Genome of Little Known Disease Offers Hope for Citrus Plants

Scientists at the University of California Riverside are hoping the RNA of an obscure infection can one day be used like a Trojan horse to deliver life-saving treatments to citrus trees. Citrus yellow vein disease, discovered 64 years ago in Riverside has finally been unraveled, a significant step toward harnessing its unique properties.

In the past decade, Huanglongbing, also known as citrus greening disease has caused a 72% decline in oranges used for juice and a 21% decrease in the American fresh citrus fruit market. Growers in other parts of the world are similarly affected, as the disease continues to spread unabated. In 1957, plant pathology professor Lewis Weathers found four limequat trees with beautiful, bright veins on their leaves, almost fluorescent yellow that was recognized as a disease.

Experiments showed the disease is not carried by any animal or other microorganism. The researchers learned that the iRNA disguises itself with plant proteins that let it pass through cellular connective tissue. Kiran Gadhave, UCR microbiologist and lead researcher of the iRNA project explains that iRNA is amazing because it can manipulate plant cells to help it replicate, despite having only one functional gene. 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.

For more details, read the article in UC Riverside News.