Frantically, researchers are developing tools to help control citrus greening, a disease that has killed thousands of acres of orange and grapefruit trees, devastating Florida's agri industry. One of the most promising treatments was recently developed in a fruit most people have never heard of, the Australian finger lime.
The finger lime, native to rainforests in Australia, looks a little like a pickle. It's just a couple inches long, grows on small trees and is gaining popularity as an exotic fruit.
Researcher Hailing Jin became interested in the fruit because it is related to oranges, but it isn't affected by citrus greening. Jin, a molecular geneticist at the University of California Riverside says, "When I heard that there are some wild citrus close relatives that show tolerance or partial resistance, then I (felt) like there must be some genes responsible for it."
In the 15 years since citrus greening first appeared in Florida, the disease has upended the industry. Orange production has plummeted, from nearly 300 million boxes in 2000 down to about 70 million boxes last year.
About five years ago, Jin discovered the gene in finger limes that makes it tolerant to the disease. It produces a peptide, a natural antibiotic that kills the bacterium responsible for citrus greening. She's now developed a way to produce it in the lab. When it's injected into trees or sprayed on leaves, the peptide has a dramatic impact. Jin says, "The bacteria titer is largely reduced. And the symptoms, the disease symptom is also largely reduced. The new flesh, the new leaves look very green and healthy."