The genome sequence of the plant pathogen Xylella fastidiosa

• Author(s): Abreu, F.; Acencio, M.; Alvarenga, R.; Alves, L.; Araya, J.; Arruda, P.; Baia, G.; Baptista, C.; Barros, M.; Bonaccorsi, E.; Bordin, S.; Bove, J.; Briones, M.; Bueno, M.; Camargo, AnaMaria; Camargo, Luis; M., D.; Reinach, F.; Simpson, A.;
• Abstract: Xylella fastidiosa is a fastidious, xylem-limited bacterium that causes a range of economically important plant diseases. Here we report the complete genome sequence of X. fastidiosa clone 9a5c, which causes citrus variegated chlorosis-a serious disease of orange trees. The genome comprises a 52.7% GC-rich 2,679,305-base-pair (bp) circular chromosome and two plasmids of 51,158 bp and 1,285 bp. We can assign putative functions to 47% of the 2,904 predicted coding regions. Efficient metabolic functions are predicted, with sugars as the principal energy and carbon source, supporting existence in the nutrient-poor xylem sap. The mechanisms associated with pathogenicity and virulence involve toxins, antibiotics and ion sequestration systems, as well as bacterium-bacterium and bacterium-host interactions mediated by a range of proteins. Orthologues of some of these proteins have only been identified in animal and human pathogens; their presence in X. fastidiosa indicates that the molecular basis for bacterial pathogenicity is both conserved and independent of host. At least 83 genes are bacteriophage-derived and include virulence-associated genes from other bacteria, providing direct evidence of phage-mediated horizontal gene transfer.
• Publication Date: Jul 2000
• Journal: Nature (London)