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He L, Ren Y, Zeng W, Wu X, Shen L, Yu R, Liu Y, Li J. Deciphering the Endophytic and Rhizospheric Microbial Communities of a Metallophyte Commelina communis in Different Cu-Polluted Soils. Microorganisms 2021; 9:microorganisms9081689. [PMID: 34442769 PMCID: PMC8399850 DOI: 10.3390/microorganisms9081689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 08/04/2021] [Indexed: 11/24/2022] Open
Abstract
Metallophytes microbiota play a key role in plant growth and resistance to heavy metal stress. Comparing to the well-studied single or some specific plant growth-promoting (PGP) bacterial strains, our current understanding of the structural and functional variations of microbiome of metallophytes is still limited. Here, we systematically investigated the endophytic and rhizosphere bacterial community profiles of a metallophyte Commelina communis growing in different Cu-polluted soils by high-throughput sequencing technology. The results showed that the rhizosphere communities of C. communis exhibited a much higher level of diversity and richness than the endosphere communities. Meanwhile, shifts in the bacterial community composition were observed between the rhizosphere and endosphere of C. communis, indicating plant compartment was a strong driver for the divergence between rhizosphere and endosphere community. Among the environmental factors, soil Cu content, followed by OM, TP and TN, played major roles in shaping the bacterial community structure of C. communis. At the highly Cu-contaminated site, Pseudomonas and Sphingomonas were the predominant genera in the endophytic and rhizospheric bacterial communities, respectively, which might enhance copper tolerance as PGP bacteria. In summary, our findings will be useful to better understand metallophyte–microbe interactions and select suitable bacterial taxa when facilitating phytoremediation.
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Affiliation(s)
- Li He
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Yanzhen Ren
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Xueling Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Li Shen
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Runlan Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Yuandong Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Key Laboratory of Biometallurgy, Ministry of Education, Central South University (CSU), Changsha 410083, China
| | - Jiaokun Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; (L.H.); (Y.R.); (W.Z.); (X.W.); (L.S.); (R.Y.); (Y.L.)
- Correspondence:
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Vidal C, Larama G, Riveros A, Meneses C, Cornejo P. Main Molecular Pathways Associated with Copper Tolerance Response in Imperata cylindrica by de novo Transcriptome Assembly. PLANTS (BASEL, SWITZERLAND) 2021; 10:357. [PMID: 33668499 PMCID: PMC7918359 DOI: 10.3390/plants10020357] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/04/2021] [Accepted: 02/07/2021] [Indexed: 12/20/2022]
Abstract
The metallophyte Imperata cylindrica inhabits copper (Cu) polluted soils in large areas from Central Chile. Here, we subjected clonal vegetative plantlets to 300 mg Cu kg-1 of substrate for 21 days to identify the main molecular pathways involved in the response to Cu stress. Transcriptomic analyses were performed for shoots and roots, with and without Cu supply. RNA-Seq and de novo transcriptome assembly were performed to identify the gene response associated with molecular mechanisms of Cu tolerance in I. cylindrica. De novo transcriptome revealed a total of 200,521 transcripts (1777 bp) comprising ~91% complete ultra-conserved genes in the eukaryote and Plantae database. The differentially expressed genes (DEGs) in roots were 7386, with 3558 of them being up-regulated and the other 3828 down-regulated. The transcriptome response in shoots was significantly less, showing only 13 up-regulated and 23 down-regulated genes. Interestingly, DEGs mainly related with actin and cytoskeleton formation, and to a minor degree, some DEGs associated with metal transporters and superoxide dismutase activity in root tissues were found. These transcriptomic results suggest that cytoskeleton could be acting as a mechanism of Cu-binding in the root, resulting in a high Cu tolerance response in this metallophyte, which deserve to be analyzed ultra-structurally. Our study contributes to reinforcing the potential of I. cylindrica as a candidate plant species to be used as a phytoremediation agent in Cu-contaminated environments.
