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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 Agric Food Chem ; 67(38): 10563-10576, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31487171

RESUMO

Sulfur (S) metabolism plays a vital role in Cd detoxification, but the collaboration between melatonin biosynthesis and S metabolism under Cd stress remains unaddressed. Using exogenous melatonin, melatonin-deficient tomato plants with a silenced caffeic acid O-methyltransferase (COMT) gene, and COMT-overexpressing plants with cosuppression of sulfate transporter (SUT)1 and SUT2 genes, we found that melatonin deficiency decreased S accumulation and aggravated Cd phytotoxicity, whereas exogenous melatonin or overexpression of COMT increased S uptake and assimilation, resulting in an improved plant growth and Cd tolerance. Melatonin deficiency promoted Cd translocation from root to shoot, but COMT overexpression caused the opposite effect. COMT overexpression failed to compensate the functional hierarchy of S when its uptake was inhibited by cosilencing of transporter SUT1 and SUT2. Our study provides genetic evidence that melatonin-mediated tolerance to Cd is closely associated with the efficient regulation of S metabolism, redox homeostasis, and Cd translocation in tomato plants.


Assuntos
Cádmio/metabolismo , Lycopersicon esculentum/metabolismo , Melatonina/metabolismo , Enxofre/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Oxirredução , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteína O-Metiltransferase/genética , Proteína O-Metiltransferase/metabolismo
3.
J Agric Food Chem ; 67(35): 9877-9884, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31398030

RESUMO

Heavy metal contaminants and nutrient deficiencies in soil negatively affect crop growth and human health. The plant cadmium resistance (PCR) protein transports heavy metals. The abundance of PCR is correlated with that of cell number regulator (CNR) protein, and the two proteins have similar conserved domains. Hence, CNR might also participate in heavy metal transport. We isolated and analyzed TaCNR5 from wheat (Triticum aestivum). The expression level of TaCNR5 in the shoots of wheat increased under cadmium (Cd), zinc (Zn), or manganese (Mn) treatments. Transgenic plants expressing TaCNR5 showed enhanced tolerance to Zn and Mn. Overexpression of TaCNR5 in Arabidopsis increased Cd, Zn, and Mn translocation from roots to shoots. The concentrations of Zn and Mn in rice grains were increased in transgenic plants expressing TaCNR5. These roles of TaCNR5 in the translocation and distribution of heavy metals mean that it has potential as a genetic biofortification tool to fortify cereal grains with micronutrients.


Assuntos
Manganês/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Triticum/genética , Zinco/metabolismo , Arabidopsis/química , Arabidopsis/genética , Arabidopsis/metabolismo , Biofortificação , Transporte Biológico , Cádmio/análise , Cádmio/metabolismo , Manganês/análise , Oryza/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Triticum/química , Triticum/metabolismo , Zinco/análise
4.
J Agric Food Chem ; 67(36): 10126-10136, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31433635

RESUMO

Soil microbes have recently been utilized to improve cadmium (Cd) tolerance and lower its accumulation in plants. Nevertheless, whether rhizobacteria can prevent Cd uptake by graminaceous plants and the underlying mechanisms remain elusive. In this study, inoculation with Enterobacter asburiae NC16 reduced transpiration rates and the expression of some iron (Fe) uptake-related genes including ZmFer, ZmYS1, ZmZIP, and ZmNAS2 in maize (Zea mays) plants, which contributed to mitigation of Cd toxicity. However, the inoculation with NC16 failed to suppress the transpiration rates and transcription of these Fe uptake-related genes in plants treated with fluridone, an abscisic acid (ABA) biosynthetic inhibitor, indicating that the impacts of NC16-inoculation observed were dependent on the actions of ABA. We found that NC16 increased the host ABA levels by mediating the metabolism of ABA rather than its synthesis. Moreover, the capacity of NC16 to inhibit plant uptake of Cd was greatly weakened in plants overexpressing ZmZIP, encoding a zinc/iron transporter. Collectively, our findings indicated that E. asburiae NC16 reduced Cd toxicity in maize plants at least partially by hampering the Fe uptake-associated pathways.


