Fig. 6.

The effect of tde-associated genes tap-1, paar, and atu3641 for cognate Tde effector translocation. Requirement of tap-1 (A and D) and paar genes (B and E) in Tde1-dependent antibacterial activity and Tde1 secretion; requirement of atu3641 in Tde2-dependent antibacterial activity (C) and type VI secretion (F). (A–C) E. coli killing assay in which attacker A. tumefaciens strains containing the plasmid only (p) or expressing the indicated genes shown on the x axis were mixed with E. coli DH10B cells expressing tdi1 or tdi2 at a 30:1 ratio for competition. The survival of E. coli cells was quantified as cfu and shown on the y axis. Data are mean ± SEM (n = 5 biological repeats from two independent experiments) computed by one-way ANOVA. Different letters above the bar indicate significant difference (P < 0.05) determined by Tukey’s HSD test. (D–F) Western blot analysis of the total (T) and secreted (S) proteins from various A. tumefaciens strains expressing the plasmid control (p) or indicated gene. Protein names and molecular weight markers are indicated at the left and right, respectively. The soluble ActC protein was used as an internal nonsecreted protein control.