but I’m finding that it really doesn’t bother me very much. I just read an article about lab-grown meat, in fact. I would be delighted to have an occasional guilt-free, suffering-free hamburger.

      My favorite plants — redwood trees — clone themselves and have been doing so for a very long time.

      Reply

      • I don’t trust labs, one mistake and we could be eating some new virus/disease. I do have an occasional piece of meat. My children like to frequent very occasionally a local buffalo farm which knowing the family we know how the meat is raised. I can’t eat it often because of a kidney problem, and really don’t care much for the taste of most meats, but I do take the time to enjoy this usually once a year.

        I love redwood trees. My grandparents took me to the redwood forest in CA when I was 9. They blew me away by their size and beauty.

        Reply

        • I trust scientists and have found food grown in labs to be subjected to far more rigorous testing than food grown outside labs. Our most deadly food-borne diseases, including E. coli and botulism, readily occur outside labs. Viruses can swap genes in an organism more easily than in the lab, which is actually how things like the 1918 flu and bird and swine flu come about. Once human flu strains acquire bits of info from animal strains, we have no immunity and are pretty much as vulnerable as we possibly could be. We’ve also been discussing biological warfare in class, and oddly enough, it’s actually pretty difficult to create a pandemic from the lab. Nature is much, much, much better at it. I don’t anticipate that the safety of lab grown meat will be an issue, although the ick factor is something else entirely.

          Reply

  2. I know you are busy, but I just nominated you for the 7 things about me award. Here are the rules:
    1. thank and link back to the person who nominated you
    2. List 7 things about yourself. It can be anything.
    3. Nominate 7 other people.

    Reply

    • Thanks! I’m just going to answer here because I feel weird devoting a post to this.
      Here’s a shout out for your blog: http://livingsimplyfree.wordpress.com/ I may have to get some tips from you about living in smaller spaces!

      Seven things about me:
      1. I have nine whorl fingerprints and one loop. According to Chinese tradition, this is supposed to mean I’m lucky. Still waiting for the luck to manifest!
      2. I’ve lived in a valley for most of my life and feel vulnerable when there aren’t mountains on the horizons all around me.
      3. My sister, who has just finished up med school, thinks I might have schizoid personality disorder.
      4. I think tardigrades are the coolest things ever.
      5. I have identified as a maker of things all of my life. Right now, I make pottery.
      6. I take tea the British way, with milk and occasionally sugar.
      7. I can’t multi-task. My brain is basically good at doing one thing at a time.

      I’m going to be a spoilsport and not nominate other people, because I think they’re all busier than I am.

      Reply

  3. Good luck in your studies–I’ll be waiting to read your research!

    Reply

    • Thanks, Becky! I hope it’s worth waiting for. I’m thinking I’ll at least get some more blogs out of being back in school…

      Reply

  4. Great post. I’ve definitely shifted to the I’d-rather-worry-about-heart-disease-than-mutagenic-food position. In general, because I’m now in grad school studying the use of compost for soilborne disease suppression, I’ve lightened up on the eco-living perfectionism. That’s my excuse, I haven’t analyzed it for equivalent weight of social impact, but I’m enjoying my life much more. Good luck with your graduate pursuits! You’ve definitely got the right attitude for it.

    Reply

    • Hi Lynn,

      You’ve been an inspiration to me! It is awesome that you worked your way to where you are, and I hope I’ll be able to do the same. Also, I am so with you about the eco-living perfectionism. I’ve begun to think that the oh-my-god-I-used-a-paper-towel type fretting is, if not counter-productive, at least stressful and time consuming. If it keeps us from going out and doing something more useful about the bigger problems we face, maybe it needs to go. You don’t need an excuse. Being happy and doing something you believe in (that may also have a great benefit for the planet) is plenty awesome.

      Reply

  5. Hi Jennifer,

    thanks for another great post! I just wanted to mention a couple of things (they don’t argue with your overall message, just fun to know):
    First, for many plants it is actually beneficial if animals eat their fruit. For example, tomatoes, strawberries and many others have hard seeds that are not digested when we eat them, so when an animal eats the fruit and has a bowel movement later, it actually spreads the seeds much more efficiently than, say, wind does.
    And second, polyploidy isn’t always bad – our hepatocytes are naturally polyploid (as well as some hematopoietic progenitor and other cells), and that’s exactly as many chromosomes as they need :)

    Good luck with your studies, it is a lot of work!
    Tatiana

    Reply

    • Hi Tatiana,

      Some plants use animals to spread their seeds, but most plants have evolved protections against having their leaves eaten or their seeds destroyed. I’m always amazed at what efficient and creative chemical factories plants are. And of course, they also have other structures, like thorns and irritating oils, that effectively deter eaters. In cultivating the nightshades, I believe we’ve bred them to contain much lower levels of the toxic alkaloids that make them bitter. I wouldn’t eat a wild plant in the nightshade family.

      I didn’t mean to imply that polyploidy was bad, though this is the first I’ve heard of human polyploid cells. Good to know!

      Reply

  6. Fabulous post. I think we humans have a very romanticized notion of the whole idea of “natural.” I am so totally impressed with your willingness to go back to school… it sounds to me like you’ve found your calling.

