FIG 1 .
(A) Induction of the Xylella fastidiosa-based DSF biosensor strain (XfDSF-biosensor strain) and (B) the Xanthomonas campestris-based DSF biosensor strain (XccDSF-biosensor strain) by various concentrations of DSF-containing culture extracts of Xylella fastidiosa strain. (C) Induction of the XccDSF-biosensor strain by extracts of Pantoea agglomerans 299R expressing XfRpfF or harboring a vector only. The extract concentration reflects the volume of culture supernatant that would have been extracted with ethyl acetate to yield that added to 1 volume of assay medium.