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Affiliation(s)
- Catalina Vidal
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Avda. Francisco Salazar, Temuco 4780000, Chile;
- Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, Avda. Francisco Salazar, Temuco 4780000, Chile
| | - Giovanni Larama
- Centro de Modelación y Computación Científica, Universidad de La Frontera, Avda. Francisco Salazar, Temuco 4780000, Chile;
| | - Aníbal Riveros
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, República 330, Santiago 8370186, Chile; (A.R.); (C.M.)
- FONDAP Center for Genome Regulation, Facultad de Ciencias de la Vida, Universidad Andrés Bello, República 330, Santiago 8370186, Chile
| | - Claudio Meneses
- Centro de Biotecnología Vegetal, Facultad de Ciencias de la Vida, Universidad Andrés Bello, República 330, Santiago 8370186, Chile; (A.R.); (C.M.)
- FONDAP Center for Genome Regulation, Facultad de Ciencias de la Vida, Universidad Andrés Bello, República 330, Santiago 8370186, Chile
| | - Pablo Cornejo
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Avda. Francisco Salazar, Temuco 4780000, Chile;
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Ke T, Zhang J, Tao Y, Zhang C, Zhang Y, Xu Y, Chen L. Individual and combined application of Cu-tolerant Bacillus spp. enhance the Cu phytoextraction efficiency of perennial ryegrass. CHEMOSPHERE 2021; 263:127952. [PMID: 32828058 DOI: 10.1016/j.chemosphere.2020.127952] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/30/2020] [Accepted: 08/08/2020] [Indexed: 05/27/2023]
Abstract
Forage grasses have recently received a remarkable amount of attention as promising candidates for decontaminating metal-polluted soils, but this strategy is time-consuming and inefficient. The present study aimed to address the beneficial effects of screened plant growth-promoting rhizobacteria (PGPR) strains Bacillus sp. EhS5 and EhS7 on perennial ryegrass and tall fescue. Single or combined inoculation considerably increased the biomass yield and Cu content of inoculated ryegrass compared with uninoculated plants, thereby enhancing the extraction efficiency at different Cu contamination levels. Bioaugmentation did not show a positive impact on the improvement of fescue's phytoextraction efficiency. Principal component analysis (PCA) and Pearson correlation coefficient results identified root development and photosynthesis as the key variables influencing ryegrass biomass. Antioxidant activities and Cu bioavailability are the key variables influencing Cu accumulation. The inoculated ryegrass showed improved photosynthetic status as the photosystem II system efficiency parameters increased and energy dissipation in the form of heat (DIo/RC) decreased with the help of PGPR. The root length, diameter, surface area, and forks of inoculated ryegrass increased remarkably. The levels of scavengers of reactive oxygen species were enhanced in these plants. Moreover, PGPR significantly increased soil Cu bioavailability by secreting siderophores and organic acid and by increasing soil organic carbon content. Dual inoculation showed better results than individual inoculation in improving ryegrass growth and Cu translocation under high Cu contamination level according to PCA. This study systematically explored the effects and mechanisms of the Bacillus-ryegrass combined remediation and provided a novel method for cleaning Cu-contaminated sites.
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Affiliation(s)
- Tan Ke
- School of Resource & Environmental Sciences, Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, PR China
| | - Jin Zhang
- School of Resource & Environmental Sciences, Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, PR China
| | - Yue Tao
- School of Resource & Environmental Sciences, Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, PR China
| | - Chao Zhang
- School of Resource & Environmental Sciences, Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, PR China
| | - Yurui Zhang
- School of Resource & Environmental Sciences, Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, PR China
| | - Yanhong Xu
- National Central City Research Institute, Zhengzhou Normal University, Zhengzhou, 450044, PR China
| | - Lanzhou Chen
- School of Resource & Environmental Sciences, Hubei Key Laboratory of Biomass Resource Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, PR China.
