Extended Data Fig. 9: Pg20(Aa) and pg36(Bra) activate plant immune responses in Arabidopsis arenosa and Brassica rapa, respectively.

a, Peptides 1-3 derived from PG6 do not activate ethylene production in A. arenosa and B. rapa. Ethylene accumulation after 4 h treatment with water (mock), or 1 µM pep1-3 in A. arenosa and B. rapa. b,d, Ethylene-inducing activity of pg20(Aa) (b) and pg36(Bra) (d) and the corresponding mutant peptides in A. arenosa (b) or B. rapa (d). EC₅₀ values were obtained from dose-response experiments using synthetic peptides. Peptide sequences are indicated at the left. Mutant residues are indicated in red. At the right panel, bars represent means ± standard deviation on a logarithmic scale. Data points are indicated as black dots. The peptide with low EC₅₀ value has high elicitor activity. The peptides that did not induce any or residual ethylene production only at 10 µM are defined as inactive peptide (stars). c,e, Total ROS production in leaf discs of A. arenosa treated with water (mock), 100 nM flg22, 1 µM pg20, or 1 µM pg20^G236A (c) or of B. rapa treated with water (mock), or 1 µM of the given elicitor (e) over 120 min. RLU, relative light unit. For a,c,e, data points are indicated as grey dots from three or two independent experiments (a, A. arenosa, n = 9; B. rapa, n = 6; c, n = 24) and plotted as box plots (centre line: median, bounds of box: the first and third quartiles, whiskers: 1.5x the interquartile range, error bar: minima and maxima). Statistically significant differences to mock treatments in the respective plant are indicated (two-sided Student’s t-test). f, Hypersensitive response-like cell death in B. rapa leaves infiltrated with water (mock), 1 µM pg36(Bra), or 1 µM pg36^Q208G, and visualized at 7 days post infiltration. Assays were performed in triplicate with similar results.