Fig. 6.

Dependence of bacterial membrane depolarisation on bacterial density after treatment with oxidized AS. Suspensions of 5 × 10⁷ (a) and (b) 5 × 10⁶ CFU/ml of P. syringae pv. tabaci, P. syringae pv. tomato DC3000 or A. tumefaciens bacteria were added to reaction mixtures containing 50 μM AS, 50 μM H₂O₂, and 0.72 U/ml POX, and various control mixtures from which one or two components were omitted. Bacterial membrane polarity was tested with the voltage sensitive DIBAC₄(3) stain added 3 h after treatments of bacteria. Error bars indicate standard deviations. Different letters above the bars denote different levels of DIBAC₄(3) fluorescence assigned by Tukey’s Test (p < 0.05). Abbreviations: Cont: non-treated control bacteria, AS: acetosyringone, HK: heat killed, POX: horseradish peroxidase, Blank: buffer only