Genetically Modified Wheat Could Provide Drought Relief

Central Oklahoma farmer Michael Peters is no stranger to the effects of drought on his hard red winter wheat crop.

"With wheat, it's not so much about how much rain you get. It's the timing of the rains," he says. "You could be wet all winter, but if it turns bone dry in April and May when the wheat is going into its reproductive stages, that's when it hurts you. It would be nice to have something to get through those dry spells."

Last fall, Peters saw firsthand a potential future solution -- a field of drought-tolerant genetically modified (GM) wheat growing in Argentina. Yet, several regulatory and cultural hurdles must be cleared before GM wheat becomes reality for U.S. wheat growers.

Bioceres Crop Solutions, a company based in Rosario, Argentina, has developed HB4 wheat, a transgenic variety that contains a gene isolated from sunflower. In 2020, the Argentine government granted approval for commercial cultivation of HB4 wheat, making it the world's first GM wheat to earn that distinction. Two other South American nations -- Brazil and Paraguay -- gave their regulatory blessing for cultivation in 2023. Bioceres is actively working to expand the list to countries on other continents.

"HB4 wheat currently is under evaluation for cultivation approval in the United States, Uruguay and Bolivia," says Martin Mariani Ventura, global seeds and traits manager at Bioceres. "We're also preparing to pursue cultivation approval in Australia in the future."

TOUGHENED TOLERANCE

As a GM crop, HB4 wheat contains HaHB4, a transcription factor that modulates the expression of several hundred genes providing drought tolerance. In the face of drought, HB4 generates more antioxidant and osmoprotectant molecules, delaying cellular deterioration and allowing the plant to maintain photosynthesis until rain returns. HB4 wheat also is tolerant to glufosinate herbicide.

Mariani Ventura says that HB4 is not a silver bullet. Rather, it's more like an insurance policy against the effects of drought, and the value of that policy becomes more pronounced in lower-yielding environments.

Data from three seasons of field trials in 34 different locations in Argentina show that when environmental conditions limited yield to less than 30 bushels per acre (bpa), varieties with HB4 technology yielded 38% more on average than the same wheat variety without the technology. The increase was even more pronounced -- 51% more on average -- when looking at data from 2022-23, a season during which Argentina suffered through a major drought.

"Even in a nonlimitation environment, where yields exceed 60 bpa, the varieties with HB4 yielded 23% more on average than the same varieties without it," Mariani Ventura explains. "From the grower perspective, this is important because it means the technology works when there is a drought situation, but it also doesn't cause a yield drag when there is no drought."

GM WHEAT REDUX

While HB4 wheat is the first to receive government approval for commercial cultivation, it's far from being the first GM wheat developed. Other efforts can be traced back more than a quarter-century, with plant geneticists attempting to confer traits for improved compositional characteristics, herbicide tolerance and insect and disease resistance.

The most notable U.S. example occurred when Monsanto, now owned by Bayer, developed GM wheat resistant to glyphosate herbicide. The USDA authorized field tests of Roundup Ready wheat in 16 states beginning in 1998.

While other genetically modified crops, such as corn and soybeans, have been approved for nearly three decades, they are predominantly used as animal feed. Wheat, on the other hand, is a staple food for billions of humans who consume it in breads, cakes, crackers and noodles. Consumer fears of unforeseen negative effects and grower fears over the potential loss of markets led Monsanto to abandon its GM wheat program in 2004.

Peter Laudeman, director of trade policy for U.S. Wheat Associates (USW), says there's tremendous interest in the potential for HB4 wheat, especially from U.S. growers in regions that have dealt with drought in recent years.

"I think they would love to have that sort of product that may provide that opportunity to have a little bit more stable and consistent yields in light of drought," he says. "HB4 wheat has been on our radar since Bioceres moved forward with commercialization, so we've engaged with the company in a number of ways."

For example, a group of farmers representing USW traveled to Argentina this past November to visit Bioceres and see HB4 wheat firsthand in the field.

"It was all headed out with nice big heads when we were there," says Peters of Okarche, Oklahoma, who currently serves as USW chair. "It was maybe a little tall for our liking, but they were beautiful plants. Some of the best wheat I've seen."

U.S. TIMELINE FOR HB4

In June 2022, the U.S. Food and Drug Administration announced that it found no safety issues with the HB4 wheat, allowing for food and feed use. Other countries have made the same determination, including Australia, Colombia, Indonesia, New Zealand, Nigeria, South Africa and Thailand. However, before Bioceres is allowed to cultivate HB4 wheat in the United States, the modified plants must be reviewed by the USDA Animal and Plant Health Inspection Service (USDA-APHIS).

In January, a spokesperson from USDA-APHIS told Progressive Farmer the agency was unable to share information related to a specific product until it concluded a review or published a draft plant pest risk assessment for public review and comment.

Should such approval occur, USW's Laudeman says U.S. wheat producers will support commercialization of transgenic wheat traits after thorough review and the development of a plan that facilitates commercialization.

"Whether it's a Bioceres trait or any GM trait that wants to come to market, we and the National Association of Wheat Growers have developed a set of guiding principles," he says. "Any GM trait coming to market needs to do so in a way that benefits the producer and doesn't disrupt markets unnecessarily. The technology provider must also seek and receive regulatory approval in our key wheat exports markets, which we've defined as those that represent at least 5% of our normal export volume based on the five-year average."

Mariani Ventura says he believes Bioceres could have some research activity underway in the U.S. once HB4 technology receives USDA clearance. He adds that the GM wheat is most likely to add value for growers in the Great Plains, including Oklahoma, where Peters battles Mother Nature each year.

"I don't know how soon or if the U.S. will ever be ready for GM wheat," the farmer says. "A lot of our overseas customers aren't really ready for that technology yet, but we need to be aware of what's going on, understand the technology and know what Bioceres is doing with it. We've got to embrace it and be ready for it if it does come our way."

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