Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.834
Filtrar
1.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3164-3174, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529892

RESUMO

To achieve the goal of remediation while producing for farmland contaminated by Cd, maize and grain amaranth (Amaranthus hypochondriacus) were planted on farmland contaminated by Cd in five different intercropping modes, including alternating wide-narrow-row of maize and single-row grain amaranth intercropped between wide rows (T1), alternating wide-narrow-row of maize and double-row grain amaranth intercropped between wide rows (T2), equidistant double-row maize and single-row grain amaranth intercropped between rows (T3), equidistant double-row maize and double-row grain amaranth intercropped between rows (T4), maize and grain amaranth intercropped with equal four rows (T5), while maize (CK1) and grain amaranth (CK2) single planted as control to explore the effects of different intercropping modes on growth and Cd accumulation of crops and hyper-accumulation plants (A. hypochondriacus). The results showed that: 1) Compared with mono-culture (CK1), grain yield of maize per plant showed an increasing trend in intercropping modes. The grain yield of maize in T1 increased by 10.5%, while that in T4 and T5 decreased by 6.3% and 5.4% respectively, and that in T2 or T3 did not change compared with monoculture of maize. The aboveground biomass per plant and yield per unit area of grain amaranth decreased by 69.5%-95.7% and 83.9%-96.9% in intercropping modes respectively compared with monoculture (CK2). 2) The Cd content of maize grain showed an increasing trend in intercropping modes compared with monoculture (CK1). The Cd content of grain amaranth showed a decreasing trend in intercropping modes compared with monoculture (CK2). 3) Compared with monoculture (CK2), the enrichment coefficient, transport coefficient, and effective transport coefficient of grain amaranth all showed an increasing trend in intercropping modes, while the aboveground Cd extraction amount per plant and per unit area of grain amaranth decreased by 40.4%-86.7% and 70.4%-88.9% in intercropping modes, respectively. The total amount of Cd extraction per unit area of maize and grain amaranth in intercropping modes was significantly higher than that in monoculture of maize and lower than that in monoculture of grain amaranth. 4) The content of available Cd in maize rhizosphere soil and the content of total/available Cd in grain amaranth rhizosphere soil both showed an increasing trend in intercropping modes compared with monoculture of both crop, but it had no significant effect on non-rhizosphere soil. In this study, T1 was beneficial to increase maize grain yield, while T5 was beneficial to maximize the Cd extraction amount of grain amaranth.


Assuntos
Amaranthus , Cádmio/metabolismo , Poluentes do Solo/metabolismo , Zea mays , Agricultura , Solo
2.
J Environ Sci (China) ; 85: 107-118, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471017

RESUMO

Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons, however, the combined effect of BC and RL in phytoremediation has not been studied until now. In this paper, the phytoremediation of petroleum hydrocarbon-contaminated soil using novel plant Spartina anglica was enhanced by the combination of biochar (BC) and rhamnolipid (RL). Samples of petroleum-contaminated soil (10, 30 and 50 g/kg) were amended by BC, BC+ RL and rhamnolipid modified biochar (RMB), respectively. After 60 day's cultivation, the removal rate of total petroleum hydrocarbons (TPHs) for unplanted soil (UP), planted soil (P), planted soil with BC addition (P-BC), planted soil with BC and RL addition (P-BC + RL) and planted soil with addition of RMB (P-RMB) were 8.6%, 19.1%, 27.7%, 32.4% and 35.1% in soil with TPHs concentration of 30 g/kg, respectively. Compared with UP, the plantation of Spartina anglica significantly decreased the concentration of C8-14 and tricyclic PAHs. Furthermore, the application of BC and RMB alleviated the toxicity of petroleum hydrocarbons to Spartina anglica via improving plant growth with increasing plant height, root vitality and total chlorophyll content. High-throughput sequencing result indicated that rhizosphere microbial community of Spartina anglica was regulated by the application of BC and RMB, with increase of bacteria and plant mycorrhizal symbiotic fungus in biochar and RMB amended soil.


Assuntos
Biodegradação Ambiental , Petróleo/análise , Poaceae/fisiologia , Poluentes do Solo/análise , Carvão Vegetal/química , Glicolipídeos/química , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos , Rizosfera , Microbiologia do Solo , Poluentes do Solo/metabolismo
3.
Environ Monit Assess ; 191(9): 540, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31378832

RESUMO

In this work, we present the results of the investigation of trace elements (Fe, Mg, Ni, Zn, Cu, Cr, Co, Cd, Pb) accumulation potential of Noccaea kovatsii (Heuff.) F. K. Mey., from the Balkan Peninsula. The study included eight populations from ultramafic soils, six from Bosnia and Herzegovina, and two from Serbia. Principal component analysis (PCA) was used to reveal relationships of elements in soil, and Pearson's correlation coefficients for analysing associations of available quantities of elements in soil and those in roots and shoots of N. kovatsii. Uptake and translocation efficiency was assessed by using bioconcentration (BCF) and translocation factors (TF). All the analysed populations of N. kovatsii emerged as strong Ni accumulators, with the highest shoot concentrations of 12,505 mg kg-1. Even thought contents of Zn in plant tissues of N. kovatsii were under the hyperaccumulation level (602 mg kg-1 and 1120 mg kg-1 respectively), BCF was up to 667, indicating that certain surveyed populations have strong accumulative potential for this element.


