Time course of cDNA-AFLP fragment abundance during the E. amylovora - Malus host-pathogen interaction. The possible involvement of specific genes in resistance or susceptibility mechanisms was inferred from their response in fire blight resistant "cv. G41" (■ symbol) and susceptible "cv. M.26" (Δ symbol) (see Discussion). Black lines indicated response in mock-inoculated leaf tissue, whereas red and blue lines E. amylovora-inoculated "cv. G41" and "cv. M.26", respectively. X-axis represents hours post inoculation (hpi) and y-axis relative gene expression (see Materials and Methods). Numbers in brackets following gene annotation refer the fragment ID number in additional file 1.