Assuntos
Cádmio/metabolismo , Enterobacter/metabolismo , Ferro/metabolismo , Zea mays/metabolismo , Inoculantes Agrícolas/metabolismo , Transporte Biológico/efeitos dos fármacos , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Piridonas/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/genética , Zea mays/microbiologia
5.
Sci Total Environ ; 688: 818-826, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31255820

RESUMO

Cd contamination in agricultural soils threatens the safety of agricultural products and poses human health risk via food chain. However, the remediation of Cd polluted alkaline soils has not drawn the public concern, and the corresponding efficient amendments that can reduce Cd accumulation in crop grains are relatively few. In current study, mercapto-modified attapulgite (MA in abbreviation) was selected as the amendment to conduct winter wheat (Triticum aestivum L.) cultivation pot experiment to investigate the effect of MA on Cd accumulation in winter wheat and Cd bioavailability in alkaline soil. MA had no adverse impact on the normal growth of winter wheat but could inhibit Cd accumulation in wheat grain of both cultivars grown in alkaline soil with a maximum reduction of 75%, while pH-regulating amendment sepiolite had no reduction effect. In the term of soil chemistry, MA could decrease the zeta potential of soil particles and enhance the sorption amount of Cd on soil particles, resulted in the increase of Fe-Mn-oxides bounded Cd fraction in alkaline soil. The enhanced sorption effect combined with complexation effect of MA itself, made the exchangeable and bioavailable Cd concentrations in the soil decrease. In the term of plant uptake, MA could inhibit the uptake of Cd via roots from the soil, and hinder Cd transfer from roots to grains. MA had environmental friendliness and capability in the aspect of soil pH, effective cation exchange capacity and available micronutrients in the soil. The high performance of MA in inhabitation of Cd in winter wheat revealed that it was an efficient immobilization agent with great application potential for Cd-polluted alkaline soil.


Assuntos
Cádmio/metabolismo , Recuperação e Remediação Ambiental/métodos , Compostos de Magnésio , Compostos de Silício , Poluentes do Solo/metabolismo , Triticum/metabolismo , Solo/química
6.
Ecotoxicol Environ Saf ; 182: 109397, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31299476

RESUMO

Cadmium (Cd) is a serious threat to plants health. Though some genes have been reported to get involved in the regulation of tolerance to Cd, the mechanisms underlying this process are not fully understood. Na+/H+ antiporter (NHX1) plays an important role in Na+/H+ trafficking. The salt and cadmium stress tolerance were found to be enhanced by NHX1 in duckweed according to our previous study, however, its function in Cd2+ flux under Cd stress has not been studied. Here we explored the Cd2+ flux in wild type (WT) and NHX1 transgenic duckweed (NHX1) under Cd stress. We found that the Cd2+ influx in NHX1 duckweed was significantly declined, followed by an increased Cd2+ efflux after 20 min treatment of Cd, which resulted a less accumulation of Cd in NHX1. Reversely, inhibition of NHX1 by amiloride treatment, enhanced Cd2+ influx in NHX1 duckweed, subsequently delayed Cd2+ efflux in both genotypes of duckweed under Cd2+ shock. H+ efflux in NHX1 duckweed was lower compare with that in WT with 20 min Cd2+ shock. NHX1 also increased the pH value with Cd2+ stress in the transgenic rhizoid. These finding suggested a new function of NHX1 in regulation of Cd2+ and H+ flow during short-term Cd2+ shock.


