UGA researchers think they’ve come up with a system to identify the genes in trees responsible for stress tolerance, which includes everything from extreme temperatures to disease. Now they’re using a new $490,000 grant to identify those genes and figure out how they work.
Identifying those stress-control genes and understanding their function could help create trees that can resist the very things that can kill them, said C.J. Tsai, the lead researcher on the project.
Tsai is a Georgia Research Alliance Eminent Scholar and professor with joint appointments in UGA’s Warnell School of Forestry and Natural Resources and the genetics department in the Franklin College of Arts and Sciences. She has been working for years on ways to create better-growing trees. Key to that is making them more resistant to stressful scenarios like extreme temperatures, disease and drought—but first they need to zero in on the genes that help with that.
“Successfully manipulating one or more of the genes under stressful scenarios could lead to better growing trees, and the results could also be translated to food crops,” said Tsai, who is also director of the Plant Center at UGA. “The implications of this project could be far reaching.”
Tsai and her team already have one candidate gene family from a previous study. The nucleoredoxin genes produce small redox proteins involved in cellular redox regulation. These genes were turned on when they increased salicylic acid in poplars.
While they gear up to identify additional candidates, the team will manipulate the nucleoredoxin genes to see the effects on plant stress response.
This project, funded by the U.S. Department of Agriculture, follows a previous study in which Tsai’s team reported that the levels of salicylic acid—a naturally occurring chemical that protects plants from harmful environmental changes—could be greatly increased in poplar trees without stunting growth, which had been a common problem in other plants. Those findings are valuable to this new project, she said.
Salicylic acid is very important to plants because it regulates processes like photosynthesis and defenses against abiotic and biotic stresses-temperature, drought and disease.
“All those stresses promote the generation of damaging oxidants, and salicylic acid is thought to mitigate some of the damaging effects,” Tsai said.
In the previous study, they identified many metabolites and genes that responded to increased salicylic acid.
In the new project, Tsai and fellow UGA researchers Scott Harding and Liangjiao Xue, also dually housed in Warnell and the genetics department, and Magdy Alabady in the plant biology department will compare tree responses to heat, drought and elevated levels of salicylic acid to identify genes that act downstream of salicylic acid to trigger defense. They also will study the involvement of small RNAs in this regulation.
By integrating the information they can obtain about gene expression, metabolite profiling and small RNA regulation from these trees, the researchers hope to identify novel cascades of cellular events that regulate plant stress tolerance.