Take your time, no rush, I’m not going to see chestnut forests in my lifetime anyway


I should look up from the spiders now and then. I did not know what was happening to forests.

Global trade and climate change are poised to make the spread and severity of arboreal plagues and pestilence worse. The hills around Syracuse are silhouetted with pale ash trees slain by emerald-colored borers. Ancient bristlecone pines out West are succumbing to bark beetle outbreaks triggered by rising temperatures. As many as 1 in 6 trees native to the Lower 48 states are at risk of extinction.

I should know. We bought a house 20 years ago that had a yard full of impressive trees, which we’ve watched steadily decline. Every few years it seems the city splashes another one with neon paint and we’re told it has to come down. But there’s hope! Science rides to the rescue, maybe! The article is about the American Chestnut, and how it’s been wiped out by a fungus.

All it takes is one gene.

The fungus infecting chestnut trees thrives by secreting a chemical called oxalic acid, which kills cells and allows the pathogen to feast on the dead tissue. But many other plants, including bananas, strawberries and wheat, avoid that fate by producing an enzyme called oxalate oxidase that breaks down the toxin.

By 2014, Powell and Maynard successfully added the wheat gene to chestnuts and were growing infection-resistant trees. The pair dubbed one line Darling 58, in honor of Herb.

Many plants use oxalate oxidase as a defense mechanism. It catalyzes the oxidation of oxalic acid into CO2 and peroxides — reactive oxygen species. Is that going to have a side effect? I don’t know. Barley makes multiple forms of oxalate oxidase, and it doesn’t seem to harm beer production.

“Making a transgenic tree — I hate to say it like this, but it isn’t that hard,” Newhouse said. The most difficult hurdle for Darling 58, he said, is winning regulatory approval.

Well. This is sort of true. Making transgenic organisms is relatively easy nowadays, EXCEPT…the difficult part is figuring out what gene to use, and since most traits have complex origins, and since the expression of the gene is going to have multiple effects on the organism, it’s difficult to predict all of the consequences. There are good reasons regulatory approval is tough to get.

But in this case, they seem to have found a relatively simple way to confer fungus resistance on a tree, and it’s been tried experimentally, and they have successfully produced healthy, blight resistant chestnut trees. However, I think uncertainty about possible outcomes is a good reason to go slow, and regulatory agencies are doing the right thing by putting the brakes on the process.

There are also bad reasons for resisting the transgenic trees, and there seem to be a lot of people blocking it. Their primary argument is this weird idea that “natural” mechanisms like breeding hybrid trees are somehow “better” than transgenic methods — this is the same reasoning that has led to GMO labeling in our grocery stores, as if somehow the fact that an agricultural scientist has intentionally tweaked a plant is bad, while wholesale, random interbreeding of varieties is more pure. I don’t get it. Don’t people realize that all of the crop plants producing your food have been extensively modified by centuries or millennia of intentional manipulation of their genomes? Everything in the supermarket is a mutant, GMO or non-GMO. I’d argue that the genetically modified plants have undergone less drastic changes than those produced the old-fashioned way.

…Powell countered that crossbreeding transfers far more genes between species. “Genetic engineering is actually a less-risky procedure than a lot of things that we’ve done in the past,” he said. “We are very precise. We’re only moving one, two — just a small number of genes into the tree.”

That the changes are small are not a reason to dismiss regulatory oversight, of course. The reason they can use only one or two genes is that they have specifically selected target genes of very large effect.

Of course, re-creating vast chestnut forests would also be a huge effect.

Comments

  1. Oggie: Mathom says

    Considering the number of times an organism has been introduced to solve x and created problem y, which required introducing organism z, which creates . . . . It makes sense to go slow.

    I am very much in favour of modified foods — be it through direct gene manipulation or through selective breeding (one of the vendors at our farmer’s market sells a dozen or so different heirloom tomatoes) — as it will make the future more livable. And finding a way to bring back the American Chestnut certainly sounds like a great idea, but I have to agree with the USFS and USDA keeping it slow. Study, study and study more. Of course, with the decades-long generations of trees, that means really slow.

  2. Kagehi says

    Huh.. Wonder if this is the same, or similar, problem that citrus trees have. We lost two lemons, and finally, most recently, a lime (the recent high winds tore the “live” part straight off the weakened trunk) to some sort of fungus that gets into the soil and attacks specifically citrus here in Arizona. Wouldn’t mind, at all, if it doesn’t have other negative side effects, seeing modified lemon and lime trees that fix this. Though.. I can see one side effect – we are trying to get rid of CO2, and trees are one way to do that, but if the fungus sticks around and the tree produces CO2 as a side effect of fighting it, that seems.. a bit less effective….

  3. Reginald Selkirk says

    What could be more “natural” than billions of American chestnut trees covering the Eastern portion of the country?

