Seeking value in GMOs

We routinely reward and punish software hackers who tinker with orthodox code.

Likewise, depending on the circumstances, society celebrates or demonizes folks who modify automobile mufflers, bicycle handlebars, firearms, constitutions, recipes and DNA.

Genetic engineering — the modification of organisms' cellular codes — apparently happens all the time, with and without human help.

While the debate over GMO foods may be polarized, the definition of genetically modified organisms is less clear.

Should we care?

A worthy beginning to the discussion lies in the microscopic nuts and bolts of GMOs, says Tom Vogelmann, a professor of plant biology at University of Vermont, and dean of the College of Agriculture and Life Sciences.

Vogelmann says it is helpful to remember that the transfer of DNA between species is a common phenomenon: a function, or tool — but not an ideology.

"Nature actually figured out how to do genetic engineering long before we did," he said earlier this month.

"It's an artificial distinction to say, 'Well, because it happens in nature it's OK; but if we do, it it's not.'"

Nature-made GMOs

Vogelmann offered crown gall — a bacterial infection of plants — as an example that enlightened 20th century researchers.

An enterprising soil bacterium, splashed into a gash of a plant's stem, will insert genes into the host's cells, he said.

Some of that code instructs the plant to build a protective, tumorous growth (the gall) around the bacterial colony.

Other codes coax the plant's metabolism to produce a specialized pair of amino acids to feed the bacteria, at the expense of the plant.

The growing ability to inventory the constituents of a strand of DNA — to sequence a genome — have given scientists an unprecedented glimpse into what makes an organism tick.

Climate change and food chains

Vogelmann recommended a conversation with Mary L. Tierney, a professor of plant biology at UVM because, he said, "She's actually doing this stuff."

Tierney spends a lot of time looking very closely at the workings of a mustard-cousin, Arabidopsis thaliana.

The plant, featuring a relatively small genome, admirably serves the purposes of researchers worldwide.

Tierney wants to learn more about what controls the way root cells take up water and nutrients.

A soil-dwelling bacteria — the same one responsible for crown gall — helps with the heavy lifting.

In the service of human interests, Tierney prompts this micro-engineer to selectively disrupt DNA in the mustard's genome.

By observing those disruptions, Tierney is able to identify, with precision, which genes respond to environmental changes in light, drought and interactions with other organisms, such as insects.

"What we learn in this model system helps us ask the right questions as we look into crop plants that share the same genes," she said.

"We could breed plants that would be more tolerant of marginal environments; breed plants that are able to grow better as our climate changes — because the current crops we have are adapted to the climate that we have."

Traditional breeding methods that pull variety from within the same species of food crop have "plateaued," and will unlikely keep pace with Earth's rapidly changing growing conditions and ballooning human population, Tierney said.

In theory, genetically modified plants would improve humanity's chances. But in most cases, the leap from lab to field remains hypothetical.

Public opposition to GMO crops, coupled with a time-consuming and costly federal approval process, have largely restricted the roll-out of transgenic plants to those with well-heeled backers.

Among the 30-or-so transgenic crops: Feed corn and soybeans, cotton, sugar beets and canola.

Food fight

With less lavish sponsorship, transgenic "golden" rice was developed about 15 years ago.

It remains unmarketable due to concerns over its inadvertent spread to non-GMO rice, and unforeseen health and environmental impacts.

At the cellular level, the mutation appears to be straightforward.

Two genes inserted into the rice facilitate the grain's content of beta-carotene, a precursor to Vitamin A that normally occurs only in the plant's leaves.

Golden rice has the potential to promptly remedy Vitamin A deficiency in the world's poorest, most poorly nourished communities, Tierney said.

Critics, such as the environmental advocacy group Greenpeace, argue that in the long run, providing a greater diversity of grains, fruits and vegetables, would offer those communities a less risky, time-tested remedy.

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Corporate profiles

A polarized discussion of GMOs plays into the hands of well-funded interest groups at each extreme of the spectrum, Tierney said.

Lost in this shuffle, she added, are useful discussions over how the general public has come to associate GMOs with the agendas of large corporations.

The correlation is understandable. Our highest-profile transgenic crops feature in quarterly earnings of Monsanto, Dupont and other giants.

But the decision to plant a monoculture or clear-cut a hillside, or spay a crop in herbicide can — and should — become decoupled from an association with GMOs, Tierney said.

