A. flavus strains used in this study

Primers used for strain construction in this study

Primers used for RT-qPCR in this study

The functions of SntB in A. flavus. (A) The colonies of WT, ΔsntB, and Com-sntB strains grown on PDA at 37°C in dark for 4 d. (B) The colony diameter statistics of the above fungal strains. (C) Microscopic examination revealed the difference in mycelia of each fungi strain at 37L in dark, scale=200 μm. (D) Microscopic examination of the hyphal septum of each strain at 37L in dark, scale=50 μm. (E) The spore production statistics. (F) All the above fungal strains were point-inoculated on CM medium and grown for 7 d at 37L. (G) The number of sclerotia of the above fungal strains. ND=Not detectable. (H) AFB1 production of the above fungal strains was detected by TLC after the strains incubating at 29L in PDB medium for 7 d.

The role of SntB on the ability of A. flavus to colonize host. (A) Phenotypic of corn and peanut kernels colonized by ΔsntB, Com-sntB, and WT strains at 29°C in dark for 7 d. (B) Statistical of the number of conidia on the surface of peanut and maize kernels. (C) TLC analysis to detect the yield of AFB1 in kernels infected by the above fungal strains after 7 d incubation. (D) Photographs of the silkworms infected by the above fungal strains. (E) The survival rate of silkworms 1 week after injection of the above strains. (F) Photographs of the dead silkworms infected by A. flavus after 6 d incubation. (G) The spore production statistics of the above fungal strains on the dead silkworms shown in (F). (H) TLC analysis of AFB1 levels produced in infected dead silkworms in (F).

SntB chords global gene expression in A. flavus. (A) The Pearson correlation results shown by heatmap. (B) Principal component analysis (PCA) on six fungal samples, including three ΔsntB (KOsnt2) and three WT fungal strains. (C) Volcano map reflecting the distribution of the differential expression genes. (D) Gene Ontology (GO) analyses of the differentially expressed genes. (E) Kyoto encyclopedia of genes and genomes (KEGG) analyses of the differentially expressed peaks related genes.

Characterization the binding regions of SntB. (A) Verification of the construction of sntB-HA strain using western blot. M means the PAGE-MASTER Protein Standard Plus (GenScript USA, MM1397). (B) The distribution of differently accumulated peaks on the genome. (C) Vennpie map of the differently accumulated peaks distribution on gene functional elements. (D) Enrichment of known motifs showing the top-ranked motif logos. (E) Enrichment of de novo motifs showing the top-ranked motif logos. (F) GO analyses of the of the differently accumulated peaks related genes. (G) KEGG analyses of the differently accumulated peak related genes.

Integration of the results of ChIP-seq and RNA-seq assays. (A) Venn diagrams of ChIP-seq and RNA-seq. (B) GO analyses of the common genes. (C) KEGG analyses of the common genes. (D) The phenotype of WT, ΔsntB, and Com-sntB strains cultured in PDA containing a series concentration of MSB for 3 d. (E) Statistical analysis of the growth inhibition rate of MSB to all the above fungal strains according to Panel D. (F) Comparation of the enrich levels of the SntB binding region of catC gene between WT and sntB-HA strains. (G) The motif logo in the SntB binding region of catC gene. (H) The relative expression level of sod1 in WT and ΔsntB strains with or without MSB treatment.

The functions of catC in A. flavus. (A) The colonies of WT and ΔcatC strains grown on PDA at 37°C in dark for 4 d. (B) The colony diameter statistics of the above fungal strains. (C) The spore production statistics of the above fungal strains. (D) All above fungal strains were point-inoculated on CM medium and grown for 7 d at 37L. (E) The number of sclerotia of the above fungal strains. (F) The phenotype of above strains cultured in PDA medium containing a series concentration of MSB for 3 d. (G) Statistical analysis of the growth inhibition rate of MSB to all the above fungal strains according to (F). (H) Relative ROS level in the WT, ΔsntB, Com-sntB, and ΔcatC strains. (I) AFB1 production of the above fungal strains was detected by TLC after the strains incubating at 29L in PDB medium for 7 d.

SntB regulate peroxisome biogenesis, fatty acid utilization, and fungal pathogenicity in A. flavus. (A) The phenotype of each strain on PDA medium containing 0.3% tributyrin, (B) Statistics of inhibition rates. The asterisk *** above the bars represents significantly different (p<0.001). (C) Mechanistic diagram of the bio-functions of SntB in A. flavus.

The construction of mutant strains. (A) PCR verification of gDNA in WT, ΔsntB and Com-sntB strains (“ORF” represents the sntB gene fragment, “AP” represents the amplification of the fusion fragment upstream with primers sntB-p1 and P801, and “BP” represents the downstream of the fusion fragment from primers P1020 and sntB-p4). (B) Southern blot analysis result of WT, ΔsntB candidate strains (The genome DNA of each strain was digested with restrictive endonuclease EcoR I and hybridized with the probe of 1533 bp). (C) qRT-PCR verification of the expression level of the sntB gene in WT and sntB gene mutant strains.

The expression of genes related to sporulation, sclerotia production, and aflatoxin synthesis. (A) The expression of sporulation-related genes steA, WetA, fluG and veA in each strain at 48 h. (B) The Expression of sclerotia-associated genes nsdC, nsdD, and sclR in each strain at 48 h. (C) The Expression of aflatoxin-associated genes in each strain at 48 h. The asterisk *** above the bars represents significantly different (p<0.001)

The changes of number of conidia, amylase, and lipase in WT, ΔsntB and Com-sntB strains. (A) Statistics of the number of conidia on the corn seed. (B) The phenotype of each strain on starch screening medium supplemented with 0.1% of soluble starch in darkness at 29℃ for 3 d, followed by addition of iodine solution. (C) HC value of the clear circle (Outer diameter / inner diameter) of the salient analysis of the mapThe asterisk ** above the bars represents significantly different (p<0.01).

Sequence information of ChIP-seq. (A) Heatmap. (B) PCA. (C) Peak distribution on the genome of SNTB-HA group. (D) Peak distribution on the genome of WT group.

PCR verification of gDNA in WT and ΔcatC

Heatmap of the DEGs related to oxidative response in transcriptome data draw by TBtools.

The binding region and motif of SntB on the catA, catB, sod1, and sod2 genes. (A) Comparation of the enrich levels of the SntB binding region of catA, catB, sod1, and sod2 genes between WT and sntB-HA strains. (B) The motif logo in the SntB binding region of catA, catB, sod1, and sod2 genes.