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    Why GMO Wine Grapes Would Be Cool
    By Steve Savage | September 25th 2013 11:28 PM | 8 comments | Print | E-mail | Track Comments
    About Steve

    Trained as a plant pathologist (Ph.D. UC Davis 1982), I've worked now for >30 years in many aspects of agricultural technology (Colorado State...

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    I am 99.9% sure that there will never be commercial production of genetically engineered wine grapes ("GMO" to use the common misnomer). Even so, I'd like to indulge in imagining what could be if we lived in some parallel universe where rational scientific thinking prevailed.

    Wine grapes are an extremely logical crop for genetic engineering because there is no tolerance for changing varieties. For annual crops like grains or vegetables, new varieties are bred on a regular basis to solve pest issues or to improve features like taste or shelf life.

    Chardonnay grown in Colorado Breeding of perennial fruit crops is a much, much slower process, but entirely new varieties are still introduced from time to time (e.g. Jazz or Pink Lady apples). Even what we call "heirloom varieties" of most vegetable or fruit crops are mostly quite young by wine grape standards.

    Conventional breeding isn't a viable option for wine grapes, not because it couldn't be done, but because in an industry so focused on quality and tradition, no one would consider it. The wine industry is based on specific varieties which are hundreds of years old and for which no new variety would ever be acceptable.

    That is true for varieties in their original appellations (e.g. Pinot Noir and Chardonnay in Burgundy or Cabernet Sauvignon and its blending partners in Bordeaux).

    It is also true for those same varieties that now make great wines in "New World" (e.g. Malbec in Argentina, Zinfandel in California, or Syrah in Australia).Therefore, wine grape varieties have been cloned for hundreds of years, specifically to avoid any genetic change (they have always been grown from rooted cuttings or from grafted buds). Grapes make seeds, but the seed won't grow up to be the same variety as the parent, thus they are never used as a way to grow new vines.

    The Downside of Ancient Varieties

    Of course, by sticking to very old varieties, wine grape growers must deal with many problems which might otherwise have been solved through breeding. Grape growers have been able to deal with some pests that attack the roots by grafting onto diverse "root stocks" with novel genetics. That was the solution to the great Phylloxera epidemic of the 19th century. But rootstocks can only help with a limited number of grape growing challenges.

    Why Genetic Engineering Would Be Logical For Grapes

    Biotechnology is a perfect solution for wine grape issues because it allows changes to address one specific problem without disrupting any of the characteristics that determine quality. Of course, each variety would have to be individually transformed, but in our imaginary rational universe the regulatory regime would be made easier for multiple uses of the same basic genetic construct

    So, genetic engineering could be a very cool solution for various challenges for grapes. I'll list a few of the diseases that might be fixable this way.


    Grape Downy Mildew infection on a leafAs I described in an earlier post, the noble grapes of Europe must now be rather intensively sprayed with fungicides because a disease called Downy Mildew was introduced in the mid-1800s from New World grape species.

    Those same North American species have a good deal of resistance to that disease, and the genes for those traits could probably be identified and moved into the traditional, high-quality varieties.

    Grape Powdery Mildew infection of young berriesThis strategy might also be employed to reduce susceptibility to another disease called Powdery Mildew which requires frequent sprays or sulfur dustings even in dry environments like that of California.

    There are even susceptibility differences between varieties which might be able to be moved.

    If the genes which control the development of the main cluster stem (rachis) could be identified, it would be possible to make less rot-prone versions of great varieties and thus reduce the amount of waste caused by Botrytis.Botrytis Bunch Rot is most problematic in grape varieties where the clusters are very "tight" (e.g. Riesling, Pinot Noir, Chardonnay, Zinfandel) and less problematic in varieties where the cluster is looser with more stem between the berries (e.g. Merlot, Cabernet Sauvignon).

    It is possible to loosen up clusters with a very well-timed spray of the plant hormone gibberellic acid, but that is difficult and can affect the next year's yields.

    If the genes which control the development of the main cluster stem (rachis) could be identified, it would be possible to make less rot-prone versions of great varieties and thus reduce the amount of waste caused by Botrytis.

    Viral Diseases

    Viral diseases of grapes, spread by insects, can shorten the productive life of a given vineyard planting. If you tour grape growing regions in the fall you may see vines with leaves that have turned red. It's sort of pretty, but it means that those vines are infected with Leafroll Virus - spread by mealy bugs. Such vineyards bear progressively less fruit and fruit of lower quality until the point at which it becomes necessary to tear out those vines and re-plant - often years before it would otherwise be necessary.

    Fall symptoms of Leafroll virus infection A transgenic solution to that virus is definitely possible as it was with a virus that nearly destroyed the Hawaiian Papaya Industry.

    Pierce's Disease - A Potentially Existential Threat

    Grapes are also susceptible to a disease which actually kills the entire vine. The pathogen is bacteria-like and is endemic to various riparian plants in the US.

    If an insect vector happens to move from those plants to a vineyard, it can lead to an infection called Pierce's Disease which will soon destroy the vine. In the Southeastern US this pathogen makes it impossible to grow the European grape varieties. In California infections were known, but were relatively rare because the native vector (the bluegreen sharpshooter) didn't tend to move very far into a vineyard.

    Then in 1994, a new vector called the Glassy Winged Sharpshooterwas introduced into Southern California and started vectoring Pierce's disease into vineyards on a large scale. For a while it looked like this new combination would be the sort of existential threat now facing the Florida Orange industry. Fortunately, growers learned how to check the population of the vector by spraying it when it was in neighboring citrus groves, before it moved to the grapes. Also, it appears that some degree of natural biocontrol has kicked-in to keep the overall population of glassy winged sharpshooters manageable.

