Diverse strategies conferring extreme cadmium (Cd) tolerance in the dark septate endophyte (DSE), Exophiala pisciphila: Evidence from RNA-seq data

Abstract Background Cadmium (Cd) is a serious heavy metal (HM) soil pollutant. To alleviate or even eliminate HM pollution in soil, environmental-friendly methods are applied. One is that special plants are cultivated to absorb the HM in the contaminated soil. As an excellent economical plant with ornamental value and sound adaptability, V. bonariensis could be adapted to this very situation. In our study, the Cd tolerance in V. bonariensis was analyzed as well as an overall analysis of transcriptome. Results In this study, the tolerance of V. bonariensis to Cd stress was investigated in four aspects: germination, development, physiological changes, and molecular alterations. The results showed that as a non-hyperaccumulator, V. bonariensis did possess the Cd tolerance and the capability to concentration Cd. Under Cd stress, all 237, 866 transcripts and 191, 370 unigenes were constructed in the transcriptome data of V. bonariensis roots. The enrichment analysis of gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed that differentially expressed genes (DEGs) under Cd stress were predominately related to cell structure, reactive oxygen species (ROS) scavenging system, chelating reaction and secondary metabolites, transpiration and photosynthesis. DEGs encoding lignin synthesis, chalcone synthase (CHS) and anthocyanidin synthase (ANS) were prominent in V. bonariensis under Cd stress. The expression patterns of 10 DEGs, validated by quantitative real-time polymerase chain reaction (qRT-PCR), were in highly accordance with the RNA-Sequence (RNA-Seq) results. The novel strategies brought by our study was not only benefit for further studies on the tolerance of Cd and functional genomics in V. bonariensis, but also for the improvement molecular breeding and phytoremediation.

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Evidence for a Dark Septate Endophyte (Exophiala Pisciphila, H93) Enhancing Phosphorus Absorption by Maize Seedlings

Plant and Soil ◽

10.1007/s11104-020-04538-9 ◽

2020 ◽

Vol 452 (1-2) ◽

pp. 249-266 ◽

Cited By ~ 1

Author(s):

Runbing Xu ◽

Tao Li ◽

Mi Shen ◽

Zhu L. Yang ◽

Zhi-Wei Zhao

Keyword(s):

Maize Seedlings ◽

Dark Septate Endophyte ◽

Phosphorus Absorption ◽

Exophiala Pisciphila

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Characterization of melanin isolated from a dark septate endophyte (DSE), Exophiala pisciphila

World Journal of Microbiology and Biotechnology ◽

10.1007/s11274-011-0712-8 ◽

2011 ◽

Vol 27 (10) ◽

pp. 2483-2489 ◽

Cited By ~ 31

Author(s):

Fangdong Zhan ◽

Yongmei He ◽

Yanqun Zu ◽

Tao Li ◽

Zhiwei Zhao

Keyword(s):

Dark Septate Endophyte ◽

Exophiala Pisciphila

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Melatonin confers heavy metal-induced tolerance by alleviating oxidative stress and reducing the heavy metal accumulation in Exophiala pisciphila, a dark septate endophyte (DSE)

BMC Microbiology ◽

10.1186/s12866-021-02098-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yang Yu ◽

Zhaowei Teng ◽

Zongmin Mou ◽

Yan Lv ◽

Tao Li ◽

...

Keyword(s):