Assuntos
Brassicaceae/metabolismo , Poluentes do Solo/análise , Solo/química , Oligoelementos/análise , Bósnia e Herzegóvina , Brassicaceae/química , Monitoramento Ambiental , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/metabolismo , Análise de Componente Principal , Sérvia , Poluentes do Solo/metabolismo , Oligoelementos/metabolismo
4.
Ying Yong Sheng Tai Xue Bao ; 30(6): 2056-2062, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31257779

RESUMO

The endophytic bacteria were isolated from the roots of polycyclic aromatic hydrocarbon (PAHs)-tolerant plant. We investigated their ability of PAHs degradation and plant growth promo-ting, with the aim to provide theoretical support for bacterial-plant cooperative soil remediation. Kochia scoparia living in coking plant area were selected for strains isolation. Eight endophytic bacteria strains, which used pyrene and 1-aminocyclopropane-1-carboxylic acid (ACC) as sole carbon and nitrogen source, were isolated from the roots of K. scoparia. Three endophytic bacteria, KSE4, KSE7 and KSE8, displayed high degradation efficiency in pyrene degradation experiment. They were identified as Bacillus sp., Pseudomonas sp., and Sphingobacterium sp., respectively. The abili-ties of those three strains to produce ACC deaminase and their effects on seed germination of K. scoparia were examined under pyrene stress through liquid culture tests. The results showed that the activity of ACC deaminase decreased with increasing pyrene concentration (0-15 mg·L-1). KSE7 had the strongest promotion effect. When pyrene concentration reached to 15 mg·L-1, the germination rate and bud length of K. scoparia increased by 44.8% and 61.1%, respectively. Our results indicated that KSE7 is a promising bacterial strain for soil remediation in coking plant area.


Assuntos
Bassia scoparia/metabolismo , Biodegradação Ambiental , Raízes de Plantas/microbiologia , Pirenos/metabolismo , Poluentes do Solo/metabolismo , Bactérias , Hidrocarbonetos Policíclicos Aromáticos
5.
Ying Yong Sheng Tai Xue Bao ; 30(6): 2063-2071, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31257780

RESUMO

Arbuscular mycorrhizal fungi (AMF) play an important role in plant growth enhancement, tolerance to heavy metal toxicity, and rehabilitation of contaminated ecosystems. An experiment was carried out with Phragmites communis and Pennisetum alopecuroides inoculated with or without Funneliformis mosseae (Fm), or Rhizophagus intraradices (Ri) under the simulated wetland system with Cd polluted water (0, 5, 10 or 20 mg·L-1). The results showed that Cd addition significantly decreased mycorrhizal colonization. AMF increased plant height, dry mass, leaf chlorophyll, N and Cd contents in shoot and root of P. communis and P. alopecuroides, enhanced Cd enrichment capability by roots, and decreased Cd transfer coefficient. Under Cd 5 mg·L-1 treatment, all of the indices in Fm + P. communis combination treatment were higher than those of other treatments, with 60.6% of AMF colonization, and the entry points and vesicles per mm root length were 2.3 and 3.7, respectively. Under the inoculation treatment, dry mass of shoot and root was improved by 69.1%, and 75.0%, nitrogen contents in shoot and root were increased by 38.7% and 27.8%, and the chlorophyll content and plant height were increased by 3.8% and 11.1%, respectively. There was a significant positive correlation between Cd concentration in wetland system and Cd content in shoot and root. Under Cd 20 mg·L-1 treatment, Fm + P. communis combination had the maximum Cd contents of 182.4 mg·kg-1 and 663.3 mg·kg-1 in shoot and root, respectively, the lowest Cd transfer coefficient (0.27), and the highest enrichment coefficient (0.55). In conclusion, Fm + P. communis was the best combination for absorbing Cd in polluted water.


