By Dusty Sonnenberg, CCA, Ohio Field Leader: a project of the Ohio Soybean Council and soybean checkoff
It is often said that a soybean’s maximum yield potential is when it is still in the bag. Once that seed is planted, everything a farmer does is to help the plant maintain that yield potential. When Professor Feng Qu joined the faculty at the Ohio Agricultural Research and Development Center over 11 years ago, his primary focus was plant pathology. Since that time, he has observed all the factors impacting soybean production.
“One thing I noticed every year was weeds were a farmer’s biggest challenge. As a pathologist I would look at the impact of soybean disease. Some years it was a concern, others it was not as much. Abiotic stress caused by drought would occur from time to time, usually in different places, but not every year across every acre. Even when it did, there is often very little a farmer can do about it,” Qu said. “Weeds are the one thing farmers have to deal with on every acre every year. My hope is that with intense research, there will be something we can do about it.”
In a project funded by the North Central Soybean Research Program, Professor Qu and his team are investigating soybean genetics and utilizing CRISPR Cas9 technology. Their goal is to genetically engineer soybeans to develop resistance to specific herbicides.
“Most of the herbicide tolerance traits in soybeans are based on genes identified from bacteria,” Qu said. “Glyphosate tolerance was originally isolated from a bacterium.”
However, there are numerous genes of a soybean itself that can be modified through precise modification to acquire the ability of tolerating herbicides. Once such genes are identified, the CRISPR Cas9 technology can be utilized to edit the DNA sequence at a precise location, changing the underlying gene into a herbicide tolerance gene. This technology does not take genetic material from a different organism and insert it into the DNA. As a result, the modified soybean is currently not regulated as GMO.
For the past year and a half, Qu and his team have been working on this project, and believe they are at the point which they have successfully modified the first of three genes.
“We think we were successful at modifying the ALS gene, and have plants in the greenhouse to begin producing seeds,” Qu said. “We are still working on two additional genes that need to be modified to accomplish a tolerance expression.”
Soybean tissues in which the other two genes are being modified are in the culture stage in John Finer’s lab at Ohio Agricultural Research and Development Center.
While proven safe to consume by all major health organizations, Genetically Modified Organisms (GMOs) have been rejected by consumers in many countries. There are activist organizations in the United States aggressively campaigning against GMOs in the domestic food supply. Soybean varieties modified with CRISPR Cas9 are not the same as GMOs, and are currently not regulated as such.
“You can think of it like remodeling a kitchen,” Qu said. “There are tools needed to do the remodeling, but once the job is done, the tools are removed, and the kitchen effectively remodeled, and the changes function without the tools that were used.”
The CRISPR technology is used to make changes to a selected gene in a cultured cell. That culture tissue is grown in a lab setting. The resulting plant will have the new genetic sequence, and the resulting seeds from that plant will contain the new genetic code.
These genetically altered crops are perfectly safe for human consumption. A person is not consuming the actual gene, but the proteins and amino acids that result from that gene which are then broken down in the digestion process. The gene is not absorbed by the body and incorporated into the human DNA.
Negative consumer perceptions of GMOs and the role scientists play will be important in allowing CRISPR technology to move forward.
“One challenge, as this technology is used in the future on crops beyond soybeans, will be the consumer acceptance,” Qu said. “There is a growing separation that exists between many consumers and how their food is produced. Many consumer decisions are emotion-driven rather than based on facts. As scientists, we need to make sure the negative narratives from activist groups do not dominate that conversation.”
Learning is always a part of the process.
“I feel we have already been successful just by what we have learned up to this point, and it can be re-applied in the future,” Qu said. “The end goal is that this will allow existing soybean genes to be modified to tolerate more herbicide families in the future in an aid to combat weeds.”
Looking ahead, Qu is reviewing literature to determine other genes that could be used to increase the spectrum of herbicide tolerance traits.
“Some research has found that some drugs used to treat malaria could also effectively be used as herbicides. Research will need to be conducted to see if a soybean gene exists that could be modified to become tolerant to these drugs,” Qu said.
While being a plant pathologist by training, Qu has learned a great deal about weeds through his research in recent years.
“Much weed science research is focused on finding new chemistries and combinations that weeds are sensitive to,” Qu said. “Looking forward, there needs to be more investigation into why and how weeds that were once sensitive to herbicides have now changed.”