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Abou Jaoudé R, Luziatelli F, Ficca AG, Ruzzi M. A plant's perception of growth-promoting bacteria and their metabolites. FRONTIERS IN PLANT SCIENCE 2024; 14:1332864. [PMID: 38328622 PMCID: PMC10848262 DOI: 10.3389/fpls.2023.1332864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 12/28/2023] [Indexed: 02/09/2024]
Abstract
Many recent studies have highlighted the importance of plant growth-promoting (rhizo)bacteria (PGPR) in supporting plant's development, particularly under biotic and abiotic stress. Most focus on the plant growth-promoting traits of selected strains and the latter's effect on plant biomass, root architecture, leaf area, and specific metabolite accumulation. Regarding energy balance, plant growth is the outcome of an input (photosynthesis) and several outputs (i.e., respiration, exudation, shedding, and herbivory), frequently neglected in classical studies on PGPR-plant interaction. Here, we discuss the primary evidence underlying the modifications triggered by PGPR and their metabolites on the plant ecophysiology. We propose to detect PGPR-induced variations in the photosynthetic activity using leaf gas exchange and recommend setting up the correct timing for monitoring plant responses according to the specific objectives of the experiment. This research identifies the challenges and tries to provide future directions to scientists working on PGPR-plant interactions to exploit the potential of microorganisms' application in improving plant value.
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Affiliation(s)
- Renée Abou Jaoudé
- Department for Innovation in Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
| | | | | | - Maurizio Ruzzi
- Department for Innovation in Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
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2
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Msaddak A, Quiñones MA, Mars M, Pueyo JJ. The Beneficial Effects of Inoculation with Selected Nodule-Associated PGPR on White Lupin Are Comparable to Those of Inoculation with Symbiotic Rhizobia. PLANTS (BASEL, SWITZERLAND) 2023; 12:4109. [PMID: 38140436 PMCID: PMC10747367 DOI: 10.3390/plants12244109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
Nodule endophytes and associated bacteria are non-symbiotic bacteria that colonize legume nodules. They accompany nodulating rhizobia and can form beneficial associations, as some of them are plant growth-promoting rhizobacteria (PGPR) that are able to promote germination and plant growth and increase tolerance to biotic and abiotic stress. White lupin (Lupinus albus) is a legume crop that is gaining relevance as a suitable alternative to soybean as a plant protein source. Eleven nodule-associated bacteria were isolated from white lupin nodules grown in a Tunisian soil. They belonged to the genera Rhizobium, Ensifer, Pseudomonas and Bacillus. Their plant growth-promoting (PGP) and enzymatic activities were tested in vitro. Strains Pseudomonas sp., L1 and L12, displayed most PGP activities tested, and were selected for in planta assays. Inoculation with strains L1 or L12 increased seed germination and had the same positive effects on all plant growth parameters as did inoculation with symbiotic Bradyrhizobium canariense, with no significant differences among treatments. Inoculation with efficient nitrogen-fixing rhizobia must compete with rhizobia present in the soil that sometimes nodulate efficiently but fix nitrogen poorly, leading to a low response to inoculation. In such cases, inoculation with highly effective PGPR might represent a feasible alternative to boost crop productivity.
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Affiliation(s)
- Abdelhakim Msaddak
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain;
- Laboratory of Biodiversity and Valorization of Arid Areas Bioresources, BVBAA, Faculty of Sciences, University of Gabès, Erriadh, Zrig, Gabès 6072, Tunisia;
| | - Miguel A. Quiñones
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain;
| | - Mohamed Mars
- Laboratory of Biodiversity and Valorization of Arid Areas Bioresources, BVBAA, Faculty of Sciences, University of Gabès, Erriadh, Zrig, Gabès 6072, Tunisia;
| | - José J. Pueyo
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain;
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3
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Goyal RK, Habtewold JZ. Evaluation of Legume-Rhizobial Symbiotic Interactions Beyond Nitrogen Fixation That Help the Host Survival and Diversification in Hostile Environments. Microorganisms 2023; 11:1454. [PMID: 37374957 DOI: 10.3390/microorganisms11061454] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/26/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Plants often experience unfavorable conditions during their life cycle that impact their growth and sometimes their survival. A temporary phase of such stress, which can result from heavy metals, drought, salinity, or extremes of temperature or pH, can cause mild to enormous damage to the plant depending on its duration and intensity. Besides environmental stress, plants are the target of many microbial pathogens, causing diseases of varying severity. In plants that harbor mutualistic bacteria, stress can affect the symbiotic interaction and its outcome. To achieve the full potential of a symbiotic relationship between the host and rhizobia, it is important that the host plant maintains good growth characteristics and stay healthy under challenging environmental conditions. The host plant cannot provide good accommodation for the symbiont if it is infested with diseases and prone to other predators. Because the bacterium relies on metabolites for survival and multiplication, it is in its best interests to keep the host plant as stress-free as possible and to keep the supply stable. Although plants have developed many mitigation strategies to cope with stress, the symbiotic bacterium has developed the capability to augment the plant's defense mechanisms against environmental stress. They also provide the host with protection against certain diseases. The protective features of rhizobial-host interaction along with nitrogen fixation appear to have played a significant role in legume diversification. When considering a legume-rhizobial symbiosis, extra benefits to the host are sometimes overlooked in favor of the symbionts' nitrogen fixation efficiency. This review examines all of those additional considerations of a symbiotic interaction that enable the host to withstand a wide range of stresses, enabling plant survival under hostile regimes. In addition, the review focuses on the rhizosphere microbiome, which has emerged as a strong pillar of evolutionary reserve to equip the symbiotic interaction in the interests of both the rhizobia and host. The evaluation would draw the researchers' attention to the symbiotic relationship as being advantageous to the host plant as a whole and the role it plays in the plant's adaptation to unfavorable environmental conditions.
