Figure 5.

The SAR-enriched phloem proteins TRXm1, TRXm4, and MLP are involved in SAR. A and D, Standard SAR assays comparing wild-type Col-0 with trxm1 and trxm4 (A) or mlp (D). Leaves of 4-week-old plants were mock inoculated (10 mm MgCl₂) or induced for SAR by pressure infiltration with 10⁶ cfu mL⁻¹ Pst DC3000/avrRpt2. Two days later, distant leaves were challenged with 10⁶ cfu mL⁻¹ Pst DC3000, and Pst levels in these leaves were quantified 3 d post inoculation (dpi). Experiments were repeated at least three times with similar results. B and C, Local resistance assays comparing wild-type Col-0 with trxm1 and trxm2 (B) or mlp (C). Local resistance to virulent (VIR; Pst DC3000) and avirulent (AVIR; Pst DC3000/avrRpt2) strains of Pst was assessed by inoculating leaves of 4-week-old plants with 10⁶ cfu mL⁻¹ of either strain. Bacterial densities were determined at 0 and 3 dpi. All values represent means ± sd of three sample replicates. Different letters indicate statistically significant differences (ANOVA, Tukey’s honestly significant difference [HSD], P < 0.05).