The Putative C2H2 Transcription Factor VadH Governs Development, Osmotic Stress Response, and Sterigmatocystin Production in Aspergillus nidulans

Xiaoyu Li; Yanxia Zhao; Heungyun Moon; Jieyin Lim; Hee-Soo Park; Zhiqiang Liu; Jae-Hyuk Yu

doi:10.3390/cells11243998

The Putative C₂H₂ Transcription Factor VadH Governs Development, Osmotic Stress Response, and Sterigmatocystin Production in Aspergillus nidulans

Cells. 2022 Dec 10;11(24):3998. doi: 10.3390/cells11243998.

Authors

Xiaoyu Li^{1

2

3}, Yanxia Zhao⁴, Heungyun Moon¹, Jieyin Lim¹, Hee-Soo Park⁵, Zhiqiang Liu^{2

3}, Jae-Hyuk Yu^{1

6}

Affiliations

¹ Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
² School of Life Sciences, Hainan University, Haikou 570228, China.
³ One Health Institute, Hainan University, Haikou 570228, China.
⁴ Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, Department of Life Science, Jiangsu Normal University, Xuzhou 221116, China.
⁵ School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea.
⁶ Department of Systems Biotechnology, Konkuk University, Seoul 05029, Republic of Korea.

Abstract

The VosA-VelB hetero-dimeric complex plays a pivotal role in regulating development and secondary metabolism in Aspergillus nidulans. In this work, we characterize a new VosA/VelB-activated gene called vadH, which is predicted to encode a 457-amino acid length protein containing four adjacent C₂H₂ zinc-finger domains. Mutational inactivation of vosA or velB led to reduced mRNA levels of vadH throughout the lifecycle, suggesting that VosA and VelB have a positive regulatory effect on the expression of vadH. The deletion of vadH resulted in decreased asexual development (conidiation) but elevated production of sexual fruiting bodies (cleistothecia), indicating that VadH balances asexual and sexual development in A. nidulans. Moreover, the vadH deletion mutant exhibited elevated susceptibility to hyperosmotic stress compared to wild type and showed elevated production of the mycotoxin sterigmatocystin (ST). Genome-wide expression analyses employing RNA-Seq have revealed that VadH is likely involved in regulating more genes and biological pathways in the developmental stages than those in the vegetative growth stage. The brlA, abaA, and wetA genes of the central regulatory pathway for conidiation are downregulated significantly in the vadH null mutant during asexual development. VadH also participates in regulating the genes, mat2, ppgA and lsdA, etc., related to sexual development, and some of the genes in the ST biosynthetic gene cluster. In summary, VadH is a putative transcription factor with four C₂H₂ finger domains and is involved in regulating asexual/sexual development, osmotic stress response, and ST production in A. nidulans.

Keywords: Aspergillus nidulans; C2H2 transcription factors; development; sterigmatocystin; stress response; velvet regulators.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aspergillus nidulans* / genetics
Fungal Proteins / metabolism
Gene Expression Regulation, Fungal
Osmoregulation
Sterigmatocystin / metabolism
Transcription Factors* / genetics
Transcription Factors* / metabolism

Substances

Transcription Factors
Sterigmatocystin
Fungal Proteins

Grants and funding

This research was financially supported by the Natural Science Foundation of Hainan Province (2019RC074) and the National Natural Science Foundation of China (32160041 and 32160371). This work was also supported by the fund of China Scholarship Council. The work at UW-Madison was supported by the National Institute of Food and Agriculture, United States Department of Agriculture, Hatch project 7000326 to Jae-Hyuk Yu.