Assuntos
Cádmio/metabolismo , Glomeromycota , Micorrizas/fisiologia , Raízes de Plantas/microbiologia , Poluentes do Solo/metabolismo , Áreas Alagadas
6.
World J Microbiol Biotechnol ; 35(8): 117, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332532

RESUMO

Iron- and sulfur-oxidizing bacteria inhabiting rice rhizoplane play a significant role on arsenic biogeochemistry in flooded rice paddies, influencing arsenic translocation to rice grains. In the present study, the selective pressure of arsenic species on these microbial populations was evaluated. Rice roots from continuously flooded plants were incubated in iron sulfide (FeS) gradient tubes and exposed to either arsenate or arsenite. The biomass developed in the visible iron-oxidation band of the enrichments was analyzed by Scanning Electron Microscopy and Energy-Dispersive Spectroscopy (SEM-EDS) and the bacterial communities were characterized by 16S rRNA gene sequencing. Different Proteobacteria communities were selected depending on exposure to arsenate and arsenite. Arsenate addition favored the versatile iron-oxidizers Dechloromonas and Azospira, associated to putative iron (hydr)oxide crystals. Arsenite exposure decreased the diversity in the enrichments, with the development of the sulfur-oxidizer Thiobacillus thioparus, likely growing on sulfide released by FeS. Whereas sulfur-oxidizers were observed in all treatments, iron-oxidizers disappeared when exposed to arsenite. These results reveal a strong impact of different inorganic arsenics on rhizospheric iron-oxidizers as well as a crucial role of sulfur-oxidizing bacteria in establishing rice rhizosphere communities under arsenic pressure.


Assuntos
Arsênico/metabolismo , DNA Bacteriano/isolamento & purificação , Oryza/efeitos dos fármacos , Oryza/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/microbiologia , Arseniatos/metabolismo , Arsenitos/metabolismo , DNA Bacteriano/genética , Ferro/metabolismo , Oxirredução , Proteobactérias/efeitos dos fármacos , Proteobactérias/isolamento & purificação , Proteobactérias/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação , Solo/química , Microbiologia do Solo , Poluentes do Solo/metabolismo , Enxofre/metabolismo
7.
Bull Environ Contam Toxicol ; 103(2): 330-335, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31263937

RESUMO

The immobilization effect and mechanism of nano-hydroxyapatite(NHAP) on Pb in the ryegrass rhizosphere soil were studied by root-bag experiment. The speciation analysis results revealed that the residual Pb concentrations in the rhizosphere soil significantly increased after NHAP application. The acid-soluble and reducible Pb concentrations significantly decreased, indicating that NHAP had obviously immobilized Pb. Meanwhile, NHAP significantly promoted the secretion of tartaric acid from ryegrass roots, resulting the rhizosphere soil pH had been below that of the control group. This helped to relieve the stress of Pb on ryegrass, also promoted the dissolution of NHAP, resulting the formation of stable precipitation with more Pb ions. NHAP increased the rhizosphere soil pH by 0.03 to 0.17, which promoted the conversion of Pb to non-utilizable bioavailability. The total Pb mass balance indicated only a very small proportion Pb transferred to the shoots through ryegrass roots. The formation of pyromorphite by Pband NHAP in soil was accordingly to interpret the dominant mechanism for Pb immobilization.


Assuntos
Durapatita/química , Chumbo/análise , Lolium/crescimento & desenvolvimento , Nanoestruturas/química , Rizosfera , Poluentes do Solo/análise , Adsorção , Disponibilidade Biológica , Concentração de Íons de Hidrogênio , Chumbo/metabolismo , Lolium/metabolismo , Minerais/química , Modelos Teóricos , Fosfatos/química , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Tartaratos/metabolismo
8.
Sci Total Environ ; 691: 605-610, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325860

RESUMO

The potential for bioaccumulation and associated genotoxicity of nonextractable residues (NERs) of polycyclic aromatic hydrocarbon (PAHs) in long-term contaminated soils have not been investigated. Here we report research in which earthworms, Eisenia fetida, were exposed to a soil containing readily available benzo[a]pyrene (B[a]P) and highly sequestered B[a]P NERs aged in soil for 350 days. B[a]P bioaccumulation was assessed and DNA damage (as DNA single strand breaks) in earthworm coelomocytes were evaluated by comet assay. The concentrations of B[a]P in earthworm tissues were generally low, particularly when the soil contained highly sequestered B[a]P NERs, with biota-soil accumulation factors ranging from 0.6 to 0.8 kgOC/kglipid. The measurements related to genotoxicity, that is percentage (%) of DNA in the tails and olive tail moments, were significantly greater (p < 0.05) in the spiked soil containing readily available B[a]P than in soil that did not have added B[a]P. For example, for the soil initially spiked at 10 mg/kg, the percentage of DNA in the tails (29.2%) of coelomocytes after exposure of earthworms to B[a]P-contaminated soils and olive tail moments (17.6) were significantly greater (p < 0.05) than those of unspiked soils (19.6% and 7.0, for percentage of DNA in tail and olive tail moment, respectively). There were no significant (p > 0.05) differences in effects over the range of B[a]P concentrations (10 and 50 mg/kg soil) investigated. In contrast, DNA damage after exposure of earthworms to B[a]P NERs in soil did not differ from background DNA damage in the unspiked soil. These findings are useful in risk assessments as they can be applied to minimise uncertainties associated with the ecological health risks from exposure to highly sequestered PAH residues in long-term contaminated soils.


Assuntos
Benzo(a)pireno/toxicidade , Oligoquetos/fisiologia , Poluentes do Solo/toxicidade , Animais , Benzo(a)pireno/metabolismo , Ensaio Cometa , Dano ao DNA , Poluentes do Solo/metabolismo
9.
Sci Total Environ ; 691: 827-834, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31326806

RESUMO

Selenium (Se) is an essential element in animals and humans, and its deficiency may cause conditions such as cardiac disease. The production of Se-enriched rice is one of the most important ways to supply Se in the human body, and thus, understanding of the mechanisms of Se-enriched rice is of great significance. A pot experiment was conducted to study the effects of Se addition on the growth, antioxidation, Se uptake and distribution, and Se speciation in three different stages of panicle initiation stage (i.e., pistil and stamen formation stage, pollen mother cell formation stage, pollen mother cell meiosis stage) and the maturity stage. The results showed that soil Se application significantly increased Se uptake in rice. Low rates of Se (<5 mg kg-1) application enhanced the plant growth and rice yield. Se speciation assays showed that SeCys and SeMet were the two main forms found in rice, of which SeMet accounted for 65.5%-100% in the ears and leaves, while SeCys accounted for 61.4%-75.6% in brown rice. SeMet was also the main Se-species found in different subcellular parts at the panicle initiation stage. However, inorganic Se was present in brown rice, mainly as Se(VI), when the soil Se addition exceeded 5 mg kg-1. Lower rates of Se (<5 mg kg-1) promoted the antioxidant capacity, while high levels of Se (≥5 mg kg-1) reduced the antioxidant capacity of rice. The results indicate that Se effects are dose dependent, and the suitable amount of soil Se application for Se-enriched rice production would be <5 mg kg-1.


Assuntos
Antioxidantes/metabolismo , Oryza/fisiologia , Selênio/metabolismo , Poluentes do Solo/metabolismo
10.
Ecotoxicol Environ Saf ; 182: 109422, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31301594

RESUMO

Breeding the rice cultivar with high cadmium (Cd) accumulation in straw but with low Cd in brown rice using marker-assisted selection (MAS) based on quantitative trait loci (QTL) is meaningful for phytoremediation as well as safety in production. A restorer rice line, YaHui2816, steadily showed low Cd translocation from straw to brown rice and carried alleles for reducing Cd concentration in brown rice (BRCdC). In this study, one F2 population (C268A/YaHui2816) was used to identify the QTLs for BRCdC in 2016, and other two different F2 populations (Lu98A/YaHui2816 and 5406A/YaHui2816) were used to furtherly validate the QTLs in 2017. Furthermore, a pot experiment was conducted to investigate the relative expression of predicted genes in the regions of these QTLs for BRCdC. Here 4 QTLs for BRCdC were identified, among which, 2 novel QTLs (qBRCdC-9 and qBRCdC-12) were identified on chromosomes 9 and 12 in rice. The YaHui2816 alleles in the QTLs qBRCdC-9 and qBRCdC-12 could effectively reduce BRCdC under different genetic backgrounds. Importantly, the QTL qBRCdC-12 was simultaneously associated with the Cd translocation from shoot to brown rice (T-s-b), genetically explaining that the low T-s-b of the YaHui2816 resulted in its low BRCdC. The interval length of the QTL qBRCdC-12 was only narrowed to 0.28 cM, making it possible to develop molecular markers and excavate genes for reducing BRCdC. It is worth noting that genes existed in these QTL regions have not been reported for regulating the Cd translocation in rice. 6 candidate genes (OS05G0198400, OS05G0178300, OS09G0544400, OS12G0161100, OS12G0162100 and OS12G0165200) up-regulated expressed in nodeⅡof the YaHui2816 in response to Cd treatment, and encoded ZRT/IRT-like protein (ZIP) 4, the protein similar to glutathione transferase (GSTs) 16, heat shock protein Hsp20 domain containing protein, MAP kinase-like protein and Cd tolerant protein 5, respectively.


Assuntos
Cádmio/metabolismo , Oryza/genética , Poluentes do Solo/metabolismo , Grão Comestível/metabolismo , Oryza/metabolismo , Locos de Características Quantitativas
11.
Environ Sci Pollut Res Int ; 26(23): 23460-23470, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31201701

