The new American chestnut tree: resistant survivor or Frankentree?

Recently posted an article about American chestnut trees due to be planted in New York City. Researchers hope that these trees will be resistant to chestnut blight, an introduced fungal disease that pretty much wiped out mature specimens over the last 100 years.

When I lived in Buffalo, I was a member of the American Chestnut Foundation and every spring I helped with efforts to replant chestnuts in the hopes that resistant individuals might be found.  The problem is that the disease doesn’t kill young trees: it can take many years to find out whether a particular tree is resistant or not.

Chestnut suckers from live roots of blight-killed tree. I saw these a lot in western NY forests in the 1990’s.

Part of the earlier research efforts involved crossing resistant European chestnut with American chestnut in hopes of creating resistant hybrids.  The downside, of course, is that such offspring would not be “pure” American chestnuts.  More importantly to many people, these hybrids might not produce the same quality of nuts.

The research mentioned in the Science Daily article involves creating transgenic plants: a wheat gene resistant to the fungus was inserted into the chestnut genome with the hopes that the resulting trees would be immune to blight.  These trees are genetically modified organisms, or GMOs.

It’s worth noting that it’s this kind of work that has been branded as “Frankentree” research, which incites a lot of fear and hysteria.  It’s what caused ecoterrorists to mistakenly firebomb the UW Center for Urban Horticulture in 2001 when I was faculty there.  It’s what causes people to freak out about eating GMO foods.

So my question for you – does the fact that transgenic chestnut trees will be “on the loose” fill you with fear?  Or does it make you hopeful that we’ve possibly found a way to overcome an introduced disease?  (As I just noticed in reading this over before posting that I used some form of the word “hope” in nearly every paragraph.  I guess it shows where I stand.)

Published by

Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and a Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - "The Garden Professors" Facebook group - Books:

14 thoughts on “The new American chestnut tree: resistant survivor or Frankentree?”

  1. I have absolutely NO issues with genetic engineering. I see no difference between traditional breeding and genetic engineering with respect to the safety of the resulting plants. I do, however, think certain GMOs should never have been developed (the terminator gene comes to mind), and I have issues with certain business practices of certain companies that pr
    omote GMOs, but I’ve yet to see any valid research that proves the technique itself (as opposed to the result of the technique, if that makes sense) is any more “unsafe” than traditional breeding.

    As for transgenic chestnuts – I’m all for them, if they are indeed resistant to blight.

    A former colleague at the University of Guelph was working on finding a resistant chestnut, and had a funny story resulting from doing a survey of the area for surviving trees. It included his very sweet, somewhat-naive technician and the local nudist colony, but that’s outside the scope of this post 😉

  2. I think GMO plants need to be studied more I do not think that scientists know what they are doing. It is breeding in double time We are messing with stuff we do not understand

  3. I might actually have a very slight preference for GMO because supporting the industry might produce something necessary someday.

  4. It makes me neither fearful nor very hopeful. As was the recent case with GMO corn, pests will eventually evolve to adapt to whatever you throw at them, so the trick is to keep evolving. This could be just another short-term fix with unknown consequences. As to GMO foods, they may or may not be safe in the long term (who really knows?), but it would be nice if they were all required to be labeled so the consumer can make the choice whether to buy them (the only sure way seems to be to buy organic, which fortunately prohibits GMO’s).

  5. Linda! Did you just have to use the F-word?!?

    The rest of your blog was quite well balanced,but that headline resurrects an old image that we had hoped to have laid to rest.

    One other point. the backcross breeding program started with a cross between American and Chinese chestnuts, not European. The European chestnut is only slightly more blight resistant than American.

    Knud “studied more”. This one really makes me crazy. I have been in the tree breeding game for 35 years and have followed “traditional” plant breeding for another 5 years on top of that.

    Before a molecular biologist inserts a gene into a plant they have at least an order of magnitude better understanding of what that gene does than the average plant breeder knows about the genes they are cheerfully scattering about.

    Plant breeders breed for “traits” like resistant vs susceptible. Today, I admit, they usually have at least a vague idea what the underlying physiology of the trait might be. But for decades they got by simply crossing and selecting until they stumbled upon a phenotype that looked promising and then selfed it until it bred true. Or grafted it onto a rootstock and named it something catchy.

    The molecular biologist can tell you the exact sequence of the gene(s) they put in and predict exactly what the amino acid sequence will be produced by those genes and in what tissues they will be produced. We certainly don’t claim to know “everything” about how the new transgenic plant will behave in every possible environment –thats why we have field tests– but if we wait until we have perfect knowledge we will never get there. and in the case of the American chestnut a once-magnificent species will go extinct while we wait.

