HopZ1a partially complements the virulence function of coronatine in bacteria growth.

(A) HopZ1a promotes the multiplication of PtoDC3118 in Arabidopsis. Arabidopsis zar1-1 plants were dip-inoculated with PtoDC3000 carrying pUCP20tk (EV), pUCP20tk::hopZ1a-HA, or PtoDC3118 carrying pUCP18 (EV), pUCP18::hopZ1a-HA or pUCP18::hopZ1a(C216A)-HA at OD600 = 0.2 (approximately 2×108 cfu/mL). Bacterial populations were determined at 0 and 3 days post inoculation. The average colony forming units per square centimeter (cfu/cm2) and standard deviations (as error bars) are presented. Different letters at the top of the bars represent data with statistically significant differences (two tailed t-test p<0.01). (B) COI1 is required for the virulence activity of HopZ1a. coi1-1, zar1-1 double mutant plants were dip-inoculated with PtoDC3118 carrying pUCP18 (EV), pUCP18::hopZ1a-HA or pUCP18::hopZ1a(C216A)-HA. Bacterial multiplications were examined at 0 and 3 days post inoculation. The average colony forming units per square centimeter (cfu/cm2) and standard deviations (as error bars) are presented. The expression of HopZ1a or HopZ1a(C216A) in P. syringae was confirmed by western blots (Fig. S8). These experiments were repeated at least five times with similar results.