RESUMO

Lead (Pb) contamination of agroecosystems is a serious issue as Pb is a persistent pollutant that is retained in soil for long, causing toxicities to organisms. This study examines biotransfer of Pb from soils treated with different concentrations of Pb through a broad bean (Vicia faba L.)-aphid (Aphis fabae Scop.)-ladybird (Coccinella transversalis Fabricius) food chain and its consequent inference for natural biological control, the ladybird. The soil was amended with Pb at the rates of 0, 25, 50, 75 and 100 mg kg-1 (w/w). The amount of Pb in plant, aphid and ladybird increased in a dose-dependent manner to Pb contents in the soil. The results showed that Pb biomagnified from soil to root with transfer coefficient always > 1. Biominimization of Pb occurred at the second trophic level in aphids and at the third trophic level in ladybirds as their respective transfer coefficients from shoot to aphid and aphid to ladybird were always < 1. The increased elimination of Pb via aphid excreta (honeydew) and pupal exuviae in a dose-dependent manner suggests that these are possible detoxification mechanisms at two different trophic levels which control Pb bioaccumulation along the food chain. The statistically significant (p ≤ 0.05) decreases in biomass and predation rate of predatory ladybirds at 100 mg kg-1 Pb indicate that high dose of Pb in soil may have sub-lethal effects on ladybirds. Further studies at cellular and sub-cellular levels are needed to further document the potential mechanisms of achieving Pb homeostasis in ladybirds under Pb stress.


Assuntos
Afídeos , Besouros , Cadeia Alimentar , Chumbo/metabolismo , Poluentes do Solo/metabolismo , Animais , Biomassa , Plantas Comestíveis , Comportamento Predatório , Solo , Poluentes do Solo/toxicidade , Vicia faba
12.
Environ Sci Pollut Res Int ; 26(23): 23583-23592, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203537

RESUMO

A field survey was conducted to investigate metal(loid) concentration in soils and native plants in the Baoshan mining area for potential application in phytoremediation. Total concentrations of arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in soil varied from 125 to 6656, 5.10 to 1061, 568 to 49294, and 241 to 17296 mg kg-1, respectively, showing severe contamination. Among 20 species native to this area, Pteris ensiformis accumulated 1091 mg kg-1 As in the shoot, and its translocation factor (TF) was greater than 1, suggesting potential capacity for As phytoextraction. Boehmeria nivea, Aster prorerus, and Hydrocotyle sibthorpioides showed potential for phytoextraction of Cd due to their high accumulation of Cd in shoots (490.3, 175.4, and 128.5 mg kg-1, respectively) and high TFs (92.0, 22.1, and 6.7, respectively). Eleusine indica and P. ensiformis were found to contain high concentrations of Pb (7474 mg kg-1) and Zn (1662 mg kg-1) in roots, but with low TFs for Pb (0.4) and Zn (0.2), suggesting potential capability for phytostabilization. There was a positive correlation (p < 0.01, N = 25) of TFs between the metal(loid)s, indicating a synergic interaction in the uptake of metal(loid)s by these plants. According to metal(loid) concentrations in shoots, bioconcentration factors (BFs), and TFs, as well as the botanical features such as wide occurrence, high biomass yield, and rapid growth of the plants, the five native species identified above have the potential for phytoremediation in the Baoshan mining area.


Assuntos
Biodegradação Ambiental , Mineração , Plantas , Poluentes do Solo/metabolismo , Arsênico/análise , Biomassa , Cádmio/análise , China , Raízes de Plantas/química , Pteris , Solo , Poluentes do Solo/análise , Zinco/análise
13.
Environ Sci Pollut Res Int ; 26(23): 23679-23688, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203543

RESUMO

This work is the first report of the ability of biochar-immobilized cadmium-resistant bacteria (CRB) on promoting the efficiency of cadmium phytoextraction by Chlorophytum laxum R.Br. The survival of CRB immobilized on biochar in cadmium-contaminated soil at a concentration of 75.45 mg kg-1 was studied. The results found that both CRB, namely Arthrobacter sp. TM6 and Micrococcus sp. MU1, can survive and grow in cadmium-contaminated soil. To study phytoextraction in the pot experiments, 2-month-old C. laxum was individually planted in cadmium-contaminated soil and divided into four treatments, including (i) untreated control, (ii) biochar, (iii) biochar-immobilized (BC) Arthrobacter sp., and (iv) BC-Micrococcus sp. The results found that biochar-immobilized CRB did not cause any effect to the root lengths and shoot heights of plants compared to the untreated control. Interestingly, inoculation of biochar-immobilized CRB significantly increased cadmium accumulation in the shoots and roots compared to the untreated control. In addition, the highest cadmium content in a whole plant, best phytoextraction performance, and greatest bioaccumulation factor was found in plant inoculated with BC-Micrococcus sp., followed by BC-Arthrobacter sp. In conclusion, inoculation of biochar-immobilized CRB enhanced cadmium accumulation and translocation of cadmium from the roots to shoots, suggesting further applying biochar-immobilized CRB in cadmium-polluted soil for promoting cadmium phytoextraction efficiency of ornamental plants. Graphical abstract.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Carvão Vegetal/química , Poluentes do Solo/metabolismo , Arthrobacter/efeitos dos fármacos , Asparagaceae/efeitos dos fármacos , Cádmio/análise , Micrococcus/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Solo , Poluentes do Solo/análise
14.
Environ Sci Pollut Res Int ; 26(23): 23638-23644, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203547

