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How Roundup Ready Soybeans Rocked the Food Economy

This 1980s-era “gene gun” fired the shot heard around the world

A prototype gene gun developed by Dennis McCabe and Brian Martinell in 1986 delivered new genetic material into the cells of plants. (NMAH )
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Among the countless relics and oddities lining the halls of the National Museum of American History, the “gene gun” on display in the American Enterprise exhibition—which traces chronologically the evolution of industry in the U.S.—is notable as much for its rugged charm as for its significance in the tumultuous history of genetic engineering.

Peering down into the gun’s glass display case, one is immediately struck by the jury-rigged appearance of the contraption, which consists of several disparate components—a plywood-mounted transformer, a voltmeter-equipped wand, a pair of bulbous vacuum tubes—haphazardly connected with wires. Complete with a 15,000-volt capacitor bearing a dramatic, sloppily scrawled warning (“Contact with these voltages would be instantly lethal!”), the device seems less like a true-life scientific breakthrough and more like an occult whatsit pilfered from the laboratory of Emmett “Doc” Brown.

Such a characterization, as it turns out, is not so far from the truth. The two men responsible for the device’s creation—Agracetus employees Dennis McCabe and Brian Martinell—assembled and tested it in their spare time in 1986, routinely exposing themselves to blinding flashes of light, thunderous booms, noxious byproduct gases, and, in general, extreme danger.

“I didn’t have switches or anything,” McCabe recalls fondly of his earliest days in the lab. “I just grabbed hold of the wires and touched them to the terminals, and that was my switch.” He remembers well the terrified look of his partner: “Brian was watching me do this, and praying I wasn’t going to kill myself.”

By zapping water droplets and harnessing the resultant shockwaves, McCabe and Martinell were able to propel DNA-coated gold particles arrayed on a Mylar surface (potato chip bags were used in the earliest prototypes) into plant cells, altering their genetic code in an unprecedented fashion and helping to usher in an era of genetically modified mass-market foods.

Though the 1986 gene gun on display at the American History Museum gave rise in subsequent years to a much safer model—a “cabinet on wheels,” as McCabe describes, “with everything embedded in it and a nice shelf to work on”—scientifically speaking, the basic mechanism of the device never changed. “The physical principles are absolutely the same,” Brian Martinell says of today’s technology.

McCabe and Martinell drew their inspiration from the work of John Sanford, an eccentric Cornell geneticist who in 1983 spent his Christmas break firing a tungsten-loaded .22-caliber pistol into raw onions. Sanford was attempting to affect the genetic makeup of the large-celled bulbs by peppering them with “microbullets” bearing genetic material—a decidedly brute-force approach. His technique stood in stark contrast to the then-de rigueur method of Agrobacterium mediation, wherein DNA was carried into plant cells via plasmids naturally released by bacteria. Sanford’s radical idea is said to have occurred to him while taking potshots at squirrels in his backyard. In any event, it was successful.

With the technical improvements made by McCabe and Martinell, Agracetus scientists were newly able to target the identity-defining germ line cells found in plants' vascular bundles, giving them the potential to alter key characteristics of species that had previously resisted all attempts at manipulation. The gene gun was ready for prime time.

Enter Monsanto, the American agriculture giant looking to recast itself in the mold of the incipient biotechnological age. Monsanto had developed in its labs a strain of bacteria containing genes that would, when expressed in target plants, protect them from the effects of Roundup weed killer (a proprietary Monsanto product). All the company needed was a means of carrying the genetic information into target cells. Agracetus’s gene gun looked to be just the ticket.

Monsanto’s offer of $5 million was one Agracetus could not refuse. “We got the gene and started shooting,” recalls Dennis McCabe. “It was just like an assembly line.”

Thanks to the labors of Agracetus, Monsanto produced the first Roundup Ready soybeans in 1989 (Monsanto acquired Agracetus in 1996). Herbicide-resistant soybean plants meant that farmers planting Roundup Ready soy could spray weed killer without fear of harming their crop; no longer would children and migrant workers be needed to “walk the beans” for hours on end hoeing up weeds. The economic consequences of this change would prove tremendous, as would the outcry of a deeply skeptical cross-section of the American public.

