Fig. 4

Expression of the genes of the cluster for ustiloxin B biosynthesis in A. oryzae wild-type (RIB40), ustR ^EX, ∆kexB, and ustR ^EX/∆kexB strains. The strains were grown in V8 medium at 30 °C for 5 days. Quantitative RT-PCR was used to determine the levels of transcription of the ustR gene and the indicated representative genes; RT-PCR was performed on total RNA with gene-specific primers (Additional file 1: Table S1). Each value represents the ratio of expression relative to that of the histone H2B gene in each strain. Error bars represent standard deviations (n = 3). ND not detectable