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Affiliation(s)
- Ravinder K Goyal
- Agriculture and Agri-Food Canada, Lacombe Research and Development Center, Lacombe, AB T4L 1W1, Canada
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Msaddak A, Mars M, Quiñones MA, Lucas MM, Pueyo JJ. Lupin, a Unique Legume That Is Nodulated by Multiple Microsymbionts: The Role of Horizontal Gene Transfer. Int J Mol Sci 2023; 24:ijms24076496. [PMID: 37047476 PMCID: PMC10094711 DOI: 10.3390/ijms24076496] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023] Open
Abstract
Lupin is a high-protein legume crop that grows in a wide range of edaphoclimatic conditions where other crops are not viable. Its unique seed nutrient profile can promote health benefits, and it has been proposed as a phytoremediation plant. Most rhizobia nodulating Lupinus species belong to the genus Bradyrhizobium, comprising strains that are phylogenetically related to B. cytisi, B. hipponenese, B. rifense, B. iriomotense/B. stylosanthis, B. diazoefficiens, B. japonicum, B. canariense/B. lupini, and B. retamae/B. valentinum. Lupins are also nodulated by fast-growing bacteria within the genera Microvirga, Ochrobactrum, Devosia, Phyllobacterium, Agrobacterium, Rhizobium, and Neorhizobium. Phylogenetic analyses of the nod and nif genes, involved in microbial colonization and symbiotic nitrogen fixation, respectively, suggest that fast-growing lupin-nodulating bacteria have acquired their symbiotic genes from rhizobial genera other than Bradyrhizobium. Horizontal transfer represents a key mechanism allowing lupin to form symbioses with bacteria that were previously considered as non-symbiotic or unable to nodulate lupin, which might favor lupin’s adaptation to specific habitats. The characterization of yet-unstudied Lupinus species, including microsymbiont whole genome analyses, will most likely expand and modify the current lupin microsymbiont taxonomy, and provide additional knowledge that might help to further increase lupin’s adaptability to marginal soils and climates.
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Affiliation(s)
- Abdelhakim Msaddak
- Department of Soil. Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain
- Laboratory of Biodiversity and Valorization of Arid Areas Bioresources, BVBAA, Faculty of Sciences, University of Gabès, Erriadh, Zrig, Gabès 6072, Tunisia
| | - Mohamed Mars
- Laboratory of Biodiversity and Valorization of Arid Areas Bioresources, BVBAA, Faculty of Sciences, University of Gabès, Erriadh, Zrig, Gabès 6072, Tunisia
| | - Miguel A. Quiñones
- Department of Soil. Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain
| | - M. Mercedes Lucas
- Department of Soil. Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain
| | - José J. Pueyo
- Department of Soil. Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, 28006 Madrid, Spain
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González-Reguero D, Robas-Mora M, Probanza A, Jiménez PA. Evaluation of the oxidative stress alleviation in Lupinus albus var. orden Dorado by the inoculation of four plant growth-promoting bacteria and their mixtures in mercury-polluted soils. Front Microbiol 2022; 13:907557. [PMID: 36246290 PMCID: PMC9556840 DOI: 10.3389/fmicb.2022.907557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/12/2022] [Indexed: 11/13/2022] Open
Abstract
Mercury (Hg) pollution is a serious environmental and public health problem. Hg has the ability to biomagnify through the trophic chain and generate various pathologies in humans. The exposure of plants to Hg affects normal plant growth and its stress levels, producing oxidative cell damage. Root inoculation with plant growth-promoting bacteria (PGPB) can help reduce the absorption of Hg, minimizing the harmful effects of this metal in the plant. This study evaluates the phytoprotective capacity of four bacterial strains selected for their PGPB capabilities, quantified by the calculation of the biomercuroremediator suitability index (IIBMR), and their consortia, in the Lupinus albus var. orden Dorado. The oxidative stress modulating capacity in the inoculated plant was analyzed by measuring the activity of the enzymes catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR). In turn, the phytoprotective capacity of these PGPBs against the bioaccumulation of Hg was studied in plants grown in soils highly contaminated by Hg vs. soils in the absence of Hg contamination. The results of the oxidative stress alleviation and Hg bioaccumulation were compared with the biometric data of Lupinus albus var. orden Dorado previously obtained under the same soil conditions of Hg concentration. The results show that the biological behavior of plants (biometrics, bioaccumulation of Hg, and activity of regulatory enzymes of reactive oxygen species [ROS]) is significantly improved by the inoculation of strains B1 (Pseudomonas moraviensis) and B2 (Pseudomonas baetica), as well as their corresponding consortium (CS5). In light of the conclusions of this work, the use of these strains, as well as their consortium, is postulated as good candidates for their subsequent use in phytostimulation and phytoprotection processes in areas contaminated with Hg.