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Yongpisanphop J, Babel S, Kurisu F, Kruatrachue M, Pokethitiyook P. Isolation and characterization of Pb-resistant plant growth promoting endophytic bacteria and their role in Pb accumulation by fast-growing trees. ENVIRONMENTAL TECHNOLOGY 2020; 41:3598-3606. [PMID: 31070994 DOI: 10.1080/09593330.2019.1615993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 05/01/2019] [Indexed: 06/09/2023]
Abstract
Lead (Pb) contamination is one of the major environmental problems on a global scale. Bacterial endophytes have been accepted as a promising technique to assist phytoremediation. In this study, three Pb-tolerant endophytic bacteria were isolated from the roots of Pityrogramma calomelanos. Based on partial 16S rRNA gene sequencing analysis, all isolates were similar to Pseudomonas and tolerated Pb concentration up to 1850mg/L, producing siderophores and solubilized phosphate. Among them, Pc isolate closely related to Pseudomonas psychrophila showed the highest water-soluble Pb in solution (Pb solubilization) and in contaminated soil. This isolate was chosen to study the effects on Pb accumulation in the roots of Acacia mangium and Eucalyptus camaldulensis by a hydroponic experiment. The results showed that, in the Hoagland nutrient solution with no Pb spiking, the roots showed no significant difference (p > 0.05), and the concentration of Pb ranged from 10 to 89 mg/kg. In the nutrient solution in the presence of 30 mg/L Pb, there were no significant changes in Pb contents in roots. However, A. mangium showed an increase in Pb concentration in the roots (6829 ± 697 mg/kg), compared to non-inoculation (6242 ± 272 mg/kg). E. camaldulensis inoculation showed a decrease in Pb content (3763 ± 592 mg/kg), compared to non-inoculation (4233 ± 264 mg/kg). These results suggest that the Pc isolate closely related to P. psychrophila was effective in promoting the phytoremediation potential of A. mangium, but it was not useful for E. camaldulensis.
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Affiliation(s)
- Jiraporn Yongpisanphop
- Department of Agro-Industrial, Food and Environmental Technology, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand
| | - Sandhya Babel
- School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University-Rangsit Campus, Pathum Thani, Thailand
| | - Futoshi Kurisu
- Research Center for Water Environment Technology, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Maleeya Kruatrachue
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Prayad Pokethitiyook
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand
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Cui JL, Zhao YP, Lu YJ, Chan TS, Zhang LL, Tsang DCW, Li XD. Distribution and speciation of copper in rice (Oryza sativa L.) from mining-impacted paddy soil: Implications for copper uptake mechanisms. ENVIRONMENT INTERNATIONAL 2019; 126:717-726. [PMID: 30878867 DOI: 10.1016/j.envint.2019.02.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 02/11/2019] [Accepted: 02/17/2019] [Indexed: 06/09/2023]
Abstract
Long term mining activities can cause significant metal pollution in the environment, thereby showing potential risk to the paddy field. Elucidating the interfacial processes of trace metals from contaminated paddy soil to rice within the rhizosphere can provide important information on metal biogeochemistry and food safety. The current study aims to explore the spatial distribution and molecular speciation of Cu from rhizosphere to rice plant in a mining-impacted paddy soil, and reveal the possible uptake mechanisms. X-ray absorption near edge structure (XANES) analysis indicated that Cu was primarily associated with iron oxide and sulfide in soil with a minor proportion of organic complexed species. In the rice samples, Cu showed much higher concentrations in the roots than the shoots, as most Cu was sequestered in the root surface and epidermis (primarily in the form of C/N ligands bound Cu species), rather than root xylem, as identified by micro X-ray fluorescence (μ-XRF) imaging coupling with μ-XANES. By contrast, in the root xylem, thiol-S bound Cu(I) complex was observed, representing the reduced product of Cu(II) by thiol-S ligands in rice root. The absorbed Cu was probably transported from the root to the aerial part as C/N ligand bound Cu complex such as Cu-histidine like species, which was observed in the root xylem. The large retention capacity and reduction of Cu(II) in rice root alleviated Cu toxicity to rice, which was beneficial for food safety (e.g., lower concentration of Cu in rice grains). These findings showed for the first time that the uptake mechanisms by rice from field contaminated sites, which shed light on Cu detoxification process and potential remediation strategies.