Assuntos
Araceae/fisiologia , Cádmio/metabolismo , Poluentes Químicos da Água/metabolismo , Araceae/metabolismo , Cádmio/toxicidade , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/metabolismo , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio , Poluentes Químicos da Água/toxicidade
7.
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
8.
Sci Total Environ ; 690: 867-877, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302551

RESUMO

Fishery targeted species living in estuaries face multiple anthropogenic pressures including habitat contamination. However, trace metal concentrations in aquatic organisms can be highly variable, making it difficult to interpret accumulation responses. Understanding sources for metal accumulation in these organisms and their biokinetics is important for management of local fisheries and ensuring safety and quality of consumed seafood, particularly in urbanised areas. In this study, we exposed Australian sand clams, school prawns and sand whiting to a combination of cadmium (Cd), manganese (Mn) and zinc (Zn) radioisotopes 1) dissolved in seawater, 2) adsorbed to suspended sediment particles and 3) in radiolabelled food. Sand clams were sensitive to Cd, Mn and Zn uptake and accumulation from all sources because of their filter feeding physiology. Mean Cd and Zn assimilation efficiencies (AE) were higher in clams fed benthic diatoms (51, 43, 63% for Cd, Mn and Zn, respectively) than clams fed an algal flagellate species (22, 32, 33% for Cd, Mn and Zn, respectively). Metal uptake by prawns from seawater was low, whereas assimilation from diet was high (67, 59, 64% mean AEs from Cd, Mn and Zn, respectively). Sand whiting did not accumulate metals from seawater, even after concentrations were increased. Assimilation from diet (labelled prawns) was also low for sand whiting, particularly for Cd and Zn (11, 26, 14% mean AEs from Cd, Mn and Zn, respectively). These results may help explain the persistence of sand whiting in contaminated estuaries. Suspended sediment exposures showed that prawns and fish are less likely than clams to be negatively affected by disturbance events such as floods, which can bring metals into estuaries. The findings of this study have implications for fisheries management, both for protection and remediation of important habitats, and to ensure safe standards for seafood consumption by humans.


Assuntos
Organismos Aquáticos/metabolismo , Pesqueiros/estatística & dados numéricos , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Cádmio/metabolismo , Manganês/metabolismo , Zinco/metabolismo
9.
Photochem Photobiol Sci ; 18(8): 2061-2070, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31339127

RESUMO

Firefly luciferases have been widely used for bioanalytical purposes during the last 5 decades. They usually emit yellow-green bioluminescence and are pH-sensitive, displaying a color change to red at acidic pH and higher temperature and in the presence of heavy metals. Besides the usual applications as bioanalytical reagents and as reporter genes, firefly luciferases' pH- and metal-sensitivities have been recently harnessed for intracellular metal and pH biosensing. Previously we cloned the luciferase of the Brazilian Amydetes vivianii firefly which displays the most blue-shifted color among known firefly luciferases. Here we purified it, characterized and investigated the kinetic properties and the pH, metal and thermal sensitivities of this firefly luciferase. This luciferase displays the lowest reported KM for ATP, the highest catalytic efficiencies, and the highest thermostability among the studied recombinant beetle luciferases, making this enzyme and its cDNA an ideal reagent for sensitive ATP assays and reporter gene. The blue-shifted spectrum, higher thermostability, lower pH- and thermal-sensitivities and protein fluorescence studies indicate a more rigid active site during light emission. This enzyme displays an unmatched selective spectral sensitivity for cadmium and mercury, making it a promising ratiometric indicator of such toxic metals. Finally, the weaker thermal-sensitivity compared to other firefly luciferases makes this enzyme a better ratiometric pH indicator at temperatures above 30 °C, suitable for mammalian cell assays.


Assuntos
Trifosfato de Adenosina/análise , Técnicas Biossensoriais , Cádmio/metabolismo , Vaga-Lumes/enzimologia , Luciferases de Vaga-Lume/metabolismo , Metais Pesados/metabolismo , Temperatura Ambiente , Animais , Cádmio/química , Fluorescência , Concentração de Íons de Hidrogênio , Cinética , Luciferases de Vaga-Lume/química , Metais Pesados/química
10.
Bioresour Technol ; 291: 121868, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31357045

