The Potential of Plant-Based Bioactive Compounds on Inhibition of Aflatoxin B1 Biosynthesis and Down-regulation of , and Genes.

The use of plant extracts in pre- and post-harvest disease management of agricultural crops to cope with aflatoxin B1 contamination has shown great promise due to their capability in managing toxins and safe-keeping the quality. We investigated the anti-aflatoxigenic effect of multiple doses of eight plant extracts (, , , , , , , ) on via LC-MS and the down-regulatory effect of them on , and genes involved in the aflatoxin B1 biosynthesis pathway using RT-qPCR analyses. Our results showed that (4 mg/mL), (6 mg/mL) and (2 mg/mL) completely stopped the production of aflatoxin B1, without inducing significant changes in growth. Furthermore, our findings showed a highly significant correlation between the gene expression and the aflatoxin B1 biosynthesis, such that certain doses of the extracts reduced or blocked the expression of the , and and consequently reduced the synthesis of aflatoxin B1. Interestingly, compared to the regulatory gene (), the down-regulation of expression in the structural genes ( and ) was more consistent and correlated with the inhibition of aflatoxin B1 production. Overall, this study reveals the anti-aflatoxigenic mechanisms of the selected plant extracts at the gene expression level and provides evidence for their use in plant and crop protection.