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Affiliation(s)
- Jin-Li Cui
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China
| | - Yan-Ping Zhao
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Ying-Jui Lu
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - Ting-Shan Chan
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - Li-Li Zhang
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Xiang-Dong Li
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
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Guan CY, Tseng YH, Tsang DCW, Hu A, Yu CP. Wetland plant microbial fuel cells for remediation of hexavalent chromium contaminated soils and electricity production. JOURNAL OF HAZARDOUS MATERIALS 2019; 365:137-145. [PMID: 30419460 DOI: 10.1016/j.jhazmat.2018.10.086] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 10/26/2018] [Accepted: 10/29/2018] [Indexed: 06/09/2023]
Abstract
The plant microbial fuel cell (PMFC) is a novel technology which integrates plants, microbes, and electrochemical elements together to create renewable energy. However, information regarding using the PMFC system to remediate metal-contaminated soils is still limited. In this study, we evaluate the potential of PMFC systems to remediate soils polluted by Cr(VI). We compare different plants and different electrode materials with regard to their electricity generation and Cr(VI) removals under different soil Cr(VI) concentrations. In PMFC systems, the soil pH was transformed from slightly acidic to neutral, and the electrical conductivity was reduced during operation. The removal efficiency of Cr(VI) in soils could reach 99%, and the total Cr of soils could also be reduced. The closed circuit voltage of PMFC systems of Chinese pennisetum using the graphite carbon felt as the electrodes could reach the daily average value of 469.21 mV. PMFC systems have successfully demonstrated the ability to remove Cr(VI) from soils collected from actual metal-contaminated sites. Our results suggest that using PMFCs to remediate contaminated soils is promising, and the effects of decontamination are mostly contributed by bioelectrochemical processes and plant uptake.
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Affiliation(s)
- Chung-Yu Guan
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan
| | - Yi-Ho Tseng
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Anyi Hu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Chang-Ping Yu
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan.
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Marastoni L, Pii Y, Maver M, Valentinuzzi F, Cesco S, Mimmo T. Role of Azospirillum brasilense in triggering different Fe chelate reductase enzymes in cucumber plants subjected to both nutrient deficiency and toxicity. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 136:118-126. [PMID: 30660677 DOI: 10.1016/j.plaphy.2019.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/10/2019] [Accepted: 01/10/2019] [Indexed: 05/17/2023]
Abstract
Azospirillum brasilense was reported to up-regulate iron (Fe) uptake mechanisms, such as Fe reduction and rhizosphere acidification, in both Fe sufficient and deficient cucumber plants (Cucumis sativus L.). Strategy I plants take up both Fe and copper (Cu) after their reduction mediated by the ferric-chelate reductase oxidase (FRO) enzyme. Interestingly, in cucumber genome only one FRO gene is reported. Thus, in the present study we applied a bioinformatics approach to identify the member of cucumber FRO gene family and allowed the identification of at least three CsFRO genes, one of which was the already identified, i.e. CsFRO1. The expression patterns of the newly identified transcripts were investigated in hydroponically grown cucumber plants treated with different Fe and Cu nutritional regimes. Gene expression was then correlated with morphological (i.e. root architecture) and physiological (Fe(III) reducing activity) parameters to shed light on: i) the CsFRO homologue responsible of the increased reduction activity in Fe-sufficient plants inoculated with A. brasilense cucumber plants, and ii) the possible effect of A. brasilense in ameliorating the symptoms of Cu toxicity in cucumber plants. The data obtained showed that all the CsFRO genes were expressed in the root tissues of cucumber plants and responded to Cu starvation, combined Cu/Fe deficiency and Cu toxicity. Only CsFRO3 was modulated by the A. brasilense in Fe-sufficient plants suggesting for the first time a different specificity of action of the three isoenzymes depending not only on the nutritional regime (either deficiency or toxicity) but also on the presence of the PGPR. Furthermore, results suggest that the PGPR could even ameliorate the stress symptoms caused by both the double (i.e. Cu and Fe) and Cu deficiency as well as Cu toxicity modulating, on one hand, the growth of the root system and, on the other hand, the root nutrient uptake.
