A Trojan Horse for Citrus Disease

Ernie Neff Diseases, Research

disease
​ Progression of citrus yellow vein disease, starting from healthy (left) to infected (right) leaves
(Photo by Gerardo Uribe/UCR) ​

Scientists are hoping the RNA of an obscure infection can one day be used like a Trojan horse to deliver treatments to citrus trees, possibly to combat HLB disease.

The infection, citrus yellow vein disease, was discovered 64 years ago in Riverside, California, and has never been seen elsewhere in the world. Decades later, University of California (UC) Riverside researchers have finally unraveled the associated pathogen’s genetic codes — a significant step toward harnessing its unique properties.

A paper describing this work was published in the journal Frontiers in Microbiology. The research opens the door to testing whether this apparently benign infection could be used as a vehicle to transport antibacterial and antiviral agents into citrus plants’ vascular systems, where infections usually take place.

Cells use RNA to convert the information stored in DNA into proteins that carry out different functions. Yellow vein disease is associated with small, independently mobile RNA, also called iRNA, which spreads through a plant’s vascular system. This spreading mechanism could be a new way to send treatments for HLB or other diseases into plants.

The story of this promising research starts in 1957 with Lewis Weathers, a UC Riverside plant pathology professor. “He found four limequat trees with beautiful, bright veins on their leaves, almost fluorescent yellow,” said Georgios Vidalakis, a plant pathology professor at UC Riverside and investigator on the new paper. “That color was recognized as a disease, and samples of it were deposited at the Citrus Clonal Protection Program disease bank where it was waiting for us to study decades later,” Vidalakis said.

Though they believe the pathogen to be benign, the research team is doing additional testing to make sure it won’t affect fruit quality or quantity, tree height or any other markers of health. Symptoms in greenhouse-grown trees were mild. Now this is being tested in a field trial.

Source: University of California Riverside

Share this Post

Sponsored Content