Seasonal Abundance and Infectivity of Philaenus spumarius (Hemiptera: Aphrophoridae), a Vector of Xylella fastidiosa in California Vineyards.

The meadow spittlebug, Philaenus spumarius (Linnaeus) (Hemiptera: Aphrophoridae), is a vector of the plant pathogen Xylella fastidiosa; however, its role in recent outbreaks of Pierce's disease of grapevine (PD) in California is unclear. While the phenology and ecology of P. spumarius can help determine its contributions to PD epidemics, both remain poorly described in the North Coast vineyards of California.

Updated pest categorisation of .

Following a request from the European Commission, the EFSA Plant Health Panel updated its pest categorisation of , previously delivered as part of the pest risk assessment published in 2015. is a Gram-negative bacterium, responsible for various plant diseases, including Pierce's disease, phony peach disease, citrus variegated chlorosis, olive quick decline syndrome, almond leaf scorch and various other leaf scorch diseases. The pathogen is endemic in the Americas and is present in Iran.

Paradigms: examples from the bacterium Xylella fastidiosa.

The history of advances in research on Xylella fastidiosa provides excellent examples of how paradigms both advance and limit our scientific understanding of plant pathogens and the plant diseases they cause. I describe this from a personal perspective, having been directly involved with many persons who made paradigm-changing discoveries, beginning with the discovery that a bacterium, not a virus, causes Pierce's disease of grape and other plant diseases in numerous plant species, including important crop and forest species.

Xylem structure of four grape varieties and 12 alternative hosts to the xylem-limited bacterium Xylella fastidious.

Background And Aims: The bacterium Xylella fastidiosa (Xf), responsible for Pierce's disease (PD) of grapevine, colonizes the xylem conduits of vines, ultimately killing the plant. However, Vitis vinifera grapevine varieties differ in their susceptibility to Xf and numerous other plant species tolerate Xf populations without showing symptoms. The aim of this study was to examine the xylem structure of grapevines with different susceptibilities to Xf infection, as well as the xylem structure of non-grape plant species that support or limit movement of Xf to determine if anatomical differences might explain some of the differences in susceptibility to Xf.

Effects of Date of Inoculation on the Within-Plant Movement of Xylella fastidiosa and Persistence of Pierce's Disease Within Field Grapevines.

ABSTRACT The effects of date of inoculation on the development of Pierce's disease (PD) were evaluated in California grapevines during 1997 through 2000 at four locations. Some vines that had been inoculated either by using blue-green sharpshooters (Graphocephala atropunctata) as vectors or mechanically by needle puncture with the PD causal bacterium Xylella fastidiosa became infected during each month and at each location where infection was attempted. Vines inoculated on the earliest inoculation dates (April to May) developed more extensive and severe PD symptoms, and only 54% of these vines recovered from PD after the following winter, compared with vines that had been inoculated during June through August, of which 88% recovered from PD after the following winter.

Effect of Benzothiadiazole on Transmission of X-Disease Phytoplasma by the Vector Colladonus montanus to Arabidopsis thaliana, a New Experimental Host Plant.

Colladonus montanus (Van Duzee), a leafhopper vector of X-disease phytoplasma (Xp), efficiently transmitted the pathogen to Arabidopsis thaliana Columbia wild type. During transmission trials, the phytoplasma was inoculated into 22-, 34-, and 40-day-old plants. Phytoplasma infections were confirmed by polymerase chain reaction (PCR) using primers specific for X Symptoms in X-positive A.

Xylella fastidiosa cultivation on a minimal solid defined medium.

A simple defined solid medium containing citrate and succinate, three amino acids (L-glutamine, L-asparagine, and L-cysteine), hemin chloride, potato starch, gellan gum (GelRite), and mineral salts supported the growth of grape strains of Xylella fastidiosa, the bacterial pathogen that causes Pierce's disease of grape. Isolation efficiency from infected grape plant samples, determined by the number of colony forming units recovered, on the defined medium was slightly less ( approximately 10-fold) or indistinguishable from two standard rich media used for culturing X. fastidiosa, PWG and PD3, respectively.

Transmission of Xylella fastidiosa to grapevines by Homalodisca coagulata (Hemiptera: Cicadellidae).

Pierce's disease (PD) of grapevines is caused by a xylem-limited bacterium Xylella fastidiosa (Wells, Raju, Hung, Weisburg, Mandelco-Paul, and Brenner) that is transmitted to plants by xylem sap-feeding insects. The introduction of the sharpshooter leafhopper Homalodisca coagulata (Say) into California has initiated new PD epidemics in southern California. In laboratory experiments, the major characteristics of H.

Cell-cell signaling controls Xylella fastidiosa interactions with both insects and plants.

Xylella fastidiosa, which causes Pierce's disease of grapevine and other important plant diseases, is a xylem-limited bacterium that depends on insect vectors for transmission. Although many studies have addressed disease symptom development and transmission of the pathogen by vectors, little is known about the bacterial mechanisms driving these processes. Recently available X.

Biological traits of Xylella fastidiosa strains from grapes and almonds.

Xylella fastidiosa is a xylem-limited bacterium that causes various diseases, among them Pierce's disease of grapevine (PD) and almond leaf scorch (ALS). PD and ALS have long been considered to be caused by the same strain of this pathogen, but recent genetic studies have revealed differences among X. fastidiosa isolated from these host plants.

Use of a green fluorescent strain for analysis of Xylella fastidiosa colonization of Vitis vinifera.

Xylella fastidiosa causes Pierce's disease of grapevine as well as several other major agricultural diseases but is a benign endophyte in most host plants. X. fastidiosa colonizes the xylem vessels of host plants and is transmitted by xylem sap-feeding insect vectors.

The biology of xylem fluid-feeding insect vectors of Xylella fastidiosa and their relation to disease epidemiology.

Xylophagous leafhopppers are common and abundant insects of tropical and subtropical environments and play important ecological roles in these ecosystems. The feeding biology of these insects is unique in terms of their high feeding rates and a digestive physiology that allows them to assimilate amino acids, organic acids, and sugars at approximately 99% efficiency. For those species well studied, fluctuations in plant xylem chemistry and tension appear to determine the diurnal and seasonal use of their host plants.

Draft sequencing and comparative genomics of Xylella fastidiosa strains reveal novel biological insights.

Draft sequencing is a rapid and efficient method for determining the near-complete sequence of microbial genomes. Here we report a comparative analysis of one complete and two draft genome sequences of the phytopathogenic bacterium, Xylella fastidiosa, which causes serious disease in plants, including citrus, almond, and oleander. We present highlights of an in silico analysis based on a comparison of reconstructions of core biological subsystems.

Whole-genome comparative analysis of three phytopathogenic Xylella fastidiosa strains.

Xylella fastidiosa (Xf) causes wilt disease in plants and is responsible for major economic and crop losses globally. Owing to the public importance of this phytopathogen we embarked on a comparative analysis of the complete genome of Xf pv citrus and the partial genomes of two recently sequenced strains of this species: Xf pv almond and Xf pv oleander, which cause leaf scorch in almond and oleander plants, respectively. We report a reanalysis of the previously sequenced Xf 9a5c (CVC, citrus) strain and the two "gapped" Xf genomes revealing ORFs encoding critical functions in pathogenicity and conjugative transfer.

Temperature-Dependent Growth and Survival of Xylella fastidiosa in Vitro and in Potted Grapevines.

Xylella fastidiosa is a xylem-inhabiting bacterium that causes Pierce's disease (PD) of grapevine. Growth rates of X. fastidiosa in a rich liquid medium were determined by culturing methods at various temperatures.