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HsfA-driven gene transcription regulates fungal morphogenesis and pathogenicity
Xin-Yi Nie1, Guolong Zhu1, Bei Qin1
1Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, State Key Laboratory of Agricultural and Forestry Biosecurity, Fujian Agriculture and Forestry University, Fuzhou, China.
Virulence
|July 22, 2026
Summary
Heat shock factor A (HsfA) in Aspergillus flavus is crucial for fungal development and pathogenicity. Targeting HsfA offers a novel strategy to combat aflatoxin contamination and enhance food safety.
Area of Science:
- Mycology
- Molecular Biology
- Food Safety
Background:
- Aspergillus flavus produces carcinogenic aflatoxins, posing risks to food safety and public health.
- The role of Heat Shock Factor A (HsfA) in A. flavus stress response and virulence is not well understood.
Purpose of the Study:
- To elucidate the function and regulatory mechanisms of HsfA in Aspergillus flavus.
- To identify HsfA's direct targets involved in fungal development and pathogenicity.
- To explore HsfA as a potential target for controlling aflatoxin contamination.
Main Methods:
- Reverse genetics, including gene knockdown and dominant-negative variants.
- Chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR).
- Electrophoretic mobility shift assay (EMSA) and transcriptional profiling.
Main Results:
- Two copies of hsfA were identified in A. flavus; their disruption impaired spore germination.
- HsfA directly regulates six non-chaperone genes (brlA, fksP, flbC, sntB, velB, vosA) by binding to heat shock elements in their promoters.
- Restoration of target gene expression partially rescued developmental and pathogenic defects in HsfA-deficient strains.
Conclusions:
- HsfA is a key transcriptional activator essential for A. flavus germination, development, and pathogenicity.
- The identified HsfA regulatory pathway provides insights into fungal virulence.
- HsfA represents a promising therapeutic target for mitigating aflatoxin contamination.
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