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BACKGROUND & AIMS: Primary biliary cholangitis (PBC), a typical autoimmune liver disease, is characterized by an increased infiltration of immune cells. However, the specific molecular mechanisms regulating immune cell migration in PBC are unknown. Engulfment and cell motility 1 (ELMO1) plays an important function in cellular dynamics. In view of this, the aim of this study was to explore the expression of ELMO1 in PBC, its effects on the proliferation, migration, and secretion of inflammatory factors by the mainly regulated immune cells and the specific molecular mechanisms behind it. METHODS: To determine the expression of ELMO1 in PBC and its major regulatory immune cells in PBC. The migratory and proliferative capacities of ELMO1-deficient macrophages were measured, and their pro-inflammatory cytokine secretion was also detected and explored mechanistically. RESULTS: ELMO1 expression was up-regulated in the PBC patients and positively correlated with alkaline phosphatase (ALP). ELMO1 mainly regulated macrophages in the liver of PBC patients. Knockdown of ELMO1 did not affect macrophage proliferation, however,knockdown of ELMO1 significantly inhibited macrophage migration,downstream RAC1 activity was diminished, and reduced F-actin synthesis. Knockdown of ELMO1 reduced macrophage inflammatory factor secretion and NF-κB signaling pathway activity was decreased. CONCLUSIONS: ELMO1 regulates macrophage directed migration and attenuates inflammation via NF-κB signaling pathway in primary biliary cholangitis.
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INTRODUCTION: Ixodes ticks are pivotal in transmitting diseases like Lyme disease and human granulocytic anaplasmosis, caused by Borrelia burgdorferi and Anaplasma phagocytophilum, respectively. These pathogens not only affect humans through single or multiple tick bites but also pose risks to animal hosts, leading to potential coinfections. Despite regional studies indicating significant prevalence, their global coinfection data remain sparse. This study aims to bridge this gap through a systematic review and meta-analysis of B. burgdorferi and A. phagocytophilum coinfections in Ixodes ticks worldwide. Addressing data limitations and study variability, it seeks to provide a nuanced understanding of coinfection patterns, their epidemiological implications and inform targeted prevention strategies. METHODS AND ANALYSIS: Following Preferred Reporting Items for Systematic Review and Meta-analysis Protocols 2015 guidelines and PROSPERO registration, this study will undertake a thorough database search without constraints on language or publication date, using standardised screening and data extraction protocols. The quality and bias of studies will be evaluated using Joanna Briggs Institute tools. In the statistical analysis phase, conducted in R, we will initially determine the use of fixed or random-effects models based on the assessment of data heterogeneity. This choice will guide the framework for subsequent analyses. Within the selected model's framework, we will perform subgroup analyses and meta-regression to investigate the effects of various factors, ensuring that each step is tailored to the initial model selection to maintain analytical consistency. ETHICS AND DISSEMINATION: As this study does not involve clinical research or data collection from subjects, ethical approval is not required. We will uphold ethical standards in synthesising and reporting data. Study outcomes will be published in peer-reviewed journals, communicating findings to the scientific community and contributing to the understanding of Ixodes tickborne diseases. PROSPERO REGISTRATION NUMBER: CRD42023449735.
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Anaplasma phagocytophilum , Borrelia burgdorferi , Coinfección , Ixodes , Enfermedad de Lyme , Metaanálisis como Asunto , Revisiones Sistemáticas como Asunto , Anaplasma phagocytophilum/aislamiento & purificación , Ixodes/microbiología , Animales , Borrelia burgdorferi/aislamiento & purificación , Coinfección/epidemiología , Enfermedad de Lyme/epidemiología , Humanos , Prevalencia , Proyectos de Investigación , Ehrlichiosis/epidemiologíaRESUMEN
The exploration of microbial resources to reduce Pb accumulation in rice attracted great attention. In this study, we found Penicillium oxalicum SL2, a Pb-tolerant strain with good capability of dissolving phosphorus and stabilizing Pb in soil, was able to colonize on the root surface of rice seedlings without additional carbon sources, and promoted the secretion of metabolites related to amino acid metabolism, organic acid metabolism, signal transduction and other pathways in rhizosphere exudates, in which the secretion of oxalate increased by 47.7 %. However, P. oxalicum SL2 increased Fe(II) proportion and Fe availability on the root surface, resulting in iron plaque content decrease. Moreover, by converting root surface Pb from Pb-Fe state to PbC2O4 and Pb-P compounds, P. oxalicum SL2 increased Pb intercept capacity of iron plaque by 118.0 %. Furthermore, P. oxalicum SL2 regulated element distribution on the root surface, and reduced the relative content of Pb on the maturation zone of root tip, which was conducive to reducing Pb uptake by apoplastic pathway and the risk of Pb accumulation in root system. Our findings further revealed the interaction between P. oxalicum SL2 and rice root, providing a theoretical basis for the development and application of microbial agents in Pb-contaminated farmland.
