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Better Wine Through Science

Posted by RPM on June 19, 2006
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Humans have been genetically engineering agricultural crops ever since plants were domesticated. Notice the difference between maize and teosinte. Or how about what we have done to create modern
wheat. By either imposing an artificial selection pressure on a few important loci (in the case of maize) or encouraging larger, polyploid individuals (wheat), we have been manipulating the genome of plants for a long, long time. More genetic manipulation of agriculture below the fold.

The difference between the genetic engineers of yore and those of today are the tools at their disposal. The molecular revolution of the past few decades has led to faster mechanisms for manipulating genomes. It all began with selective breeding of individuals with favorable characteristics — ie, larger fruits, increased milk production, etc.

Another simple trick involves crossing your strain of interest with another strain that has some property that you would like in your strain. For example, say your favorite tree species has been devastated due to an invasive pathogen, but a related species from the pathogen’s native habitat carries one or multiple resistance genes. If you can cross the two species, you can select hybrids that are resistant to the pathogen. In order to recover the traits characteristic of your species, you will then backcross the hybrids to your species, again selecting for resistant individuals. You will continue these backcrosses for multiple generations until you have created a resistant strain of your species. The goal in these hybrid backcross projects is to introgress the resistance genes (and only the resistance genes) into your species from the other species.

While the traditional approaches work, they can be extremely time consuming. That’s why scientists are looking more and more towards using molecular tools to genetically engineer agricultural plants and animals. Grape wine cultivars have been bred for many generations to produce certain flavors and aromas in the finished product. If a certain strain of grapes are susceptible to a pathogen, viticulturalist are tentative to perform hybrid backcrosses to transfer resistance genes from another strain for fear of losing the characteristics that give those grapes their desirable properties.

A group at Missouri State University is working to characterize genes in American grape varieties that make them resistant to fungal infections. They plan to transfer those genes into European strains so that they can be grown in the humid Midwestern climate. Missouri’s not exactly a hotbed for wine production, but that could change if the vineyards are able to produce grapes that can tolerate the new environment.

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  1. #1 afarensis
    June 19, 2006

    Missouri’s not exactly a hotbed for wine production

    Actually it is, we have a large number of wineries in the state – some of whom put out some excellent wine (I speak from experience I’ve been to a number of them).

  2. #2 Ewen
    June 19, 2006

    Most grapes grown in Europe are a hybrid between European vines and New World rootstocks, the result of an aphid infestation that wiped out many of Europe’s grapes in the 19th century.

    In an article last week Eric Asimov, the NY Times wine critic wrote:

    “Phylloxera, a ravenous aphid accidentally imported from North America, slaughtered European vineyards in the mid 19th century by attacking the roots of the vines. Just as native Americans succumbed to diseases brought by the European conquerors, vitis vinifera, the European vine species that is the source of all the world’s great wine grapes, had no resistance to phylloxera. The cost was staggering. Almost 6.2 million acres of vines in France alone were destroyed.

    “A solution was found in the late 19th century when scientists discovered that grafting European vines on to American rootstocks, which were resistant to the aphids, offered protection against phylloxera. Nowadays, virtually all the fine wines of the world come from vinifera grapes grafted onto American roots. Still, questions nag. Does grafting somehow impede the flow of character from earth to grape? What would wines taste like if the scourge had never come?”

    He goes on to review a Champagne from Bollinger produced from ungrafted grapes (a handful of vinyards exist in France, and quite a few in Spain and Portugal).

    From a scientific perspective, I think the Missouri study sounds interesting, and I can see a lot of large vinyards like Mondavi going GM.

    I personally would avoid wine grown from GM grapes, and I think many vinticulturists, especially European, would feel the same way. I’m not so naive to believe that GM grapes would somehow be a health risk or even taste all that different. The idea of GM wine just does not sit well with me.

  3. #3 RPM
    June 19, 2006

    I’ll keep my eyes peeled for some Mizzou wines next time I venture into my local, state run Wine Shoppe (inside joke for all the Pennsylvanians). In general, I’m not a big fan of US wines. They tend to cater to American tastes, which favor sweet over dry. That rules out much of Upstate NY (big on Rieslings). Also, the Napa wines always seem to taste very stereotypical to me (ie, the wineries try to create the typical chardonnay and end up with a wine that has no unique aspects and is overpriced to boot).

  4. #4 afarensis
    June 19, 2006

    Yeah, you see the sweet wine thing here in MO, we do have a couple of nice red wines though…

  5. #5 Sandra Porter
    June 19, 2006

    One of the best conferences, I ever attended, was on grape bioinformatics, at a resort in California. And of course, the wine tasting session was excellent.