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Quiñones MA, Lucas MM, Pueyo JJ. Adaptive Mechanisms Make Lupin a Choice Crop for Acidic Soils Affected by Aluminum Toxicity. FRONTIERS IN PLANT SCIENCE 2022; 12:810692. [PMID: 35069669 PMCID: PMC8766672 DOI: 10.3389/fpls.2021.810692] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 12/14/2021] [Indexed: 05/25/2023]
Abstract
Almost half of the world's agricultural soils are acidic, and most of them present significant levels of aluminum (Al) contamination, with Al3+ as the prevailing phytotoxic species. Lupin is a protein crop that is considered as an optimal alternative to soybean cultivation in cold climates. Lupins establish symbiosis with certain soil bacteria, collectively known as rhizobia, which are capable of fixing atmospheric nitrogen. Moreover, some lupin species, especially white lupin, form cluster roots, bottlebrush-like structures specialized in the mobilization and uptake of nutrients in poor soils. Cluster roots are also induced by Al toxicity. They exude phenolic compounds and organic acids that chelate Al to form non-phytotoxic complexes in the rhizosphere and inside the root cells, where Al complexes are accumulated in the vacuole. Lupins flourish in highly acidic soils where most crops, including other legumes, are unable to grow. Some lupin response mechanisms to Al toxicity are common to other plants, but lupin presents specific tolerance mechanisms, partly as a result of the formation of cluster roots. Al-induced lupin organic acid secretion differs from P-induced secretion, and organic acid transporters functions differ from those in other legumes. Additionally, symbiotic rhizobia can contribute to Al detoxification. After revising the existing knowledge on lupin distinct Al tolerance mechanisms, we conclude that further research is required to elucidate the specific organic acid secretion and Al accumulation mechanisms in this unique legume, but definitely, white lupin arises as a choice crop for cultivation in Al-rich acidic soils in temperate climate regions.
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Evaluation of the PGPR Capacity of Four Bacterial Strains and Their Mixtures, Tested on Lupinus albus var. Dorado Seedlings, for the Bioremediation of Mercury-Polluted Soils. Processes (Basel) 2021. [DOI: 10.3390/pr9081293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Soil contamination by mercury, which is one of the most toxic heavy metals due to its bioaccumulative capacity, poses a risk to the environment as well as health. The Almadén mining district in Ciudad Real, Spain is one of the most heavily-polluted sites in the world, making the soils unusable. Bioremediation, and more specifically phyto-rhizoremediation, based on the synergistic interaction established between plant and Plant Growth Promoting Rhizobacteria (PGPR), improves the plant’s ability to grow, mobilize, accumulate, and extract contaminants from the soil. The objective of this study is to evaluate the plant growth-promoting ability of four PGPR strains (and mixtures), isolated from the bulk soil and rhizosphere of naturally grown plants in the Almadén mining district, when they are inoculated in emerged seeds of Lupinus albus, var. Dorado in the presence of high concentrations of mercury. After 20 days of incubation and subsequent harvesting of the seedlings, biometric measurements were carried out at the root and aerial levels. The results obtained show that the seeds treatment with PGPR strains improves plants biometry in the presence of mercury. Specifically, strain B2 (Pseudomonas baetica) and B1 (Pseudomonas moraviensis) were those that contributed the most to plant growth, both individually and as part of mixtures (CS5 and CS3). Thus, these are postulated to be good candidates for further in situ phyto-rhizoremediation tests of mercury-contaminated soils.
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Mei L, Zhu Y, Zhang X, Zhou X, Zhong Z, Li H, Li Y, Li X, Daud MK, Chen J, Zhu S. Mercury-Induced Phytotoxicity and Responses in Upland Cotton ( Gossypium hirsutum L.) Seedlings. PLANTS 2021; 10:plants10081494. [PMID: 34451539 PMCID: PMC8398479 DOI: 10.3390/plants10081494] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/15/2021] [Accepted: 06/15/2021] [Indexed: 11/16/2022]
Abstract
Cotton is a potential and excellent candidate to balance both agricultural production and remediation of mercury-contained soil, as its main production fiber hardly involves into food chains. However, in cotton, there is known rarely about the tolerance and response to mercury (Hg) environments. In this study, the biochemical and physiological damages, in response to Hg concentrations (0, 1, 10, 50 and 100 µM), were investigated in upland cotton seedlings. The results on germination of cottonseeds indicated the germination rates were suppressed by high Hg levels, as the decrease of percentage was more than 10% at 1000 µM Hg. Shoots and roots' growth were significantly inhibited over 10 µM Hg. The inhibitor rates (IR) in fresh weight were close in values between shoots and roots, whereas those in dry weight the root growth were more obviously influenced by Hg. In comparison of organs, the growth inhibition ranked as root > leaf > stem. The declining of translocation factor (TF) opposed the Hg level as even low to 0.05 at 50 µM Hg. The assimilation in terms of photosynthesis, of cotton plants, was affected negatively by Hg, as evidenced from the performances on pigments (chlorophyll a and b) and gas exchange (Intercellular CO2 concentration (Ci), CO2 assimilation rate (Pn) and stomatal conductance (Gs)). Sick phenotypes on leaf surface included small white zone, shrinking and necrosis. Membrane lipid peroxidation and leakage were Hg dose-dependent as indicated by malondialdehyde (MDA) content and relative conductivity (RC) values in leaves and roots. More than 10 µM Hg damaged antioxidant enzyme system in both leaves and roots (p < 0.05). Concludingly, 10 µM Hg post negative consequences to upland cotton plants in growth, physiology and biochemistry, whereas high phytotoxicity and damage appeared at more than 50 µM Hg concentration.
