The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/toxins14120822/s1, Table S1: Oligonucleotide primers used in this study; Figure S1: Genome sequencing validation of the xyIPAflgsA strain of A. flavus. AflgsA AP is the upstream noncoding region of the AflgsA gene. The mutations in the AflgsA CDS are synonymous mutations; Figure S2: Analysis of the growth, mycelial morphology, conidial germination, and conidiophore formation of WT and xyIPAflgsA strains. (A) The mycelial morphology of WT and xyIPAflgsA strains on the medium containing 10 g/L and 20 g/L xylose. (B) The colony morphology of WT and xyIPAflgsA strains. (C) Statistical analysis of the diameter from panel (B). (D) Conidial germination of WT and xyIPAflgsA strains. (E) Statistical analysis of the conidial germination rate from panel (D). (F) Microscopic view of the conidiophore formation of the above two A. flavus strains. (G) The number of conidia produced by the above two A. flavus strains. ND indicates no detection. ** indicates a significance level of ppt-tests with three replicates. The medium containing 10 g/L xylose: 5 g/L yeast extract, 10 g/L glucose, 10 g/L xylose, 1 mL/L trace elements, and 1.5% agar. The medium containing 20 g/L xylose (YXT medium): 5 g/L yeast extract, 20 g/L xylose, 1 mL/L trace elements, and 1.5% agar; Figure S3: Analysis of the growth of WT and xyIPAflgsA strains. (A) The colony morphology of the WT and xyIPAflgsA strains on YXT medium containing 10 mM glutamine (GluN) or/and ammonium tartrate (NH4+) as nitrogen sources. (B) Statistical analysis of the diameter from panel (A). *** indicates a significance level of pt-tests with three replicates; Figure S4: Analysis of the growth of WT and xyIPAflgsA strains. (A) The colony morphology of the WT and xyIPAflgsA strains on YGT medium containing 10 mM glutamate (Glu) or on YXT medium. (B) Statistical analysis of the diameter from panel (A). ND indicates no detection. *** indicates a significance level of pt-tests with three replicates; Figure S5: AflGsA regulates sclerotia formation in A. flavus. (A) Phenotypic observation of sclerotia formation in WT and xyIPAflgsA strains on YXT medium containing 10 mM glutamine (GluN). (B) The number of sclerotia produced by the above two A. flavus strains. ND indicates no detection. * indicates a significance level of pt-tests with three replicates; Figure S6: The role of AflGsA in resistance to oxidative stress in A. flavus. (A) Growth phenotype of the WT and xyIPAflgsA strains cultured in medium (with or without GluN) with 0.8 mM tBOOH oxidative stress. (B) The growth inhibition rate of different strains in media under oxidative stress (as in panel (A)). *** indicates a significance level of pA. flavus. (A) The mycelial morphology of the A. flavus WT strain was inhibited by L-α-aminoadipic acid (0–3.2 mg/mL). (B) The conidial germination of the A. flavus WT strain was inhibited by L-α-aminoadipic acid (0–3.2 mg/mL). (C) Statistical analysis of the conidial germination rate from panel B. ND indicates no detection. * indicates a significance level of pppghd gene in the WT and xyIPAflgsA strains. (B) Relative expression of the AflgsA gene of the WT strains treated with the inhibitor. * indicates a significance level of pt-tests or one-way ANOVA with three replicates.