    More important, the molecular biologist knows much more than the typical plant breeder knows about what all got changed in the process of developing a new variety.

    I am not knocking plant breeding. it has a couple of centuries of proven success to be proud of. It is essential to our current standard of living. and in the coming century it will be even more important. and breeding will be extremely important for the implementation of genetic engineering of plants. transgenes are just one more source of genes. for most crops, the original line that was transformed with some new gene is not the one that gets released as a new variety, It just serves as raw material for the breeder, who will then breed it into his or her elite germplasm to try out in various combinations of genes before releasing a new variety. But even in this case I will bet good money that the breeder knows more about mode-of-action of the transgene than any other gene in the new variety.

    Pardon me, I will get back down off my soapbox now. It’s just that the idea we have to know everything before we can do anything that make me crazy.

  6. Oops, sorry about that Charles! It’s been too long since I followed the chestnut program and I should have looked up what the cross was rather than relying on 20+ year old memories. Thanks for correcting!
    (And I hope you know that the title was tongue in cheek, based on what I said later about Toby Bradshaw’s poplar breeding program.)

  7. I stopped in this morning to see if anybody else had anything to say.
    One important point I missed. The chestnut trees we planted in the NY Botanical Garden are there under a TEST permit. Before the USDA lets us put a single tree in the ground, we have to convince them that they will NOT be “on the loose.” We have to check the area around each test site for other chestnut trees that might be pollinated by our transgenics. We have to monitor the trees for flowering, we have to either bag or remove any flowers that form. Finally, we have to KEEP checking for volunteers for at least two years after we remove our transgenic trees. We sincerely hope someday to see the very best of our blight-resistant chestnut trees PURPOSELY “Set free to enrich the dwindling remnant populations…” But that day is still some time (and many more tests AND two additional federal agencies) in the future. Today they may be out in public, but like all the dogs in the park, our chestnut trees are on a darn short leash.

  8. Thanks for the addition, Chuck, it’s interesting to know that you’ll be keeping them from “sowing their oats” as it were. I’m curious, though, if you’ll be trying to produce nuts (elsewhere maybe) and compare their quality to others?

  9. Chuck, I am not against the transgenic work, but I have to say I am skeptical about your claim that transgenic work is accompanied by such a greater of knowledge of what’s going on. Isn’t the amino acid sequence that a gene will produce just the beginning of the biochemical implications? I was taught that interactions between transcribed products were not well understood and that the simple gene to protein model was a gross simplification. Another thing I was taught was that “natural” genetic recombination is more limited in its possible results than transgenic techniques. for example , transgenic techniques could place the introduced gene in the middle of another gene, splitting it and creating unknown results which are nearly impossible to receive from traditional reproduction (whether aided by wind, insect or human).

    All that said, I am not at all involved in molecular biology so please tell us more! I really would like a professional opinion on these ideas I’ve acquired.

  10. Linda,

    Thanks for letting me contribute my rather lengthy posts to your website. YES! We are allowing some of our trees to flower and are bagging then. The very first transgenic chestnut went in t
    he ground in 2006. These first trees had very low oxalate oxidase gene expression, too low to be effective at stopping the necrosis as our newer trees do. But the marker genes that were also on the construct have perfectly fine expression, so we left the trees in the ground. Last spring they flowered! We checked our permit and one of the options for controlling “escape” was bagging! We quickly bagged the flowers, and called up an expert chestnut breeder, Sara Fitzsimmons, from Pen State. She dropped everything, drove ~6 hours, and showed us how to do chestnut pollinations. We did, they took, and in the fall we collected 34 nuts! Andy Newhouse did the crosses, and he did a great job. We had the highest %-filled seed I have ever seen. We stratified them over the winter and began checking for germination some time in March. The whole lab went nuts when we sent “baby pictures” showing the tiny GFP+ radical emerging from the nut! As of today (5/7/2012), we have about a dozen seedlings expressing GFP growing in the greenhouse and 6 that went to the NY Chapter of The American Chestnut Foundation. They will be planted near Buffalo later this spring. We had every expectation that our transgenic chestnut trees would flower and be fertile, but it is still very exciting to be proud parents of some second-generation transgenic chestnut seedlings.

  11. I have a neighbor down the street that has an American Chestnut tree in his front yard. The tree is about 50 feet high and produces beautiful chests.i was wondering if ya’llcould recommend anyone in my area that could test this tree for diseaes resistance and possible cross breeding with other trees?

Leave a Reply