Courtesy of the California Department of Food and AgriculturePierce's disease causes leaf scorching, among other symptoms, in grapes.A genetic one-two punch may keep Pierce's disease, a deadly threat to the California winegrape industry, down for the count.
University of California, Davis, plant sciences professor Abhaya Dandekar led the study into using two immune system defenses to fight the Pierce's disease bacterium, according to a news release.
Pierce's disease is caused by Xylella fastidiosa, which plugs the xylem—or water-carrying tissues in the plant.
Strains of the same bacterium also infest citrus, stone fruit, almonds, oleander and some shade trees. It is harmless to humans.
Dandekar and colleagues engineered a hybrid gene by fusing together two genes responsible for two different immune functions in the plant.
One recognizes X. fastidiosa as a bacterial invader, and the other destroys its outer membranes, causing the organism to die.
They then inserted the hybrid gene into grapevines.
Sap from the genetically engineered grapevines killed X. fastidiosa in the laboratory.
Grapevines with the hybrid gene had significantly less leaf scorching and xylem clogging.
The Los Alamos national Laboratory in New Mexico and the U.S. Department of Agriculture collaborated on the project.