    And I must say that I totally agree on the eco-perfectionism front. It’s not that personal choices don’t matter, but I think many of us would benefit from some big picture perspective.

    Reply

    • Thank you, Cat! It’s been suggested that my blog has increasingly been about my frustration with the naturalistic fallacy in the environmental movement. Lately, I’ve been feeling pretty fed up with this attitude that we need to forsake all technological advancement in order to be green.

      I agree, big picture perspective is probably more important than the four [100% recycled, unbleached] paper towels I used to clean up a mess last week when the cat decided to use the rug as toilet paper.

      Reply

      • Ha! Well, don’t feel too bad about the rug… somebody over here peed in my tennis shoes! Still haven’t identified the guilty party – I’m taking it as a hint that perhaps I need to be better at putting things away!

        Reply

  7. Good for you for getting out there and going back to school. I secretly love science too. I have been pondering the idea of grad school too myself, just have not worked up the guts to do it…

    The one thing I don’t like about genetic engineering, in fact the worst thing, is how Monsanto is so greedy and mean to farmers. But I see the point you are making. I am not worried about GMO food making me sick. I am more worried about monocrops and roundup ready crops that encourage the heavy use of chemicals that kill soils, etc… I don’t know, it has such a ripple effect.

    Reply

    • Roundup is a LOT safer than many alternatives, many of which have been banned; and it makes no sense for farmers to use more than necessary because of the cost; farmers dont have to use Monsanto’s technology, but they do so because it benefits them to do so. Seems to me that RR crops allow for low-till or no-till regimes which is def better for the soil. Organic ag for example generally requires more tilling- they dont have the option of herbicides so tilling is one of the ways necessary to control weeds; even so, organic yields are lower. I agree more competition in the GE sector would be better, but I would lay the blame for this on activists who have successfully imposed such punitive barriers against independent scientists and smaller biotech co. that only the big players can actually afford to bring a trait to market. And we all suffer as a result.

      Reply

      • Posted by Rosa on 09/22/2012 at 12:43

        RR crops can be hard to get away from; once you invest in the technology, especially if you simultaneously go no-till as many do, you’re kind of on the treadmill. We have a friend who does part RR and part not, but since he saves seeds even his “not” is probably part RR, and Monsanto has a fairly old history of going after people who have their patented genes without paying the license fee, even if they’ve *never* purchased RR.

        There’s also the problem of weeds developing resistance, which for at least a few years leads to using more and more Roundup. Eventually the cost becomes a serious factor, but again the capital costs and labor costs make it difficult to go back to a more tilling-intensive system – a farmer who expands a lot by going to a more chemical-intensive and less labor-intensive system can’t go back without investing a lot in labor at key times when that labor can be hard to find, much less pay.

        Reply

    • Hi Sherry,

      I definitely share your uneasiness with monopolistic biotech and some of Monsanto’s policies. Unfortunately, I think the quantity of regulation around genetic engineering (MUCH more than required of traditional hybridization, polyploidy, or mutagenesis) has actually discouraged smaller companies from GE and makes it unprofitable for all but the biggest companies. Monocropping is not a unique feature of GE crops, but rather an aspect of our current food production systems that stress efficiency over everything else. I’m interested in seeing a type of farming that follows integrated pest management (choosing whichever tool will get the job done best and with the lowest impact in a particular situation, regardless of biotech, organic, or conventional) — in some cases, a synthetic pesticide can be more effective, require smaller quantities of chemicals, and biodegrade better with fewer health effects than an organic approved one. I also think there’s room for both small scale organic farming and large scale efficiency farming.

      Reply

  8. Great post entertaining and informing! Im sharing it with all my permaculture students, most of whom suffer badly from naturalistic fallacies and GE-phobia (is there a proper word for that?!) Thanks!

    Reply

    • Thanks, Graham! Would you ever be interested in guest posting about permaculture? It’s something I don’t know much about but would like to.

      Reply

  9. Posted by Andrea on 09/21/2012 at 08:18

    As far as I’m concerned, scientists can do whatever they want as long as they prove the end product is safe before it hits store shelves. How come pharmaceutical companies have to jump through many hoops to introduce new drugs, but all sorts of dangerous stuff (which may or may not deserve the name “food”) is readily available in the supermarket, unlabelled? By volume, we eat way more food than meds, so it really makes no sense that the safety procedures vary so drastically.

    Reply

    • Hi Andrea,

      If all food had to go through long term safety testing, I’m pretty sure hot dogs and alcohol wouldn’t make it through. :-) I think one reason why so little of our food actually goes through testing (I suspect GMs go through more than anything else) is the sheer time and cost required. From a genetic standpoint, a product of traditional breeding involves a lot of genetic changes and would need to be tested as much as something created in the lab that involved a lot of genetic changes. So would all new imports that are novel to a population (goji berries, for example) for allergen risk.

      I dunno…I think we have so much more evidence of the harm of processed food that whole produce should get at least a relative pass. (And even as I write this sentence, I’m thinking of thorn apples and amanita mushrooms…hence the ‘relative’ part.) I’d love to see more emphasis on eating fruits and veggies (organic, conventional, mutant, or otherwise) rather than get caught up in its risks.

      Reply

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    Reply

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