Comparative transcriptome analysis of Armillaria gallica 012m in response to ethephon treatment

Haiying Yang; Kaixiang He; Yapu Cao; Zhihao Li; Qiaolin Ji; Jingxian Sun; Ganpeng Li; Xin Chen; Haiying Mo; Gang Du; Qingqing Li

doi:10.7717/peerj.14714

Comparative transcriptome analysis of Armillaria gallica 012m in response to ethephon treatment

PeerJ. 2023 Jan 17:11:e14714. doi: 10.7717/peerj.14714. eCollection 2023.

Authors

Haiying Yang¹, Kaixiang He¹, Yapu Cao², Zhihao Li², Qiaolin Ji², Jingxian Sun², Ganpeng Li², Xin Chen², Haiying Mo², Gang Du², Qingqing Li^{3

4}

Affiliations

¹ Yunnan Minzu University, School of Chemistry and Environment, Kunming, Yunnan, China.
² Yunnan Minzu University, Key Laboratory of Chemistry in Ethnic Medicinal Resources Ministry of Education, Kunming, Yunnan, China.
³ Southwest Forestry University, Life Science College, Kunming, Yunnan, China.
⁴ Kunming Xianghao Technology Co. Ltd, Kunming, Yunnan, China.

Abstract

Background: Gastrodia elata, known as a rootless, leafless, achlorophyllous and fully mycoheterotrophic orchid, needs to establish symbionts with particular Armillaria species to acquire nutrition and energy. Previous research findings had approved that ethylene (ET) played an important role in plant-fungi interaction and some receptors of ET had been discovered in microorganisms. However, the molecular mechanisms underlying the role of ET in the interaction between G. elata and Armillaria species remain unknown.

Methods: Exiguous ethephon (ETH) was added to agar and liquid media to observe the morphological features of mycelium and count the biomass respectively. Mycelium cultured in liquid media with exiguous ETH (0.1 ppm, 2.0 ppm, 5.0 ppm) were chosen to perform whole-transcriptome profiling through the RNA-seq technology (Illumina NGS sequencing). The DEGs of growth-related genes and candidate ET receptor domains were predicted on SMART.

Results: ETH-0.1 ppm and ETH-2 ppm could significantly improve the mycelium growth of A. gallica 012m, while ETH-5 ppm inhibited the mycelium growth in both solid and liquid media. The number of up-regulated or down-regulated genes increased along with the concentrations of ETH. The growth of mycelia might benefit from the up-regulated expression of Pyr_redox (Pyridine nucleotide-disulphide oxidoreductase), GAL4 (C6 zinc finger) and HMG (High Mobility Group) genes in the ETH-0.1 ppm and ETH-2 ppm. Therefore, the growth of mycelia might be impaired by the down-regulated expression of ZnF_C2H2 and ribosomal protein S4 proteins in the ETH-5 ppm. Seven ET receptor domains were predicted in A. gallica 012m. Based on cluster analysis and comparative studies of proteins, the putative ETH receptor domains of A. gallica 012m have a higher homologous correlation with fungi.

Conclusions: The responses of A. gallica 012m to ETH had a concentration effect similar to the plants' responses to ET. Therefore, the number of up-regulated or down-regulated genes are increased along with the concentrations of ETH. Seven ET receptor protein domains were predicted in the genome and transcriptome of A. gallica 012m. We speculate that ETH receptors exist in A. gallica 012m and ethylene might play an important role in the plant-fungi interaction.

Keywords: Differential expression genes; ET; ET receptor; ETH; RNA-Seq; Response.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Armillaria*
Ethylenes / pharmacology
Fungi
Gene Expression Profiling
Transcriptome / genetics

Substances

ethephon
Ethylenes

Supplementary concepts

Armillaria gallica

Grants and funding

This work was financially supported by the National Natural Science Foundation of China (Nos. 81860624). We received funding from the National Natural Science Foundation of China: 81860624.