title: TolC is required for pathogenicity of Xylella fastidiosa in Vitis vinifera grapevines.
abstract: Xylella fastidiosa infects a wide range of hosts and causes serious diseases on some of them. The complete genomic sequences of both a citrus variegated chlorosis (CVC) and a Pierce's disease (PD) strain revealed two type I protein secretion plus two multidrug resistance efflux systems, and all evidently were dependent on a single tolC homolog. Marker exchange mutagenesis of the single tolC gene in PD strain Temecula resulted in a total loss of pathogenicity on grape. Importantly, the tolC- mutant strains were not recovered after inoculation into grape xylem, strongly indicating that multidrug efflux is critical to survival of this fastidious pathogen. Both survival and pathogenicity were restored by complementation using tolC cloned in shuttle vector pBBR1MCS-5, which was shown to replicate autonomously, without selection, for 60 days in Temecula growing in planta. These results also demonstrate the ability to complement mutations in X. fastidiosa.
authors.affiliation: Department of Plant Pathology, University of Florida, Gainesville 32601, USA.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Reddy
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Reddy
authors.forename: Don L
authors.initials: DL
authors.lastname: Hopkins
authors.forename: Dean W
authors.initials: DW
authors.lastname: Gabriel
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D005816:Genetic Complementation Test; D026901:Membrane Transport Proteins / Q000235:genetics / Q000502:physiology; D050296:Microbial Viability / Q000187:drug effects; D017646:Organosilicon Compounds / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology*; D014774:Virulence; D027843:Vitis / Q000737:chemistry / Q000382:microbiology*; D044167:Xylella / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D052584:Xylem / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D017646:Organosilicon Compounds; C473569:silwet L-77