Solving the Soybean Rubik's Cube

By Barb Baylor Anderson

Puzzle solvers know that a Rubik’s Cube requires multiple moves to match like colors on each of its six faces. Every twist of the 3-D cube puts completion further ahead or further behind.

Similarly, researchers who have tried to solve the soybean protein composition puzzle for years know that generally increasing protein content reduces soybean yields. The national soybean checkoff is addressing this continuing conundrum by funding projects that may lead to increased protein content and more consistent quality with no yield penalty. Better meeting the needs of U.S. soybean buyers supports long-term environmental and financial sustainability for farmers.  

solving the soybean rubiks cube

One recent project, “Effect of a Mutant Danbaekkong Allele on Soybean Seed Yield, Protein and Oil Concentration” was led by University of Tennessee research associate Mia Cunicelli.

“We were interested in a specific gene, Danbaekkong, which is known for increasing protein content in soybeans. We wanted to find out if the gene was present and if it could increase protein concentration while maintaining oil concentration and yield,” says Cunicelli. “This is a difficult task because of the negative genetic correlation of protein with both oil and yield.”

Three of the lines identified by the multi-year study funded by the United Soybean Board (USB) and Tennessee soybean checkoff had the high protein Danbaekkong gene and no statistically significant differences in yield from wild type lines without the Danaekkong gene. Those three lines were used as parents last summer in hopes of creating lines with the Danbaekkong gene for high protein and other valuable agronomic and seed quality traits. Cunicelli says work with the lines will take 7-10 years to become registered varieties and commercially available.

“Increasing the protein concentration in soybeans can lead to an increase in soybean value, because the higher quality protein with a better amino acid profile is available for livestock,” she says. “This can cut the cost of supplementation to livestock farmers.”

Pumping Up Protein with Relatives

Similarly, Rouf Mian, research geneticist with USDA-ARS leads a group of 16 public soybean scientists from across the nation who are using genetically diverse cultivated soybeans and wild soybean relatives to develop new germplasm and varieties with consistently elevated protein and yields comparable to commercial varieties. The project in the current fiscal year is jointly funded by USB and the Foundation for Food and Agriculture Research (FFAR).

“The goal of our research group is to develop U.S.-adapted soybean varieties and germplasm that combine high seed protein (more than 36 percent) with high yield and more than 48 percent meal protein,” says Mian. “Using this unorthodox approach and the power of the latest genomic and DNA technologies, we are demonstrating measurable progress in solving the intractable problem of combining high seed protein with high seed yield in soybeans.”

Agreeing with Cunicelli, Mian says U.S. soybeans with such low meal protein is a disadvantage in the international market. The USB Value Task Force Report estimates if no changes were made, the projected 2030 meal protein content could drop to 45.5 percent. The is well below the minimum meal protein value of 47.5 percent required by the marketplace. 

solving the soybean rubiks cube

Mian cites a study from USB that indicates just a one percent increase in seed protein in soybeans without any loss in seed yield or seed oil may add an estimated $3 billion to the value of the U.S. soybean crop. U.S. soybean varieties with improved meal protein and high yield will be more competitive with the soybean crop from South America, he explains, which will contribute to higher demand and market prices for U.S. soybeans in the international market.

“This is an ongoing project to solve an intractable problem,” he says. “However, our group has released more than 10 varieties and germplasm with more than 48 percent meal protein contents in maturity groups 0 – VII during the last two years. These lines are highly competitive with commercial cultivars in seed yield in their respective maturity groups.”

The majority of lines are already available for licensing to private companies for breeding so they can develop new cultivars with improved protein. However, Mian explains the time it takes to place the research’s benefit in private commercial cultivars depends on companies concerned. Some varieties are being commercialized by regional companies serving niche markets.

The highly diverse genes and genetic materials from this project are mostly unique,” says Mian. “They will definitely be the foundation for further research and development on genetic diversity and improvement of the seed protein found in soybeans.”

Check Out Other Checkoff Protein Projects

A $3.2 million investment between the United Soybean Board and the Foundation for Food and Agriculture Research is enhancing the U.S. soy industry’s competitive advantage, driving opportunities for American soybean farmers. This partnership specifically funds research to improve the protein content and quality of U.S. soybeans while protecting yield.

“Leveraging USB funds in this manner with other public and private collaborators extends the reach and potential impact of USB investments, as well as increases buy-in from key value chain partners,” says USB Vice President of Meal Strategy Keenan McRoberts. “USB will continue to seek and act on opportunities like this to amplify the soy checkoff’s investment reach, impact and returns through critical partnerships and leveraged funding sources.”

USB and FFAR are co-funding soybean research to support four projects, including Rouf Mian and colleague’s work with diverse soybeans and wild relatives. Here is a look at three more:

  • University of Nebraska-Lincoln’s George Graef is leading an interdisciplinary team to improve genetic diversity, seed composition and yield using highly productive genetic resources, breeding, genomics and biotechnology to identify and understand key genes involved in soybean seed protein composition. The project includes developing soybeans with 48 percent protein meal and 11 pounds of oil per bushel, with good amino acid balance and yield that meets or exceeds elite varieties in the 0-V Maturity Groups.
  • USDA-Donald Danforth Plant Science Center researcher Doug Allen is identifying novel amino acid composition genes in a mutant variety and taking advantage of a new analytical method to create more nutritious soybeans. Soybean meal, the gold standard of protein sources, contains an inadequate amount of sulfur amino acids. Earlier research found soybeans with enhanced sulfur-containing amino acids in a mutant variety.
  • USDA-Donald Danforth Plant Science Center scientist Yong-Qiang An is looking for genes that result in elevated protein and using them in commercial soybean variety breeding efforts. The identification and validation of these genes has the potential to create a more nutritious soybean for consumers and a more profitable one for farmers.

Learn more about these efforts at: