Figure 3.

Both local generation/transmission and systemic perception/propagation of phloem-mobile SAR signals depends on BXL4. Leaves of Col-0 and bxl4-1 plants were inoculated with either 10⁷ cfu/mL of Pst/AvrRpm1 (S) or a corresponding mock (M) solution. One day later, petiole exudates (PetEx) were collected from the inoculated leaves and syringe-infiltrated into leaves of naïve Col-0 and bxl4-1 recipient plants. One day later, the inoculated recipient leaves were either collected for qRT-PCR analysis or challenged with 10⁵ cfu/mL of Pst. (A, B) Bacterial titers in challenge-inoculated leaves of receiver plants were monitored at 4 dpi. Box plots represent average Pst titers in Col-0 (A) and bxl4-1 (B) recipient plants from four to twelve biologically independent experiments ± min and max values. Letters above the box plots indicate statistically significant differences for means (one-way ANOVA and Tukey’s test for P=<0.05, for (A, Col-0 recipients): F(3, 191)=35.07, Col-0 M n=51, Col-0 S n=48, bxl4-1 M n=49, bxl4-1 S n=47; for (B, bxl4-1 recipients): F(3, 116)=0.4254, Col-0 M n=45, Col-0 S n=44, bxl4-1 M n=16, bxl4-1 S n=15). (C) Transcript abundance of FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1) was determined by qRT-PCR, normalized to that of UBIQUITIN, and is shown relative to the normalized transcript levels of the appropriate Col-0 mock (M) control. Black dots represent three biologically independent data points and lines indicate the respective mean values ± SD. The letters above the scatter dot plots indicate statistically significant differences (one-way ANOVA and Tukey’s test for P=<0.05, n=3, F (5, 12)=17.77).