Fig. 2.

BTH-induced rice blast resistance of 5th leaves, expression analysis by q-RT-PCR, and the concentration of SA in KASBL and K209 cultivars. a. The 5th leaves of KASBL and K209 were sprayed with 50 μΜ BTH or water. After 2 days, the leaves were spray-inoculated with blast fungal conidia suspension (isolate Kyu89–246, 4.0 × 10⁴ spores ml⁻¹). Disease symptoms were evaluated by percentage of diseased leaves 10 days after inoculation. The experiments were performed three times with similar results. b. The expression of Pb1, WRKY45, NH1 and PR1a in the 5th leaves were analyzed by q-RT-PCR. Leaves after mock (M) or BTH treatment (BTH) for 2 days (left column) or 4 days (right column) were used for the expression analyses. The Y-axis indicates the mRNA expression relative to that of UBQ. The averages with SD are shown. Different letters indicate significant differences among the different lines at p < 0.05 (one-way ANOVA). Experiments were repeated twice with similar results. c. Free (left) and total (right) SA content of 25th leaves of KASBL and K209 measured by high performance liquid chromatography (HPLC). Letters indicate significant differences among the different lines at p < 0.05 (one-way ANOVA). Experiments were repeated three times with similar results