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Affiliation(s)
- Lei Mei
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
- Enshi Tujia & Miao Autonomous Prefecture Academy of Agricultural Sciences, Enshi 445000, China
- Correspondence: (L.M.); (S.Z.)
| | - Yueyi Zhu
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
| | - Xianwen Zhang
- The Agricultural Experiment Station, Zhejiang University, Hangzhou 310058, China;
| | - Xiujuan Zhou
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
| | - Zhentao Zhong
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
| | - Huazu Li
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
| | - Yingjun Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiaohu Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Muhammad Khan Daud
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat 26000, Pakistan;
| | - Jinhong Chen
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
| | - Shuijin Zhu
- Institution of Crop Science, Zhejiang University, Hangzhou 310058, China; (Y.Z.); (X.Z.); (Z.Z.); (H.L.); (J.C.)
- Correspondence: (L.M.); (S.Z.)
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Abstract
Abandoned mine lands (AMLs), which are considered some of the most dangerous anthropogenic activities in the world, are a source of hazards relating to potentially toxic elements (PTEs). Traditional reclamation techniques, which are expensive, time-consuming and not well accepted by the general public, cannot be used on a large scale. However, plant-based techniques have gained acceptance as an environmentally friendly alternative over the last 20 years. Plants can be used in AMLs for PTE phytoextraction, phytostabilization, and phytovolatilization. We reviewed these phytoremediation techniques, paying particular attention to the selection of appropriate plants in each case. In order to assess the suitability of plants for phytoremediation purposes, the accumulation capacity and tolerance mechanisms of PTEs was described. We also compiled a collection of interesting actual examples of AML phytoremediation. On-site studies have shown positive results in terms of soil quality improvement, reduced PTE bioavailability, and increased biodiversity. However, phytoremediation strategies need to better characterize potential plant candidates in order to improve PTE extraction and to reduce the negative impact on AMLs.
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Pueyo JJ, Quiñones MA, Coba de la Peña T, Fedorova EE, Lucas MM. Nitrogen and Phosphorus Interplay in Lupin Root Nodules and Cluster Roots. FRONTIERS IN PLANT SCIENCE 2021; 12:644218. [PMID: 33747024 PMCID: PMC7966414 DOI: 10.3389/fpls.2021.644218] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 01/25/2021] [Indexed: 05/17/2023]
Abstract
Nitrogen (N) and phosphorus (P) are two major plant nutrients, and their deficiencies often limit plant growth and crop yield. The uptakes of N or P affect each other, and consequently, understanding N-P interactions is fundamental. Their signaling mechanisms have been studied mostly separately, and integrating N-P interactive regulation is becoming the aim of some recent works. Lupins are singular plants, as, under N and P deficiencies, they are capable to develop new organs, the N2-fixing symbiotic nodules, and some species can also transform their root architecture to form cluster roots, hundreds of short rootlets that alter their metabolism to induce a high-affinity P transport system and enhance synthesis and secretion of organic acids, flavonoids, proteases, acid phosphatases, and proton efflux. These modifications lead to mobilization in the soil of, otherwise unavailable, P. White lupin (Lupinus albus) represents a model plant to study cluster roots and for understanding plant acclimation to nutrient deficiency. It tolerates simultaneous P and N deficiencies and also enhances uptake of additional nutrients. Here, we present the structural and functional modifications that occur in conditions of P and N deficiencies and lead to the organogenesis and altered metabolism of nodules and cluster roots. Some known N and P signaling mechanisms include different factors, including phytohormones and miRNAs. The combination of the individual N and P mechanisms uncovers interactive regulation pathways that concur in nodules and cluster roots. L. albus interlinks N and P recycling processes both in the plant itself and in nature.
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Affiliation(s)
- José J. Pueyo
- Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | | | | | - Elena E. Fedorova
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Moscow, Russia
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Phytoremediation and Microorganisms-Assisted Phytoremediation of Mercury-Contaminated Soils: Challenges and Perspectives. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18052435. [PMID: 33801363 PMCID: PMC7967564 DOI: 10.3390/ijerph18052435] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/18/2021] [Accepted: 02/24/2021] [Indexed: 01/01/2023]
Abstract
Mercury (Hg) pollution is a global threat to human and environmental health because of its toxicity, mobility and long-term persistence. Although costly engineering-based technologies can be used to treat heavily Hg-contaminated areas, they are not suitable for decontaminating agricultural or extensively-polluted soils. Emerging phyto- and bioremediation strategies for decontaminating Hg-polluted soils generally involve low investment, simple operation, and in situ application, and they are less destructive for the ecosystem. Current understanding of the uptake, translocation and sequestration of Hg in plants is reviewed to highlight new avenues for exploration in phytoremediation research, and different phytoremediation strategies (phytostabilization, phytoextraction and phytovolatilization) are discussed. Research aimed at identifying suitable plant species and associated-microorganisms for use in phytoremediation of Hg-contaminated soils is also surveyed. Investigation into the potential use of transgenic plants in Hg-phytoremediation is described. Recent research on exploiting the beneficial interactions between plants and microorganisms (bacteria and fungi) that are Hg-resistant and secrete plant growth promoting compounds is reviewed. We highlight areas where more research is required into the effective use of phytoremediation on Hg-contaminated sites, and conclude that the approaches it offers provide considerable potential for the future.
