Fig. 3: The Sr35 resistosome forms a Ca²⁺-permeable non-selective cation channel.

a, Representative measurements from two-electrode (TEVC) recordings from Xenopus oocytes expressing Sr35, AvrSr35 and Sr35/AvrSr35. Effects of CaCCinh-A01 (Ca²⁺-activated chloride channel inhibitor) and LaCl₃ (Ca²⁺ channel blocker) on the Sr35-mediated currents in ND96 solution (96 mM NaCl, 2.5 mM KCl, 1 mM MgCl₂, 1.8 mM CaCl₂, 5 mM HEPES, pH 7.6). Current traces shown at different voltages from −110 mV to +70 mV in 20 mV increments and current amplitudes at −110 mV. b, Quantitative measurements of data as in a. c, Structure-based mutagenesis of Sr35 residues at the interface between the LRR domain of Sr35 and AvrSr35, and Sr35 α1-helix. TEVC recordings in ND96 solution, and current amplitudes at −110 mV. d, Wheat protoplast data of Sr35 mutations at α1-helix. Relative luminescence as readout for cell death. EV treatment defined the relative baseline (mean ± s.e.m.; n = 5). Test statistics derived from ANOVA and Tukey post hoc tests (P < 0.05). Exact P values are provided in Supplementary Table 3. e, Tobacco cell death data of Sr35 and Sr35 channel mutants. Representative data shown from a minimum of three replicates. f, The Sr35 channel is selective for cations. TEVC recordings performed in various solutions, including KCl (96 mM), K-gluconate (96 mM), NaCl (96 mM), Na-gluconate (96 mM) and TBA-Cl (96 mM). g, Cationic currents of CaCl₂, Ca-Glu, MgCl₂ and Mg-Glu in the presence of CaCCinh-A01 and CaCCinh-A01+LaCl₃. Data are mean ± s.e.m., n ≥ 8 (b,c,f,g). *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001, one-way ANOVA analyses and Tukey post hoc test in b, c and g, and two-sided Student’s t-tests in f.