First report of causing root rot in (L.) in California.

In June of 2020 we observed greenhouse grown in Sonoma County, CA and Monterey County, CA showing stress symptoms: stunting, leaf chlorosis, and leaf senescence, when moved to flower production conditions. We uprooted symptomatic and healthy plants and observed disease symptoms only in symptomatic plants: reduced root mass, reduced root hair density, and necrosis. Roots and growth substrate samples were taken from infected and healthy plants for further analysis.

First report of causing crown rot in greenhouse grown (L.) in California.

In April of 2020 cuttings of (L.) in a greenhouse in San Mateo County, CA were observed collapsing, and further observation revealed: water-soaked stems, tan discoloration to the cortex, and discolored roots. The greenhouse irrigation system was supplied by a local stream.

Insights into the Activity and Substrate Binding of Xylella fastidiosa Polygalacturonase by Modification of a Unique QMK Amino Acid Motif Using Protein Chimeras.

Polygalacturonases (EC 3.2.1.

Localization and characterization of Xylella fastidiosa haemagglutinin adhesins.

Xylella fastidiosa is a gram-negative, xylem-inhabiting, plant-pathogenic bacterium responsible for several important diseases including Pierce's disease (PD) of grapevines. The bacteria form biofilms in grapevine xylem that contribute to the occlusion of the xylem vessels. X.

Xylella fastidiosa requires polygalacturonase for colonization and pathogenicity in Vitis vinifera grapevines.

Xylella fastidiosa is the causal agent of Pierce's disease of grape, an economically significant disease for the grape industry. X. fastidiosa systemically colonizes the xylem elements of grapevines and is able to breach the pit pore membranes separating xylem vessels by unknown mechanisms.

Persistence of Xylella fastidiosa in Riparian Hosts Near Northern California Vineyards.

The spread of Pierce's disease (PD) from riparian hosts to grapevines in California's northcoastal grape-growing region is a function of the proportion of Graphocephala atropunctata (blue-green sharpshooters [BGSSs]) that acquire Xylella fastidiosa from infected plant tissue. Riparian hosts that do not maintain sufficient X. fastidiosa populations for acquisition may not be significant inoculum reservoirs.