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12
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Arregui G, Hipólito P, Pallol B, Lara-Dampier V, García-Rodríguez D, Varela HP, Tavakoli Zaniani P, Balomenos D, Paape T, Coba de la Peña T, Lucas MM, Pueyo JJ. Mercury-Tolerant Ensifer medicae Strains Display High Mercuric Reductase Activity and a Protective Effect on Nitrogen Fixation in Medicago truncatula Nodules Under Mercury Stress. FRONTIERS IN PLANT SCIENCE 2021; 11:560768. [PMID: 33519831 PMCID: PMC7840509 DOI: 10.3389/fpls.2020.560768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 12/22/2020] [Indexed: 05/27/2023]
Abstract
Mercury (Hg) is extremely toxic for all living organisms. Hg-tolerant symbiotic rhizobia have the potential to increase legume tolerance, and to our knowledge, the mechanisms underlying Hg tolerance in rhizobia have not been investigated to date. Rhizobial strains of Ensifer medicae, Rhizobium leguminosarum bv. trifolii and Bradyrhizobium canariense previously isolated from severely Hg-contaminated soils showed different levels of Hg tolerance. The ability of the strains to reduce mercury Hg2+ to Hg0, a volatile and less toxic form of mercury, was assessed using a Hg volatilization assay. In general, tolerant strains displayed high mercuric reductase activity, which appeared to be inducible in some strains when grown at a sub-lethal HgCl2 concentration. A strong correlation between Hg tolerance and mercuric reductase activity was observed for E. medicae strains, whereas this was not the case for the B. canariense strains, suggesting that additional Hg tolerance mechanisms could be playing a role in B. canariense. Transcript abundance from merA, the gene that encodes mercuric reductase, was quantified in tolerant and sensitive E. medicae and R. leguminosarum strains. Tolerant strains presented higher merA expression than sensitive ones, and an increase in transcript abundance was observed for some strains when bacteria were grown in the presence of a sub-lethal HgCl2 concentration. These results suggest a regulation of mercuric reductase in rhizobia. Expression of merA genes and mercuric reductase activity were confirmed in Medicago truncatula nodules formed by a sensitive or a tolerant E. medicae strain. Transcript accumulation in nodules formed by the tolerant strain increased when Hg stress was applied, while a significant decrease in expression occurred upon stress application in nodules formed by the Hg-sensitive strain. The effect of Hg stress on nitrogen fixation was evaluated, and in our experimental conditions, nitrogenase activity was not affected in nodules formed by the tolerant strain, while a significant decrease in activity was observed in nodules elicited by the Hg-sensitive bacteria. Our results suggest that the combination of tolerant legumes with tolerant rhizobia constitutes a potentially powerful tool in the bioremediation of Hg-contaminated soils.
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Affiliation(s)
- Gabriela Arregui
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Pablo Hipólito
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Beatriz Pallol
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Victoria Lara-Dampier
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Diego García-Rodríguez
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - Higinio P. Varela
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | | | | | - Timothy Paape
- Brookhaven National Laboratory, Upton, NY, United States
| | | | - M. Mercedes Lucas
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
| | - José J. Pueyo
- Department of Soil, Plant and Environmental Quality, Institute of Agricultural Sciences, ICA-CSIC, Madrid, Spain
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13
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Wang L, Hou D, Cao Y, Ok YS, Tack FMG, Rinklebe J, O'Connor D. Remediation of mercury contaminated soil, water, and air: A review of emerging materials and innovative technologies. ENVIRONMENT INTERNATIONAL 2020; 134:105281. [PMID: 31726360 DOI: 10.1016/j.envint.2019.105281] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/23/2019] [Accepted: 10/20/2019] [Indexed: 05/24/2023]
Abstract
Mercury contamination in soil, water and air is associated with potential toxicity to humans and ecosystems. Industrial activities such as coal combustion have led to increased mercury (Hg) concentrations in different environmental media. This review critically evaluates recent developments in technological approaches for the remediation of Hg contaminated soil, water and air, with a focus on emerging materials and innovative technologies. Extensive research on various nanomaterials, such as carbon nanotubes (CNTs), nanosheets and magnetic nanocomposites, for mercury removal are investigated. This paper also examines other emerging materials and their characteristics, including graphene, biochar, metal organic frameworks (MOFs), covalent organic frameworks (COFs), layered double hydroxides (LDHs) as well as other materials such as clay minerals and manganese oxides. Based on approaches including adsorption/desorption, oxidation/reduction and stabilization/containment, the performances of innovative technologies with the aid of these materials were examined. In addition, technologies involving organisms, such as phytoremediation, algae-based mercury removal, microbial reduction and constructed wetlands, were also reviewed, and the role of organisms, especially microorganisms, in these techniques are illustrated.