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Oryza , Penicillium , Contaminantes del Suelo , Hierro/análisis , Plomo/análisis , Contaminantes del Suelo/análisis , Suelo/química , Raíces de Plantas/metabolismoRESUMEN
OBJECTIVES: Given the limited research and its potential hazards, the study aimed to determine the prevalence of Mediterranean spotted fever (MSF) caused by Rickettsia conorii (R. conorii), a tick-borne disease, in Yunnan Province, China. METHODS: Through stratified sampling across five distinct regions in Yunnan, 5358 blood samples were obtained from the general healthy population. Enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and Polymerase chain reaction (PCR) were employed for analysis. RESULTS: IFA identified 27 (0.50%) subjects with immunoglobulin G (IgG) positivity; none were positive for immunoglobulin M (IgM) via ELISA. PCR detected one individual with R. conorii outer membrane protein A (ompA). Significant seroprevalence variation was observed, particularly in Southern Yunnan (P = 0.032), with R. conorii subsp. conorii confirmed in the PCR-positive sample. CONCLUSIONS: This research reveals a correlation between MSF prevalence, geography, and climate in Yunnan. The paucity of prior studies underscores MSF's potential diagnostic challenges in the region. Comprehensive understanding of the pathogen's distribution is pivotal for intervention. Given the study's scope and Yunnan's unique setting, additional research is advocated.
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Fiebre Botonosa , Rickettsia , Humanos , Fiebre Botonosa/epidemiología , Fiebre Botonosa/diagnóstico , Estudios Seroepidemiológicos , China/epidemiologíaRESUMEN
Cd contamination in rice urgently needs to be addressed. Nano hydroxyapatite (n-HAP) is an eco-friendly material with excellent Cd fixation ability. However, due to its own high reactivity, innovative application of n-HAP in the treatment of Cd contamination in rice is needed. In this study, we proposed a new application, namely n-HAP pre-treatment, which can effectively reduce Cd accumulation in rice and alleviate Cd stress. The results showed that 80 mg/L n-HAP pre-treatment significantly reduced Cd content in rice shoot by 35.1%. Biochemical and combined transcriptomic-proteomic analysis revealed the possible molecular mechanisms by which n-HAP pre-treatment promoted rice growth and reduced Cd accumulation. (1) n-HAP pre-treatment regulated gibberellin and jasmonic acid synthesis-related pathways, increased gibberellin content and decreased jasmonic acid content in rice root, which promoted rice growth; (2) n-HAP pre-treatment up-regulated gene CATA1 expression and down-regulated gene OsGpx1 expression, which increased rice CAT activity and GSH content; (3) n-HAP pre-treatment up-regulated gene OsZIP1 expression and down-regulated gene OsNramp1 expression, which reduced Cd uptake, increased Cd efflux from rice root cells.
