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1.
Ecotoxicol Environ Saf ; 214: 112119, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714137

RESUMEN

Rice cultivation under cadmium (Cd) contaminated soil often results in reduced growth with excess grain Cd concentrations. A pot experiment was conducted to assess the potential of ultrasonic seed treatment to alleviate Cd stress in rice. Seeds of two aromatic rice cultivars i.e., Xiangyaxiangzhan and Meixiangzhan 2 and two non-aromatic rice cultivars i.e., Huahang 31 and Guangyan 1 were exposed to ultrasonic waves for 1.5 min in 20-40 KHz mixing frequency. The experimental treatments were comprised of untreated seeds (U0) and ultrasonic treated seeds (U1) transplanted in un-contaminated soil (H0) and Cd-contaminated soil (H1). Results revealed that Cd contents and Cd accumulation in grain in U1 were 33.33-42.31% and 12.86-57.58% lower than U0 for fragrant rice cultivars under H1. Meanwhile, biomass production was higher in U1 than U0 under H0 and better yield was assessed in U1 for all cultivars under H1. The activity of peroxidase (POD) in flag leaves was increased by 8.28-115.65% for all cultivars while malondialdehyde (MDA) contents were significantly decreased in U1 compared with U0 under H0. Conclusively, ultrasonic treatment modulated Cd distribution and accumulation in different parts while improved physiological performance as well as yield and grain quality of rice under Cd contaminated conditions.


Asunto(s)
Cadmio/metabolismo , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Contaminantes del Suelo/metabolismo , Ondas Ultrasónicas , Grano Comestible/crecimiento & desarrollo , Grano Comestible/metabolismo , Malondialdehído/metabolismo , Peroxidasas/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Semillas/crecimiento & desarrollo
2.
Ecotoxicol Environ Saf ; 214: 112125, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714138

RESUMEN

Phytomanagement is proposed as a cost-effective and environmentally-friendly suggestion for sustainable use of large metal-contaminated areas. In the current work, the energy crop miscanthus (Miscanthus × giganteus) was grown in ex situ conditions on agricultural soils presenting a Cd, Pb and Zn contamination gradient. After 93 days of culture, shoot and root growth parameters were measured. Soils and plants were sampled as well to study the TE accumulation in miscanthus and the effects of this plant on TE mobility in soils. Results demonstrated that miscanthus growth depended more on the soils silt content rather than TE-contamination level. Moreover, soil organic carbon at T93 increased in the soils after miscanthus cultivation by 25.5-45.3%, whereas CaCl2-extractible TEs decreased due to complex rhizosphere processes driving plant mineral uptake, and organic carbon inputs into the rhizosphere. In the contaminated soils, miscanthus accumulated Cd, Pb and Zn mainly in roots (BCF in roots: Cd " Zn > Pb), while strongly reducing the transfer of these elements from soil to all organs and from roots to rhizomes, stems and leaves (average TFs: 0.01-0.06, 0.11-1.15 and 0.09-0.79 corresponding to Cd, Pb and Zn respectively). Therefore, miscanthus could be considered a TE-excluder, hence a potential candidate crop for coupling phytostabilization and biomass production on the studied Metaleurop TE-contaminated soils.


Asunto(s)
Metales Pesados/metabolismo , Poaceae/metabolismo , Contaminantes del Suelo/metabolismo , Biodegradación Ambiental , Biomasa , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/metabolismo , Poaceae/crecimiento & desarrollo , Rizosfera
3.
Ecotoxicol Environ Saf ; 214: 112112, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714140

RESUMEN

Sole biochar addition or microbial inoculation as a soil amendment helps to reduce cadmium (Cd) toxicity in polluted agricultural soils. Yet the synergistic effects of microorganisms and biochar application on Cd absorption and plant productivity remain unclear. Therefore, a pot experiment was conducted to investigate the combined effect of microorganisms (Trichoderma harzianum L. and Bacillus subtilis L.), biochar (maize straw, cow manure, and poultry manure), and Cd (0, 10, and 30 ppm) on plant physiology and growth to test how biochar influences microbial growth and plant nutrient uptake, and how biochar ameliorates under Cd-stressed soil. Results showed that in comparison to non-Cd polluted soil, the highest reduction in chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency, and intercellular CO2 were observed in Cd2 (30 ppm), which were 9.34%, 22.95%, 40.45%, 29.07%, 20.67%, and 22.55% respectively less than the control Cd0 (0 ppm). Among sole inoculation of microorganisms, highest stomatal conductance, water use efficiency, and intercellular CO2 were recorded with combined inoculation of both microorganisms (M3), which were 5.92%, 7.65%, and 7.28% respectively higher than the control, and reduced the Cd concentration in soil, root, and shoot by 21.34%, 28.36%, and 20.95%, respectively, compared to the control. Similarly, co-application of microorganisms and biochar ameliorated the adverse effect of Cd in soybean as well as significantly improved plant biomass, photosynthetic activity, nutrient contents, and antioxidant enzyme activities, and minimized the production of reactive oxygen species and Cd content in plants. Soil amended with poultry manure biochar had significantly improved the soil organic carbon, total nitrogen, total phosphorous, and available potassium by 43.53%, 36.97%, 22.28%, and 4.24%, respectively, and decreased the concentration of Cd in plant root and shoot by 34.68% and 47.96%, respectively, compared to the control. These findings indicate that the combined use of microorganisms and biochar as an amendment have important synergistic effects not only on the absorption of nutrients but also on the reduction of soybean Cd intake, and improve plant physiology of soybean cultivated in Cd-polluted soils as compared to sole application of microorganisms or biochar.


Asunto(s)
Bacillus subtilis , Cadmio/análisis , Carbón Orgánico , Hypocreales , Contaminantes del Suelo/análisis , Soja/crecimiento & desarrollo , Soja/metabolismo , Cadmio/metabolismo , Estiércol , Nitrógeno/metabolismo , Fósforo/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Potasio/metabolismo , Contaminantes del Suelo/metabolismo , Zea mays
4.
Ecotoxicol Environ Saf ; 214: 112019, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33639494

RESUMEN

Cd is a common pollutant that contaminates the ecological environment of soil-crop systems and threatens food security and human health. Sorghum (Sorghum bicolor (L.) Moench) has a great potential for use as energy feedstock and Cd phytoremediation. Therefore, the identification of sorghum genotypes with high Cd accumulation is of great significance to Cd pollution remediation and production of bioenergy. A total of 126 biomass sorghum genotypes grown in a Cd-polluted field were investigated, and their agronomic traits were analyzed, including plant height, leaf number, shoot dry weight (SDW), soil and plant analyzer development (SPAD) value, and concentration of metal ions at seedling stage. Plant height was an important factor for screening potential biomass sorghum species because it presented a significant correlation with the Cd concentration in shoots and SDW (P < 0.01). The highest and lowest Cd concentration in sorghum shoots were 7.88 and 0.99 mg kg-1, respectively. The Cd concentration presented a negative and significant correlation with Mn in sorghum shoots (r = -0.303, P < 0.01), which was in agreement with the results that sorghum species with high Cd concentrations have lower Mn concentrations. In the mature stage, sorghum 12530 presented higher Cd concentration and dry weight in shoots compared with other genotypes. In summary, plant height, SDW, and concentration of Mn in sorghum shoots are critical parameters that synthetically influence the accumulation of Cd in sorghum shoots.


Asunto(s)
Cadmio/metabolismo , Contaminantes del Suelo/metabolismo , Biodegradación Ambiental , Biomasa , Cadmio/análisis , Grano Comestible/química , Restauración y Remediación Ambiental , Genotipo , Humanos , Fenotipo , Desarrollo de la Planta , Hojas de la Planta/química , Plantones/química , Suelo , Contaminantes del Suelo/análisis , Sorghum/crecimiento & desarrollo
5.
Ecotoxicol Environ Saf ; 212: 112014, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33548569

RESUMEN

The biosorption and bioaugmentation performances of Mucor circinelloides were investigated under different contact time, initial metal(loid) concentration and species. The microbe-plant interaction appeared synergistic with enhancing plant growth and alleviating oxidative damages induced by lead, cadmium and arsenic. The bioaugmentation with M. circinelloides led to significant immobilization on lead, cadmium and arsenic as indicated by the decreases of metal(loid) transfer and bioavailability in plant-microbe aqueous system. Lead, cadmium and arsenic were mainly allocated on cell wall and a few parts entered into intercellular system, suggesting cell wall adsorption and intracellular bioaccumulation served as the main mechanisms of M. circinelloides. The adsorption kinetics and isotherms on lead, cadmium and arsenic were fitted well with the pseudo-second-order and Langmuir models, with the maximum adsorption capacities of 500, 15.4 and 29.4 mg·g-1 fungal biomass at pH 6.0 and 25 â„ƒ. The optimum initial concentration and contact time were 300-10-20 mg·L-1 and 2 h. This study provides a basis for M. circinelloides as a promising adsorbent and bioaugmented agent for the cleanup of soil/aqueous environment contaminated with lead, cadmium and arsenic.


Asunto(s)
Arsénico/metabolismo , Cadmio/metabolismo , Plomo/metabolismo , Mucor/metabolismo , Contaminantes del Suelo/metabolismo , Solanum nigrum , Adsorción , Arsénico/análisis , Bioacumulación , Biodegradación Ambiental , Disponibilidad Biológica , Biomasa , Cadmio/análisis , Concentración de Iones de Hidrógeno , Cinética , Plomo/análisis , Modelos Teóricos , Mucor/crecimiento & desarrollo , Contaminantes del Suelo/análisis , Solanum nigrum/metabolismo , Solanum nigrum/microbiología
6.
Ecotoxicol Environ Saf ; 212: 112016, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33550079

