Private and public researchers are investigating what is causing citrus greening disease, which is threatening U.S. citrus trees.

The Florida Citrus Production Research Advisory Council has renewed funding for a study by Athena Biotechnologies Inc., Newark, Del., and the University of Maryland School of Medicine to research healthy and diseased citrus.

Scientists haven’t discovered any effective preventive measures to control or prevent the spread of the bacteria once it’s established in a tree.

In the $350,000 project, researchers plan to analyze healthy and diseased tissues which could show scientists what is causing microorganisms to spread the greening bacteria, huanglongbing, also known as HLB, said Jerry Quinn, Athena’s chief operating officer.

The project’s goal, Quinn said, is to identify the disease and find a way to control it or avoid it.

The study plans to use DNA sequencing technology. Understanding the microbiomes or biology of healthy and infected plant samples should provide scientists more clues on the complex nature of the bacteria, he said.

“What chemistry did to the world of medicine and agriculture in the 1960s, 1970s and 1980s, biology starting about now will help with everything from renewable energy to finding out how to grow HLB, to medicine,” Quinn said. “We have researchers trying to grow bacteria they believe causes cancer cells. Researchers are working to try to grow bacteria. We should successfully achieve some of this.”

If the one-year project shows results, Quinn said researchers would apply for more grants from the industry and university-controlled citrus advisory council.