Introduction Xylella fastidiosa (Xf) is a Gram negative, xylem-limited, insect-vectored bacterium and is the causal agent of Pierce's Disease (PD) of grapevine (Hopkins and Purcell 2002). PD is endemic to California but the recent introduction of a more effective vector, the Glassy-Winged SharpShooter (GWSS), Homalodisca vitripennis, to Southern California shifted the epidemiology of PD from a ...

Homalodisca vitripennis (Germar) ( H. coagulata [Say]) (Hemiptera: Cicadellidae) invaded French Polynesia in 1999. A classical biological control program against H. vitripennis was initiated in 2004 aiming to introduce the exotic egg parasitoid Gonatocerus ashmeadi (Girault) (Hymenoptera: Mymaridae) to the Society Islands archipelago. Prior to any release, two risks were assessed: (a) continued...

Xylella fastidiosa is the causal agent of citrus variegated chlorosis and Pierce's disease which are the major threat to the citrus and wine industries. The most accepted hypothesis for Xf diseases affirms that it is a vascular occlusion caused by bacterial biofilm, embedded in an extracellular translucent matrix that was deduced to be the exopolysaccharide fastidian. Fourier transform infrared...

Xylella fastidiosa is a xylem-limited bacterium in plant hosts and causes Pierce's disease (PD) of grapevines, which differ in susceptibility according to the Vitis species (spp.). In this work we compared X. fastidiosa biofilm formation and population dynamics when cultured in xylem saps from PD-susceptible and -resistant Vitis spp. under different conditions. Behaviors in a closed-culture sys...

Cell-cell signaling in Xylella fastidiosa, a xylem-colonizing plant pathogenic bacterium, mediated by a fatty acid Diffusible Signaling Factor (DSF), is required to colonize insect vectors and to suppress virulence to grape. Here, we show that a hybrid two-component regulatory protein RpfC is involved in negative regulation of DSF synthesis by RpfF in X. fastidiosa. X. fastidiosa rpfC mutants h...

Pierce’s disease (PD) causes symptoms of leaf scorch and fruit cluster wilt on wine, table and raisin grapes, and is caused by the bacterial pathogen Xylella fastidiosa. These fastidious, gram-negative bacteria occur only in the xylem of infected plants and are transmitted by xylem-feeding insects; leafhoppers and sharpshooters. The close association of plants with bacteria, either pathogenic o...

Transposons are mobile genetic elements found within the genomes of various organisms including bacteria, fungi, plants and animals. Fragments of the transposon Tn1721 were found included in the genome of Xylella fastidiosa strain 9a5c. Regions from such fragments were PCR-amplified using specially designed primers (TNP(1) and TNP(2)). In order to detect insertions of the Tn1721 element, both p...

A cosmid library was made of the 2.7 Mb genome of the Gram-negative plant pathogenic bacterium Xylella fastidiosa and analysed by hybridisation mapping. Clones taken from the library as well as genomic restriction fragments of rarely cutting enzymes were used as probes. The latter served as a backbone for ordering the initial map contigs and thus facilitated gap closure. Also, the co-linearity ...

Xylella fastidiosa (Xf) is a fastidious gram-negative, xylem-limited bacterium that causes diseases in many crops of economic importance, such as grape (Pierce’s disease), almond, peach, coffee, plum and citrus. Xf can infect all known Citrus sinensis cultivars and causes Citrus variegated chlorosis (CVC). One major endophyte isolated from CVC-asymptomatic plants is the bacterium Curtobacterium...