Fig. 5

Roles of oxylipins in mediating downregulation of AfPXG gene expression and decreased aflatoxicogenicity in A. flavus. a 7-day old fungal growth on PDA-plates in the presence or absence of exogenous oxylipins at concentrations of 50 and 100 μM, referred to as to oxylipin50 and oxylipin100, respectively. b Measurements of conidia number and fungal mycelium dry weight for each treatment compared with controls. c Transcript levels of AfPXG genes, evaluated by RT-qPCR, and peroxygenase activity of AfPXG, measured by the hydroxylation of aniline at 310 nm. d Micrographs of LDs viewed at 40× magnification immediately after preparation. Bar represents 5 μm. e Sections of TLC-plate showing the blue-fluorescent spot under UV corresponding to AFB1 extracted from oxylipin-treated fungi compared to a control. f Quantitative data for AFB1 production estimated by UV-detector HPLC. g Relative quantification RQ ₌ 2^{(−∆∆CT)} of AF-biosynthesis cluster genes in oxylipin-treated fungi compared to controls. The colour scale (white-red-black) indicates relative changes of transcripts of 1, − 20 and − 40 fold, respectively where the expression level for each gene in controls was defined as 1