Dimethylformamide Inhibits Fungal Growth and Aflatoxin B1 Biosynthesis in Aspergillus flavus by Down-Regulating Glucose Metabolism and Amino Acid Biosynthesis

Abstract

Aflatoxins (AFs) are secondary metabolites produced by plant fungal pathogens infecting crops with strong carcinogenic and mutagenic properties. Dimethylformamide (DMF) is an excellent solvent widely used in biology, medicine and other fields. However, the effect and mechanism of DMF as a common organic solvent against fungal growth and AFs production are not clear. Here, we discovered that DMF had obvious inhibitory effect against A. flavus, as well as displayed complete strong capacity to combat AFs production. Hereafter, the inhibition mechanism of DMF act on AFs production was revealed by the transcriptional expression analysis of genes referred to AFs biosynthesis. With 1% DMF treatment, two positive regulatory genes of AFs biosynthetic pathway aflS and aflR were down-regulated, leading to the suppression of the structural genes in AFs cluster like aflW, aflP. These changes may be due to the suppression of VeA and the subsequent up-regulation of FluG. Exposure to DMF caused the damage of cell wall and the dysfunction of mitochondria. In particular, it is worth noting that most amino acid biosynthesis and glucose metabolism pathway were down-regulated by 1% DMF using Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Taken together, these RNA-Seq data strongly suggest that DMF inhibits fungal growth and aflatoxin B1 (AFB1) production by A. flavus via the synergistic interference of glucose metabolism, amino acid biosynthesis and oxidative phosphorylation.

Linolenic Acid-Derived Oxylipins Inhibit Aflatoxin Biosynthesis in Aspergillus flavus through Activation of Imizoquin Biosynthesis

“…Analysis of the coregulatory gene expression network under conditions with and without AF production occurring showed that the expression levels of genes involved in the TCA cycle and glycolysis were significantly reduced in the non-aflatoxigenic conditions . Pan et al showed that dimethylformamide inhibition of AFB1 biosynthesis may be due to downregulation of pathways related to the TCA cycle and glycolysis . Here, our multiomics, qRT-PCR, and 13 C-glucose parallel labeling results together revealed that AL promoted the TCA cycle.…”

SfgA Renders Aspergillus flavus More Stable to the External Environment

“…These results suggested that the deletion of sfgA may affect the main components of the fungal cell wall of A. flavus , including chitin and structural polysaccharides. Consequently, the cells will generate a defensive response to by over-expressing alpha-1,3-glucan synthase genes to overcome stimulation [ 59 ]. In general, it is possible that the response of sfgA to environmental stress resistance could be linked to the differential expression of these genes.…”

Selection of green carrier solvent for the effective creation of bio-inspired liquid formulation and anti-fungal potency evaluation

“…As a result, methyl oleate's reduced fungal toxicity may be partly explained by its higher log P value of 7.45 (Table 4). According to hazard identi cation and ecotoxicity values, methyl oleate (commonly known as biodiesel) is regarded nonhazardous and less harmful than other hazardous solvents such as DMF (Pan et al, 2020). (Table 4).…”