RESUMO

The efficiency of heavy metal (HM) phytoextraction from contaminated soil directly depends on the pollutant bioavailability, which can be increased by some soil amendments. In field test, the impacts of soil-applied ethylenediaminetetraacetic acid (EDTA) and amorphous silicon dioxide (ASD) and foliar-applied monosilicic acid (MS) on cadmium (Cd) uptake by rice plants from contaminated paddy soil were investigated. Without EDTA, the solid or liquid Si materials reduced the Cd accumulation in the aboveground part of rice by 26 to 52%. If EDTA was applied, the Cd accumulation by plants was increased by 60 to 92%; however, the biomass was reduced by 16 to 35%. The combined application of Si-rich materials and EDTA provided enhanced plant tolerance to a negative influence of EDTA, while kept high Cd content in the rice stems and leaves. As a result, the Cd amounts extracted by the stems and leaves from the unit area of contaminated paddy soil were greater by 25 and 37% in comparison with those for only EDTA treatment.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Ácido Edético/química , Fertilizantes/análise , Silício/química , Poluentes do Solo/metabolismo , Disponibilidade Biológica , Cádmio/análise , Metais Pesados , Oryza , Folhas de Planta/química , Solo , Poluentes do Solo/análise
15.
Ecotoxicol Environ Saf ; 181: 18-25, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31154116

RESUMO

Effective phytoremediation of Mn contaminated soil requires the selection of a species with good manganese tolerance. Broussonetia papyrifera is an important economic plant and pioneer species, it could be well adapted to drought and saline-alkali environment. In order to understand the effect of Mn stress on B. papyrifera, the effects of different concentrations of Mn (0-50 mmol/L) stress on the growth, morphology, Mn tolerance and physiological indexes of the plant were explored. The results showed that the biomass, surface area, length, root volume, tips, forks, and crossings of B. papyrifera reached the maximum at the Mn concentration of 1 mmol/L. Mn content in the tissue and TF in plants increased with the increase of concentration, while the BCF increased first and then decreased, and the maximum BCF was 0.154 at 10 mmol/L. The accumulation of Mn lead to cell membrane lipid peroxidation, which increased toxic substances in plants, resulting in the increase of MDA and PRO, and affected the synthesis of chlorophyll. However, B. papyrifera could effectively alleviate oxidative stress by increasing the activities of antioxidant enzymes (SOD, POD, CAT), protein and soluble sugar. The results suggested that B. papyrifera had a good oxidative stress mechanism to Mn stress and could be used as candidates for remediation of pollution in mining areas.


Assuntos
Broussonetia/efeitos dos fármacos , Manganês/metabolismo , Poluentes do Solo/metabolismo , Solo/química , Estresse Fisiológico/efeitos dos fármacos , Antioxidantes/metabolismo , Biodegradação Ambiental , Biomassa , Broussonetia/fisiologia , Clorofila/metabolismo , Secas , Manganês/toxicidade , Poluentes do Solo/toxicidade
16.
Nat Commun ; 10(1): 2562, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31189898

RESUMO

Cadmium (Cd) accumulation in rice grain poses a serious threat to human health. While several transport systems have been reported, the complicity of rice Cd transport and accumulation indicates the necessity of identifying additional genes, especially those that are responsible for Cd accumulation divergence between indica and japonica rice subspecies. Here, we show that a gene, OsCd1, belonging to the major facilitator superfamily is involved in root Cd uptake and contributes to grain accumulation in rice. Natural variation in OsCd1 with a missense mutation Val449Asp is responsible for the divergence of rice grain Cd accumulation between indica and japonica. Near-isogenic line tests confirm that the indica variety carrying the japonica allele OsCd1V449 can reduce the grain Cd accumulation. Thus, the japonica allele OsCd1V449 may be useful for reducing grain Cd accumulation of indica rice cultivars through breeding.


Assuntos
Cádmio/metabolismo , Grão Comestível/metabolismo , Proteínas de Membrana/metabolismo , Oryza/metabolismo , Poluentes do Solo/metabolismo , Alelos , Asparagina/genética , Cádmio/análise , Membrana Celular/metabolismo , Grão Comestível/química , Humanos , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Oryza/química , Oryza/genética , Filogenia , Melhoramento Vegetal/métodos , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único , Poluentes do Solo/análise , Valina/genética
17.
BMC Plant Biol ; 19(1): 250, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185911