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Affiliation(s)
- Liuwei Wang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Deyi Hou
- School of Environment, Tsinghua University, Beijing 100084, China.
| | - Yining Cao
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Yong Sik Ok
- Korea Biochar Research Center & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Filip M G Tack
- Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, Wuppertal 42285, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, 98 Gunja-Dong, Seoul, Republic of Korea
| | - David O'Connor
- School of Environment, Tsinghua University, Beijing 100084, China
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Trukhin AM, Kalinchuk VV. Hair mercury concentrations in the spotted seal (Phoca largha) pups from the Sea of Japan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:27133-27140. [PMID: 30022391 DOI: 10.1007/s11356-018-2731-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
This publication presents the results of a study of the total mercury (THg) concentration in the fetal hair (lanugo) of the young spotted seals inhabiting the Peter the Great Bay, Sea of Japan. We analyzed samples from pups that were collected in 2014-2017 at the seal breeding grounds. The concentration of total mercury was determined by atomic absorption spectrometry. The concentration of THg ranged from 1.52 to 6.68 μg/g dry weight. Mercury concentration in the lanugo exceeds that found in the environment (bottom sediments, sea water) and in other animals inhabiting the Bay. At the same time, the level was generally lower than that found in young seals of most other pinniped species (Steller sea lion Eumetopias jubatus, Northern fur seal Callorhinus ursinus, Harbor seal Phoca vitulina richardsi, Northern elephant seal Mirounga angustirostris, California sea lion Zalophus californianus) from the North Pacific.
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Affiliation(s)
- Alexey M Trukhin
- V.I.Il'ichev Pacific Oceanological Institute, FEB RAS, 43, Baltiyskaya Street, Vladivostok, Russia, 6900041.
| | - Viktor V Kalinchuk
- V.I.Il'ichev Pacific Oceanological Institute, FEB RAS, 43, Baltiyskaya Street, Vladivostok, Russia, 6900041
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Chen SC, Lin WH, Chien CC, Tsang DCW, Kao CM. Development of a two-stage biotransformation system for mercury-contaminated soil remediation. CHEMOSPHERE 2018; 200:266-273. [PMID: 29494907 DOI: 10.1016/j.chemosphere.2018.02.085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 02/13/2018] [Accepted: 02/14/2018] [Indexed: 06/08/2023]
Abstract
Utilization of bacterial volatilization can be problematic to remediate mercury (Hg)-contaminated soils because most of the Hg in soils is bound to soil particles. The objective of this study was to develop a two-stage system (chemical extraction followed by microbial reduction) for Hg-contaminated soil remediation. The tasks were to (1) select the extraction reagents for Hg extraction, (2) assess the effects of extraction reagents on the growth of Hg-reducing bacterial strains, and (3) evaluate the effectiveness of Ca2+ and Mg2+ addition on merA gene (Hg reductase) induction. Bacterial inhibition was observed with the addition of 0.1 M ethylenediaminetetraacetic acid or citric acid. Up to 65% of Hg was biotransformed (Hg concentration = 69 mg/kg) from the soils after a 24 h extraction using 0.5 M ammonium thiosulfate. Ca2+ and Mg2+ were selected because they have the same electric charge as Hg and the studied groundwater contained high concentrations of Ca2+ and Mg2+. Results showed that the addition of 200 mg/L Ca2+ or 650 mg/L Mg2+ could reach effective merA induction. In the two-stage experiment, 120 mg/kg Hg-contaminated soils were extracted with 2 rounds of extraction processes for 10 h using 0.5 M ammonium thiosulfate. Approximately 77% of Hg was extracted from the soils after the first-step extraction process. Up to 81% of Hg2+ was transformed from the washing solution via the biotransformation processes with Enterobacter cloacae addition and Ca2+ and Mg2+ supplementation. The two-stage remedial system has the potential to be developed into a practical technology to remediate Hg-contaminated sites.
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Affiliation(s)
- S C Chen
- Department of Life Sciences, National Central University, Chung-Li, Taiwan
| | - W H Lin
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - C C Chien
- Graduate School of Biotechnology & Bioengineering, Yuan Ze University, Taoyuan City, Taiwan
| | - D C W Tsang
- Department of Civil and Environmental Engr., Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan.