RESUMEN

The effects of Bacillus subtilis inoculation on the growth and Cd uptake of alfalfa were evaluated in this research using pot experiments, and the relevant biochemical mechanisms were first investigated by combined microbial diversity and nontarget metabolomics analyses. The results indicated that inoculation with alfalfa significantly decreased the amount of plant malondialdehyde (MDA) and improved the activities of plant antioxidant enzymes and soil nutrient cycling-involved enzymes, thereby promoting biomass by 29.4%. Inoculation also increased Cd bioavailability in rhizosphere soil by 12.0% and Cd removal efficiency by 139.3%. The biochemical mechanisms included enhanced bacterial diversity, transformed microbial community composition, regulated amounts of amino acids, fatty acids, carbohydrates, flavonoids and phenols in rhizosphere soil metabolites, and modulations of the corresponding Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These responses were beneficial to microbial activity, nutrient cycling, and Cd mobilization, detoxification, and decontamination by alfalfa in soil. This study, especially the newly identified differential metabolites and metabolic pathways, provides new insights into mechanism revelation and strategy development in microbe-assisted phytomanagement of heavy metal-contaminated soils.


Asunto(s)
Bacillus subtilis/metabolismo , Cadmio/metabolismo , Medicago sativa/metabolismo , Rizosfera , Contaminantes del Suelo/metabolismo , Bacillus subtilis/crecimiento & desarrollo , Biodegradación Ambiental , Biodiversidad , Biomasa , Cadmio/análisis , Medicago sativa/microbiología , Metabolómica , Suelo/química , Microbiología del Suelo , Contaminantes del Suelo/análisis
7.
Ecotoxicol Environ Saf ; 212: 112009, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33556811

RESUMEN

Cu pollution is a problem in mining areas in Peru. Here we evaluate the phytoextraction capacity, physiological and proteomic responses of four species growing in copper-contaminated areas in Arequipa, Peru. The plants used in the experiments were obtained by collecting seedlings (Tessaria integrifolia, Bacharis salicifolia), rhizomes (Eleocharis montevidensis) and seeds (Chenopodium murale) along a polluted river. They were exposed to solutions containing 2, 4, 8, 16 and 32 mg Cu L-1 during 20 days. Growth was affected in a concentration-dependent way. According to the tolerance index, B. salicifolia and C. murale were the most sensitive species, but with greater Cu phytoextraction capacity and accumulation in the biomass. The content and ratio of photosynthetic pigments changed differently for each specie and carotenoids level were less affected than chlorophyll. Cu also induced changes in the protein and sugar contents. Antioxidant enzyme activities (catalase and superoxide dismutase) increased with a decrease in the malondialdehyde. There were marked changes in the protein 2D-PAGE profiles with an increase in the abundance of metallothioneins (MT) of class II type I and II. Our results suggest that these species can grow in Cu polluted areas because they developed multiple tolerance mechanisms, such as and MTs production seems a important one.


Asunto(s)
Adaptación Biológica/efectos de los fármacos , Cobre/toxicidad , Contaminantes Ambientales/toxicidad , Metalotioneína/metabolismo , Desarrollo de la Planta/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Antioxidantes/metabolismo , Biodegradación Ambiental , Biomasa , Clorofila/metabolismo , Cobre/metabolismo , Contaminantes Ambientales/metabolismo , Minería , Perú , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Proteómica , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Contaminantes del Suelo/metabolismo , Especificidad de la Especie
8.
Ecotoxicol Environ Saf ; 213: 112023, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33578096

RESUMEN

Arbuscular mycorrhizal fungi (AMF) play an important role in improving plant tolerance and accumulation of zinc (Zn) and cadmium (Cd). The growth, physiology and absorption of elements and transport in Phragmites australis (P. australis) were investigated under Zn and Cd stress to identify the transport mechanisms of toxic trace elements (TE) under the influence of AMF. Thus, AMF were observed to alleviate the toxic effects of Zn and Cd on P. australis by increasing plant biomass and through different regulatory patterns under different TE concentrations. The activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) increased under Zn stress, and the activities of SOD, catalase (CAT), peroxidase (POD), and APX significantly increased under high concentrations of Cd. AMF differ in their strategies of regulating the transport of different metals under TE stress. Under Zn stress, the concentration of Zn in P. australis decreased by 10-57%, and the effect on Zn translocation factor (TFZn) was concentration-dependent. AMF increased the TFZn under low concentration stress, but decreased under high concentration stress. Under Cd stress, the concentration of Cd increased by as much as 17-40%, and the TFCd decreased. AMF were also found to change the interaction of Zn×Cd. In the absence of AMF, Cd exposure decreased the Zn concentrations in P. australis at Zn100 mg/L and Zn300 mg/L, while it increased the contents of Zn at Zn700 mg/L. The opposite trend was observed following treatment with AMF. However, regardless of the concentration of Cd, the addition of Zn decreased the concentration of Cd in both treatments in both the presence and absence of AMF. Under different TE stress conditions, the regulation of metal elements by AMF in host plants does not follow a single strategy but a trade-off between different trends of transportations. The findings of our study are important for applying AMF-P. australis systems in the phytoremediation of Zn-Cd co-contaminated ecosystems.


