The transcription factor SKN7 regulates conidiation, thermotolerance, apoptotic-like cell death and parasitism in the nematode endoparasitic fungus Hirsutella minnesotensis

Sci Rep. 2016 Jul 20:6:30047. doi: 10.1038/srep30047.

Abstract

The transcription factor SKN7 is a highly conserved protein among fungi and was initially recognized as a response regulator that protects cells from oxidative stress and maintains cell wall integrity in yeast. Orthologs of SKN7 are extensively present in biocontrol agents of plant pathogens, but they had not been functionally characterized. Here, we identified and characterized the transcription factor SKN7 in the nematode endoparasitic fungus Hirsutella minnesotensis. Null mutant lacking HIM-SKN7 (HIM_03620), which was generated by a gene disruption strategy, demonstrated reduced conidiation, increased sensitivity to high temperature, hydrogen peroxide, mannitol and ethanol, and reduced fungal resistance to farnesol. However, over-expression mutant showed increased conidial production, thermotolerance and resistance to farnesol, suggesting that HIM-SKN7 regulates antiapoptotic-like cell death in H. minnesotensis. Moreover, the results showed that in null mutant, H. minnesotensis had decreased endoparasitic ability as compared to wild type and over-expression strain. During the infection process, the relative expression of the HIM-SKN7 gene was significantly induced in the wild type and over-expression strain. The results of the present study advance our understanding of the functions of the SKN7 gene in biocontrol agents, in particular, nematode endoparasitic fungi.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Death
  • Gene Deletion
  • Gene Expression
  • Gene Expression Profiling
  • Gene Expression Regulation, Fungal*
  • Host-Parasite Interactions*
  • Hot Temperature
  • Hypocreales / genetics*
  • Hypocreales / growth & development
  • Hypocreales / metabolism
  • Hypocreales / radiation effects
  • Nematoda / microbiology*
  • Spores, Fungal / growth & development
  • Thermotolerance
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic*

Substances

  • Transcription Factors