Isoborneol as a natural sporulation quenching agent to control Aspergillus flavus

In an effort to seek natural antisporulating agents used in the control of Aspergillus flavus, 54 essential oil compounds were employed to evaluate their antisporulating activity against A. flavus at the concentration of 100 μg/mL. The results indicated that isoborneol could inhibit spore production at 100 μg/mL. The light microscopy and scanning electron microscopy (SEM) observations revealed that A. flavus did not produce any conidia, vesicles, phialides and conidiophores after treatment with isoborneol at 80 μg/mL, confirming the effectiveness of isoborneol. The in vivo bioassay results demonstrated that isoborneol could prevent the peanuts from A. flavus contamination by inhibiting the sporulation when treated with isoborneol at concentrations higher than 100 μg/mL. RT-qPCR results suggested that isoborneol exerts its antisporulating activity by suppressing the fluG expression. These results proved that isoborneol could be used as a natural and safe antisporulating agent for commercial applications to control spore infections of A. flavus.