Asunto(s)
Micorrizas/fisiología , Poaceae/fisiología , Contaminantes del Suelo/toxicidad , Biodegradación Ambiental , Biomasa , Cadmio/metabolismo , Cadmio/toxicidad , Ecosistema , Raíces de Plantas/efectos de los fármacos , Plantas/efectos de los fármacos , Poaceae/efectos de los fármacos , Poaceae/microbiología , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Oligoelementos/metabolismo , Oligoelementos/toxicidad , Zinc/farmacología
9.
Ecotoxicol Environ Saf ; 213: 112042, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33607336

RESUMEN

Aluminum (Al) toxicity severely decreases plant growth and productivity in acidic soil globally. Ectomycorrhizal (ECM) fungi can promote host plant's Al-tolerance by acting as a physical barrier or bio-filter. However, little information is available on the role of ECM fungus on Al immobilization with respect to Al-tolerance. This present study aimed to screen a promising indigenous ECM fungus with high Al-tolerance and to understand its role in Al immobilization related to Al-tolerance. Two ECM fungal strains (Lactarius deliciosus 2 and Pisolithus tinctorius 715) isolated from forest stands in Southwest China were cultured in vitro with 0.0, 1.0 or 2.0 mM Al addition for 21 days to compare their Al accumulation and Al-tolerance. Meanwhile, fungal mycelia were incubated in 0.037 mM Al3+ solutions, and then Al3+ concentrations in the solution were determined at time 2, 5, 10, 20, 40, 60, 120, 180, and 240 min, and the Al3+ immobilization characteristics were evaluated using the pseudo-first order, pseudo-second order and intraparticle diffusion models. Results showed that 1.0 or 2.0 mM Al3+ addition significantly increased fungal biomass production by 23% or 41% in L. deliciosus 2, not in P. tinctorius 715. Fungal Al3+ concentrations in L. deliciosus 2 and P. tinctorius 715 were significantly increased by 293% and 103% under 2.0 mM than under 1.0 mM Al3+ addition. The pH values in the culture solution were significantly decreased by 0.43 after 21 d fungus growth but no changes between these two fungi under the same Al3+ addition. Fungal Al3+ immobilization showed a three-stage trend with initially a rapid rate followed a relatively slower rate until reaching equilibrium. The pseudo-second order model was the best (R2 = 0.98 and 0.99 for L. deliciosus 2 and P. tinctorius 715) to fit the experimentally observed data among the three models. Compared to P. tinctorius 715, L. deliciosus 2 also had greater intercept value, cation exchange capacity (CEC), and extracellular Al3+ proportion in fungal mycelia. Additionally, bio-concentration on Al3+, active site numbers for Al3+, boundary layer thickness, CEC, and immobilization on the cell wall in fungal mycelia were involved in ECM fungal Al-tolerance. These results show that both ECM fungi are Al-tolerant while L. deliciosus 2 is a promising indigenous ECM isolate with higher Al-tolerance in Southwest China, and they can be hence applied to the afforestation and ecological restoration in acidic soil.


Asunto(s)
Aluminio/metabolismo , Basidiomycota/fisiología , Contaminantes del Suelo/metabolismo , Agaricales , Basidiomycota/crecimiento & desarrollo , Biodegradación Ambiental , Biomasa , China , Bosques , Micelio/crecimiento & desarrollo , Micorrizas/crecimiento & desarrollo , Micorrizas/fisiología , Suelo/química , Microbiología del Suelo
10.
Ecotoxicol Environ Saf ; 213: 112039, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33636469

RESUMEN

Chlorpyrifos (O, O-diethyl O-3, 5, 6-trichloropyridin-2-yl phosphorothioate) is a toxic and chlorinated organic contaminant in soils across the globe. The present study examines the chlorpyrifos (CP) degrading potential of gram-negative bacterium Dyadobacter jiangsuensis (MTCC 12851), to be a promising and sustainable remedial approach. The proliferation of D. jiangsuensis in the chlorpyrifos spiked minimal salt media indicated the ability of this strain to utilize CP as a sole carbon source and also confirmed the utilization of 3,5,6- trichloro-2-pyridinyl (TCP) through silver nitrate assay. The strain 12851 degraded 80.36% and 76.93% chlorpyrifos (CP) in aqueous medium and soil environment, respectively. The water dispersible granules (WDG) of 45% (v/w) inoculum (bacterial suspension) were developed using talcum powder, acacia gum and alginic acid as key ingredients. The formulated strain (12851) achieved 21.13% enhanced CP degradation in soil under microcosm condition as compared to the unformulated one on 15th day of the treatment. The intermediate metabolites namely 3,5,6-trichloro-2-pyridinol (TCP), tetrahydropyridine, thiophosphate and phenol, 1, 3-bis (1,1-dimethylethyl) were detected during the CP degradation. The current investigation reveals D. jiangsuensis as a potential microbe for CP degradation and opens up the possibility of exploiting its formulations to remediate the CP polluted soils.


