Adaption to hydrogen sulfide-rich environments: Strategies for active detoxification in deep-sea symbiotic mussels, Gigantidas platifrons
Adaption to hydrogen sulfide-rich environments: Strategies for active detoxification in deep-sea symbiotic mussels, Gigantidas platifrons
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适应富含硫化氢的环境：深海共生贻贝主动解毒的策略
DOI：
10.1016/j.scitotenv.2021.150054
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发表时间：
2021
影响因子：
9.8
通讯作者：
Li Chaolun
中科院分区：
文献类型：
--
作者：
Sun Yan;Wang Minxiao;Zhong Zhaoshan;Chen Hao;Wang Hao;Zhou Li;Cao Lei;Fu Lulu;Zhang Huan;Lian Chao;Sun Song;Li Chaolun
深海贻贝Gigantidasplatifronsis是一个典型的物种，它依靠化能自养内共生细菌提供的营养在热液喷口和甲烷渗漏环境中生存。然而，喷口和渗漏生境具有不同的地球化学特征，喷口比渗漏更严酷，因为喷口含有大量有毒化学物质，特别是硫化氢。到目前为止，G.在异质环境中对硫化物的解毒机制尚不清楚。本研究对G.为了解环境适应和硫化物解毒机制提供了一个模型，并通过为期3天的实验室控制的Na2S胁迫实验，测试了硫化物胁迫下转录组学的响应。结果表明，G.扁额鳃首先，表生弯曲杆菌属细菌在喷口贻贝中更丰富，并通过细胞外H2S的活性氧化促进环境适应。值得注意的是，一个关键的硫化物氧化基因，硫化物：醌氧化还原酶（sqr），来自甲烷营养型内共生体，显着上调在喷口贻贝，表明细胞内硫化物的内共生体的氧化。此外，转录组学比较进一步表明，氧化磷酸化和线粒体硫化物氧化途径相关基因在宿主贻贝的硫化物耐受性中起重要作用。此外，转录组分析Na2S强调贻贝证实了上调氧化磷酸化和硫化物氧化基因在硫化物暴露。总体而言，这项研究提供了一个系统的转录分析的活性细菌群落成员和宿主贻贝，这表明，外共生体，内共生体，贻贝宿主合作的硫化物解毒从细胞外到细胞内的空间，以适应恶劣的H2S丰富的环境。
The deep-sea musselGigantidas platifronsis a representative species that relies on nutrition provided by chemoautotrophic endosymbiotic bacteria to survive in both hydrothermal vent and methane seep environments. However, vent and seep habitats have distinct geochemical features, with vents being more harsh than seeps because of abundant toxic chemical substances, particularly hydrogen sulfide (H2S). Until now, the adaptive strategies ofG. platifronsin a heterogeneous environment and their sulfide detoxification mechanisms are still unclear. Herein, we conducted 16S rDNA sequencing and metatranscriptome sequencing ofG. platifronscollected from a methane seep at Formosa Ridge in the South China Sea and a hydrothermal vent at Iheya North Knoll in the Mid-Okinawa Trough to provide a model for understanding environmental adaption and sulfide detoxification mechanisms, and a three-day laboratory controlled Na2S stress experiment to test the transcriptomic responses under sulfide stress. The results revealed the active detoxification of sulfide inG. platifronsgills. First, epibiotic Campylobacterota bacteria were more abundant in vent mussels and contributed to environmental adaptation by active oxidation of extracellular H2S. Notably, a key sulfide-oxidizing gene, sulfide:quinone oxidoreductase (sqr), derived from the methanotrophic endosymbiont, was significantly upregulated in vent mussels, indicating the oxidization of intracellular sulfide by the endosymbiont. In addition, transcriptomic comparison further suggested that genes involved in oxidative phosphorylation and mitochondrial sulfide oxidization pathway played important roles in the sulfide tolerance of the host mussels. Moreover, transcriptomic analysis of Na2S stressed mussels confirmed the upregulation of oxidative phosphorylation and sulfide oxidization genes in response to sulfide exposure. Overall, this study provided a systematic transcriptional analysis of both the active bacterial community members and the host mussels, suggesting that the epibionts, endosymbionts, and mussel host collaborated on sulfide detoxification from extracellular to intracellular space to adapt to harsh H2S-rich environments.