Xylella fastidiosa – a versatile bacterium

Xylella fastidiosa causes disease in numerous plants. It is unusual compared to most bacteria that cause plant diseases in that it can multiply within most plant species; the majority of its host plants have no symptoms when infected. So far, only one other plant pathogenic bacterium that colonizes its host plants’ water-conducting system, the xylem, is transmitted from plant to plant by sucking insects that feed on xylem sap.

As researchers in The University of California’s Agricultural Experiment Station, our first responsibility is to pursue scientific discovery about X. fastidiosa and its ecology (disease epidemiology) to better manage the diseases it causes. Because scientific discovery grows fastest when widely shared, we attempt to open doors to the wide range of aspects of this increasingly notorious bacterium that are affecting a growing diversity of crops and countries on other continents. The goal of this website is to provide technically accessible information on X. fastidiosa to a wide audience, from farmers to students pursuing class projects, as well as scientists and policymakers.

Rising from relative international obscurity even 30 years ago, X. fastidiosa now concerns a growing list of crops and countries where it is becoming a problem. Thirty years ago, more than 95% of the interest and research in X. fastidiosa was conducted in California and Florida. If you live in North Africa, southern Europe, non-desert areas of tropical Africa or Asia, some strain of X. fastidiosa may bring destruction to your country. A previously unknown strain of X. fastidiosa is now raging through the heel of Italy, eliminating thousands of hectares of olive trees from a land that exported olive oil before the birth of Rome. No one can predict with certainty how far it will spread or how much damage it will cause to crops and ecosystems. International efforts are needed to deal with this bacterium, and we hope the content of this website will be of assistance.