Transcriptomic analyses reveal the pathways associated with the volatilization and resistance of mercury(II) in the fungus Lecythophora sp. DC-F1

Junjun Chang; Guangzheng Si; Jia Dong; Qingchen Yang; Yu Shi; Yaling Chen; Kexin Zhou; Jinquan Chen

doi:10.1016/j.scitotenv.2020.142172

Transcriptomic analyses reveal the pathways associated with the volatilization and resistance of mercury(II) in the fungus Lecythophora sp. DC-F1

Sci Total Environ. 2021 Jan 15:752:142172. doi: 10.1016/j.scitotenv.2020.142172. Epub 2020 Sep 2.

Authors

Junjun Chang¹, Guangzheng Si², Jia Dong³, Qingchen Yang², Yu Shi², Yaling Chen⁴, Kexin Zhou⁴, Jinquan Chen⁵

Affiliations

¹ Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China; Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China; International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management of Yunnan Kunming, 650091, China.
² Institute of International Rivers and Eco-security, Yunnan University, Kunming 650091, China.
³ International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management of Yunnan Kunming, 650091, China.
⁴ Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China.
⁵ Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China; Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China; International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management of Yunnan Kunming, 650091, China. Electronic address: chengjinquan@ynu.edu.cn.

PMID: 33207499
DOI: 10.1016/j.scitotenv.2020.142172

Abstract

The biotic enzymatic reduction of mercury II [Hg(II)] to elemental Hg [Hg(0)] is an important pathway for Hg detoxification in natural ecosystems. However, the mechanisms of Hg(II) volatilization and resistance in fungi have not been understood completely. In the present study, we investigated the mechanisms of Hg(II) volatilization and resistance in the fungus Lecythophora sp. DC-F1. Hg(II) volatilization occurred during the investigation via the reduction of Hg(II) to Hg(0) in DC-F1. Comparative transcriptome analyses of DC-F1 revealed 3439 differentially expressed genes under 10 mg/L Hg(II) stress, among which 2770 were up-regulated and 669 were down-regulated. Functional enrichment analyses of genes and pathways further suggested that the Hg(II) resistance of DC-F1 is a multisystem collaborative process with three important transcriptional responses to Hg(II) stress: a mer-mediated Hg detoxification system, a thiol compound metabolism, and a cell reactive oxygen species stress response system. The phylogenetic analysis of merA protein homologs suggests that the Hg(II) reduction by merA is widely distributed in fungi. Overall, this study provides evidence for the reduction of Hg(II) to Hg(0) in fungi via the mer-mediated Hg detoxification system and offers a comprehensive explanation for its role within Hg biogeochemical cycling. These findings offer a strong theoretical basis for the application of fungi in the bioremediation of Hg-contaminated envionments.

Keywords: Fungus; Hg(II) resistance; Hg(II) volatilization; MerA; RNA-Seq.

MeSH terms

Ecosystem
Fungi
Gene Expression Profiling
Mercury*
Phylogeny
Transcriptome
Volatilization

Substances

Mercury