Molecular quantification of Xylella fastidiosa cells transmitted by Homalodisca vitripennis.

• Author(s): Bextine, Blake;
• Abstract: Transmission of Pierces disease (PD) between plant hosts involves three main steps, acquisition of Xylella fastidiosa (Xf) by a vector, inoculation of a host plant by the vector, and establishment of sufficient titers of Xf in the host to cause disease. Understanding the basic biology of the transmission process may be key to limiting the spread of PD. Glassy-winged sharpshooters, Homalodisca vitripennis (Hemiptera, cicadellidae), with acquired titers of Xf were allowed access to chrysanthemum plant cuttings for between 30, 60, 90 or 120 minutes and the number of Xf cells present in the insect foregut and transmitted to the plant were determined using quantitative real-time PCR. The amount of time feeding and the number of probes were also monitored using video surveillance. Using multiple linear regression, there was a lack of correlation between the amount of time spent feeding per probe and the number of Xf cells inoculated, but the number of probes was significantly correlated with the number of Xf cells inoculated. Due to the highly variable nature of transmission, R2 values were too low to have predictive value, but these findings suggest that the mechanism of transmission is dependant on probing behaviors more than ingestion time.
• Publication Date: Mar 2007
• Journal: Proceedings Of The 55Th Annual Meeting Of The Southwestern Branch Of The Entomological Society Of America