Study on the bZIP-Type Transcription Factors NapA and RsmA in the Regulation of Intracellular Reactive Species Levels and Sterigmatocystin Production of Aspergillus nidulans

Int J Mol Sci. 2021 Oct 27;22(21):11577. doi: 10.3390/ijms222111577.


Basic leucine zipper (bZIP) transcription factors play a crucial role in the environmental stress response of eukaryotes. In this work, we studied the effect of gene manipulations, including both deletions and overexpressions, of two selected bZIP transcription factors, NapA and RsmA, in the oxidative stress response and sterigmatocystin production of Aspergillus nidulans. We found that NapA was important in the oxidative stress response by negatively regulating intracellular reactive species production and positively regulating catalase activities, whereas RsmA slightly negatively regulated catalase activities. Concerning sterigmatocystin production, the highest concentration was measured in the ΔrsmAΔnapA double deletion mutant, but elevated sterigmatocystin production was also found in the OErsmA OEnapA strain. Our results indicate that NapA influences sterigmatocystin production via regulating reactive species level whereas RsmA modulates toxin production independently of the redox regulation of the cells.

Keywords: Aspergillus nidulans; bZIP-type transcription factors; catalase; oxidative stress; reactive 0 species; secondary metabolite production; sterigmatocystin.

MeSH terms

  • Aspergillus nidulans / genetics*
  • Aspergillus nidulans / metabolism*
  • Basic-Leucine Zipper Transcription Factors / genetics*
  • Basic-Leucine Zipper Transcription Factors / metabolism
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Fungal / genetics
  • Oxidation-Reduction
  • Oxidative Stress / genetics
  • Reactive Oxygen Species / metabolism*
  • Sterigmatocystin / metabolism*
  • Stress, Physiological / genetics


  • Basic-Leucine Zipper Transcription Factors
  • Fungal Proteins
  • Reactive Oxygen Species
  • Sterigmatocystin