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Affiliation(s)
- Laura Marastoni
- Faculty of Science and Technology, Free University of Bozen-Bolzano, I-39100, Bolzano, Italy
| | - Youry Pii
- Faculty of Science and Technology, Free University of Bozen-Bolzano, I-39100, Bolzano, Italy.
| | - Mauro Maver
- Faculty of Science and Technology, Free University of Bozen-Bolzano, I-39100, Bolzano, Italy
| | - Fabio Valentinuzzi
- Faculty of Science and Technology, Free University of Bozen-Bolzano, I-39100, Bolzano, Italy
| | - Stefano Cesco
- Faculty of Science and Technology, Free University of Bozen-Bolzano, I-39100, Bolzano, Italy
| | - Tanja Mimmo
- Faculty of Science and Technology, Free University of Bozen-Bolzano, I-39100, Bolzano, Italy
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Ju W, Liu L, Fang L, Cui Y, Duan C, Wu H. Impact of co-inoculation with plant-growth-promoting rhizobacteria and rhizobium on the biochemical responses of alfalfa-soil system in copper contaminated soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 167:218-226. [PMID: 30342354 DOI: 10.1016/j.ecoenv.2018.10.016] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/06/2018] [Accepted: 10/05/2018] [Indexed: 05/27/2023]
Abstract
The effects and regulatory mechanisms of co-inoculation of plant-growth-promoting rhizobacteria (PGPRs) and rhizobium in plant-soil systems remain unclear, despite numerous reports that PGPRs or rhizobium can alleviate metal toxicity. We used the co-inoculation of the PGPR Paenibacillus mucilaginosus and the metal-resistant rhizobium Sinorhizobium meliloti for exploring the physiological and biochemical responses of the plant-soil system in metal-contaminated soil. The co-inoculation with the PGPR and rhizobium significantly increased the nutrient (N, P, and K) contents in plant tissues and promoted plant growth in soil contaminated with copper (Cu). Stress from Cu-induced reactive oxygen species and lipid peroxidation were largely attenuated by the co-inoculation by increasing the activities of antioxidant enzymes. The contents and uptake of Cu in plant tissues increased significantly in the co-inoculation treatment compared with the uninoculated control and individual inoculation treatment. Co-inoculation with PGPR and rhizobium significantly increased soil microbial biomass, enzymatic activities, total nitrogen, available phosphorus, and soil organic matter contents compared with the uninoculated control. Interestingly, co-inoculation also affected the composition of the rhizospheric microbial community, and slightly increased rhizospheric microbial diversity. These improvements of the soil fertility and biological activity also had a beneficial impact on plant growth under Cu stress. Our results suggested that alfalfa co-inoculated with PGPR and rhizobium could increase plant growth and Cu uptake in metal-contaminated soil by alleviating plant Cu stress and improving soil biochemical properties. These results indicate that the co-application of PGPR and rhizobium can have a positive effect on the biochemical responses of alfalfa-soil systems in soil contaminated by heavy metals and can provide an efficient strategy for the phytomanagement of metal-contaminated land.
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Affiliation(s)
- Wenliang Ju
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Insti tute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Liu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Insti tute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China
| | - Linchuan Fang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Insti tute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China.
| | - Yongxing Cui
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chengjiao Duan
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Wu
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
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Egamberdieva D, Abd-Allah EF, Teixeira da Silva JA. Microbially Assisted Phytoremediation of Heavy Metal–Contaminated Soils. PLANT METAL INTERACTION 2016:483-498. [DOI: 10.1016/b978-0-12-803158-2.00020-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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