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Oryza , Contaminantes del Suelo , Plantones , Cadmio/metabolismo , Proteómica , Giberelinas/farmacología , Giberelinas/análisis , Giberelinas/metabolismo , Contaminantes del Suelo/metabolismo , Raíces de Plantas/metabolismoRESUMEN
The mechanisms of the P. oxalicum SL2-mediated microbial community on phosphorus solubilization and Pb stabilization were investigated through a 90-day soil experiment. In the treatments inoculated with P. oxalicum SL2, the amount of P. oxalicum SL2-GFP remained at 77.8%-138.6% of the initial inoculation amount after 90 days, and the available phosphorus (AP) content increased 21.7%-40.8% while EDTA-Pb decreased 29.9%-43.2% compared with CK treatment. SEM-EDS results showed that P. oxalicum SL2 changed the agglomeration degree of microaggregates and promoted the combination of Pb with C and O elements. These phenomena were enhanced when applied with Ca3(PO4)2. Microbial community analysis showed that P. oxalicum SL2 improved soil microbial activity, in which the fungi absolute abundance increased about 15 times within 90 days. Correlation analyses and a partial least-squares path model showed that the activation of Penicillium, Ascobolus, Humicola, and Spizellomyces in a fungal community increased the content of oxalate and AP, which directly decreased EDTA-Pb content, while the change of Bacillus, Ramlibacter, Gemmatimonas, and Candidatus Solibacter in the bacterial community regulated Fe/Mn/S/N cycle-related functions, thus promoting the conversion of Pb to oxidizable state. Our findings highlight that P. oxalicum SL2 enhanced the microbial-induced phosphate precipitation process by activating soil microbial communities and regulating their ecological functions.
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Penicillium , Fósforo , Plomo , Suelo , Ácido EdéticoRESUMEN
The morbidity and mortality associated with Alzheimer disease (AD), one of the most common neurodegenerative diseases, are increasing each year. Although both amyloid ß and tau proteins are known to be involved in AD pathology, their detailed functions in the pathogenesis of the disease are not fully understood. There is increasing evidence that neuroinflammation contributes to the development and progression of AD, with astrocytes, microglia, and the cytokines and chemokines they secrete acting coordinately in these processes. Signaling involving chemokine (C-C motif) ligand 5 (CCL5) and its main receptor C-C chemokine receptor 5 (CCR5) plays an important role in normal physiologic processes as well as pathologic conditions such as neurodegeneration. In recent years, many studies have shown that the CCL5/CCR5 axis plays a major effect in the pathogenesis of AD, but there are also a few studies that contradict this. In short, the role of CCL5/CCR5 axis in the pathogenesis of AD is still intricate. This review summarizes the structure, distribution, physiologic functions of the CCL5/CCR5 axis, and the progress in understanding its involvement in the pathogenesis of AD.
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Enfermedad de Alzheimer , Quimiocina CCL5 , Humanos , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides , Quimiocina CCL5/metabolismo , Quimiocinas , Receptores CCR5/metabolismo , Receptores de Quimiocina/metabolismoRESUMEN
Cadmium (Cd) contamination in paddy soil has become a worldwide concern and severely endangered human health. Nano hydroxyapatite (n-HAP) is a practical material to manage paddy Cd pollution, but its dosage should not be excessive. Based on previous studies, we validated the effect of n-HAP pre-treatment on rice Cd uptake in pot and field experiments. The results indicated that n-HAP pre-treatment effectively restricted Cd translocation in the soil-rice system. In pot experiment, when soil n-HAP concentration was 5000 mg/kg, the Cd content in the grains of n-HAP pre-treated rice was 0.171 mg/kg, decreased by 29.3% compared with normal rice (0.242 mg/kg). In field experiment, when soil n-HAP concentration was 20,000 mg/kg, the Cd content in the grains of n-HAP pre-treated rice was 0.156 mg/kg, decreased by 35.3% compared with normal rice (0.241 mg/kg). The primary mechanism was that n-HAP pre-treatment altered the formation and composition of iron plaque and therefore enhanced the Cd binding ability of iron plaque. The available N and P content and urease activity in paddy field were increased. We further investigated the impact of n-HAP on the diversity and structure of paddy microbial communities. The Chao1 and Shannon diversity indices showed no significant difference. The relative abundance of Actinobacteria and Proteobacteria was significantly decreased by n-HAP, indicating that Cd pollution might be alleviated. Desulfobacterota, Gemmatimonadota, and Geobacteraceae were significantly enriched by n-HAP. The declining relative abundance of Basidiomycota and the increasing relative abundance of other fungal taxa also suggested that n-HAP could alleviate Cd toxicity in soil.
