SDSU Researchers to Improve Heat Tolerance in Wheat Crops

By Addison Dehaven

Wheat is the world's second-most produced cereal crop and an essential ingredient for bread, pasta, pizza, beer, breakfast cereals and many other foods. South Dakota plays a key role in the United States’ overall wheat production, with over 60 million bushels produced in 2023 — worth roughly half a billion dollars.

Ideal temperatures for growing wheat, according to NASA, vary between 70 F and 75 F, but some varieties, like winter wheat, can grow in temperatures as low as 40 F. But when temperatures exceed 90 F, heat stress can cause significant yield loss. This is a growing concern as the "wheat basket of the world" — i.e. the Great Plains of North America — is predicted to see more frequent heat waves and higher average summer temperatures in the face of a changing climate.

Researchers are concerned these climatic changes may cause future wheat production to decline, threatening global food security and regional agricultural economies. A team from South Dakota State University intends to address this issue by editing the genetic code of wheat varieties to make them more tolerant to heat stress.

"Our goal is to improve heat tolerance of wheat via precision genome editing technology," said Wanlong Li, primary investigator on the project and a professor in SDSU's Department of Biology and Microbiology.

This work is being funded through a $270,244 grant from the U.S. Department of Agriculture's National Institute of Food and Agriculture.

Heat tolerant wheat varieties are needed, but breeding heat tolerance in wheat is hindered by complicated genetics mechanisms. Conventional plant breeding methods can also take decades to successfully introduce new or improved traits, like heat tolerance. Plant genome editing technology is a tool that allows researchers to add, remove or alter DNA in the genome in an efficient manner. Rather than decades, a new trait can be introduced in just a few short years with this advanced technology.

Li believes that a promising, recently emerged enzyme, Rubisco activase, can enhance heat tolerance and photosynthesis in wheat varieties. To test his theory, the research team will utilize a tool called "clustered regularly interspaced short palindromic repeats (CRISPR)" to precisely edit the targeted gene, resulting in novel wheat plants that will be tested in a variety of temperatures and climatic conditions.

"These results are expected to have a positive impact on the improvement of wheat heat tolerance," Li added.

"This award will allow Dr. Li and his team to investigate gene alterations that will increase the thermostability of Ruisco activase, an enzyme linked to heat tolerance in wheat and other plant species," said Jeremy Chambers, head of SDSU's Department of Biology and Microbiology. "His team will use advanced gene editing to sustain wheat health by adjusting the temperature optimum in anticipation of warmer crop seasons."

The expected two-year project, titled "Precision Editing of TARCA2 for Enhanced Heat Tolerance in Wheat," has the potential for impact far beyond South Dakota's borders. Food insecurity is an international concern, and with rising populations and rising temperatures, ensuring essential cereal crops, like wheat, can grow in changing climatic conditions is a global priority.

"I cannot wait to see this work's impact on our agricultural community and economy in South Dakota and beyond," Chambers added