USDA clears mildew-resistant biotech wheat

Capital Press file Wheat is shown in this file photo. The Animal and Plant Health Inspection Service has found that a new mildew resistant wheat cultivar doesn't fall under its jurisdiction for regulating genetically engineered crops.

A wheat variety rendered mildew-resistant through the targeted “knockout” of a gene can be commercialized without clearing USDA regulatory hurdles for biotech crops.

The agency’s Animal and Plant Health Inspection Service has found that the cultivar doesn’t fall under its jurisdiction for regulating genetically engineered crops, which is limited to possible plant pests and pathogens.

While the wheat was developed with genetic elements from disease-causing bacteria, they aren’t contained in the crop and thus it’s not subject to USDA’s deregulatory process, which includes environmental analysis and public comment, according to APHIS.

Most biotech crops commonly grown in the U.S. have undergone deregulation, and in some cases, lawsuits over the adequacy of this process have delayed their commercialization.

Calyxt, a subsidiary of the biopharmaceutical company Cellectis, developed “MLO_KO” wheat with genetic sequences from bacteria and corn that remove a gene that suppresses the plant’s defenses against powdery mildew.

The wheat’s DNA is repaired during natural cellular processes and no foreign genetic material remains.

“It does not change the wheat’s basic biology or produce a plant that would directly feed on, infect, parasitize, or contaminate plants, or adversely affect other organisms that are beneficial to plants,” Calyxt said in a letter to APHIS.

The gene eliminated by Calyxt is involved in the plant’s biological processes but the mildew fungus also relies on it to “trick” and penetrate the wheat crop, said Luc Mathis, the company’s CEO.

Even without the gene, the wheat’s biology remains unaffected due to other genes that perform duplicative roles, he said. “When you remove this function, the plant behaves normally.”

Though the USDA has decided the wheat cultivar can be commercialized, Mathis said he doesn’t expect the crop to be sold to farmers until 2022.

Calyxt must first conduct trials to ensure the trait is reliable in the field while simultaneously incorporating the mildew resistance into geographically suitable wheat varieties, he said.

The company also aims to stack it with other traits that improve wheat’s digestibility in humans, Mathis said.

In 2013, a regulated biotech wheat variety was found growing without USDA authorization in an Oregon field, which temporarily disrupted exports to Asia.

The episode prompted farmers to file a class action lawsuit against Monsanto, the crop’s developer, that was later settled for roughly $2.7 million.

Mathis said his company has met with agricultural regulators in foreign markets and does not expect its wheat variety to experience export problems because the technology accelerated a process that could have occurred naturally.

“From a technical viewpoint, there is no difference. There is no foreign DNA,” he said.

The U.S. wheat industry plans to educate its foreign customers about the new cultivar during the years that Calyxt prepares the trait for market, said Steve Joehl, research and technology director for the National Association of Wheat Growers.

Calyxt’s variety is the first product the wheat industry will have to evaluate in this way, he said. “It is a milestone.”

Before the trait can be commercialized, breeders from universities or seed companies will likely ensure there is a market for the crop before incorporating the mildew resistance into geographically-suitable varieties, Joehl said.

Despite this caution over market reaction, Joehl said the Calyxt cultivar and gene editing technology are exciting developments for the wheat industry.

Currently, less than $170 million a year are invested in wheat research, compared to roughly $3 billion for corn, he estimated.

“We desperately need new technology in wheat.”

U.S. Wheat Associates, an organization dedicated to wheat exports, does not consider the Calyxt variety a genetically modified crop because it doesn’t contain any new genetic material, said Steve Mercer, its vice president of communications.

The organization nonetheless plans “step back and take a look at it” with foreign customers, Mercer said. “Ultimately, the marketplace will determine whether varieties developed with this new gene editing technology will be accepted.”

Critics of genetically engineered crops are troubled by the USDA’s refusal to regulate Calyxt’s wheat and other biotech crops simply because they aren’t potential plant pests or pathogens.

“This is a specific instance of a general problem,” said Doug Gurian-Sherman, director of sustainable agriculture for the Center for Food Safety, which has fought the USDA over deregulating biotech crops.

The agency has unnecessarily created a “giant loophole” in its regulatory authority, even though it can exercise greater control over biotech crops under federal law, he said.

The loophole is actually widening as the biotech industry becomes less dependent on plant pathogens to genetically engineer crops, he said. “As the technology has moved along, the need for those genes or gene sequences has gone by the wayside.”

USDA was also too quick to assume the biotech crop doesn’t pose a weed risk, Gurian-Sherman said. “That is not an assessment, that is a summary judgment.”

While wheat itself is unlikely to become a weed, the mildew-resistant trait can transfer to jointed goatgrass through cross-pollination, he said.

Mildew-resistance could then make such goatgrass more competitive, Gurian-Sherman said. “Without knowing more, this has the potential for making a very serious agricultural weed an even worse weed.”

Mathis, of Calyxt, said this possibility is unlikely because the mildew-resistant trait would become greatly diluted after crossing with wild relatives of wheat.

“It’s not a dominant mutation,” he said. “We don’t see that as an issue.”

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