Fig. 2

RGS1 negatively regulates XLG2-mediated immune signaling and disease resistance to a bacterial pathogen. a rgs1-2 displays enhanced ROS production in response to flg22. The rgs1-2 line was stably transformed with RGS1-FLAG-GFP under the control of RGS1 native promoter. A T2 transgenic line and the rgs1-2 mutant were tested for flg22-induced H₂O₂ production. Different letters indicate significant difference at P < 0.05 (mean ± SD, n ≥ 6, one-way ANOVA followed by Tukey’s post hoc test). b rgs1-2 displays reduced stomatal aperture and is insensitive to Pst DC3000 hrcC⁻ treatment. The indicated genotypes were subjected to stomata measurement assay and the stomata opening is showed by calculating the ratio of width to length. (mean ± SD, n ≥ 6, one-way ANOVA followed by Tukey’s post hoc test). c, d rgs1-2 mutant shows enhanced defense gene expression upon flg22 (c) and chitin (d) treatment. Leaves of Col-0, xlg2 xlg3, and rgs1-2 plants were infiltrated with flg22 or chitin for 3 h, and total RNA were extracted and subjected to qPCR analysis of the indicated genes. Different letters indicate significant difference at P < 0.05 (mean ± SD, n ≥ 6, one-way ANOVA followed by Tukey’s post hoc test). e rgs1-2 displays increased resistance to Pseudomonas syringae pv tomato (Pst) bacteria. Plants of the indicated genotypes were inoculated by spray with Pst DC3000, and bacterial population in the leaf was determined at 0 and 3 days after inoculation. Different letters indicate significant difference at P < 0.01 (mean ± SD, n ≥ 6, one-way ANOVA followed by Tukey’s post hoc test). f XLG2/XLG3 act downstream of RGS1 to regulate immune signaling. Plants of the indicated genotypes were examined for flg22-induced H₂O₂ production. Different letters indicate significant difference at P < 0.05 (mean ± SD, n ≥ 6, one-way ANOVA followed by Tukey’s post hoc test). The experiments were performed two (a, c, d) or three (b, e, f) times with similar results