Oxidative Stress ◽

Heavy Metal ◽

Stress Tolerance ◽

Metal Accumulation ◽

Heavy Metal Accumulation ◽

Biosynthetic Enzyme ◽

Dark Septate Endophyte ◽

Induced Stress ◽

Exophiala Pisciphila

Abstract Background Melatonin (MT), ubiquitous in almost all organisms, functions as a free radical scavenger. Despite several reports on its role as an antioxidant in animals, plants, and some microorganisms, extensive studies in filamentous fungi are limited. Based upon the role of melatonin as an antioxidant, we investigated its role in heavy metal-induced stress tolerance in Exophiala pisciphila, a dark septate endophyte (DSE), by studying the underlying mechanisms in alleviating oxidative stress and reducing heavy metal accumulation. Results A significant decrease in malondialdehyde (MDA) and oxygen free radical (OFR) in E. pisciphila was recorded under Cd, Zn, and Pb stresses as compared to the control. Pretreatment of E. pisciphila with 200.0 μM exogenous melatonin significantly increased the activity of superoxide dismutase (SOD) under Zn and Pb stresses. Pretreatment with 200.0 μM melatonin also lowered Cd, Zn, and Pb concentrations significantly. Melatonin production was enhanced by Cd, Cu, and Zn after 2 d, and melatonin biosynthetic enzyme genes, E. pisciphila tryptophan decarboxylase (EpTDC1) and serotonin N-acetyltransferase (EpSNAT1), were transcriptionally upregulated. The overexpression of EpTDC1 and N-acetylserotonin O-methyltransferase (EpASMT1) in Escherichia coli and Arabidopsis thaliana enhanced its heavy metal-induced stress tolerance. The overexpression of EpTDC1 and EpASMT1 reduced the Cd accumulation in the whole A. thaliana plants, especially in the roots. Conclusions Melatonin conferred heavy metal-induced stress tolerance by alleviating oxidative stress, activating antioxidant enzyme SOD, and reducing heavy metal accumulation in E. pisciphila. Melatonin biosynthetic enzyme genes of E. pisciphila also played key roles in limiting excessive heavy metal accumulation in A. thaliana. These findings can be extended to understand the role of melatonin in other DSEs associated with economically important plants and help develop new strategies in sustainable agriculture practice where plants can grow in soils contaminated with heavy metals.

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Melatonin confers heavy metal-induced tolerance by alleviating oxidative stress and reducing the heavy metal accumulation in Exophiala pisciphila, a dark septate endophyte (DSE)

10.21203/rs.3.rs-54820/v2 ◽

2020 ◽

Author(s):

Yang Yu ◽

Zhaowei Teng ◽

Zongmin Mou ◽

Yan Lv ◽

Tao Li ◽

...

Keyword(s):

Oxidative Stress ◽

Heavy Metal ◽

Stress Tolerance ◽

Metal Accumulation ◽

Heavy Metal Accumulation ◽

Biosynthetic Enzyme ◽

Dark Septate Endophyte ◽

Induced Stress ◽

Exophiala Pisciphila

Abstract Background: Melatonin (MT), ubiquitous in almost all organisms, functions as a free radical scavenger. Despite several reports on its role as an antioxidant in animals, plants, and some microorganisms, extensive studies in filamentous fungi are limited. Based upon the role of melatonin as an antioxidant, we investigated its role in heavy metal-induced stress tolerance in Exophiala pisciphila, a dark septate endophyte (DSE), by studying the underlying mechanisms in alleviating oxidative stress and reducing heavy metal accumulation.Results: A significant decrease in malondialdehyde (MDA) and oxygen free radical (OFR) in E. pisciphila was recorded under Cd, Zn, and Pb stresses as compared to the control. Pretreatment of E. pisciphila with 200.0 μM exogenous melatonin significantly increased the activity of superoxide dismutase (SOD) under Zn and Pb stresses. Pretreatment with 200.0 μM melatonin also lowered Cd, Zn, and Pb concentrations significantly. Melatonin production was enhanced by Cd, Cu, and Zn after 2 d, and melatonin biosynthetic enzyme genes, E. pisciphila tryptophan decarboxylase (EpTDC1) and serotonin N-acetyltransferase (EpSNAT1), were transcriptionally upregulated. The overexpression of EpTDC1 and N-acetylserotonin O-methyltransferase (EpASMT1) in Escherichia coli and Arabidopsis thaliana enhanced its heavy metal-induced stress tolerance. The overexpression of EpTDC1 and EpASMT1 reduced the Cd accumulation in the whole A. thaliana plants, especially in the roots.Conclusions: Melatonin conferred heavy metal-induced stress tolerance by alleviating oxidative stress, activating antioxidant enzyme SOD, and reducing heavy metal accumulation in E. pisciphila. Melatonin biosynthetic enzyme genes of E. pisciphila also played key roles in limiting excessive heavy metal accumulation in A. thaliana. These findings can be extended to understand the role of melatonin in other DSEs associated with economically important plants and help develop new strategies in sustainable agriculture practice where plants can grow in soils contaminated with heavy metals.

