Xylella fastidiosa bacteria in a xylem vessel of a Coffee root. Transversal sections, above, 3,000X, and below 6,000X. The presence of the bacteria in this root system indicates their descending, longitudinal translocation in the xylem, since inoculation occurred in the aerial parts of the plant. Ascendant translocation, however, is probably many times more efficient, being the normal direction of flow of xylem sap.

6000X