Figure 5

Mixture of wild-type and mutant Xylella fastidiosa strains after third isolation. The XfΔpilJ mutants confirmed in Figure 4 (isolates 4 and 17) were streaked onto PW agar plates amended with kanamycin and the genotype assessed for 16 single colonies. Each number denotes a single colony. A. The pilJE/pilJF (EF) primers amplified a 2030 bp band for non-transformed bacteria and no equivalent band for the XfΔpilJ strains or the deletion plasmid (P). B. The pilJA/pilJD (AD) primers amplified a 3082 bp band for non-transformed cells and a 2200 bp fragment from the XfΔpilJ strains and the deletion plasmid (P). Wild-type X. fastidiosa DNA (wt) was used as a positive control for the PCR reactions, while primer reaction without template DNA represented by H₂O, was used as negative controls for both PCR reactions.