By Scott Learn
Researchers who identified Monsanto’s genetically modified wheat in a northeastern Oregon field are questioning the seed giant’s emphasis on the potential for faulty test results.
A Monsanto spokesman said the company is “operating on the assumption” that the test results announced 10 days ago are valid. But in a press conference call last week, company officials stressed the potential for false positives and noted that Monsanto hasn’t been given plant samples to test.
Robb Fraley, Monsanto’s chief technology officer, said the company has the only test that can pinpoint the genetically modified strain last planted in Oregon test fields a dozen years ago.
“Let me emphasize, this is the only reliable test,” Fraley said. “We provided it to regulators and we don’t know if anyone else besides us is using it now.”
Federal investigators looking into the rogue wheat are “certain” their testing is accurate and the plants are Monsanto’s strain. Researchers at Oregon State University, who ran the first round of tests, said the implication that the results could be wrong is off base.
“It’s kind of making it sound like, ‘We’re Monsanto, we know how to do the test and other people don’t,'” said Robert Zimetra, a wheat breeder at OSU’s Department of Crop and Soil Science. “What this is showing is other people do know how.”
The presence of the transgenic plants, never approved for commercial sale and last grown in Oregon in 2001, is a real head scratcher for both Monsanto and outside researchers. That’s left lots of room for speculation.
But faulty test results aren’t the explanation, said Carol Mallory-Smith, the weed science professor who conducted OSU’s testing. Genetic analysis confirmed the plant contained the gene from a soil-based agrobacterium that Monsanto inserted to generate resistance to its Roundup herbicide, she said.
It’s true that Roundup Ready seeds approved for commercial use — soybeans, corn and canola — have the same gene modification, she said. Dust from those crops left behind in trucks or other shipping containers could contaminate wheat seed or grain, leading to a false positive test result. That’s a concern for grain tested by foreign countries that don’t want genetic modifications.
“Strip tests” of marker proteins in genetically modified seeds can also return high false positives.
But Mallory-Smith said the OSU lab used more sophisticated DNA tests that specifically singled out the inserted gene, using controls from other wheat varieties to guard against false positives.
The tests were also on Roundup resistant plants taken straight from a field, she said, not on stored seeds or grain. The only potential for contamination of the wheat plants from other crops would have been if other crops were pollinating in April when the volunteer wheat was reported, she said, and they weren’t.
“There really is no possibility for cross contamination,” she said.
A spokesman with the USDA’s Animal Plant Health Inspection Service, which is conducting the investigation, said Monsanto provided “the procedures and methods” to confirm that the plants were the specific strain, known as the “MON 71800 event.”
APHIS used “event-specific” polymerase chain reaction tests — highly familiar to DNA testers — to pinpoint that it was indeed Monsanto’s plant, the spokesman said, adding: “We are certain of the result.”
Monsanto has requested samples of the plants to run its own tests.
Monsanto officials say the seeds from the planting trials were either destroyed or securely stored at Monsanto or USDA facilities after it abandoned the project. But the company also stressed the potential for sabotage — a deliberate saving and planting of the seed despite federal prohibitions.
Other explanations can’t be ruled out yet, outside researchers say, though there’s no evidence of a large-scale spread.
Oregon test plots were far from the farm in question, but windborn pollen still may have crossed into conventional wheat closer to the test plots at levels low enough to remain undetected for years. Seeds from the testing could also have escaped in small quantities, spilled from the back of a truck, for example.
Kent Bradford, a professor and director of the Seed Biotechnology Center at the University of California, Davis, said he’d like to see APHIS’s testing details to make sure the methodology is sound. He questioned why APHIS didn’t provide samples for Monsanto to test before the high-stakes public announcement of the results.
“If they’re so positive,” Bradford said, “they should release the data.”
The APHIS spokesman declined to comment on whether the agency would send the plants to Monsanto, citing the continuing investigation. Mallory-Smith of Oregon State said it doesn’t surprise her Monsanto hasn’t received the plants.
“They’re investigating Monsanto,” she said. “Why would you send that information to the company you’re investigating?”