Fig. 5

The CAPE1 peptide of SlPR1 induces root defenses to increase resistance to Fol infection. a Production of ROS in tomato roots treated with 250 nM CAPE1, SlPR1-MBP, MBP, and 50 nM flg22. The mean values (± SEM) of eight replicates are shown. The experiments were repeated three times, each yielding similar observation. b H₂O₂ production in the root tissues was detected after CAPE1 treatment. DAB was used to visualize the H₂O₂ accumulation. The images are representative of the results of three biological repeats. c Quantification of H₂O₂ in mock- or CAPE1-treated roots, as in b. d Production of SA, JA, JA-Ile, and OPDA in the roots after irrigation with or without 250 nM CAPE1. e Hierarchical clustering of the abundance of transcripts of SA and JA signaling pathway genes in tomato roots and leaves. At 2 and 4 h after irrigation with a solution of CAPE1, the roots and leaves were collected and ultimately subjected to qRT-PCR. f Resistance of tomato seedlings pre-treated with or without CAPE1 prior to Fol inoculation. The disease assay was carried out 4 h after application of 250 nM CAPE1 peptide to the tomato roots. g Disease index at 14 dpi of 20 plants shown in f. For c, d, and g, statistical significance was revealed by Student’s t-test. The P values are shown