Asunto(s)
Biodegradación Ambiental , Cloropirifos/metabolismo , Cytophagaceae/fisiología , Contaminantes del Suelo/metabolismo , Suelo
11.
Ecotoxicol Environ Saf ; 213: 112076, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33639562

RESUMEN

We executed a pot experiment to examine the differences of absorption, chemical forms, subcellular distribution, and toxicity of Cd between two cultivars of Chinese flowering cabbage Brassica campestris [Lvbao701 (low-Cd cultivar) and Chicaixin No.4 (high-Cd cultivar)]. Compared to Chicaixin No.4, the presence of Lvbao701 enhanced the proportion of insoluble Cd forms in soil, Lvbao701 roots and leaves had higher proportion of Cd converted into insoluble phosphate precipitates and pectate-or protein-bound forms and lower proportion of inorganic Cd, which result in low accumulation and toxicity of Cd to Lvbao701 and cutworm Spodoptera litura fed on Lvbao701 leaves. Instead of total Cd, Cd transfer and toxicity in B. campestris-S. litura system depend on chemical Cd forms in soil and cabbages and subcellular Cd distributions in cabbages and insects, and the proportions of them were not the highest among all chemical forms and subcellular distributions of Cd. Although exchangeable Cd was major Cd chemical form in cabbage planted soil, Cd bound to iron and manganese oxides and to organic matter were significantly correlated with growth indices and photosynthesis parameters of cabbages. Despite major part of Cd was precipitated in cell wall of roots, Cd in organelle fraction was closely associated with the fitness of cabbages. Metal-rich granules, not cytosolic fraction (the major subcellular Cd distribution), affected the food utilization of S. litura. Therefore, cabbage cultivars significantly affected Cd transfer and toxicity in B. campestris-S. litura system, and the use of Lvbao701 in Cd polluted soil could reduce potential risks for Cd entering food chains.


Asunto(s)
Brassica/fisiología , Cadmio/toxicidad , Contaminantes del Suelo/toxicidad , Animales , Brassica/metabolismo , Cadmio/metabolismo , China , Cadena Alimentaria , Larva/metabolismo , Raíces de Plantas/metabolismo , Reproducción , Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Spodoptera/crecimiento & desarrollo , Spodoptera/fisiología
12.
Ecotoxicol Environ Saf ; 208: 111624, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396144

RESUMEN

Phthalate esters (PAEs), such as dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), are used extensively as additives and plasticizers, and have become ubiquitous in the environment. PAEs in the soil could have adverse effects on crop plants as well as humans via accumulations in food chain. Thus, it is important to explore strategies to reduce the bioavailability of phthalate esters. We investigated the effects of Fe-Mn oxide-modified biochar composite (FMBC) applications on the quality of wheat grown in DBP- and DEHP-polluted brown soil. The application of FMBC and biochar (BC) increased the wheat grain biomass by 9.71-223.01% and 5.40-120.15% in the DBP-polluted soil, and 10.52-186.21% and 4.50-99.53% in the DEHP-spiked soil in comparison to the controls. All FMBC treatments were better than the BC treatments, in terms of decreasing DBP and DEHP bioavailability for the wheat grains. The activities of the glutamine synthetase and glutamic-pyruvic transaminase in the flag leaves at the filling stage and of granule-bound starch synthase, soluble starch synthase, and adenosine diphosphate-glucose pyrophosphorylase in the grains at maturity increased significantly with increases in either the BC or FMBC applications. This, in turn, increased the starch, protein, and amino acid content in the wheat grains. Compared with the BC treatment, the FMBC amendment induced only slight increases in the aforementioned factors. This study offers novel insights into potential strategies for decreasing PAEs bioavailability in soil, with potential positive implications for crop quality and environmental health improvements.


Asunto(s)
Carbón Orgánico/química , Restauración y Remediación Ambiental/métodos , Ácidos Ftálicos/química , Contaminantes del Suelo/metabolismo , Triticum/fisiología , Dibutil Ftalato/análisis , Dibutil Ftalato/metabolismo , Dietilhexil Ftalato/metabolismo , Grano Comestible/química , Contaminación Ambiental , Ésteres/análisis , Humanos , Hierro/análisis , Óxidos/análisis , Plastificantes/análisis , Suelo/química , Contaminantes del Suelo/análisis , Triticum/metabolismo
13.
Ecotoxicol Environ Saf ; 208: 111750, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396075

RESUMEN

Contamination of agricultural land and water by heavy metals due to rapid industrialization and urbanization including various natural processes have become one of the major constraints to crop growth and productivity. Several studies have reported that to counteract heavy metal stress, plants should be able to maneuver various physiological, biochemical and molecular processes to improve their growth and development under heavy metal stress. With the advent of modern biotechnological tools and techniques it is now possible to tailor legume and other plants overexpressing stress-induced genes, transcription factors, proteins, and metabolites that are directly involved in heavy metal stress tolerance. This review provides an in-depth overview of various biotechnological approaches and/or strategies that can be used for enhancing detoxification of the heavy metals by stimulating phytoremediation processes. Synthetic biology tools involved in the engineering of legume and other crop plants against heavy metal stress tolerance are also discussed herewith some pioneering examples where synthetic biology tools that have been used to modify plants for specific traits. Also, CRISPR based genetic engineering of plants, including their role in modulating the expression of several genes/ transcription factors in the improvement of abiotic stress tolerance and phytoremediation ability using knockdown and knockout strategies has also been critically discussed.


