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Journal of Microbiology

, Volume 56, Issue 12, pp 893–901 | Cite as

Characterization of the velvet regulators in Aspergillus flavus

  • Tae-Jin Eom
  • Heungyun Moon
  • Jae-Hyuk Yu
  • Hee-Soo Park
Article

Abstract

Fungal development and secondary metabolism are closely associated via the activities of the fungal NK-kB-type velvet regulators that are highly conserved in filamentous fungi. Here, we investigated the roles of the velvet genes in the aflatoxigenic fungus Aspergillus flavus. Distinct from other Aspergillus species, the A. flavus genome contains five velvet genes, veA, velB, velC, velD, and vosA. The deletion of velD blocks the production of aflatoxin B1, but does not affect the formation of sclerotia. Expression analyses revealed that vosA and velB mRNAs accumulated at high levels during the late phase of asexual development and in conidia. The absence of vosA or velB decreased the content of conidial trehalose and the tolerance of conidia to the thermal and UV stresses. In addition, double mutant analyses demonstrated that VosA and VelB play an inter-dependent role in trehalose biosynthesis and conidial stress tolerance. Together with the findings of previous studies, the results of the present study suggest that the velvet regulators play the conserved and vital role in sporogenesis, conidial trehalose biogenesis, stress tolerance, and aflatoxin biosynthesis in A. flavus.

Keywords

Aspergillus flavus velvet regulators conidia aflatoxin VosA VelB 

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Copyright information

© The Microbiological Society of Korea and Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.School of Food Science and Biotechnology, Institute of Agricultural Science and TechnologyKyungpook National UniversityDaeguRepublic of Korea
  2. 2.Departments of Bacteriology and GeneticsUniversity of WisconsinMadisonUSA
  3. 3.Department of Systems BiotechnologyKonkuk UniversitySeoulRepublic of Korea

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