Scientists joining to fight Pierce's Disease.
The Agricultural Research Service of the United States Department of Agriculture (ARS, USDA), the California Department of Food and Agriculture (CDFA) and Brazilian scientists are combining to target the genome of the microbe that causes Pierce's Disease (RD.) in grapevines.
The Brazilian scientists are with the Organization for Nucleotide Sequencing and Analysis (ONSA) in the Virtual Genomics Institute funded by the state of Sao Paulo Research Foundation.
The American Vineyard Foundation (AVF) of Napa and CDFA are contributing $62,500 each, marching the ARS planned funding of $125,000. The Sao Paulo research organization is providing $250,000. (This is not enough money for research--Ed.)
The idea is to determine the genetic makeup of the disease, which has ravaged vineyards and other crops in the past, and develop, and, hopefully, via science, undermine the deadly gene or genes.
As has been reported earlier, RD. is caused by a bacterium, Xylella fastidiosa. The major culprit in spreading the disease, at least of late, is the glassy-winged sharpshooter (GWSS). The problem with P.D., as growers know, is that as of yet there is no cure; severely-infected vines suffer from internal clogging and water and other nutrients are deprived, causing vine death.
USDA reported P.D. has cost growers $33 million from 1995 to 1997; the Temecula region of Southern California has been the hardest-hit recently, costing vineyard operators some $6 million.
Edwin L. Civerolo of the ARS Crops Genetic and Pathology Research Unit at Davis, Calif. will provide the Brazilian scientists with Xylella genetic material from infected Temecula vines.
Andrew J.G. Simpson of the Ludwig Institute for Cancer Research at Sao Paulo is coordinating the Brazilian research to "determine the exact sequence of the units, known as nucleotide pairs, that make up each X. fastidiosa gene." He is DNA Coordinator of the Organization for Nucleotide Sequencing and Analysis at Sao Paulo. ONSA scientists sequenced the genome of the chlorosis-causing Xylella strain, making them the first in the world to sequence the genome of a plant pathogen.
Besides the genomics project, ARS scientists are experimenting with repellents and insecticides, including a fungus, a cinnamon extract and a clay-based product. Also, biological control of the GWSS is being explored, per the ARS.