Across the United States from California to Florida and as far north as Virginia, grapevines are succumbing to Pierce’s Disease (PD) which currently infects more than 30% of grapevines and is a threat to the $30 billion wine industry. PD is caused by the bacterial pathogen, Xylella fastidiosa, which blocks water from flowing through the xylem of plants. Affected grapevines develop leaves that a...

Many phytopathogenic bacteria, such as Ralstonia solanacearum, Pantoea stewartii, and Xanthomonas campestris, produce exopolysaccharides (EPSs) that aid in virulence, colonization, and survival. EPS can also contribute to host xylem vessel blockage. The genome of Xylella fastidiosa, the causal agent of Pierce's disease (PD) of grapevine, contains an operon that is strikingly similar to the X. c...

2 Department of Environmental Science, Policy, and Management, University of California, 8 Berkeley, CA 94720, USA. 9 10 *Corresponding author: Nabil Killiny, email: [email protected] 11 Tel: +1 863-956-8833. Fax: +1 863-956-4631 12 13 Running title: Xylella fastidiosa transmission 14 15 AEM Accepts, published online ahead of print on 1 November 2013 Appl. Environ. Microbiol. doi:10.1128/AEM...

Xylella fastidiosa has been recognized as a pathogen of landscape trees for over 25 years. Collectively, these diseases are referred to as bacterial leaf scorch (BLS). Arborists, property owners, and communities are now beginning to recognize BLS as a serious threat to the urban forest. Although advances in symptom awareness and diagnostic techniques have enabled arborists to diagnose BLS, ther...

Xylella fastidiosa is the causal agent of almond leaf scorch disease (ALSD), which is currently reemerging in California as a potential threat to almond (Prunus dulcis) production. We previously reported the presence of different colony morphotypes of X. fastidiosa ALSD strains on periwinkle wilt medium solidified with Gelrite and their association with genotypes or pathotypes after a low numbe...

The utilization of genomic data and widespread availability of genomics tools is still incipient in plant pathology. The first genome of a plant pathogen, that of the bacterium Xylella fastidiosa, was only completed in 2000 (Simpson et al. 2000). Since then, many bacterial plant pathogens have been sequenced, but much of the scientific knowledge extracted from these data is still limited, espec...

Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases including Pierce's disease of grapevines. X. fastidiosa is thought to induce disease by colonizing and clogging xylem vessels through the formation of cell aggregates and bacterial biofilms. Here we examine the role in X. fastidiosa virulence of an uncharacterized gene, PD1671, annotated as a tw...

The xylem-limited, insect-transmitted bacterium Xylella fastidiosa causes Pierce's disease in grapes through cell aggregation and vascular clogging. GacA controls various physiological processes and pathogenicity factors in many gram-negative bacteria, including biofilm formation in Pseudomonas syringae pv. tomato DC3000. Cloned gacA of X. fastidiosa was found to restore the hypersensitive resp...

INTRODUCTION Current approaches to understanding the progression of Pierce’s disease are limited by the lack of genetic techniques that can be used to study the biology of Xylella fastidiosa (Xf). In particular, extrachromosomal elements, such as plasmids, having long-term stability in Xf when grown in lab cultures or en planta, have not yet been satisfactorily developed. We will develop vector...

Xylella fastidiosa (Xf) is a xylem-limited bacterium that lives as a harmless endophyte in most plant species but is pathogenic in several agriculturally important crops such as coffee, citrus, and grapevine (Vitis vinifera L.). In susceptible cultivars of grapevine, Xf infection results in leaf scorch, premature leaf senescence, and eventually vine death; a suite of symptoms collectively refer...