DdaCrz1, a C2H2-Type Transcription Factor, Regulates Growth, Conidiation, and Stress Resistance in the Nematode-Trapping Fungus Drechslerella dactyloides

Xiaozhou Zhao; Yani Fan; Meichun Xiang; Seogchan Kang; Shunxian Wang; Xingzhong Liu

doi:10.3390/jof8070750

DdaCrz1, a C₂H₂-Type Transcription Factor, Regulates Growth, Conidiation, and Stress Resistance in the Nematode-Trapping Fungus Drechslerella dactyloides

J Fungi (Basel). 2022 Jul 20;8(7):750. doi: 10.3390/jof8070750.

Authors

Xiaozhou Zhao¹, Yani Fan^{2

3}, Meichun Xiang^{2

3}, Seogchan Kang⁴, Shunxian Wang¹, Xingzhong Liu^{1

2}

Affiliations

¹ State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China.
² State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, Texas, PA 16802, USA.

Abstract

The Ca²⁺/calmodulin-dependent signaling pathway regulates diverse cellular processes. Calcineurin is a calcium-dependent phosphatase acting in fungi mainly through Crz1, a zinc finger transcription factor. Although the likely involvement of Ca²⁺ in fungal carnivorism has been documented, how Crz1 functions in nematode-trapping fungi remains unknown. Here, we identified the Crz1 gene (named as DdaCrz1) in Drechslerella dactyloides, a species that forms constricting rings to trap nematodes. The deletion of DdaCrz1 significantly reduced hyphal growth and conidiation, trap formation, and ring cell inflation. Moreover, the mutation increased sensitivity to Mn²⁺ but decreased sensitivity to Ca²⁺, Mg²⁺, Zn²⁺, and Li⁺. Similarly, the mutant showed increased tolerance to osmotic stress but was more sensitive to Congo red, a cell wall-damaging agent. Our results confirmed the critical roles of the Ca²⁺/calmodulin-dependent signaling pathway in regulating growth, conidiation, and the stress response, and suggested its involvement in trapping nematodes.

Keywords: DdaCrz1; Drechslerella dactyloides; calcium signaling; fungal growth; predatism; stress response.

Grants and funding

The research described here is jointly supported by the National Natural Science Foundation of China (No. 3202010300) and the National Key Research and Development Program (2018YFD0201202).