Weed control, new insect pest, industrial products mark soybean research

The field of genetic manipulation in agriculture is moving fast. The changes, which some are calling a second wave, are outrunning not only the ability of regulatory agencies to keep up with them, but the ability of the public to grasp them.

In October the 2020 Nobel Prize in Chemistry was awarded jointly to Emmanuelle Charpentier and Jennifer A. Doudna “for the development of a method for genome editing.” The two women developed a method for turning a particular enzyme, CRISPR-Cas9, into a molecular “scissors” to cut away and rearrange DNA sequences.

The enzyme is directed to a specific DNA sequence by the guide RNA. The “scissor” enzyme makes a specific DNA cut and the cell machinery repairs the cut, creating an indel (insertion or deletion) of one or a couple of nucleotides. These are mutations that modify gene expression. The technology also can be used to cut and insert DNA.

In nature, CRISPR was originally part of a bacterial cell’s immune and defense system, allowing a defending cell to cut out parts of an invading cell’s DNA in order to remember it for defense. As a technique, CRISPR gene editing has only been available since 2012, when the key papers began to be published in Science.

China has already emerged as a leader in CRISPR technology, seeing it as a way to speed up its agricultural development. It’s also being used in South America, Southeast Asia and Africa. But CRISPR is only one example of a broader and rapidly evolving field of gene editing techniques.

When we speak of “gene editing,” we could be talking about deleting existing gene sequences, rearranging existing sequences or activating existing but dormant genes. The very definition of what counts as gene-edited or gene-modified is in flux, as the boundary between gene editing in the lab and traditional plant breeding becomes increasingly blurred. Regulatory agencies around the world are struggling with whether and how to name and label these changes.

This past May, the U.S. Department of Agriculture issued its SECURE Rule that changed its guidance for what it considers a genetically modified organism. Plants that have their genes edited using techniques like CRISPR, but that aren’t transgenic—that is, don’t import genes from another organism—will no longer be considered GMO, but instead will be regarded as similar to traditional plant breeding. The High Court of the European Union doesn’t agree: In 2018, it ruled that gene-edited products should be regulated the same as GMOs.

Within the U.S., the result of this regulatory relaxation has been to open up gene editing to more players and to jumpstart the field. In 2019, seven varieties of gene-edited plants were approved by the USDA. So far in 2020, 70 varieties have been approved. It’s no longer just big players with deep pockets like Corteva, Bayer, Syngenta and BASF in the game. Smaller firms and startups like Inari Agriculture, Pairwise, and CoverCress have various genetic traits in development, along with university research departments.

Soybean genetics

According to the USDA, in 2018 soybeans considered GMO made up 94% of all soybeans planted, 94% of all cotton planted, and 92% of all corn planted. While every U.S. scientific body has declared GMOs safe, “non-GMO” labels remain on many food products.

While faster and cheaper than earlier methods of gene editing, CRISPR can still result in a high failure rate of modified plants to grow and reproduce. While gene editing is definitely a tool of soybean researchers, it is not a magic bullet. “Once we figure out how best to use CRISPR techniques on soybeans, we may be able to apply it more effectively,” said Ed Anderson, senior director of research at the Iowa Soybean Association. Scientists are working on developing more enzyme scissors to cut particular DNA sequences in soybeans and other plant species.

EU approves Bayer gene-edited soybean variety

Among the most welcome news for Bayer in a tough year has been the European Union’s recent announcement that it has approved importation of Bayer’s XtendFlex soybeans, genetically engineered to resist three herbicides: dicamba, glyphosate and glufosinate.

In the U.S., weed control remains the biggest single challenge for raising soybeans, and integrated approaches that include different chemistries, traits and cultural practices work best, said Anderson. Seed companies have bet that engineering stacks of multiple herbicide resistances into soybeans is the way out of the current genetic arms race with adaptive weeds like Palmer amaranth that are developing resistances of their own to current herbicides. The hope is herbicides could be rotated from year to year with the same seeds to keep weeds off-balance enough to prevent them developing too strong resistance to any one type of herbicide. Multiple herbicides can be used in the same year if herbicide-resistance is a problem in the weed population, said Anderson.