Asunto(s)
Productos Agrícolas/fisiología , Fabaceae/fisiología , Metales Pesados/toxicidad , Contaminantes del Suelo/toxicidad , Biodegradación Ambiental , Biotecnología , Productos Agrícolas/metabolismo , Fabaceae/metabolismo , Metales Pesados/análisis , Metales Pesados/metabolismo , Contaminantes del Suelo/metabolismo , Estrés Fisiológico , Verduras/metabolismo
14.
Ecotoxicol Environ Saf ; 208: 111757, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396080

RESUMEN

A pot study was performed to assess the phytoremedial potential of Cymbopogon citratus (D.C.) Staf. for reclamation of coal mine overburden dump wastes, emphasizing the outcome of amendment practices using cow dung manure (CM) and garden soil mixtures on the revegetation of over-burden wastes (OB). Wastes amendment with cow dung manure and garden soil resulted in a significant increase in soil health and nutrient status along with an increment in the phytoavailability of Zn and Cu which are usually considered as micronutrients, essential for plant growth. A significant increment in the total biomass of lemongrass by 38.6% under CM20 (OB: CM 80:20) was observed along with improved growth parameters under amended treatments as compared to OB (100% waste). Furthermore, the proportionate increases in the assimilative rate, water use efficiency, and chlorophyll fluorescence have been observed with the manure application rates. Lemongrass emerged out to be an efficient metal-tolerant herb species owing to its high metal-tolerance index (>100%). Additionally, lemongrass efficiently phytostablized Pb and Ni in the roots. Based on the strong plant performances, the present study highly encourages the cultivation of lemongrass in coal mining dumpsites for phytostabilization coupled with cow-dung manure application (20% w/w).


Asunto(s)
Biodegradación Ambiental , Cymbopogon/fisiología , Estiércol , Contaminantes del Suelo/metabolismo , Animales , Biomasa , Bovinos , Carbón Mineral , Minas de Carbón , Cymbopogon/crecimiento & desarrollo , Metales , Desarrollo de la Planta , Raíces de Plantas/química , Plantas , Suelo , Contaminantes del Suelo/análisis
15.
Ecotoxicol Environ Saf ; 208: 111582, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396105

RESUMEN

In recent years, heavy metal pollution has caused immeasurable harm to the environment. As an emerging technology, phytoremediation technology has gained a place in the treatment of heavy metal pollution with its unique advantages. This study analyzes the toxic effects of mulberry (Morus alba) seeds, seedling growth and silkworm under heavy metal stress of lead (Pb) and cadmium (Cd), and explore the accumulation and migration of Pb and Cd in the soil-mulberry tree-silkworm system. The main results were as follows: (1) Seed germination and potted seedling experiments were conducted under heavy metal Pb and Cd stresses, and it was found that Pb and Cd had inhibitory effects on mulberry seed germination, growth and photosynthesis of mulberry seedlings, and as the concentration of heavy metals increased, the stronger the inhibitory effect. Moreover, Pb and Cd have a synergistic effect under compound stress. (2) The accumulation and transfer rules of Pb and Cd ions in mulberry were different. The content of Pb in mulberry was root > leaf > stem and the content of Cd was root > stem > leaf. The combined stress promoted the transfer of Pb and Cd from the underground part to the aerial portion of mulberry. (3) The silkworm feeds on mulberry leaves contaminated with heavy metals in this experiment and found that: with the increase of silkworm feeding, the heavy metal content in the silkworm body increased significantly, but the content remained in the silkworm body was less, most of it was excreted with silkworm excrement. Combined stress has no significant effect on the detoxification mechanism of silkworm. It is indispensable to think of the synergistic effect of heavy metals on plants germination when seeds are used for phytoremediation.


Asunto(s)
Bombyx/fisiología , Cadmio/toxicidad , Cadena Alimentaria , Plomo/toxicidad , Morus/fisiología , Contaminantes del Suelo/toxicidad , Suelo/química , Animales , Biodegradación Ambiental , Cadmio/análisis , Cadmio/metabolismo , Frutas/química , Metales Pesados/análisis , Fotosíntesis , Hojas de la Planta/química , Plantones/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo
16.
Ecotoxicol Environ Saf ; 208: 111584, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396107