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Oryza , Contaminantes del Suelo , Humanos , Cadmio/análisis , Oryza/química , Contaminantes del Suelo/análisis , Hierro/metabolismo , Suelo/química , Bacterias/metabolismoRESUMEN
The validity of USEPA Method 3060A as universal Cr(VI) analysis method for remediated soil is controversial. We investigated soil Cr(VI) remediation performance by commonly used reductants (FeSO4, CaSx, Na2S) under different operating conditions (dosage, curing time and degree of mixing) using Method 3060A, and developed modified 3060A specific for sulfide-based reductants. Results showed that Cr(VI) was primarily removed during analysis stage rather than remediation stage. Thereinto, chemical dosage played a much more important role than curing time and degree of mixing. Besides, soil Cr(VI) concentration decreased to below the detection limit with residual reductant content increasing. Comparing standard and toluene-mercuric modified 3060A, Cr(VI) removal efficiency decreased from 100 % to 38.9-45.4 %, 67.1-68.8 % and 94.1-96.3 %, corresponding to mixing degree of 33 %, 67 % and 100 %, for treated soil using 1× and 2× the molar stoichiometric ratio of CaSx. Subsequently, the optimization mechanism was revealed. Elemental sulfur, remediation product of sulfide-based reductants, was removed from soil by toluene preventing its disproportionation to sulfide at Method 3060A stage. Sulfide was fixed by mercuric oxide in species of mercuric sulfide. This method also proved suitable for different types of soils. Therefore, an effective way for scientific evaluation of soil Cr(VI) remediation was provided in this study.
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As a potential bioremediation strain for Pb contamination, Penicillium oxalicum SL2 sometimes has secondary activation of Pb, so it is crucial to clarify its effect on Pb morphology and its intracellular response to Pb stress. We investigated the effect of P. oxalicum SL2 in medium on Pb2+ and Pb availability in eight minerals, and revealed the prioritization of Pb products. (i)Pb was stabilized within 30 days as Pb3(PO4)2 or Pb5(PO4)3Cl with sufficient phosphorus (P); (ii) under P deficiency but sulfur (S) sufficient, Pb was stabilized mainly in the form of PbSO4; (iii) under conditions of P and S deficiency, Pb was stabilized mainly in the form of PbC2O2. With the help of proteomic and metabolomics analysis, a total of 578 different proteins and 194 different metabolites were found to be matched in 52 pathways. Among them, the activation of chitin synthesis, oxalate production, sulfur metabolism and transporters improved the Pb tolerance of P. oxalicum SL2, and promoted the synergistic effect of extracellular adsorption, bio-precipitation and transmembrane transport on Pb stabilization. Our results fill the gap in the intracellular response of P. oxalicum SL2 to Pb and provide new insights into the development of bioremediation agent and technology for Pb contamination.
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Biodegradación Ambiental , Plomo , Penicillium , Adsorción , Plomo/metabolismo , Proteómica , Azufre/metabolismoRESUMEN
Nowadays, Lead (Pb) and Cadmium (Cd) contamination in rice is an important worldwide environmental concern. Fe3O4 nanoparticles (Fe3O4 NPs) and Nano hydroxyapatite (n-HAP) are promising materials to manage Pb and Cd contamination. This study systematically investigated the effect of Fe3O4 NPs and n-HAP on Pb and Cd stressed rice seedlings' growth, oxidative stress, Pb and Cd uptake and subcellular distribution in roots. Furthermore, we clarified the immobilization mechanism of Pb and Cd in the hydroponic system. Fe3O4 NPs and n-HAP could reduce Pb and Cd uptake of rice mainly through decreasing Pb and Cd concentrations in culture solution and combining with Pb and Cd in root tissues. Pb and Cd were immobilized by Fe3O4 NPs through complex sorption processes and by n-HAP through dissolution-precipitation and cation exchange, respectively. On the 7th day, 1000 mg/L Fe3O4 NPs reduced the contents of Pb and Cd in shoots by 90.4% and 95.8%, in roots by 23.6% and 12.6%, 2000 mg/L n-HAP reduced the contents of Pb and Cd in shoots by 94.7% and 97.3%, in roots by 93.7% and 77.6%, respectively. Both NPs enhanced the growth of rice seedlings by alleviating oxidative stress and upregulating glutathione secretion and antioxidant enzymes activity. However, Cd uptake of rice was promoted at certain concentrations of NPs. The subcellular distribution of Pb and Cd in roots indicated that both NPs decreased the percentage of Pb and Cd in the cell wall, which was unfavorable for Pb and Cd immobilization in roots. Cautious choice was needed when using these NPs to manage rice Pb and Cd contamination.