  4. wzrd1 says

    Just last week I was regaled on how much more nutritious corn in the original cultivar was.
    All one inch of each ear…
    And how selective breeding is also GMO.
    Apparently, some are eager to going back to eating plain grass seeds and the widespread starvation that that would bring.

    Don’t get me started on GMO labeling. There are tons of labels proclaiming thar the peanut butter is GMO free.
    No shit, there are zero GM peanuts.

    As for reactive oxygen species, as I recall, chloroplasts and mitochondria produce and successfully handle reactive oxygen species on a continuous basis without harm.

  5. richardh says

    Kagehi@2: “if the fungus sticks around and the tree produces CO2 as a side effect of fighting it, that seems.. a bit less effective….”
    but the CO2 is a breakdown product of oxalate produced by the fungus from… something else. I don’t know what that “something else” is (biology is complicated) but would not be surprised to learn that the relevant metabolic pathway takes CO2 as one of its starting materials.

  6. consciousness razor says

    But there’s hope! Science rides to the rescue, maybe! The article is about the American Chestnut, and how it’s been wiped out by a fungus.

    If you were a fungus fanatic instead of being obsessed with those (scary) spiders, it might seem a lot less obvious that the trees are the ones you ought to be rooting for (no pun intended).

    I mean, there’s definitely a ton of loaded language about “plagues,” “pestilence,” a “pathogen” and so forth, which is apparently supposed to do the job; but I don’t see a clear argument for why “science” should come to the rescue by fucking around with some genes…. And for whom? Presumably not the trees. Homeowners, I guess?

    So, who are they rescuing from what, and why is that thought to be so important? Not saying there couldn’t be decent answers, but those kinds of questions do at least need to be asked. The idea that you can just point at other GMOs and say “see? too late to do anything about it now” is pretty wild. Is that all the Jurassic Park dude would have needed to say? Same thing, too late now, move along. That doesn’t sound like a good argument.

  7. birgerjohansson says

    One tiny change In the genome is not much compared with the myriad random virus-induced changes that occur all the time.
    As chestnut trees are well-know organisms I very much doubt this change will do harm.
    And if the young saplings start killing the local ecosystem, just bring out the chain saw.

  8. KG says

    this is the same reasoning that has led to GMO labeling in our grocery stores, as if somehow the fact that an agricultural scientist has intentionally tweaked a plant is bad, while wholesale, random interbreeding of varieties is more pure. I don’t get it. – PZM

    That could be because you always ignore answers to your frequently-expressed puzzlement. Sure, there are lots of bad reasons for opposing GMO crops. There are also at least two good ones:
    1) Almost all the safety testing (safety for consumers and the environment) is done or funded by the companies producing the GMOs. Now they are not going to deliberately poison people, but when you know what answers your employer or funder wants, there must be some risk you’ll – even unintentionally – shade the results of your work.
    2) Because GMOs are eminently patentable, they are highly likely to reinforce the dominance of the handful of mega-corporations who control far too much of the world’s food supply. Indeed, it is likely that the specific GMOs developed will have been chosen with precisely this aim in mind.

    And how selective breeding is also GMO. – wzrd1@4

    Yeah, yeah. We need some term to distinguish between selective breeding, crossing and other techniques that have been around for millennia, and the new, direct genetic manipulation techniques of biotechnology. After all, if the latter can’t achieve anything novel, why would anyone use them? The term in common use happens to be “GMO”. The frequency with which GMO-boosters bring up this terminological gripe suggests an eagerness to distract from the real issues.

  9. dictyostelium says

    What about variation not being passed on? Are GMO/breeding done in a way keeping diversity?

    If the plants have difficulty getting minerals, maybe modifications(GMO or not) can either make it easier for them to take it up, or reduce their use of it. But the latter is likely to also reduce the presence of the mineral in the product.

    Of course, that the latter might be a fine choice depending on the situation, certainly a choice people should have an interest in i guess. (but then, that goes for pretty much everything..)

  10. Jackson says

    That could be because you always ignore answers to your frequently-expressed puzzlement. Sure, there are lots of bad reasons for opposing GMO crops. There are also at least two good ones:

    1) Almost all the safety testing (safety for consumers and the environment) is done or funded by the companies producing the GMOs. Now they are not going to deliberately poison people, but when you know what answers your employer or funder wants, there must be some risk you’ll – even unintentionally – shade the results of your work.

    True, and this is something you and GMO producers can agree on. I wish the government would pay for those regulatory trials.

    2) Because GMOs are eminently patentable, they are highly likely to reinforce the dominance of the handful of mega-corporations who control far too much of the world’s food supply. Indeed, it is likely that the specific GMOs developed will have been chosen with precisely this aim in mind.

    Eh, GMOs are just as patentable as new varieties that are made through crossing, or mutagenesis, or any other type of breeding. So GMOs don’t really help concentrate control any more than any breeding method that came before it. The GMOs I help develop don’t have this precisely in mind, but the regulatory environment and distribution and marketing are things that need to be considered somewhere along the line.