RESUMO

To clarify the adsorption behaviors of typical heavy metals onto sludge extracellular polymeric substances (EPS), the adsorption capacities and mechanisms, as well as the contributions of the different EPS components (proteins, humic acids and polysaccharides), to the adsorption of Zn2+, Cu2+ and Cd2+ were separately explored. Overall, proteins exhibited a relatively high adsorption capacity for the three metals ions, followed by humic acid, whereas least for polysaccharides. The adsorption of Cu2+ and Cd2+ onto proteins, humic acid and polysaccharides fit well to the Freundlich isotherm, whereas Langmuir model was the best fit for Zn2+ bindings onto polysaccharides/humic acid. The binding of Cu2+, Zn2+ and Cd2+ onto the three EPS components was exothermically favorable, and significant electrostatic interactions were observed for the heavy metals sorption onto humic acid and proteins. In addition, the effect of metal ions sorption on the spectrum of the proteins, polysaccharides and humic acid was also explored.


Assuntos
Cádmio/química , Cobre/química , Substâncias Húmicas , Polissacarídeos/química , Proteínas/metabolismo , Esgotos , Zinco/química , Adsorção , Cádmio/metabolismo , Cobre/metabolismo , Proteínas/química , Esgotos/química , Zinco/metabolismo
11.
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
12.
Ecotoxicol Environ Saf ; 182: 109444, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31310903

RESUMO

Solanum nigrum L. has a high potential for the remediation of Cd-contaminated soil, and nitrogen fertilizer supply is an effective method to further improve its phytoremediation potential. The soil pot culture experiment was used to explore 4 kinds of nitrogen fertilizers the best fertilizer addition concentrations and their strengthening mechanisms. The results showed that S. nigrum biomass increased with increasing N doses until 800 mg kg-1, where the biomass reached maximum and no longer improved (p < 0.05). However, Cd concentration accumulated by S. nigrum and the extractable Cd concentration in soil did not show a significant decrease (p < 0.05). In this experiment, when N fertilizer was added at 800 mg kg-1 (NH4HCO3, NH4Cl, (NH4)2SO4 and CH4N2O fertilizers), the biomass of the aboveground S. nigrum parts improved to the maximum under (NH4)2SO4 and CH4N2O treatments, i.e. 5.86 g pot-1 and 5.83 g pot-1, increased by 5.92- and 5.89-fold, respectively (p < 0.05), compared to the controls without N fertilizers addition. At the same time, Cd phytoaccumulation in plants was elevated to 128.40 µg pot-1 and 129.14 µg pot-1, increased by 6.20- and 6.24-fold, respectively (p < 0.05), compared to control with no fertilizer added. The results of this experiment demonstrated that Cd phytoextraction capacity (µg pot-1) was the strongest under (NH4)2SO4 and CH4N2O treatments at N content of 800 mg kg-1, when plant nutrient recovery reached the maximum, and these 2 types of nitrogen fertilizers could be utilized to remediate Cd-contaminated soil in field experiments or even in practice.


Assuntos
Cádmio/metabolismo , Fertilizantes/análise , Nitrogênio , Poluentes do Solo/metabolismo , Solanum nigrum/fisiologia , Biodegradação Ambiental , Biomassa , Cádmio/análise , Solo , Poluentes do Solo/análise
13.
Environ Pollut ; 253: 959-965, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351304

RESUMO

Application of Zinc (Zn) is considered an effective measure to reduce Cadmium (Cd) uptake and toxicity in Cd-contaminated soils for many plant species. However, interaction between Zn and Cd in rice plant is complex and uncertain. In this study, four indica rice cultivars were selected to evaluate the effect of Zn exposure in an EGTA-buffered nutrient solution under varying Zn activities and a field level of Cd activity to characterize the interaction between Zn and Cd in rice. Severe depression in shoots' biomass, tiller number, and SPAD (Soil and Plant Analyzer Development) value were found at both Zn deficiency and Zn phytotoxicity levels among four tested rice cultivars. There existed a strong antagonism interaction between Zn and Cd in both shoot and root from Zn deficiency to Zn phytotoxicity. The reduction of Cd accumulation in roots and shoots could be explained by the competition between Zn and Cd as well as the dilution effect of increasing biomass. The conflicting effect of Zn supply on Cd uptake may be attributed to the increasing transfer ratio of Cd from root to shoot with the increasing Zn2+ activities and the strong depression of Fe and Mn in shoots with the increasing Zn2+ activities as well as the variation of genotypes. Balance between Zn and Cd should be considered in field application.