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Nanopartículas , Oryza , Contaminantes del Suelo , Plantones , Cadmio/análisis , Plomo/toxicidad , Antioxidantes/farmacología , Raíces de Plantas/química , Contaminantes del Suelo/farmacologíaRESUMEN
Excess chromium (Cr) and arsenic (As) coexist in soil such as chromated copper arsenate (CCA) contaminated sites, leading to high risks of pollution. Fe-biochar with adjustable redox activity offers the possibility of simultaneous stabilization of Cr and As. Here, a series of Fe-biochar with distinct Fe/C structure were rationally produced for the remediation of Cr and As contaminated soil (BCX-Fe, X represented the biomass/Fe ratio). Adsorption tests showed that maximal adsorption of BC5-Fe for Cr(VI) and As(III) reached 73.7 and 81.3 mg/g. A 90-day soil remediation experiment indicated that the introduction of 3% (w/w) Fe-biochar reduced the leaching state of Cr(VI) by 93.8-99.7% and As by 75.2-95.6%. Under simulated groundwater erosion for 10 years and acid rain leaching for 7.5 years, the release levels of Cr(VI) and As in the BC5-Fe remediated soil could meet the groundwater class IV standard in China (Cr(VI)<0.1 mg/L, As<0.05 mg/L). Accelerated aging tests demonstrated that BC5-Fe had long-term Cr and As stabilization ability. The quenching experiment, EPR, and XPS suggested that the corrosion products of Fe dominated the adsorption and redox reactions, while the O groups acted as electron transfer stations and constituted redox microcirculation in the synchronous uptake of Cr/As. Based on these insights, we believe that our study will provide meaningful information about the application potential of Fe-biochar for the heavy metal contaminated soil remediation.
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Arsénico , Contaminantes del Suelo , Suelo , Carbón Orgánico/química , Cromo/análisis , Contaminantes del Suelo/análisis , AdsorciónRESUMEN
The toxic chemical element cadmium (Cd) in paddy fields triggered increasing problems of growth inhibition and food security in rice consistently. In this study, we found Metarhizium robertsii, which is widely used as a bioinsecticide and biofertilizer in agriculture and recently found to be resistant to Cd, developed intraradical and extraradical symbiotic hyphae in rice seedlings, and successfully colonized in the rice rhizosphere soil to more than 103 CFUs g-1 soil at harvesting. M. robertsii colonization significantly reduced Cd accumulations in both hydroponically cultured seedlings and the matured rice cultured in Cd contaminated potting soil (2 ppm). Notably, Cd accumulation reduction of the roots, stems, leaves, husks and grains of the matured rice induced by the fungus were 44.3%, 32.1%, 35.3%, 31.9% and 24.7%, respectively. It was caused by the M. robertsii-induced suppression of Cd intake transporter gene osNramp5 in the rice roots, and the chemical stabilizing of Cd to the residual fraction in the rhizosphere soil. In addition, the colonization of M. robertsii significantly promoted the growth characters and the photosynthesis of the rice plants. This is achieved by the increase of endogenous hormone levels of indole-3-acetic, gibberellin A3 and brassinolide induced by M. robertsii. Furthermore, the fungus enhanced the antioxidative capacities via increasing enzyme activities of catalase, peroxidase and the production of glutathione, ascorbic acid, proline in the rice plants. Our work provides theoretical basis for expanding the use of M. robertsii as in situ Cd accumulation reduction and detoxification agents for rice in contaminated paddy fields.
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Oryza , Contaminantes del Suelo , Cadmio/análisis , Metarhizium , Oryza/genética , Raíces de Plantas/química , Plantones , Suelo , Contaminantes del Suelo/análisisRESUMEN
Due to the high migration capacity in agricultural soil-crop systems, cadmium (Cd) is accumulated in various crops and severely inhibits plant growth. In this study, we showed that, under Cd stress, the plant-symbiotic fungus Metarhizium robertsii reduced Cd accumulation in Arabidopsis thaliana shoots and roots by 21.8 % and 23.8 %, respectively. This is achieved by M. robertsii colonization-induced elevation of Cd efflux capacity via upregulation of three PCR genes, which is confirmed by the fact that the extent to which M. robertsii reduced Cd accumulation in the WT plants was greater than the inactivating mutants of the PCR genes. M. robertsii also alleviated Cd-induced leaf etiolation in A. thaliana by increasing the chlorophyll amount and modified plant physiological status to increase Cd stress tolerance via increasing production of catalase, peroxidase and glutathione and upregulating multiple HIPP proteins involved in sequestration of Cd. Notably, consistent with that in A. thaliana, the colonization of M. robertsii also reduced the Cd accumulation in Oryza sativa seedlings by upregulating the PCR gene OsPCR1, and increased chlorophyll amount and alleviated oxidative stress. Therefore, M. robertsii colonization reduced Cd accumulation in plants, and promoted plant growth and health by elevating Cd efflux capacity and modifying physiological status.