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Melatonin Confers Heavy Metal Tolerance of a Dark Septate Endophyte (DSE) Exophiala Pisciphila Via Lowering Oxidative Stress and Heavy Metal Accumulation

10.21203/rs.3.rs-54820/v1 ◽

2020 ◽

Author(s):

Yang Yu ◽

Zhaowei Teng ◽

Zongmin Mou ◽

Yan Lv ◽

Tao Li ◽

...

Keyword(s):

Oxidative Stress ◽

Heavy Metal ◽

Metal Accumulation ◽

Metal Tolerance ◽

Heavy Metal Tolerance ◽

Heavy Metal Stress ◽

Heavy Metal Accumulation ◽

Metal Stress ◽

Dark Septate Endophyte ◽

Exophiala Pisciphila

Abstract Background: The high antioxidant capacity of melatonin contributing to heavy metal tolerance for plants and animals is widely studied, while researches on microorganisms especially in filamentous fungi are rare. One typical dark septate endophyte (DSE), Exophiala pisciphila, showed significant resistance to heavy metals.Results: In this study, exogenous melatonin was verified to reduce heavy metal damage via relieving oxidative stress, activating antioxidant systems, and decreasing heavy metal accumulation in E. pisciphila. Melatonin biosynthesis enzyme genes were upregulated under heavy metal stress. Furthermore, the overexpression of E. pisciphila TDC1 (EpTDC1) and E. pisciphila ASMT1 (EpASMT1) responsible for melatonin biosynthesis in Escherichia coli and Arabidopsis thaliana, enhanced heavy metal stress tolerance for the two organisms by lowering the oxidative stress and reducing the Cd accumulation in the whole plants, especially in the roots.Conclusions: Our results indicate that melatonin confers heavy metal resistance in E. pisciphila by lowering oxidative stress and heavy metal accumulation.

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Effects of the Dark Septate Endophyte (DSE) Exophiala pisciphila on the Growth of Root Cell Wall Polysaccharides and the Cadmium Content of Zea mays L. under Cadmium Stress

Journal of Fungi ◽

10.3390/jof7121035 ◽

2021 ◽

Vol 7 (12) ◽

pp. 1035

Author(s):

Yao Xiao ◽

Meng-Xue Dai ◽

Guang-Qun Zhang ◽

Zhi-Xin Yang ◽

Yong-Mei He ◽

...

Keyword(s):

Cell Wall ◽

Zea Mays ◽

Host Plants ◽

Zea Mays L ◽

Root Cell ◽

Cadmium Content ◽

Cd Stress ◽

Cd Tolerance ◽

Exophiala Pisciphila ◽

Root Cell Wall

This paper aims to investigate the mechanism by which dark septate endophytes (DSEs) enhance cadmium (Cd) tolerance in there host plants. Maize (Zea mays L.) was inoculated with a DSE, Exophiala pisciphila, under Cd stress at different concentrations (0, 5, 10, and 20 mg·kg−1). The results show that, under 20 mg/kg Cd stress, DSE significantly increased maize biomass and plant height, indicating that DSE colonization can be utilized to increase the Cd tolerance of host plants. More Cd was retained in DSE-inoculated roots, especially that fixed in the root cell wall (RCW). The capability of DSE to induce a higher Cd holding capacity in the RCW is caused by modulation of the total sugar and uronic acid of DSE-colonized RCW, mainly the pectin and hemicellulose fractions. The fourier-transform spectroscopy analysis results show that carboxyl, hydroxyl, and acidic groups are involved in Cd retention in the DSE-inoculated RCW. The promotion of the growth of maize and improvement in its tolerance to Cd due to DSEs are related to restriction of the translocation of Cd from roots to shoots; resistance of Cd uptake Cd inside cells; and the increase in RCW-integrated Cd through modulating RCW polysaccharide components.