Assuntos
Cádmio/metabolismo , Oryza/fisiologia , Poluentes do Solo/metabolismo , Zinco/metabolismo , Transporte Biológico/efeitos dos fármacos , Biomassa , Cádmio/análise , Poluição Ambiental , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
14.
Environ Pollut ; 252(Pt B): 1791-1800, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31299508

RESUMO

Phytochelatins (PCs) play a vital role in the tolerance and enrichment of cadmium (Cd) in higher plants by chelating with Cd2+. The aim of this study was to perform a full-scale metabolomics analysis of metabolic responses highly correlated with PCs generation. These metabolites and metabolic pathways were expected to promote PCs generation and further optimize Cd absorption in plants. In the current study, Amaranthus hypochondriacus, a potential species for phytoremediation, was first adopted to investigate physiological responses to Cd stress via LCMS/MS-based metabolomics and the HPLC based determination of thiol compounds. The results showed that the leaves of A. hypochondriacus under high Cd stress accumulated 40 times the amount of Cd compared to the leaves of the plants not under Cd stress and had an increased content of three types of PCs. Metabolomics qualitatively identified 12084 substances in total, among which 41 were significantly different metabolites (SDMs) between the two groups and involved in 7 metabolic pathways. Among the SDMs, 12 metabolites were highly linearly correlated with PCs involved in three pathways (Val, Leu and Ile biosynthesis; Ala, Asp and Glu metabolism; and Arg and Pro metabolism). These results provide an innovative method to promote PCs synthesis for the restoration of Cd-contaminated-soil.


Assuntos
Amaranthus/metabolismo , Cádmio/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fitoquelatinas/biossíntese , Poluentes do Solo/metabolismo , Amaranthus/efeitos dos fármacos , Biodegradação Ambiental , Cádmio/toxicidade , Metabolômica , Modelos Teóricos , Solo/química , Poluentes do Solo/toxicidade
15.
Environ Sci Pollut Res Int ; 26(24): 25167-25177, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31256392

RESUMO

Cadmium (Cd) is a common environmental pollutant that threatens humans' and animals' health. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used drugs due to their wide therapeutic action; however, they have significant side effects. Since, under many circumstances, humans and animals may be co-exposed to Cd and NSAIDs, the current investigation was assigned to explore the intertwining relationship between Cd and NSAIDs. Four groups of male Wister rats were used: control group: rats received saline; Cd group: rats received cadmium (Cd, 2 mg/kg) orally; Px group: rats received a NSAID (piroxicam, Px, 7 mg/kg, i.p.); and Cd+Px group: rats received both Cd+Px. All treatments were given once a day for 28 consecutive days. Then, blood samples, stomach, liver, and kidney tissues were collected. The results indicated that Px provoked gastric ulcer indicated by high ulcer index, while Cd had no effect on the gastric mucosa. In addition, treatment with Cd or Px alone significantly induced liver and kidney injuries indicated by serum elevations of AST, ALT, ALP, ALB, total protein, creatinine, and urea along with histopathological alterations. Significant increases in malondialdehyde and reduction in GSH and CAT contents were reported along with up-regulated expression of Bax and Bcl-2 after Cd or Px exposure. However, when Cd and Px were given in a combination, Cd obviously potentiated the Px-inflicted cellular injury and death in the liver and kidney but not in the stomach when compared to their individual exposure. This study concluded that oxidative stress mechanisms were supposed to be the main modulator in promoting Cd and Px toxicities when given in combination.


