Xylella fastidiosa strain 9a5c is a gram-negative phytopathogen that is the causal agent of citrus variegated chlorosis (CVC), a disease that is responsible for economic losses in Brazilian agriculture. The most well-known mechanism of pathogenicity for this bacterial pathogen is xylem vessel occlusion, which results from bacterial movement and the formation of biofilms. The molecular mechanism...

Polygalacturonases (EC 3.2.1.15) catalyze the random hydrolysis of 1, 4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. Xylella fastidiosa possesses a single polygalacturonase gene, pglA (PD1485), and X. fastidiosa mutants deficient in the production of polygalacturonase are non-pathogenic and show a compromised ability to systemically infect grapevines. These results sugg...

Principal Investigator: CoPrincipal Investigator: Cooperator: Thomas J. Burr Harvey C. Hoch Steven Lindow Dept. of Plant Pathology Dept. of Plant Pathology Dept. of Plant and Microbial Biology Cornell University Cornell University University of California NYSAES NYSAES 111 Koshland Hall Geneva, New York 14456 Geneva, New York 14456 Berkeley CA 94720-3112 Phone: 315-787-2312 Phone: 315-787-2312 ...

INTRODUCTION Xylella fastidiosa (Xf) is a Gram-negative xylem-limited bacterium that causes Pierce’s disease (PD), plum leaf scald, almond leaf scorch, phony peach disease and many other diseases. For many plant species there is no resistant germplasm. Xylem vessels may be filled with exopolysaccharides produced by the bacterium, and pectins, gums and tyloses produced by the plant. There has be...

Xylella fastidiosa, the causal agent of almond leaf scorch disease (ALSD), is currently re-emerging as a serious concern in California. Efficient pathogen detection is critical for ALSD epidemiological studies, particularly when a large sample size is involved. We here report a PCR procedure to detect X. fastidiosa directly from infected almond tissue without the laborious DNA extraction. Plant...

We report two of our recent efforts for improvement of PCR detection and genomic analysis of Xylella fastidiosa (Xf). We evaluated the use of PCR primers from a hyper-variable locus to monitor diversity within strains of the same pathotype. The pspB (PD1208) locus, encoding a serine protease, was selected and analyzed. It was observed that tandem repeat sequences in pspB locus were highly varia...

Citrus variegated chlorosis (CVC) is a disease of sweet orange [Citrus sinensis (L.)] caused by Xylella fastidiosa subsp. pauca, a phytopathogenic bacterium that has been shown to infect all sweet orange cultivars. Xylella fastidiosa is a fastidious Gram-negative, xylem-limited bacterium which was rapidly disseminated by infected nursery trees and by several xylem-feeding sharpshooter insect ve...

Xylella fastidiosa is a Gram negative plant pathogen causing many economically important diseases, and analyses of completely sequenced X. fastidiosa genome strains allowed the identification of many prophage-like elements and possibly phage remnants, accounting for up to 15% of the genome composition. To better evaluate the recent evolution of the X. fastidiosa chromosome backbone among distin...