Knowledge Bank

Xylella fastidiosa is a plant bacterial pathogen that colonizes the xylem of a wide range of host plants and is spread by sap-sucking insect vectors. There have been large economic losses attributed to the presence of X. fastidiosa within crops. X. fastidiosa is known as Pierce's disease in grapevine. Pierce's disease is a problem that affects grape crops and there has yet to be an effective way to reliably identify its presence in crops at an early stage of infection to prevent spreading and crop loss. This project developed a method to test for Pierce's disease in wild Vitis labrusca and cultivated V. vinifera grapevine, suspected to be infected with X. fastidiosa. Previous studies provided support for using polymerase chain reaction (PCR) as a method to target and amplify genes present in the X. fastidiosa genome to identify the presence of Pierce's disease in grapevine. Primers from previous papers, as well as self-designed primers, were used to test the DNA isolated from V. labrusca and V. vinifera grapevine leaves. The PCR results showed no amplification of the X. fastidiosa genes, but primer-dimers or non-target amplification were detected in some cases. The lack of amplification could suggest the absence of X. fastidiosa within the tested grapevine leaves or that the X. fastidioa DNA was present at such a low concentration, it was not amplified by the primers. Further testing is needed for developing reliable methodology for amplification of the trace amounts of X. fastidiosa DNA found within grapevines.