Chemical Could Cure Toxic Citrus Greening

University of Florida (UF) researchers are cautiously optimistic after reportedly discovering the chemical cure to the toxic citrus greening disease that is devastating Florida's $9 billion citrus crop.

The team, led by Claudio Gonzalez and Graciela Lorca, examined three biochemical treatments: phloretin, hexestrol and benzbromarone.

After spraying the chemicals on tree shoots, they found benzbromarone effectively stopped the spread of bacteria in 80 percent of the shoots.

The chemical targets a specific protein, known as LdtR. It binds to and inactivates the protein, which "disrupts a cell wall remodeling process critical for the greening bacterium's survival inside a citrus tree," the UF news release stated.

"As a consequence of the chemical treatment, several genes were not expressed and the bacteria were not able to survive inside the phloem of the plant where osmotic pressure from sugar is high," said Fernando Pagliai, a co-author of the study and a UF graduate assistant.

The Asian citrus psyllid, a tiny bug that sucks on leaf sap and leaves behind bacteria, is to blame for this devastating citrus greening. The bacteria then spread through the tree's phloem - the living tissue that carries organic nutrients to all parts of the plant.

Starving of nutrients and with damaged roots, trees start producing green and misshapen fruits, and usually die within a few years.

Millions of citrus trees in North America have been affected with the disease, and Florida crop owners are especially trying to figure out ways to battle the sap-sucking insect to protect their valuable orange juice industry.

"Every grower I know is just hanging by their fingernails, hoping and praying for a new discovery for treatment," said Ellis Hunt Jr. of Lake Wales, whose family has been in the citrus business since 1922.

It could be between five to seven years before a treatment for the disease becomes commercially available due to mandatory field testing. Initial results of this research are promising, but there are no guarantees that it will pass field testing.