Fig. 2

Effects of priming by 3OC8-HSL and pathogen challenge on H₂O₂ accumulation. a, Microscopic observation of H₂O₂ accumulation. Hydroponically grown Arabidopsis plants were pretreated in Hoagland medium containing 10 μM 3OC8-HSL or without 3OC8-HSL (control) for 2 days, then the leaves were sprayed with PstDC3000 (OD₆₀₀ = 0.1) solution and collected at 0, 6, 12, and 24 hpi. The leaves were incubated in DAB staining solution for 24 h. After de-staining, the leaves were photographed under a microscope at the indicated times (bar = 200 μm). The experiments were performed with six leaves per treatment, and similar results were obtained in three independent experiments. b, H₂O₂ quantification in Arabidopsis with 3OC8-HSL pretreatment and pathogen challenge. The samples were collected as described above, and the H₂O₂ content was detected according to the method described by Velikova et al. (1971). Values are means ±SD of three independent experiments. Different letters indicate statistically significant differences (P < 0.05, Duncan’s test)