Research projects

New research projects to explore sorghum

KANSAS CITY, MISSOURI, USA — Three separate research projects are exploring sorghum, an ancient grain known for its ability to withstand drought. A project funded by the United Sorghum Checkoff Program will seek to maximize sorghum harvest by determining effective trait combinations for different environments. Research at the Donald Danforth Plant Science Center in St. Louis will study the gene networks underlying sorghum’s stress resilience, and research at the Nebraska Food for Health Center in Lincoln focused on how sorghum affects the human gut microbiome.

Krishna Jagadish, PhD, a professor in the Department of Plant and Soil Sciences at Texas Tech University in Lubbock, Texas, USA, received $1.6 million in funding from the United Sorghum Checkoff Program in partnership with the Texas A&M University, Kansas State University, US Department of Agriculture locations in Lubbock and Manhattan, Kansas, USA, and industry partners. The five-year project will seek to develop sorghum hybrids based on traits specifically targeted to thrive in water-poor areas considered favorable for growing sorghum.

“The project brings together major government sorghum improvement programs in the United States,” Jagadish said. “The transdisciplinary team aims to achieve project goals by integrating agronomy, crop physiology, breeding, machine learning, and crop and climate modeling.”

The three-year, $2.7 million project at the Donald Danforth Plant Science Center has received support from the U.S. Department of Energy’s Genome-Compatible Plant Biology Program. The project will seek to define the functions of critical genes in sorghum and how they are regulated.

“There is extraordinary genetic diversity underlying sorghum’s adaptation to stressful environments, and we want to harness this in precise ways to inform engineering and breeding strategies for future climates,” said Andrea Eveland, PhD, associate member of the center. “We know little about what most of the more than 30,000 genes in the sorghum genome do and whether functionally conserved genes have unique control mechanisms in drought-adapted sorghum. This information could also help efforts to make other crops more stress-resistant.

Researchers from the Nebraska Food for Health Center have demonstrated that natural genetic variation within crop plants may play a role in controlling the growth of specific organisms in the human gut microbiome. In a study published online September 26 in Nature Communication they used sorghum, which has a large number of bioactive models that stimulate body cells, including gut microbes. The researchers had access to 294 different kinds of sorghum. Qinnan Yang, PhD, scientist at the center, made flour from each type of sorghum. An automated system measured the impact of flour from each type of sorghum on the human gut microbiome.

In two cases, Yang noticed that the same region of the sorghum genome that caused major changes in the human gut microbiome also controlled color differences in sorghum seeds and sorghum flour. Two parts of the genome contained two genes, called Tan1 and Tan2, which control the production of condensed tannins, a group of compounds that add flavor to red wine and dark chocolate.

Sorghum varieties with intact versions of the Tan1 and Tan2 genes had dark-colored seeds and stimulated the growth of microbes, including Faecalibacterium, Rose Buria and Christensenella. Numerous studies have shown that the organisms can help prevent conditions such as inflammatory bowel disease. Other sorghum varieties with mutations in either gene produced light-colored seeds that failed to stimulate growth.

“It’s not just about tannin or even sorghum,” Yang said. “Now that we have shown that plant genes can control changes in the human gut microbiome, we can use our approach to screen hundreds or thousands of samples from different cultures. This allows plant breeding programs to exploit natural genetic variation in crops to create new crop varieties that improve human health by promoting beneficial bacteria in the human gut.