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Vishnivetskaya TA, Hu H, Van Nostrand JD, Wymore AM, Xu X, Qiu G, Feng X, Zhou J, Brown SD, Brandt CC, Podar M, Gu B, Elias DA. Microbial community structure with trends in methylation gene diversity and abundance in mercury-contaminated rice paddy soils in Guizhou, China. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:673-685. [PMID: 29504614 DOI: 10.1039/c7em00558j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Paddy soils from mercury (Hg)-contaminated rice fields in Guizhou, China were studied with respect to total mercury (THg) and methylmercury (MeHg) concentrations as well as Bacterial and Archaeal community composition. Total Hg (0.25-990 μg g-1) and MeHg (1.3-30.5 ng g-1) varied between samples. Pyrosequencing (454 FLX) of the hypervariable v1-v3 regions of the 16S rRNA genes showed that Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, Euryarchaeota, and Crenarchaeota were dominant in all samples. The Bacterial α-diversity was higher in samples with relatively Low THg and MeHg and decreased with increasing THg and MeHg concentrations. In contrast, Archaeal α-diversity increased with increasing of MeHg concentrations but did not correlate with changes in THg concentrations. Overall, the methylation gene hgcAB copy number increased with both increasing THg and MeHg concentrations. The microbial communities at High THg and High MeHg appear to be adapted by species that are both Hg resistant and carry hgcAB genes for MeHg production. The relatively high abundance of both sulfate-reducing δ-Proteobacteria and methanogenic Archaea, as well as their positive correlations with increasing THg and MeHg concentrations, suggests that these microorganisms are the primary Hg-methylators in the rice paddy soils in Guizhou, China.
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Stępkowski T, Banasiewicz J, Granada CE, Andrews M, Passaglia LMP. Phylogeny and Phylogeography of Rhizobial Symbionts Nodulating Legumes of the Tribe Genisteae. Genes (Basel) 2018. [PMID: 29538303 PMCID: PMC5867884 DOI: 10.3390/genes9030163] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The legume tribe Genisteae comprises 618, predominantly temperate species, showing an amphi-Atlantic distribution that was caused by several long-distance dispersal events. Seven out of the 16 authenticated rhizobial genera can nodulate particular Genisteae species. Bradyrhizobium predominates among rhizobia nodulating Genisteae legumes. Bradyrhizobium strains that infect Genisteae species belong to both the Bradyrhizobium japonicum and Bradyrhizobium elkanii superclades. In symbiotic gene phylogenies, Genisteae bradyrhizobia are scattered among several distinct clades, comprising strains that originate from phylogenetically distant legumes. This indicates that the capacity for nodulation of Genisteae spp. has evolved independently in various symbiotic gene clades, and that it has not been a long-multi-step process. The exception is Bradyrhizobium Clade II, which unlike other clades comprises strains that are specialized in nodulation of Genisteae, but also Loteae spp. Presumably, Clade II represents an example of long-lasting co-evolution of bradyrhizobial symbionts with their legume hosts.
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Affiliation(s)
- Tomasz Stępkowski
- Autonomous Department of Microbial Biology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Joanna Banasiewicz
- Autonomous Department of Microbial Biology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Camille E Granada
- Universidade do Vale do Taquari-UNIVATES, Rua Avelino Tallini, 171, 95900-000 Lajeado, RS, Brazil.
| | - Mitchell Andrews
- Faculty of Agriculture and Life Sciences, Lincoln University, P.O. Box 84, Lincoln 7647, New Zealand.
| | - Luciane M P Passaglia
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul. Av. Bento Gonçalves, 9500, Caixa Postal 15.053, 91501-970 Porto Alegre, RS, Brazil.
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Carro L, Nouioui I. Taxonomy and systematics of plant probiotic bacteria in the genomic era. AIMS Microbiol 2017; 3:383-412. [PMID: 31294168 PMCID: PMC6604993 DOI: 10.3934/microbiol.2017.3.383] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/22/2017] [Indexed: 12/20/2022] Open
Abstract
Recent decades have predicted significant changes within our concept of plant endophytes, from only a small number specific microorganisms being able to colonize plant tissues, to whole communities that live and interact with their hosts and each other. Many of these microorganisms are responsible for health status of the plant, and have become known in recent years as plant probiotics. Contrary to human probiotics, they belong to many different phyla and have usually had each genus analysed independently, which has resulted in lack of a complete taxonomic analysis as a group. This review scrutinizes the plant probiotic concept, and the taxonomic status of plant probiotic bacteria, based on both traditional and more recent approaches. Phylogenomic studies and genes with implications in plant-beneficial effects are discussed. This report covers some representative probiotic bacteria of the phylum Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes, but also includes minor representatives and less studied groups within these phyla which have been identified as plant probiotics.
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Affiliation(s)
- Lorena Carro
- School of Biology, Newcastle University, Newcastle upon Tyne, UK
| | - Imen Nouioui
- School of Biology, Newcastle University, Newcastle upon Tyne, UK
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Cozzolino V, De Martino A, Nebbioso A, Di Meo V, Salluzzo A, Piccolo A. Plant tolerance to mercury in a contaminated soil is enhanced by the combined effects of humic matter addition and inoculation with arbuscular mycorrhizal fungi. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:11312-11322. [PMID: 26931658 DOI: 10.1007/s11356-016-6337-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 02/21/2016] [Indexed: 06/05/2023]
Abstract
In a greenhouse pot experiment, lettuce plants (Lactuca sativa L.) were grown in a Hg-contaminated sandy soil with and without inoculation with arbuscular mycorrhizal fungi (AMF) (a commercial inoculum containing infective propagules of Rhizophagus irregularis and Funneliformis mosseae) amended with different rates of a humic acid (0, 1, and 2 g kg(-1) of soil), with the objective of verifying the synergistic effects of the two soil treatments on the Hg tolerance of lettuce plants. Our results indicated that the plant biomass was significantly increased by the combined effect of AMF and humic acid treatments. Addition of humic matter to soil boosted the AMF effect on improving the nutritional plant status, enhancing the pigment content in plant leaves, and inhibiting both Hg uptake and Hg translocation from the roots to the shoots. This was attributed not only to the Hg immobilization by stable complexes with HA and with extraradical mycorrhizal mycelium in soil and root surfaces but also to an improved mineral nutrition promoted by AMF. This work indicates that the combined use of AMF and humic acids may become a useful practice in Hg-contaminated soils to reduce Hg toxicity to crops.