Bayer has said it is launching XtendFlex for the 2021 growing season and expects to plant up to 20 million acres in the U.S. and Canada, matching the extent of Roundup Ready 2 Xtend beans in their first launch year. Bayer is reportedly working on a four-way stack, or a soybean product genetically designed to resist four types of herbicides, by the mid-2020s and a five-way stack to be ready by 2028.

Jim Sutter, CEO of the U.S. Soybean Export Council, said farmers could be pleased that “they can use the latest soy technology without interrupting their participation in world export markets.” The U.S. exports about 60% of its soy crop, and Sutter said, “We have to make sure that regulatory processes keep up with demand and with farmer interest.”

On Oct. 5, Corteva Agriscience announced its own new soybean pre-emergence herbicide mix, which it is calling Kyber. The herbicide boasts three effective modes of action, using ingredients including pyroxasulfone (Group 15), flumioxazin (Group 14) and metribuzin (Group 5), to deliver what Corteva calls “a new level of clean.”

Dicamba formulations approved

On Oct. 27, Environmental Protection Agency Administrator Andrew Wheeler announced that EPA is approving new five-year registrations for two dicamba products and extending the registration of an additional dicamba product. All three registrations include new control measures to ensure these products can be used effectively while protecting the environment, including non-target plants, animals and other crops not tolerant to dicamba.

EPA approved new registrations for two “over-the-top” dicamba products—XtendiMax with VaporGrip Technology and Engenia Herbicide—and extended the registration for an additional OTT dicamba product, Tavium Plus VaporGrip Technology. These registrations are only for use on dicamba-tolerant cotton and soybeans and will expire in 2025. Wheeler said the registration provides “certainty to American agriculture for the upcoming growing season and beyond.”

Soybean gall midge

Besides weeds, a newly emergent insect threat, the soybean gall midge, is the focus of intensive research efforts in several agricultural states. The gall midge was identified as a new species in 2018 after having been first spotted and identified in Nebraska in 2011 and South Dakota in 2015.

The North Central Soybean Research Program and other checkoff programs are funding research and Extension projects to better understand and manage this emerging insect pest. The Nebraska Soybean board and collaborators have set up alert programs with consultants and researchers using cages at 27 sites in four states to collect sample populations that can be used to learn more about this threat and its life cycle, to develop insecticides and other countermeasures.

The adult fly lays its eggs in soybean stems near the soil surface. The larvae feed on interior stem tissues to girdle and kill the plant. According to Anderson, as few as five or six larvae can destroy an entire soy plant. According to one website, it appears that the larvae don’t attack until the soy plant is in the v3 growth stage.

More reliable, verified information about all these traits and vulnerabilities must be gathered to enable entomologists, agronomists, geneticists and breeders to develop the best ways of protecting plants against the gall midge.

Ultra-high protein soybeans

While CRISPR adds an important tool to the genetic toolbox, breeding techniques that don’t involve genetic manipulation are also undergoing development. They may or may not use GE techniques, while taking a data-intensive moneyball approach, precisely controlling inputs and using artificial intelligence models to model and control desired traits.

In March, St. Louis-based crop improvement company Benson Hill announced it was releasing its ultra-high protein soybean varieties for the 2021 crop year. The company said these varieties are the first commercially available soybeans that can effectively replace soy protein concentrate via typical soybean crushing. “This innovation enables food companies to eliminate costly energy and water-intensive processing steps across the consumer food, animal feed and aquaculture markets,” according to Benson Hill’s website.

“While soybean yields have improved over the past decades, protein levels have fallen,” said David Iverson, United Soybean Board meal target area coordinator and a South Dakota grower. “These ultra-high protein varieties demonstrate how we can work together via soy checkoff investments to improve protein content for end-users. We continue to work with public and private partners, including Benson Hill, to serve as a catalyst to enable new technology, farmer choice, and innovation across our soybean industry.”

