Fig. 3
Effect of rac-4BD on BIT-induced disease resistance in rice. Rice plants at the 3.5 leaf stage were pretreated with rac-4BD (30 µM in pot) and 1 day later with BIT (0.5 or 0.1 mg in pot) using the soil drenching method prior to RNA analysis and rice blast inoculation. (a) Expression of SAR marker gene. Rice leaves were sampled 1 and 3 days after treatment with the BIT (0.5 mg in pot). The expression levels of OsWRKY45 in the fourth leaves of plants were analyzed using RT-qPCR 1 or 3 days after treatment with compounds. The expression levels were normalized against the expression levels of OsUBQ measured in the same samples. Statistical analysis was performed for each sampling point. (b) Rice blast inoculation assay. Spreading lesions on the fourth leaf were counted five days after inoculation. Statistical analysis was performed for each BIT concentration (0.5 mg or 0.1 mg/pot). (c) Photograph of representative disease symptoms taken 5 days after inoculation. Different letters indicate significant difference. (ANOVA, Tukey’s test, p < 0.05).