    Yeah, yeah. We need some term to distinguish between selective breeding, crossing and other techniques that have been around for millennia, and the new, direct genetic manipulation techniques of biotechnology. After all, if the latter can’t achieve anything novel, why would anyone use them? The term in common use happens to be “GMO”. The frequency with which GMO-boosters bring up this terminological gripe suggests an eagerness to distract from the real issues.

    When most people say “GMO” they mean it (whether they realize it or not) as a short hand for: Offspring of organisms that have had their genome modified through the use of in-vitro recombination techniques.

  11. Rob Grigjanis says

    Jackson @9:

    GMOs are just as patentable as new varieties that are made through crossing, or mutagenesis, or any other type of breeding.

    The patents sought by GMO companies aren’t quite the same as ‘regular’ plant patents.

    Interestingly, GMO companies often don’t seek plant patents for their plants and seeds. Instead, they obtain utility patents, a different type of patent with more stringent requirements on the description of the invention.

    Therefore, utility patents provide more extensive protection for GMO plants.

    https://sitn.hms.harvard.edu/flash/2015/the-patent-landscape-of-genetically-modified-organisms/

  12. birgerjohansson says

    If you have badly degraded topsoil you can introduce lupins.*.They are nitrogen-fixing legumes and are so fecund they have become invasive plants in many places
    They need lots of sun, so if you plant a forest once the soil has recovered the lupins will stop being a problem.

    Iceland is doing just that.

  13. Jackson says

    GMOs do not have to be patented, see eg Golden Rice.

    I think the golden rice trait was patented, just that it will be licensed for free to small farms. So that would be more an example that not all patents are nefarious or bad.

  14. brightmoon says

    Lupines are gorgeous and I keep thinking of that Dennis Moore the highwayman skit from Monty python every time someone mentions them

  15. unclefrogy says

    generally GMO’s in principle are neither good nor bad they are just produced by a different technique then the ones that have been used for millennia. It is how they are used and what is produced that is problematic first. It is who uses them and how the market is manipulated with them creating market control secondly. That is different from the process of genetic manipulation and is much more a legal issue and an ethical issue and a social issue.
    bringing back the American Chestnut is a great project i hope it succeeds far beyond their hopes. There are other great valuable and useful trees that would benefit from similar efforts

  16. rblackadar says

    Your picture looks like a horse-chestnut to me — different order and not subject to blight. In any case I don’t think any living American chestnuts are that large, i.e. larger than shrubs.

    As for your condemned trees, let me guess: American elms, beautiful trees that grow quite tall but eventually tend to succumb to Dutch elm disease, another fungus.

  17. Kagehi says

    Thing is.. While its true that changing/adding a gene can, maybe, cause some other effects, how complicated is it, really, to figure out that this is happening? How many times, exactly, HAS THIS HAPPENED, compared to cross breeding? I have heard a fair number of claims, but they all seem to go back to, ironically, anti-GMO companies, that ran bad lab tests, often without proper controls, and with joke results, which are no better than some of the crap we have seen out of the “anti-artificial sweetner” groups, and the like. Could a problem happen? Maybe. Could it happen with normal hybridization? Absolutely. Is it more likely to happen when someone is adding a single “known gene”, which they, presumably, already know the function of in the original plant, and, one certainly hopes, they picked because it didn’t seem to do much of anything else, vs. mixing things at random, in hopes to get a good result? This seems implausible to me.

    Heck, half the protests are stupid shit like ignoring real problems, like preventing small farmers from profiting, to the benefit of large scale factory farms, due to patenting, while rambling endlessly about “poisons in food from herbicide resistant crops!!” – which literally don’t make herbicides (they just don’t die from them easily. I.e. the equivalent of protesting that sun screen causes cancer, not sunlight.). :shakes head:

    I would love something evidence based, not… “Well, there might be a problem so we should do what we don’t with almost any natural food, even hybrids, and spend years making sure its safe!” OK… but no one seems to know if this testing is “already happening”, like.. as a part of the process of developing the things? I would think that this would kind of be a prerequisite – “it has to still be edible, otherwise it doesn’t matter if its got more Vitamin C.” I don’t think anyone even “asks” this question, at all, they just whine about if its been “tested” by some vague standard, like its a new medicine, or a literally unknown, we don’t know if its even consumable, item from a jungle some place.

    Lets see an evidence, not fear based, policy idea, which makes some sort of sense, not vague, “Well, they should be doing something, and we don’t think they are, or are doing enough!!!” Its incoherent.

    Just my opinion on the subject.

  18. DanDare says

    The GMO anxiety is not about the science I think. Its about distrust of the corporations that wish to profit from it. “Oh, this will cause all the frogs to die? Bury that study we have billions of dollars to make”
    And there’s also the “oh deat, the seeds have escaped into the wild before all the tests are done? Ok. Full speed ahead on production then.”