The initial launch will include more than 20,000 acres in 2021, the company said, expanding tenfold in 2022. A particular selling point is that the ultra-high protein varieties were developed through traditional breeding, allowing non-GMO certification and unrestricted use in U.S. and export markets, including Europe.

Industrial uses

One of the big success stories in soybean genetic research has been the development of high-oleic soybeans. High oleic soybean oil is in high demand from food processors because of its health benefits, stability, and performance in frying and high heat uses. It has been touted as a healthy replacement for trans fats. It has also found industrial uses as an element in asphalt, a concrete sealer, a tire ingredient and many others. According to Anderson, it is now also being used to spray asphalt shingles to increase their wear and extend life, and to replace elastomers in the auto industry.

However, there has been a falling off of interest among U.S. soybean farmers in high-oleic varieties in the past few years. The United Soybean board is promoting renewed interest in high-oleic beans. According to John Jansen, vice president of oil strategy for the United Soybean Board, U.S. farmers planted about 500,000 acres of high-oleic soybeans last year, mostly in Indiana and Ohio, and some in the DelMarVa peninsula. That’s down from 2017 and a far cry from the potential demand the USB sees; it projects a need for 16 million planted acres by 2027.

Sutter said demand for high-oleic beans is high right now, both domestically and internationally. While high oleic beans are planted and raised the same way as commodity beans, weed control can remain an issue, because the high-oleic bean varieties don’t yet include stacked herbicide-resistance traits.

Soy Innovation Challenge

On Oct. 13,after a review of more than 89 worldwide applicants, the Yield Lab Institute—in partnership with the United Soybean Board, Syngenta and Amazon Web Services—announced the cohort finalists for the Soy Innovation Challenge, a group of innovations and technologies that have potential to capture value for farmers and “disrupt the soy value chain.”

“All of these innovations are game-changers and will enable farmers to stay ahead of end-user demands, delivering sustainable outcomes while still keeping farmer profitability at the forefront,” said Andy Fabin, USB’s sustainability target area coordinator and a farmer from Indiana, Pennsylvania. “Access to new technology at our fingertips to make more strategic decisions will allow us to farm smarter in lockstep with the soybean supply chain as a whole.”

Launched in March, the Soy Innovation Challenge finalists developed solutions to accelerate sustainability enhancements and maximize profit opportunities through technology that’s seamless for soybean farmers to use.

Aquaculture

Aquaculture, another encouraging field for expansion of soybean use, has exploded in the past decade as it has become clear that the world’s taste for seafood protein is far outrunning the ability of wild species to meet it. Fishmeal-based salmon feed, experimented with in the early days, proved costly and unsustainable. Soybean-based salmon meal contains both omega-6 and omega-3, like the seaweed from which wild fish ultimately obtain their amino acids—and unlike corn-based feeds. Soy-based aquaculture even has its own advocacy organization, the Soy Aquaculture Alliance.

Soy-based artificial ‘skin’

Yet another more recently developed use for soy products is as a prime ingredient in artificial skin used in skin and wound repair. A company called NeuEsse Inc., says it is revolutionizing medicine by creating healing “skin” from soybeans. Its flagship product, OmegaSkin, spins soybean protein into a mesh patch or scaffold which is applied to the skin as a bandage, or by using touch-free spray device to promote wound closure, healing and skin regeneration. OmegaSkin can be electrospun into large sheets for shelf storage and immediate application when needed.

Market outlook

As this article was being written, the news broke that Brazil, the world’s largest soybean exporter, had committed virtually all its current crop to China and was looking to import beans. Because Brazil won’t allow the importation of U.S. GMO beans, its options are limited to its partners in the MERCOSUR trading block—Argentina, Paraguay and Uruguay. Venezuela is a suspended member. China has been quickly rebuilding its swine herd after the devastations of swine flu. To make up its remaining soybean needs, China will have to resort to the U.S. and Argentina.

Whether or not these developments will increase or reduce interest among U.S. farmers in planting specialized soybeans remains to be seen.

David Murray can be reached at [email protected].