The mycotoxigenic Fusarium proliferatum is a common fungus and contaminates plant hosts with mycotoxin, posing serious threats to human and animal health. The conserved activator protein-1 (AP1) transcription factor is found in filamentous fungi in response to oxidative stress. However, no information is available regarding its role in regulating growth and pathogenicity of F. proliferatum on plant hosts. In this study, we characterized FpAP1 in F. proliferatum sharing a conserved DNA-binding domain of YAP family and exhibiting transcriptional activation activity. FpAP1 deletion mutant (ΔFpap1) showed higher fumonisins content but was defective in virulence to banana fruit and Nicotiana benthamiana compared to wild type. Importantly, FpAP1 regulated tolerance to reactive oxygen species and fungicide stresses, revealing a connection between stress response and virulence of F. proliferatum. DNA affinity purification sequencing and transcriptome analysis identified 393 direct target genes of FpAP1-mediated regulation. Dual-luciferase report and electrophoretic mobility shift assay highlighted a new regulatory network of FpAP1 in regulating the expression of genes associated with a diverse range of F. proliferatum growth, stress response and virulence. Our findings uncovered the FpAP1-mediated regulatory network in controlling F. proliferatum growth and virulence, which offers promising targets for effective control of Fusarium diseases and mycotoxin contamination.
Wang et al. (Mon,) studied this question.