Farmers in the major U.S. citrus-producing regions—Florida, California, Texas and Arizona, in particular—see their fruits being decimated by an incurable disease, a lethal, bacterial infection known as “citrus greening”—or Huanglongbing.
The disease was found in South Florida in 2005 and has spread throughout the state. It has also been found and quarantined in California’s San Joaquin Valley’s citrus belt, a threat to the state’s $3 billion-a-year citrus industry.
There’s good news from the lab, however. Researchers at the University of Florida’s Institute of Food and Agricultural Sciences have hit the trifecta; they’ve developed genetically engineered citrus trees that show not only resistance to greening but also to canker and black spot, two other perennial problems for citrus producers.
The plant biologists inserted a gene isolated from the Arabidopsis plant—a member of the mustard family—to create enhanced resistance to greening and reduced disease severity. Several trees remained disease-free after 36 months in a field with a high number of diseased trees.
Nevertheless, it will be a decade or more before these disease-resistant trees have received regulatory approvals, been planted widely and are yielding fruit. Citrus growers are also concerned that the public might be resistant to the concept of genetically engineered fruit, even though virtually all of the foods in the North American and European diets have been modified in some way.