Fig. 1

Transgenic soybean lines overexpressing GmPAO display significantly boosting H₂O₂ production at the P. sojae infection sites. WT: wild-type soybean cultivar Williams 82; CK: non-GmPAO transgenic soybean line. T1-1 (including T1-1-1, T1-1-3, T1-1-4, and T1-1-5) and T1-4-1 are progenies of two independent transgenic soybean lines overexpressing GmPAO gene. a Changes in the contents of putrescine (Put), spermidine (Spd), and spermine (Spm) in WT plants in response to P. sojae infection. Error bar represents mean ± SD, n = 3, n represents sample number. b, d PAO enzymatic activity and H₂O₂ content in transgenic soybean plants during P. sojae infection. RU: relative activity units (Error bar represents mean ± SD, n = 3, n represents sample number). c DAB staining of H₂O₂ at 16 hpi. Scale bar: 1 cm (upper). Micrograph of DAB staining at P. sojae infection sites. Scale bar: 20 μm (lower). All the experiments were performed three times (biological replicates) with similar results. The data in a, b, and d were analyzed by Shapiro–Wilk test to determine the Normality and Lognormality Tests across groups, and then analyzed by one-way ANOVA with post-hoc Dunnett's multiple comparisons test for groups that had passed the normality test (ns, no significant difference; *P < 0.05; **P < 0.01). The exact n, SD values, and P values are shown in the data