A Putative Guanosine Triphosphate Cyclohydrolase I Named CaGCH1 Is Involved in Hyphal Branching and Fruiting Development in Cyclocybe aegerita

Nan Tao; Bopu Cheng; Hongmei Chai; Xianghua Cui; Yuanhao Ma; Jinping Yan; Yongchang Zhao; Weimin Chen

doi:10.3389/fmicb.2022.870658

A Putative Guanosine Triphosphate Cyclohydrolase I Named CaGCH1 Is Involved in Hyphal Branching and Fruiting Development in Cyclocybe aegerita

Front Microbiol. 2022 Apr 22:13:870658. doi: 10.3389/fmicb.2022.870658. eCollection 2022.

Authors

Nan Tao^{1

2

3}, Bopu Cheng^{1

4}, Hongmei Chai^{1

2

3}, Xianghua Cui^{1

2

3}, Yuanhao Ma^{1

2

3}, Jinping Yan⁵, Yongchang Zhao^{1

2

3}, Weimin Chen^{1

2

3}

Affiliations

¹ Biotechnology and Germplasm Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming, China.
² Yunnan Provincial Key Lab of Agricultural Biotechnology, Kunming, China.
³ Key Lab of Southwestern Crop Gene Resources and Germplasm Innovation, Ministry of Agriculture, Kunming, China.
⁴ College of Life Sciences, Southwest Forestry University, Kunming, China.
⁵ Life Science and Technology College, Kunming University of Science and Technology, Kunming, China.

Abstract

Guanosine triphosphate (GTP) cyclohydrolase I (GCH1) is the limiting enzyme of the tetrahydrobiopterin (BH4) synthesis pathway. The disruption of gch1 gene may cause conditional lethality due to folic acid auxotrophy in microorganisms, although the function of gch1 in basidiomycetes has not been deciphered so far. In the present study, gch1 expression in Cyclocybe aegerita (cagch1) was downregulated using the RNAi method, which resulted in growth retardation in both solid and liquid medium, with the hyphal tips exhibiting increased branching compared to that in the wild strain. The development of fruiting bodies in the mutant strains was significantly blocked, and there were short and bottle-shaped stipes. The transcriptional profile revealed that the genes of the MAPK pathway may be involved in the regulation of these effects caused by cagch1 knockdown, which provided an opportunity to study the role of gch1 in the development process of basidiomycetes.

Keywords: Cyclocybe aegerita; GCH1; RNAi; fruiting body development; hyphal branch.