RESUMEN

Cadmium (Cd) is highly toxic for plant metabolic processes even in low concentration due to higher retention rates, longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of Cd tolerant PGPR, Serratia sp. CP-13 together with two differentially Cd tolerant maize cultivars (MMRI-Yellow, Sahiwal-2002) selected amongst ten cultivars after screening. The maize cultivars were grown under different Cd treatments (0, 6, 12, 18, 24, 30 µM) in Petri plates both with and without Serratia sp. CP-13 inoculation. Treated plants were analyzed for their biomass accumulation, chlorophylls, carotenoids, proline, anthocyanin, protein, malondialdehyde (MDA), H2O2 as well as for antioxidants (POD, SOD, CAT) and mineral elements (Ca, Mg, Zn, K, Fe, Na, Cd). The maize cultivar MMRI-Yellow (tolerant) and Sahiwal-2002 (sensitive) exhibited significant reduction in leaf area, nutrient contents, plant biomass, activity of antioxidants, total proteins, photosynthetic pigments as well as flavonoids with increased production of H2O2, proline, MDA and relative membrane permeability (RMP) under Cd stress. However, this reduction was cultivar specific and recorded higher in cv. Sahiwal-2002 as compared to MMRI-Yellow. Application of Serratia sp. CP-13 significantly augmented plant biomass, photosynthetic pigments, antioxidative machinery, as well as flavonoids and proline while diminishing H2O2, RMP MDA production even under Cd stress in studied cultivars. Furthermore, CP-13 inoculation assisted the Cd stressed plants to sustain an optimal level of essential nutrients (Ca, Mg, Zn, K, Fe) except for Na and Cd which responded antagonistically. It was inferred that both inoculated maize cultivars exhibited better health and metabolism but substantial Cd tolerance was acquired by the sensitive cv. Sahiwal-2002 than the tolerant cv. MMRI-Yellow under applied Cd regimes. Furthermore, studied maize cultivars depicted maximum Cd tolerance in order of 30 < 24 < 18 < 12 < 6 < 0 µM Cd treatments under Serratia sp. CP-13 inoculation. Findings of current work highlighted the importance of Serratia sp. CP-13 and its inoculation impact on morpho-physio-biochemical attributes of maize growth under Cd dominant environment, which is likely an addition towards efficient approaches for bacterially-assisted Cd bioremediation and minimal Cd retention in edible plant parts.


Asunto(s)
Cadmio/toxicidad , Serratia/fisiología , Contaminantes del Suelo/toxicidad , Zea mays/fisiología , Antioxidantes/metabolismo , Biodegradación Ambiental , Transporte Biológico , Biomasa , Cadmio/metabolismo , Clorofila/metabolismo , Peróxido de Hidrógeno/metabolismo , Fotosíntesis , Hojas de la Planta/metabolismo , Serratia/metabolismo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Zea mays/metabolismo , Zea mays/microbiología
17.
Ecotoxicol Environ Saf ; 208: 111703, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396034

RESUMEN

Polychlorinated biphenyls (PCBs) are widespread persistent pollutants deleterious for environment and very dangerous for human kind. As the bioremediation of PCB polluted sites by model white-rot fungi is still unsatisfactory, the use of efficient native strains which have the natural capacity to develop on polluted sites may constitute a relevant alternative strategy. In this study, we isolated 12 fungal strains from PCB contaminated soil and sediment, improved the screening method to obtain the most efficient ones in biodegradation and detoxification of PCBs and characterized potential underlying enzymatic activities. Four strains Penicillium chrysogenum, P. citreosulfuratum, P. canescens and Aspergillus jensenii, showed remarkable biodegradation capacities, greater than 70%. The remaining PCB-toxicity of their culture, including that of Trametes versicolor and Acremonium sclerotigenum, which present interesting ecological and metabolic properties, was studied. Only P. canescens was able to significantly reduce the toxicity related to PCBs and their metabolites. The enzymatic activities induced by PCBs were different according to the strains, namely laccases in T. versicolor and peroxidases in Ac. sclerotigenum. Our promising results show that the use of native fungal strains can constitute an effective strategy in the depollution of PCB polluted sites.


Asunto(s)
Hongos/aislamiento & purificación , Hongos/metabolismo , Bifenilos Policlorados/metabolismo , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Biodegradación Ambiental , Proteínas Fúngicas/metabolismo , Hongos/clasificación , Humanos , Lacasa/metabolismo , Peroxidasas/metabolismo
18.
Ecotoxicol Environ Saf ; 208: 111616, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396136

RESUMEN

Our previous studies showed that exogenous glutathione (GSH) decreased cadmium (Cd) concentration in shoots and alleviated the growth inhibition in pakchoi (Brassica chinensis L.) under Cd stress. Nevertheless, it is largely unknown how GSH decreases Cd accumulation in edible parts of pakchoi. This experiment mainly explored the mechanisms of GSH-induced reduction of Cd accumulation in shoot of pakchoi. The results showed that compared with sole Cd treatment, Cd + GSH treatment remarkably increased the expression of BcIRT1 and BcIRT2, and further enhanced the concentrations of Cd and Fe in root. By contrast, GSH application declined the concentration of Cd in the xylem sap. However, these results were not caused by xylem loading process because the expression of BcHMA2 and BcHMA4 had not significant difference between sole Cd treatment and Cd + GSH treatment. In addition, exogenous GSH significantly enhanced the expression of BcPCS1 and promoted the synthesis of PC2, PC3 and PC4 under Cd stress. At the same time, exogenous GSH also significantly improved the expression of BcABCC1 and BcABCC2 in the roots of seedling under Cd stress, suggesting that more PCs-Cd complexes may be sequestrated into vacuoles by ABCC1 and ABCC2 transporters. The results showed that exogenous GSH could up-regulate the expression of BcIRT1/2 to increase the Cd accumulation in root, and the improvement of PCs contents and the expression of BcABCC1/2 enhanced the compartmentalization of Cd in root vacuole of pakchoi under Cd stress. To sum up, exogenous GSH reduce the concentration of free Cd2+ in the cytoplast of root cells and then dropped the loading of Cd into the xylem, which eventually given rise to the reduction of Cd accumulation in edible portion of pakchoi.


Asunto(s)
Brassica/metabolismo , Cadmio/metabolismo , Glutatión/metabolismo , Raíces de Plantas/metabolismo , Plantones/metabolismo , Contaminantes del Suelo/metabolismo , Vacuolas/metabolismo , Transporte Biológico , Brassica/efectos de los fármacos , Brassica/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Plantas/genética , Plantones/efectos de los fármacos
19.
Ecotoxicol Environ Saf ; 208: 111675, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396007

RESUMEN

Metal bioavailability controls its behaviors in soil-plant system, especially involved in biochar amendment. This study compared a rhizospheric pore-water extraction against a BCR sequential extraction method to understand cadmium (Cd) bioavailability in two typical Chinese soils. Soils were spiked with five levels of Cd (CdCl2) and remediated with 3% corn-straw derived biochar. After 60 days of lettuce growth, Cd accumulation and enzyme activities in tissues were analyzed. Results showed that biochar increased soil properties (pH, CEC and SOM) compared to un-amended soils, but decreased contents of bioavailable Cd in soil pore-water (Cdpore-water) and BCR extracted Cd (CdFi+Fii). Contents of Cdpore-water were lower in yellow-brown soils than that in red soils. Pearson analysis showed that bioavailable Cd is negatively correlated with soil pH and CEC (p < 0.05). Cd accumulation in lettuce roots and leaves both were decreased by biochar addition, and the established linear equations proved that soil Cdpore-water is the best predictor for Cd accumulation in lettuce roots (r2 = 0.964) and in leaves (r2 = 0.953), followed by CdFi+Fii. Transfer factor (TF) values of Cd from roots to leaves were lower than 1, and slightly better correlated with soil Cdpore-water (r = -0.674, p < 0.01) than CdFi+Fii (r = -0.615, p < 0.01). Aggregated boosted tree (ABT) analyses indicated that soil properties together with Cdpore-water contribute more than 50% to root enzyme activities. Collectively, soil Cdpore-water is a promising predictor of Cd bioavailability, accumulation and toxicity in soil-plant system with biochar addition.


Asunto(s)
Bioacumulación/efectos de los fármacos , Cadmio/toxicidad , Carbón Orgánico/química , Lechuga/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Disponibilidad Biológica , Transporte Biológico , Cadmio/metabolismo , Lechuga/metabolismo , Modelos Teóricos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Tallos de la Planta/química , Rizosfera , Suelo/química , Contaminantes del Suelo/metabolismo , Agua/química , Zea mays/química
20.
Ecotoxicol Environ Saf ; 211: 111904, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33453639

RESUMEN

This original research was performed to assess the possible effects of solid biochar (25 g biochar kg-1 soil) and biochar-based nanocomposites (BNCs) of magnesium oxide (25 g BNC-MgO kg-1 soil), manganese oxide (25 g BNC-MnO biochar kg-1 soil) and combined use of these nanocomposites (12.5 g BNC-MgO + 12.5 g BNC-MnO kg-1 soil) on soil properties and salinity (non-saline, 6 and 12 dSm-1) tolerance of safflower plants (Carthamus tinctorius L.). Application of biochar, particularly BNCs increased the pH and cation exchange capacity of soil, and the contents of water, potassium, calcium, magnesium, manganese, chlorophyll (a & b), nutrients uptake, water use efficiency and plant growth. Sodium adsorption ratio (SAR), exchangeable sodium percentage (ESP) of soil, sodium absorption rate of plants and osmolyte production (soluble carbohydrates and proteins, proline and glycine betaine) under 6 and 12 dSm-1 salinities were decreased by biochar and BNCs treatments. Sodium sorption capacity of BNCs was much higher than the solid biochar, which reflected the superiority of BNCs in decreasing sodium uptake by plants. The combined application of BNC-MgO + BNC-MnO proved to be the preferable treatment for decreasing salt toxicity in safflower. Biochar and BNCs improved root and shoot growth by lowering SAR, ESP, sodium absorption rate of plants and osmotic stress under saline conditions. These results conclude that BNCs can enrich the plant cells with nutrients, increase the nutrients absorption rate and maintain the plant tissue water content at an optimum level to improve plant growth under salt stress.


Asunto(s)
Carbón Orgánico , Magnesio/química , Manganeso/química , Adsorción , Carthamus tinctorius/metabolismo , Clorofila , Iones/metabolismo , Magnesio/metabolismo , Manganeso/metabolismo , Nanocompuestos , Óxidos/metabolismo , Potasio/metabolismo , Salinidad , Estrés Salino , Tolerancia a la Sal , Sodio/metabolismo , Suelo/química , Contaminantes del Suelo/metabolismo
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