Applied Microbiology and Biotechnology

, Volume 103, Issue 5, pp 2251–2262 | Cite as

The homeobox gene MaH1 governs microcycle conidiation for increased conidial yield by mediating transcription of conidiation pattern shift-related genes in Metarhizium acridum

  • Pingping Gao
  • Muchun Li
  • Kai JinEmail author
  • Yuxian XiaEmail author
Applied genetics and molecular biotechnology


Conidiation capacity and conidial quality are very important for the production and application of mycopesticides. Most filamentous ascomycetous fungi have two distinct patterns of conidiation. Conidiation through microcycle conidiation proceeds to more rapidly achieve a maximum of conidial yield than normal conidiation and hence is of greater merit for exploitation in mass production of fungal insect pathogens, such as Metarhizium acridum. In this study, the mechanism underlying the conidiation pattern shift in M. acridum was explored by characterization of the fungal homeobox gene MaH1. MaH1 was evidently localized to the nuclei of hyphae and transcriptionally expressed at a maximal level when conidiation began. Intriguingly, deletion of MaH1 in M. acridum resulted in a shift of normal conidiation to microcycle conidiation on one-quarter strength Sabouraud’s dextrose agar medium, and hence accelerated conidiation and increased conidial yield. In the deletion mutant, moreover, conidia became larger in size and hyphae cells were shorter in length while conidial virulence and stress tolerance were not altered. As revealed by digital gene expression profiling, MaH1 controlled the shift of conidiation patterns by mediating transcription of a set of genes related to hyphal growth, cell differentiation, conidiation, and some important signaling pathways. These findings indicate that MaH1 and its downstream genes can be exploited to increase the conidial yield for more efficient production of mycopesticides.


Metarhizium acridum Homeobox gene Transcription factor Microcycle conidiation Conidiation pattern shift 



This work was supported by the Natural Science Foundation of China (no. 31272090), the Natural Science Foundation Project of Chongqing (cstc 2018jcyjAX0554), and the Fundamental Research Funds for the Central Universities (106112017CDJQJ298831).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This article does not contain any studies with human participants performed by any of the authors.

Supplementary material

253_2018_9558_MOESM1_ESM.pdf (322 kb)
ESM 1 (PDF 321 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Genetic Engineering Research Center, School of Life SciencesChongqing UniversityChongqingPeople’s Republic of China
  2. 2.Chongqing Engineering Research Center for Fungal InsecticideChongqingPeople’s Republic of China
  3. 3.Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education CommissionChongqingPeople’s Republic of China

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