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Arabidopsis , Oryza , Antioxidantes/metabolismo , Arabidopsis/metabolismo , Cadmio/metabolismo , Cadmio/toxicidad , Clorofila/metabolismo , Metarhizium , Oryza/metabolismo , Estrés Oxidativo , Raíces de Plantas/metabolismo , Plantones/metabolismo , Estrés FisiológicoRESUMEN
Copper oxide nanoparticles (CuO NPs) are widely used as fungicides in agriculture. Arsenic (As) is a ubiquitous contaminant in paddy soil. The present study was focused on the adsorption behavior of CuO NPs with regard to As as well as the characteristics of the microbial community changes in As-contaminated soil-rice systems in response to CuO NPs. The study found that CuO NPs could be a temporary sink of As in soil; a high dose of CuO NPs promoted the release of As from crystalline iron oxide, which increased the As content in the liquid phase. The study also found that the As bioavailability changed significantly when the dose of CuO NPs was higher than 50 mg kg-1 in the soil-rice system. The addition of 100 mg kg-1 CuO NPs increased the microbial diversity and the abundance of genes involved in As cycling, decreased the abundance of Fe(III)-reducing bacteria and sulfate-reducing genes, and decreased As accumulation in grains. Treatment with 500 mg kg-1 CuO NPs increased the abundance of Fe(III)-reducing bacteria and sulfate-reducing genes, decreased Fe plaques, and increased As accumulation in rice. The adverse effects of CuO NPs on crops and associated risks need to be considered carefully.
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Arsénico , Nanopartículas del Metal , Nanopartículas , Oryza , Contaminantes del Suelo , Adsorción , Arsénico/análisis , Bacterias/genética , Cobre/química , Compuestos Férricos , Nanopartículas del Metal/química , Óxidos , Suelo/química , Contaminantes del Suelo/química , SulfatosRESUMEN
Penicillium oxalicum SL2 (SL2) is a previously screened Pb-tolerant fungus that can promote crops growth. The relationship between SL2 colonization and Pb immobilization was studied to provide a theoretical basis for microbial remediation of Pb-contaminated paddy soil. In this study, green fluorescent protein (GFP) labeled SL2 was inoculated into different Pb-contaminated paddy soils (S1-S6). The Pb extracted from the soil by HNO3, EDTA and CaCl2 were used to characterize the available Pb. The results showed that the colonization of SL2 was divided into lag phase (0-7 days), growth phase (7-30 days), and mortality phase (30-90 days). SL2 colonized well in sandy soils rich in clay and total phosphorus with initial pH of 4.5-7.0. In addition, SL2 increased soil pH and decreased soil Eh, which was beneficial to immobilize Pb. In different soils, the highest percentages of CaCl2-Pb, EDTA-Pb, and HNO3-Pb immobilized by SL2 were 34.34%-40.53%, 17.05%-20.11%, and 7.39%-15.62%, respectively. Pearson correlation analysis showed that the percentages of CaCl2-Pb and EDTA-Pb immobilized by SL2 were significantly positively correlated with the number of SL2 during the growth phase. SL2 mainly immobilized Pb in the growth phase and a higher peak number of SL2 was beneficial to the immobilization of Pb.
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Contaminantes del Suelo , Suelo , Cloruro de Calcio , Ácido Edético , Plomo/análisis , Penicillium , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
Heavy metal contamination in agricultural soil and its associated risk of food safety are of great concern globally. It is therefore an urgent need to develop sustainable option to mitigate the accumulation of metals in crop plants. Here we investigated the potential of phosphorus-solubilizing fungus, Penicillium oxalicum SL2, on regulating the bioavailability of Pb in a lead (Pb) polluted soil-rice system. Our results showed that the content of Pb in rice grain was significantly decreased by ~80% with the application of P. oxalicum SL2. The competition between oxalate and phosphate for the complexation of Pb showed to be effective in mediating the bioavailability of Pb, and such impact varied with water fluctuation in paddy soil. The solubilization of phosphorus also played an important role in alleviating the dissolution of iron plaque caused by oxalic acid, which helped maintaining the biomass of iron plaque as a barrier to the uptake of Pb by root. The predominant indigenous microbial community was not affected by the inoculation with P. oxalicum SL2, suggesting it as an eco-friendly strain. Therefore, we suggest P. oxalicum SL2 as a promising fungus in enhancing the safe use of moderately Pb polluted paddy soil for safe rice.
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Oryza , Penicillium , Contaminantes del Suelo , Cadmio/análisis , Plomo , Suelo , Contaminantes del Suelo/análisisRESUMEN
Multiple potentially toxic elements (PTEs) wastes are produced in the process of electroplating, which pollute the surrounding soils. However, the priority pollutants and critical risk factors in electroplating sites are still unclear. Hence, a typical demolished electroplating site (operation for 31â¯years) in the Yangtze River Delta was investigated. Results showed that the soil was severely polluted by Cr(VI) (1711.3â¯mgâ¯kg-1), Ni (6754.0â¯mgâ¯kg-1) and Pb (2784.4â¯mgâ¯kg-1). The spatial distribution of soil PTEs performed by ArcGIS illustrated that the soil pollution varied with plating workshops. Hard Cr electroplating workshops (HCE), decorative Cr electroplating workshops (DCE) and sludge storage station (SS) were the hot spots in the site. Besides, the toxicity characteristic leaching procedure (TCLP) - extractable Cr and Ni contents in different workshops were significantly related (Pâ¯<â¯0.05) to their bioavailable fractions (exchangeable fraction (F1)â¯+â¯bound to carbonate fraction (F2)), which pose potential risk to humans. Although the soil total Pb concentration was high, its mobility was very low (<0.007%). Moreover, the soil microbial community dynamics under the stress of long term and high contents of PTEs were further revealed. The soil microbiota was significantly disturbed by long term and high concentration of PTEs. A bit of bacteria (Caulobacter) and fungi (Cladosporium and Monocillium) showed tolerance potential to multiple metals. Furthermore, the canonical correspondence analysis (CCA) showed that the bioavailable fractions (F1â¯+â¯F2) of Cr and Ni were the most critical environmental variables affecting microbiota. Therefore, remediation strategies are required urgently to reduce the bioavailability of soil Cr and Ni. The results of this study provide an overview of the pollution distribution and microbial dynamics of a typical plating site, laying a foundation for ecological remediation of electroplating sites in Yangtze River Delta of China.
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Metales Pesados , Microbiota , Contaminantes del Suelo , China , Galvanoplastia , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisisRESUMEN
Copper oxide nanoparticles (CuO NPs) are widely used as a fungicide in agriculture. The application of CuO NPs in agriculture affects the growth of rice and metal accumulation in rice. However, the mechanism of CuO NPs on arsenic (As) accumulation in rice remains unclear. In this study, a hydroponic culture was produced to investigate the mechanism of the effect of 50 and 100 mg L-1 CuO NPs on As accumulation in rice. Our results showed that CuO NPs decreased As(III/V) accumulation in the roots and shoots by adsorbing As(III/V), oxidizing of As(III) on the surface, and thickening the root cell wall. The addition of CuO NPs regulated the expression of the OsNIP1;1, OsHAC1;1, and OsHAC4 genes, which decreased As(III) transport and promoted As(V) reduction in the roots. Moreover, when CuO NPs were co-exposed to As, a negative correlation between the concentration of Cu and As in rice was also found in our study. However, CuO NPs significantly increased Cu accumulation in rice and constrained the rice growth. In conclusion, CuO NPs might be a promising way to decrease As accumulation in rice, but the negative effects such as growth inhibition should be further considered. Therefore, the application of CuO NPs in rice plants should take a more restrained approach.