Assuntos
Anti-Inflamatórios não Esteroides/metabolismo , Cádmio/metabolismo , Piroxicam/metabolismo , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Creatinina/metabolismo , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar
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.
Environ Sci Pollut Res Int ; 26(22): 22625-22640, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31168715

RESUMO

Endogeic earthworm Metaphire posthuma (Valliant, 1868) is a common biological component of the tropical soil of India and other countries. The species is reported to influence fertility and porosity of soil and bear a high composting potential. Intensive agricultural, industrial, and mining activities increase the amount of toxic metals in soil causing physiological adversity in earthworm and other biotic components in soil. Coelomocytes, the chief immunoeffector cells of earthworm, perform diverse physiological functions under the challenge of toxins and pathogens. The experimental earthworms collected separately from soils with agricultural and tannery activities were subjected to quantitation of prooxidation and antioxidation parameters for estimation of oxidative stress. Total count, cellular aggregation, generation of reactive oxygen species (ROS), superoxide anion, nitric oxide, activities of phenoloxidase, superoxide dismutase, catalase and glutathione-s-transferase, and amount of total protein were estimated in the coelomocytes of M. posthuma as experimental end points of toxicity screening. Concentrations of cadmium, chromium, lead, and mercury were determined in the soil samples to assess the degree of toxic contamination. The increase in the amount of prooxidants and decrease in the activities of antioxidant enzymes indicated the signs of oxidative stress in the coelomocytes of the organism. Aggregation of circulating coelomocytes is considered as an immune response involved in pathogen encapsulation response as reported in many invertebrates. Decrease in coelomocyte aggregation in earthworm collected from contaminated sites suggested a state of inappropriate shift of the innate immune status. Toxin-induced oxidative stress and reductions in cell aggregation response are the signs of immunocompromisation of M. posthuma. Present findings bear a prospect of this experimental species as an indicator of soil pollution.


Assuntos
Coelomomyces/fisiologia , Metais/toxicidade , Oligoquetos/fisiologia , Poluentes do Solo/toxicidade , Agricultura , Animais , Antioxidantes/metabolismo , Cádmio/metabolismo , Catalase/metabolismo , Agregação Celular , Monitoramento Ambiental , Poluição Ambiental , Glutationa Transferase/metabolismo , Índia , Mineração , Oligoquetos/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Solo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
18.
Environ Sci Pollut Res Int ; 26(22): 22826-22834, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31175573

RESUMO

A greenhouse experiment was performed to evaluate the growth, accumulation, and uptake rate of Eichhornia crassipes subject to high cadmium concentrations. Three doses of Cd were added to polluted river water (1, 5, and 10 mg Cd/L), and polluted water with basal Cd concentration (0.070 mg/L) was used as a control. The experiment lasted for 7 days. Signs of stress and toxicity were visible in all treatments from day 3 of the experiment. The growth of the water hyacinth was slightly stimulated in the presence of low Cd concentration (1 mg/L), but this could also be due to the chloride and other nutrients present in the polluted water. Cd was accumulated mainly in roots, showing a maximum concentration of 1742.1 mg Cd/kg dw (10 mg Cd/L). The translocation from roots to leaves was low, with a maximum accumulation of 147.4 mg Cd/kg dw (10 mg Cd/L). The uptake rate for roots reached a maximum of 248.7 mg Cd/kg·day while the uptake rate for leaves did not saturate in the range of the studied concentrations (max. 20.8 mg Cd/kg·day). The water hyacinth showed promising results for the application in the treatment of Cd-polluted waters given its ability to tolerate high Cd concentrations in the media (up to 10 mg Cd/L) and its capacity for uptake and accumulation.