    Should this disease become a major problem in the future, a genetic engineering solution might be the only viable solution.

    Voluntary "GMO labeling" Would Be Easy for Wine

    Because wine grapes can be extremely valuable (e.g. as much as $10-20,000/acre), and because quality is closely connected with the location where they are grown,"identity preservation" is common in the industry. It would be entirely feasible for grapes which were or were not "GMO" to be kept separate to what ever extent was desired. So, one winery could proudly label their wine as "improved via biotechnology to provide disease resistance," while the neighboring winery could confidently claim not to be "non-GMO" if they so desired.

    Again, remember I'm talking about what could happen in a parallel universe where reason prevails. In our universe (as has already been demonstrated in both France and in Mendocino County California) reason quickly yielded to the politics of fear and unfounded concerns about "genetic contamination."

    So, there will probably never be commercial "GMO grapes" in our universe, but that doesn't change the fact that it is a cool concept.

    You are welcome to comment here and/or to email me at savage.sd@gmail.com.


    Colorado Chardonnay image SDSavage>

    Grape Downy Mildew (Plasmopara viticola) image from the University of Georgia Photo Archive

    Grape Powdery Mildew image from Wikipedia

    Rotting Chardonnay image SDSavage

    Merlot image from Naotake Murayama

    Leafroll virus image from Oklahoma State University


    Sorry about the formatting issues here.  Not sure what happened
    Steve Savage
    But that's the point that it was not easy to grow vines. Wine is not done in the laboratory only on the vineyard. If vines can be grown as well as corn and always would be just as good and that had the same taste and aroma that would be boring :(

    Rafal,Oh, don't worry.  Even without some disease issues there are plenty of things that are challenging about growing grapes and getting the best quality from them.  It would just be nice to spend more time on the many tasks of viticulture and less on spraying.  I get a taste of all that with my little back yard vineyard.
    Steve Savage
    I'd split a GMO winery with you. Maybe we should do a crowdfunding....?

    Mary,Thats actually a good idea, but it would take several quite a bit to pay for the research and regulatory.  Also one would have to add a fair amount for fences and security to keep out the eco-vandals.
    Steve Savage
    In the near future, UC Davis will have probably finished developing their grapevine varieties that are resistant to Pierce's Disease and begin distributing them to nurseries. They discovered a region on chromosome 13 of Vitis arizonica (A cousin of Vitis vinifera) that gives the plant natural resistance to the disease. I did some work a few years ago as an undergraduate in collaboration with the Walker Lab at UC Davis on identifying some of the candidate resistance genes in this region. I haven't checked in on the current status of the research but thanks to this article I'm now going to go do some digging... Last I checked, they were able to create a 97% Vitis vinifera variety that is resistant to the disease by traditional introgression (crossbreeding Vitis vinifera with Vitis arizonica), however, when you cross-breed like this, you lose all the varietal characteristics that make the variety marketable. Since grapevine is highly heterozygous, after you cross-breed, that plant is no longer Chardonnay, Pinot Noir, Cabernet etc.... and since no one wants to drink wine labeled "UC Davis Clone 172" a more attractive solution to this problem is the use of transgenic technology.

    Todd,Thanks for that perfect example.  At least if PD becomes much more serious in the future that will have been a demonstration of what genes would be good to move with GE methods.  
    Steve Savage
    Bonny Bonobo alias Brat
    Great article Steve, as usual you have explained succinctly and beautifully the very good arguments for using genetical engineering on plants such as these grapes, to better overcome current global pests and diseases. We need to find more ways like this to cut down on the unnecessary amount of spraying of herbicides. pesticides, fungicides and fertilizers that then run off into our waterways and pollute our water that we drink and bathe in and potentially enable unhealthy, toxic algal blooms that accumulate in our fish and crustaceans which we then eat.

    Especially now that Australian Researchers have discovered the potential for blue green algae to cause Motor Neurone Disease (MND) and Lou Gehrigs's ALS in up to 90% of cases and also in other neurodegenerative diseases like Alzheimer's and Parkinson's just to mention a few. A toxin known as β-N-methylamino-l-alanine (BMAA), which is found in blue-green algae, has been shown in this article published yesterday by the Motor Neurone Disease Association (mnda) to cause proteins inside cells in affected humans to clump together and cause cell death. 

    This finding suggests that BMAA may be a potential cause of globally increasing neurodegenerative diseases like Alzheimer’s, Parkinson's and MND and could lead to the development of new treatments like L-serine, L-serine precursors, L-serine derivatives and L-serine conjugates for treatment, amelioration and/or prevention of protein aggregation/tangles/plaques and diseases associated with protein aggregation/tangles/plaques that was recently patented by Dr Rachael Dunlop et al in June this year. These treatments will hopefully reverse the absorption of BMAA and help prevent further absorption of this deadly toxin in our food and even in our drinking water. Especially as BMAA cannot be easily detected in water or food or killed with boiling and disinfectants. Even algicides do not render it any less toxic as the toxin remains after the blue green algae has been killed. Only carbon filtration of water and not eating infected food, in particular fish and crustaceans are the only way to avoid consuming it at present.

    I am personally a bit bored with the flavours of Shiraz, Chardonnay, Pinot Noir, Cabernet and would love to try new wines and flavours from Clone 172 for example! There's no reason why genetically engineered and cloned wine can't be named after whoever patented the genetic engineering is there? A nice bottle of Savage 2013 would go down well I'm sure and could even indirectly help to save a lot of people from the terrible worldwide suffering of neurodegenerative diseases potentially being caused by unnecessary toxins in our environment. Maybe this discovery of the toxic effects of blue green algae and BMAA will help boost the cause for more genetic engineering and stop the growing opposition? I am now converted to this GMO cause!
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine