Plant & Animal Genomes XVII Conference

January 10-14, 2009
Town & Country Convention Center
San Diego, CA

Applied Genomics In Vector Entomology: Genetic Diversity Anaylsis Of Xylella fastidisa

Blake R. Bextine¹ , Lisa Morano² , Stanley Gunawan¹ , Henry Schreiber Jr.¹

¹  University of Texas at Tyler 3900 University Blvd Tyler, Texas

²  University of Houston-Downtown Department of Natural Sciences Houston, Texas 77002

Multiple subspecies of Xylella fastidiosa exist which are differentially pathogenic. Previously, DNA sequence analysis of the mopB and gyrB gene has been used to separate X. fastidiosa strains into their subspecies groups. The TonB gene family can be used to confirm this genetic diversity between X. fastidiosa strains and regions within these genes can be used to separate strains beyond subspecies due to increased variability. TonB protein is a cytoplasmic outer membrane protein that can be found on gram negative bacteria, such as X. fastidiosa. The protein functions as an energy transducer to support a variety of transport events across the outer membrane and interacts with outer membrane receptor proteins which carry out high-affinity binding and energy-dependant uptake of specific substrates into periplasmic space. In this study, five different TonB genes (TonB-a through TonB-e) were used to differentiate between three X. fastidiosa strains (grape, ragweed, and oleander). The results of this study were consistent with genotype differentiation using conserved mopB and gyrB genes. Additionally, sequencing of another gene, analogous to the zonula occludens toxin (ZOT) gene, was used to separate groups below the strain level. The discovery of new variable genes provides another genomic location to be exploited for the improvement of diagnostics to aid in the management of Pierce’s disease.