By the early 2000s, Roundup Ready had come to dominate American soybean production, accounting for four-fifths of the nation’s output. No mean feat, bearing in mind that soybeans are the second most widely grown crop in the land (some four billion bushels were cultivated in 2015), and that costly trial-and-error analysis was required at every turn to ensure that the genetic changes wrought by gene guns were, in fact, the ones desired. This overhead spending increased the price of seeds, but farmers found that the added cost was more than offset by the money they saved on crop maintenance. And so, contentedly, they planted and planted.

As Americans began consuming genetically modified foods like never before, protests were quick to materialize. Voices like that of Pure Food Campaign founder Jeremy Rifkin inveighed against so-called “Frankenfoods” with vigor. In a 2000 interview with PBS, Rifkin succinctly articulated a major concern: “Many of the genetically modified foods will be safe, I'm sure. Will most of them be safe? Nobody knows.”

Many decriers of GMOs rely on a corruption-of-nature defense, expressing fear over genetically manipulated crops by dint of their being “unnatural.”

However, as Peter Liebhold, curator of agriculture at the American History Museum, says: “Humans have been screwing around with nature for millennia.”

Liebhold, whose office bookshelves teem with agriculture-themed literature, was more than happy to expand upon this point. Liebhold notes that virtually all major crops currently grown in the United States are nonnative (corn is Mexican in origin, wheat is Turkish, etc.), implying that a large degree of baseline human artifice is part and parcel of modern agriculture.

Liebhold adds that there's a very subtle distinction between post-gene gun “genetic modification” and pre-gene gun mutagenesis. “If you’re a hybridizer,” Liebhold says, “you want to take your source, mutate it, find something that has good qualities, then propagate it.”

To effect mutations, seed companies were—and still are—in the habit of bombarding plant cells with direct radiation, nuking them in many cases with what Liebhold terms “atomic guns.” In an ironic twist, this patently unnatural process has resurged in popularity with the growth of the anti-GMO movement, since the offspring of plants mutated in this way can legally be labeled “organic.”

“Organic,” Liebhold notes, is a word widely spoken yet poorly understood. To say that “organic” implies “pesticide-free,” for instance, is misleading: organic crops are treated with natural pesticides, which can potentially be just as environmentally harmful as the synthetic pesticides used on their non-organic counterparts. Further, many organic and non-organic farmers alike engage in monocropping, refusing to rotate their crops for reasons of efficiency and profit. The consequences of this practice, which is a catalyst for soil depletion, can be dire.

Organic farming also carries with it its own unique health risks. Where non-organic farmers can infuse synthetically generated nitrogen into their soil to give plants the nutrients they need, organic farmers cannot, and often elect to use manure instead. While safe if handled correctly, manure can easily give rise to disease-causing bacteria like salmonella, listeria and E. coli, if not.

In short, Liebhold says, modern agriculture is a complex, nuanced picture—more complex than many are willing to concede. At the end of the day, however, the principal driver for farmers is simple: economics. What consumers are willing to pay for is what farmers are willing to produce. In America, Liebhold says, “We talk significantly about values, but… usually vote with our pocketbook.”

Even in light of the recent National Academy of Sciences study affirming that no deleterious health effects whatsoever are known to be causally linked with the ingestion of genetically modified foods (concerns regarding Roundup itself and other herbicides are a separate issue), Liebhold doesn’t see organic produce going away any time soon. “If you want handmade food,” he muses, “people will be delighted to make it for you.”

As far as debate over GMO safety goes, gene gun co-creator Brian Martinell is hopeful that, as awareness of the foods’ flawless 30-year health record grows, doubters will begin to revise their views. “I have to believe that in the end science will prevail,” he tells me. “But I’m an optimist, what can I say.”

About Ryan P. Smith
Ryan P. Smith

Ryan is a fourth-year college student currently pursuing a major in Science, Technology and Society at Stanford University. His avocations include moviegoing and crossword puzzle construction.

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