Figure 4. A. tumefaciens is unable to suppress HrpZ-elicited SA production.

A. The leaf shown was inoculated with A. tumefaciens GV3101 (AtGV3101 10⁷ cfu/ml), or 10 mM MgCl₂(AS) (Mg), followed by inoculation with P. syringae pv. tabaci 11528 (Pta), P. s. pv. tomato DC3000 (Pto) (10⁵ cfu/ml), HrpZ (0.1 mg/ml) or 10 mM MgCl₂ after 48 hours. The SA biosensor ADPWH-lux was inoculated into leaves 24 hours after infiltration with P. syringae or HrpZ. SA-induced luminescence was measured one hour after biosensor inoculation using a photon-counting camera. B. Numerical SA values were calculated using a calibration curve as described in Huang et al. [26]. The bars show the average SA values from three independent experiments. Bars show standard error of the mean. General Linear Model (GLM) analysis revealed statistical differences between treatments (F = 22.4936; p<0.0001; df = 23). Means with the same letter were not significantly different at the 5% confidence level based on Student's t test.