Assuntos
Cádmio/metabolismo , Eichhornia/fisiologia , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Transporte Biológico , Cádmio/análise , Cádmio/toxicidade , Folhas de Planta/química , Raízes de Plantas/química , Rios , Poluentes Químicos da Água/toxicidade , Poluição da Água
19.
BMC Plant Biol ; 19(1): 283, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31248369

RESUMO

BACKGROUND: Metal homeostasis is critical for plant growth, development and adaptation to environmental stresses and largely governed by a variety of metal transporters. The plant ZIP (Zn-regulated transporter, Iron-regulated transporter-like Protein) family proteins belong to the integral membrane transporters responsible for uptake and allocation of essential and non-essential metals. However, whether the ZIP family members mediate metal efflux and its regulatory mechanism remains unknown. RESULTS: In this report, we provided evidence that OsZIP1 is a metal-detoxified transporter through preventing excess Zn, Cu and Cd accumulation in rice. OsZIP1 is abundantly expressed in roots throughout the life span and sufficiently induced by excess Zn, Cu and Cd but not by Mn and Fe at transcriptional and translational levels. Expression of OsZIP-GFP fusion in rice protoplasts and tobacco leaves shows that OsZIP1 resides in the endoplasmic reticulum (ER) and plasma membrane (PM). The yeast (Saccharomyces cerevisiae) complementation test shows that expression of OsZIP1 reduced Zn accumulation. Transgenic rice overexpressing OsZIP1 grew better under excess metal stress but accumulated less of the metals in plants. In contrast, both oszip1 mutant and RNA interference (RNAi) lines accumulated more metal in roots and contributed to metal sensitive phenotypes. These results suggest OsZIP1 is able to function as a metal exporter in rice when Zn, Cu and Cd are excess in environment. We further identified the DNA methylation of histone H3K9me2 of OsZIP1 and found that OsZIP1 locus, whose transcribed regions imbed a 242 bp sequence, is demethylated, suggesting that epigenetic modification is likely associated with OsZIP1 function under Cd stress. CONCLUSION: OsZIP1 is a transporter that is required for detoxification of excess Zn, Cu and Cd in rice.


Assuntos
Cádmio/metabolismo , Proteínas de Transporte de Cátions/genética , Cobre/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/genética , Proteínas de Plantas/genética , Zinco/metabolismo , Transporte Biológico/efeitos dos fármacos , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Oryza/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Estresse Fisiológico
20.
Environ Sci Pollut Res Int ; 26(23): 23453-23459, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31201704

RESUMO

Cadmium (Cd) as a widespread toxic heavy metal accumulates in animal food including chicken meat through food chain enrichment and finally threatens human health. Selenium (Se) is an essential mineral and possesses antagonistic effects on Cd-induced multiple organs' toxicity in chickens. The objective of the present study was to reveal the antagonistic mechanisms of Se to Cd from the aspects of oxidative stress, inflammation, and meat quality in chicken breast muscles. Firstly, the results showed that Cd significantly elevated the levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and protein carbonyl, and declined the levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) to trigger oxidative stress in chicken breast muscles. However, Se treatment significantly alleviated Cd-induced oxidative stress by increasing the levels of GSH-Px, SOD, and CAT, and decreasing the levels of MDA, H2O2, and protein carbonyl. Secondly, Se obviously inhibited the expressions of Cd-activated inflammation-related genes including tumor necrosis factor (TNF-α), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), inducible nitric oxide synthase (iNOS), prostaglandin-endoperoxide synthase 2 (COX-2), and prostaglandin E synthase (PTGEs) in chicken breast muscles. Thirdly, meat quality-related parameters including pH45min, ultimate pH (pHu), and drip loss were also detected, and the results showed that Se markedly recovered Cd-induced dropt of pH45min and increase of drip loss in chicken breast muscles. In brief, these findings demonstrated that Se significantly alleviated Cd-induced oxidative stress and inflammation, and declined meat quality of chicken breast muscles.


Assuntos
Antioxidantes/metabolismo , Cádmio/toxicidade , Galinhas/fisiologia , Poluentes Ambientais/toxicidade , Carne/análise , Selênio/metabolismo , Animais , Cádmio/metabolismo , Catalase/metabolismo , Galinhas/metabolismo , Glutationa Peroxidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Inflamação , Malondialdeído/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo
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