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Comparative root transcriptome analysis of two soybean cultivars with different cadmium sensitivities reveals the underlying tolerant mechanisms

Genome ◽

10.1139/gen-2021-0048 ◽

2021 ◽

Author(s):

Yuan Ma ◽

Kuichen Liu ◽

Chunyu Zhang ◽

Feng Lin ◽

Wenbo Hu ◽

...

Keyword(s):

Heavy Metal ◽

Kegg Pathway ◽

Economic Value ◽

Rna Seq ◽

Cd Stress ◽

Toxic Heavy Metal ◽

Soybean Cultivars ◽

Cd Tolerance ◽

Transgenic Hairy Roots ◽

Soybean Roots

The soybean can provide rich protein and fat and has great economic value worldwide. Cadmium (Cd) is a toxic heavy metal to organisms. It can accumulate in plants and be transmitted to the human body via food chain. Cd is a serious threat to soybean development, especially to root growth. Some soybean cultivars present tolerant symptoms under Cd stress; however, the potential mechanisms are not fully understood. Here, we optimized RNA-seq to identify the differentially expressed genes (DEGs) in Cd-sensitive (KUAI) and Cd-tolerant (KAIYU) soybean roots and compared the DEGs between KAIYU and KUAI. A total of 1,506 and 1,870 DEGs were identified in the roots of KUAI and KAIYU, respectively. Through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene function analyses, we found that genes related to antioxidants and sequestration were responsible for Cd tolerance in KAIYU. In addition, overexpression of Glyma11g02661, which encodes a heavy metal transporting ATPase, significantly improved Cd tolerance in transgenic hairy roots. These results provide a preliminary understanding of the tolerance mechanisms in response to Cd stress in soybean root development and are of great importance in developing Cd-resistant soybean cultivars by using the identified DEGs through genetic modification.

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Transcriptomic analysis of Verbena bonariensis roots in response to cadmium stress

10.21203/rs.2.10519/v2 ◽

2019 ◽

Author(s):

Meng-qi Wang ◽

Zhen-yu Bai ◽

Ya-fang Xiao ◽

Yan Li ◽

Qing-lin Liu ◽

...

Keyword(s):

Cell Structure ◽

Expression Patterns ◽

Enrichment Analysis ◽

Cadmium Stress ◽

The Novel ◽

Rna Seq ◽

Cd Stress ◽

Ros Scavenging ◽

Molecular Alterations ◽

Cd Tolerance

Abstract Background: Cadmium (Cd) is a serious heavy metal (HM) soil pollutant. To alleviate or even eliminate HM pollution in soil, environmental-friendly methods are applied. One is that special plants are cultivated to absorb the HM in the contaminated soil. As an excellent economical plant with ornamental value and sound adaptability, V.bonariensis could be adapted to this very situation. In our study, the Cd tolerance in V.bonariensis was analyzed as well as overall analysis of transcriptome. Results: In this study, the tolerance of V.bonariensis to Cd stress was investigated in four aspects: germination, development, pysiological changes, and molecular alterations. The results showed that as a non-hyperaccumulator, V. bonariensis did possess the Cd tolerance and the capability to concentration Cd. Under Cd stress, all 237,866 transcripts and 191,370 unigenes were constructed in the transcriptome data of V.bonariensis roots . The enrichment analysis of gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed that differentially expressed genes (DEGs) under Cd stress were predominately related to cell structure, reactive oxygen species (ROS) scavenging system, chelating reaction and secondary metabolites, transpiration and photosynthesis. DEGs encoding lignin synthesis, chalcone synthase (CHS) and anthocyanidin synthase (ANS) were prominent in V. bonariensis under Cd stress. The expression patterns of 10 DEGs, validated by quantitative real-time polymerase chain reaction (qRT-PCR), were in highly accordance with the RNA-Sequence (RNA-Seq) results. The novel strategies brought by our study was not only benefit for further studies on the tolerance of Cd and functional genomics in V. bonariensis , but also for the improvement molecular breeding and phytoremediation.

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