Just as plausible, she added, are transgenic plants that enhance local food systems and reduce pesticide use.

Avoiding GMO foods

The notion provokes yet another tricky conversation.

Step one is pretty simple, Tierney says: Stay away from high-fructose corn syrup and soybean oil — the most common source of transgenic plants in processed food.

Step two: Restrict your diet to certified organic foods, which are produced without GMOs.

But a closer look shreds any notion of purity.

"There can't be a 'zero tolerance' for GMOs," Tierney said. "It's impossible. For example, in the case of corn, you'd have to test every kernel on every ear — because each of those is an individual pollination event."

Thorough, fool-proof testing, in other words, would not only be prohibitively expensive and time consuming, but would reduce every kernel in that ear of corn to mush.

Tierney offered one glimmer of certainty: A broad swath of scientists, relying on a plethora of peer-reviewed research on pre- and post-GMO health statistics, have found no credible reason to conclude that foods produced from current GMO crops are unsafe to eat.

Mutant biofuel

Elsewhere on the UVM campus, the subject veered in the direction of GMO-propelled cars.

Transgenic corn, which is fermented by yeast into ethanol, has already transformed vast tracks of the Midwest.

Other techniques for cultivating biofuels — from diesels to aviation fuels — are being tested on a much smaller scale at the lab of Mary Dunlop, a bioengineer and professor at College of Engineering and Mathematical Sciences.

Yet again, bacteria play a leading role.

E. coli, a gut-friendly organism, converts sugars into alcohols or other hydrocarbons. As with yeast in a batch of wine, alcohol concentrations reach a level of toxicity to the bacteria, and the process stops.

Dunlop is examining ways to boost E. coli's production.

Using a genetic process called transformation, she is able to introduce genes that control tolerance to biofuels, and the efficiency by which that metabolic "waste" is released.

Dunlop sticks with E. coli because of its rapid reproductive rate, its relatively simple cellular structure "and because you can just put them in the freezer for the weekend if you want to go home."

Designer drugs

Before returning to her work, Dunlop noted another arena for genetically modified E. coli: the production of insulin for diabetics.

Dean Tom Vogelmann elaborated.

"People overlook that this new technology has transformed pharmaceuticals and medicine," he said.

"You can imagine the relief worldwide when all of the sudden you could make pure human insulin within bacterial cells. It seems to be accepted."

E. coli can be selectively modified not only to kick off vaccines, but also to perish if it escapes the confines of the lab — a safety measure more secure than the old-school method of cultivating, storing and transporting deadly pathogens, Vogelmann added.

Quickly, naturally mutating microbes pose the ultimate biological threat to humanity, he concludes.

"Viruses and retroviruses are notorious for dumping DNA into human cells," Vogelmann said. "You carry foreign DNA around in you until the end of your days."

Contact Joel Banner Baird at 660-1843 or joelbaird@FreePressMedia.com. Follow him on Twitter at www.twitter.com/vtgoingup.

GMO roundup

Crops that have been genetically modified with other species' genomes include:

• Alfalfa (Medicago sativa)
• Apple (Malus x Domestica)
• Argentine Canola (Brassica napus)
• Bean (Phaseolus vulgaris)
• Carnation (Dianthus caryophyllus)
• Chicory (Cichorium intybus)
• Cotton (Gossypium hirsutum L.)
• Creeping Bentgrass (Agrostis stolonifera)
• Eggplant (Solanum melongena)
• Eucalyptus (Eucalyptus sp.)
• Flax (Linum usitatissumum L.)
• Maize (Zea mays L.)
• Melon (Cucumis melo)
• Papaya (Carica papaya)
• Petunia (Petunia hybrida)
• Plum (Prunus domestica)
• Polish canola (Brassica rapa)
• Poplar (Populus sp.)
• Potato (Solanum tuberosum L.)
• Rice (Oryza sativa L.)
• Rose (Rosa hybrida)
• Soybean (Glycine max L.)
• Squash (Cucurbita pepo)
• Sugar Beet (Beta vulgaris)
• Sugarcane (Saccharum sp)
• Sweet pepper (Capsicum annuum)
• Tobacco (Nicotiana tabacum L.)
• Tomato (Lycopersicon esculentum)
• Wheat (Triticum aestivum)

Source: International Service for the Acquisition of Agri-Biotech Applications.

Details on the crops and their provenance can be found at the organization's online GM Approval Database: www.isaaa.org/gmapprovaldatabase/default.asp