RESUMO

BACKGROUND: Cadmium (Cd) is a widespread toxic heavy metal pollutant in agricultural soil, and Cd accumulation in rice grains is a major intake source of Cd for Asian populations that adversely affect human health. However, the molecular mechanism underlying Cd uptake, translocation and accumulation has not been fully understood in rice plants. RESULTS: In this study, a mutant displaying extremely low Cd accumulation (lcd1) in rice plant and grain was generated by EMS mutagenesis from indica rice cultivar 9311 seeds. The candidate SNPs associated with low Cd accumulation phenotype in the lcd1 mutant were identified by MutMap and the transcriptome changes between lcd1 and WT under Cd exposure were analyzed by RNA-seq. The lcd1 mutant had lower Cd uptake and accumulation in rice root and shoot, as well as less growth inhibition compared with WT in the presence of 5 µM Cd. Genetic analysis showed that lcd1 was a single locus recessive mutation. The SNP responsible for low Cd accumulation in the lcd1 mutant located at position 8,887,787 on chromosome 7, corresponding to the seventh exon of OsNRAMP5. This SNP led to a Pro236Leu amino acid substitution in the highly conserved region of OsNRAMP5 in the lcd1 mutant. A total of 1208 genes were differentially expressed between lcd1 and WT roots under Cd exposure, and DEGs were enriched in transmembrane transport process GO term. Increased OsHMA3 expression probably adds to the effect of OsNRAMP5 mutation to account for the significant decreases in Cd accumulation in rice plant and grain of the lcd1 mutant. CONCLUSIONS: An extremely low Cd mutant lcd1 was isolated and identified using MutMap and RNA-seq. A Pro236Leu amino acid substitution in the highly conserved region of OsNRAMP5 is likely responsible for low Cd accumulation in the lcd1 mutant. This work provides more insight into the mechanism of Cd uptake and accumulation in rice, and will be helpful for developing low Cd accumulation rice by marker-assisted breeding.


Assuntos
Cádmio/metabolismo , Proteínas de Transporte de Cátions/genética , Oryza/genética , Proteínas de Plantas/genética , Poluentes do Solo/metabolismo , Sequência de Aminoácidos , Transporte Biológico , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Perfilação da Expressão Gênica , Oryza/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Alinhamento de Sequência
18.
Pol J Microbiol ; 68(2): 193-201, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250589

RESUMO

The present study aimed to isolate the high-efficiency petrol metabolizing thermophilic bacteria from petrol contaminated soil samples. Isolation was carried out through enrichment culture, serial dilution and pour plate methods using the petrol supplemented minimal salt media. The isolated bacteria were analyzed to document growth behavior, petrol removal efficiencies, antibiotic resistance profile, and biochemical characteristics. The 16S rRNA based phylogenetic analysis helped to reveal the identity of isolated bacterial species and construct the phylogenetic trees. Total nine bacteria were isolated, out of which three (IUBP2, IUBP3, IUBP5) were identified as Brevibacillus formosus, one (IUBP1) was found similar to Brevibacillus agri, four (IUBP7, IUBP8, IUBP13, and IUBP14) shared homology with Burkholderia lata, and one (IUBP15) with Burkholderia pyrrocinia. All the isolates were fast growing and exhibited considerable petrol degradation potential. The highest petrol removal efficiency (69.5% ± 13.44/6 days) was recorded for the strain IUBP15 at a petrol concentration of 0.1% (v/v). All bacteria studied (100%) were positive for esculinase and phosphatase. Many strains exhibited positive responses for arginine dehydrolase (22%), ß-naphthylamidase (11%), ß-D-glucosaminide (33%), mannitol (55%), sorbitol (66%) and inulin (88%) fermentation test. While all were sensitive to the antibiotics, some of them were found resistant against chloramphenicol and oxacillin. The remarkable biochemical characteristics and considerable petrol removal potential (40-70%) highlights utilization of the bacteria isolated for petrol bioremediation, mineralization of organophosphates, dairy and food industry, and also as biofertilizers and biocontrol agents.The present study aimed to isolate the high-efficiency petrol metabolizing thermophilic bacteria from petrol contaminated soil samples. Isolation was carried out through enrichment culture, serial dilution and pour plate methods using the petrol supplemented minimal salt media. The isolated bacteria were analyzed to document growth behavior, petrol removal efficiencies, antibiotic resistance profile, and biochemical characteristics. The 16S rRNA based phylogenetic analysis helped to reveal the identity of isolated bacterial species and construct the phylogenetic trees. Total nine bacteria were isolated, out of which three (IUBP2, IUBP3, IUBP5) were identified as Brevibacillus formosus, one (IUBP1) was found similar to Brevibacillus agri, four (IUBP7, IUBP8, IUBP13, and IUBP14) shared homology with Burkholderia lata, and one (IUBP15) with Burkholderia pyrrocinia. All the isolates were fast growing and exhibited considerable petrol degradation potential. The highest petrol removal efficiency (69.5% ± 13.44/6 days) was recorded for the strain IUBP15 at a petrol concentration of 0.1% (v/v). All bacteria studied (100%) were positive for esculinase and phosphatase. Many strains exhibited positive responses for arginine dehydrolase (22%), ß-naphthylamidase (11%), ß-D-glucosaminide (33%), mannitol (55%), sorbitol (66%) and inulin (88%) fermentation test. While all were sensitive to the antibiotics, some of them were found resistant against chloramphenicol and oxacillin. The remarkable biochemical characteristics and considerable petrol removal potential (40­70%) highlights utilization of the bacteria isolated for petrol bioremediation, mineralization of organophosphates, dairy and food industry, and also as biofertilizers and biocontrol agents.


Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Petróleo/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Antibacterianos/farmacologia , Bactérias/classificação , Bactérias/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Farmacorresistência Bacteriana , Enzimas/análise , Testes de Sensibilidade Microbiana , Poluição por Petróleo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
19.
Environ Pollut ; 249: 1029-1037, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31146309

RESUMO

In 2015, the Fundão tailing dam collapsed over the district of Bento Rodrigues (Mariana, Minas Gerais, Brazil) causing deaths, hundreds of homeless families and incalculable environmental degradation. Environmentally, economically and socially sustainable strategies are needed for the recovery of the affected areas. The main goal of this study was to evaluate the development, biomass production and toxic mineral elements absorption of three species of aromatic grasses (Chrysopogon zizanioides, Cymbopogon citratus and Cymbopogon winterianus). These three species were planted on polypropylene pots filled with the iron ore tailings collected from the topsoil of the Bento Rodrigues district. The pots were fertilized with increasing doses of organic compost associated with mycorrhizae as a phytomanagement strategy. A 4 × 2 factorial scheme was used. The seedlings were fertilized with four doses of organic compost, with or without mycorrhizae. At the highest dose of the organic compost (2 kg.plant-1), the total dry matter (dry matter of the aerial part + dry matter of the roots) for C. zizanioides was 4.5 times higher than the control (tailing only). For C. winterianus and C. Citratus was 3.8 and 2.8 times higher than the control, respectively. Inoculation with mycorrhizae improved biomass production, especially in C. zizanioides. The Fe and Mn levels found in the aerial part of the plants fertilized with organic compost were lower than those just growing on the iron ore tailings for the three species, which suggest that the organic matter apparently helped the plants in the exclusion of the hazardous substances and therefore increased the tolerance to these adverse environmental conditions. C. zizanioides, associated with organic matter and mycorrhizae, would be the recommended species. The proposed phytomanagement strategy can have a significant contribution to the gradual recovery of the affected area and also serve as a source of income for the local population.


Assuntos
Vetiveria/crescimento & desenvolvimento , Ferro/metabolismo , Mineração , Poluentes do Solo/metabolismo , Colapso Estrutural , Biodegradação Ambiental , Biomassa , Brasil , Vetiveria/metabolismo , Compostagem , Micorrizas/crescimento & desenvolvimento , Micorrizas/metabolismo , Solo/química
20.
Chemosphere ; 232: 70-75, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31152905

RESUMO

Polycyclic aromatic hydrocarbons are an important group of pollutants that are widely distributed in the environment. The present study aimed to investigate the effect of salicylic acid (a phenolic phytohormone) and mycorrhizal fungi on the growth and phytoremediation ability of tall fescue in the soil contaminated by fluoranthene. The initial concentrations of fluoranthene in this study were 100, 200, and 300 mg kg-1. The experimental treatments were included: T0 uncultivated soil; T1 cultivated soil with tall fescue; T2 cultivated soil with tall fescue + salicylic acid application; T3 cultivated soil with tall fescue + application of mycorrhizal fungi; T4 cultivated soil with tall fescue + salicylic acid and mycorrhizal fungi application; and P planting tall fescue in uncontaminated soil. The removal of fluoranthene was measured after 90 days. Furthermore, at the end of the experiment, the amount of shoot and root biomass, soil bacteria, and dehydrogenase activity were measured. According to the results, in all levels of contamination, removal of fluoranthene in cultivated treatments significantly was higher than uncultivated treatments. Increasing the concentration of fluoranthene had a negative effect on the shoot and root biomass in different treatments. Salicylic acid and mycorrhizal fungi significantly increased the shoot and root biomass and also the number of soil bacteria, dehydrogenase activity, and fluoranthene removal in T2, T3, and T4 treatments compared to T1. At the highest concentration of fluoranthene, as a result of simultaneous application of salicylic acid and mycorrhizal fungi (T4), the fluoranthene removal increased by 63, 21, 13, and 16% in comparison with T0, T1, T2, and T3, respectively. Based on the results, salicylic acid and mycorrhizal fungi, either alone or in combination, have a significant effect on the improvement of phytoremediation potential in tall fescue.


Assuntos
Biodegradação Ambiental , Festuca/metabolismo , Micorrizas/fisiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Ácido Salicílico/metabolismo , Poluentes do Solo/metabolismo , Biomassa , Festuca/microbiologia , Fluorenos , Reguladores de Crescimento de Planta , Raízes de Plantas/crescimento & desenvolvimento , Solo , Microbiologia do Solo , Simbiose
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA