Figure 6.

XopP targets EXO70B without activating its guarding NLR immune receptor, TN2. A, Expression in N. benthamiana leaves of BnTN2 fused C-terminally to the YFP epitope tag. Micrographs were obtained via confocal microscopy at 3 dpi. Bars = 10 μm. B and C, Transient co-expression of the NLR immune receptor BnTN2-YFP with EXO70B1-HF and XopP-myc in N. tabacum leaves (B) and quantification of the resulting HR (C). EXO70B1-HF suppressed the BnTN2-YFP-dependent HR induction when combined in a 1:1 ratio. In contrast, XopP-myc itself was not able to abolish the BnTN2-YFP-dependent HR induction at the 1:1 expression ratio. However, when combining all three constructs in a 1:1:1 ratio, no HR reaction was observed at 72 hpi. The experiment was repeated four times with identical results. The vertical axis shows the average number of plants from all four experiments that either produce or do not produce the HR. For the HR quantification, 10 plants were used for the statistical analysis (four independent experiments) and two-way ANOVA tests were performed. The P-value for interaction was <0.0001. Additional Y2H screenings and in planta experiments using TN2 are presented in Supplemental Figure S8. Bar = 1 cm.