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Affiliation(s)
- V Cozzolino
- Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agroalimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, Portici, 80055, Italy.
| | - A De Martino
- Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, Portici, 80055, Italy.
| | - A Nebbioso
- Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agroalimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, Portici, 80055, Italy
| | - V Di Meo
- Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, Portici, 80055, Italy
| | - A Salluzzo
- ENEA, Italian National Agency for New Technologies, Energy and the Environment, Centre of Research of Portici, Naples, Italy
| | - A Piccolo
- Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare per l'Ambiente, l'Agroalimentare ed i Nuovi Materiali (CERMANU), Università di Napoli Federico II, Via Università 100, Portici, 80055, Italy
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20
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Possible reasons for tolerance to mercury of Lupinus albus cv. G1 inoculated with Hg-resistant and sensitive Bradyrhizobium canariense strains. Symbiosis 2015. [DOI: 10.1007/s13199-015-0362-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Hao X, Xie P, Zhu YG, Taghavi S, Wei G, Rensing C. Copper tolerance mechanisms of Mesorhizobium amorphae and its role in aiding phytostabilization by Robinia pseudoacacia in copper contaminated soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2328-2340. [PMID: 25594414 DOI: 10.1021/es504956a] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The legume-rhizobium symbiosis has been proposed as an important system for phytoremediation of heavy metal contaminated soils due to its beneficial activity of symbiotic nitrogen fixation. However, little is known about metal resistant mechanism of rhizobia and the role of metal resistance determinants in phytoremediation. In this study, copper resistance mechanisms were investigated for a multiple metal resistant plant growth promoting rhizobium, Mesorhizobium amorphae 186. Three categories of determinants involved in copper resistance were identified through transposon mutagenesis, including genes encoding a P-type ATPase (CopA), hypothetical proteins, and other proteins (a GTP-binding protein and a ribosomal protein). Among these determinants, copA played the dominant role in copper homeostasis of M. amorphae 186. Mutagenesis of a hypothetical gene lipA in mutant MlipA exhibited pleiotropic phenotypes including sensitivity to copper, blocked symbiotic capacity and inhibited growth. In addition, the expression of cusB encoding part of an RND-type efflux system was induced by copper. To explore the possible role of copper resistance mechanism in phytoremediation of copper contaminated soil, the symbiotic nodulation and nitrogen fixation abilities were compared using a wild-type strain, a copA-defective mutant, and a lipA-defective mutant. Results showed that a copA deletion did not affect the symbiotic capacity of rhizobia under uncontaminated condition, but the protective role of copA in symbiotic processes at high copper concentration is likely concentration-dependent. In contrast, inoculation of a lipA-defective strain led to significant decreases in the functional nodule numbers, total N content, plant biomass and leghemoglobin expression level of Robinia pseudoacacia even under conditions of uncontaminated soil. Moreover, plants inoculated with lipA-defective strain accumulated much less copper than both the wild-type strain and the copA-defective strain, suggesting an important role of a healthy symbiotic relationship between legume and rhizobia in phytostabilization.
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Affiliation(s)
- Xiuli Hao
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Sciences, Northwest A&F University , Yangling, Shaanxi 712100, China
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Xie P, Hao X, Herzberg M, Luo Y, Nies DH, Wei G. Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China. J Environ Sci (China) 2015; 27:179-187. [PMID: 25597676 DOI: 10.1016/j.jes.2014.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/11/2014] [Accepted: 07/31/2014] [Indexed: 06/04/2023]
Abstract
To better understand the diversity of metal resistance genetic determinant from microbes that survived at metal tailings in northwest of China, a highly elevated level of heavy metal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria (PGPB). It shows that: Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF (Cation Diffusion Facilitator), HupE/UreJ and CHR (chromate ion transporter) family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative CopA/CueO system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while ZntA transporter, assisted with putative CzcD, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid (IAA) secretion, indicating a potential in-site phytoremediation usage in the mining tailing regions of China.
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Affiliation(s)
- Pin Xie
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China; Molecular Microbiology, Institute for Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), 06120, Germany.
| | - Xiuli Hao
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Martin Herzberg
- Molecular Microbiology, Institute for Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Yantao Luo
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Dietrich H Nies
- Molecular Microbiology, Institute for Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Gehong Wei
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
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Higueras P, Fernández-Martínez R, Esbrí JM, Rucandio I, Loredo J, Ordóñez A, Álvarez R. Mercury Soil Pollution in Spain: A Review. ENVIRONMENT, ENERGY AND CLIMATE CHANGE I 2014. [DOI: 10.1007/698_2014_280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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