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1.
J Environ Manage ; 289: 112434, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33799064

RESUMO

Salix cupularis is a common shrub for ecological restoration of the desertified alpine meadow on the Tibetan Plateau. However, the effect of S. cupularis on spatial heterogeneity of soil resources (i.e., resource islands effect) has not been systematically evaluated, and the influence of shrub patches on the rehabilitation of understory herbs has also been unknown. In this study, we randomly selected S. cupularis individuals in the early restoration stage of desertified alpine meadow, where the three native forages (Elymus nutans, Elymus sibiricus and Festuca sinensis) were sown at different microsites around S. cupularis to explore the effects of S. cupularis on soil resources and emergence rates of the native forages. The results showed that S. cupularis significantly increased SWC (soil water content), C (carbon) and N (nitrogen) nutrients (p < 0.01) and enzyme activities (p < 0.05) under canopy compared with the bare land, and the improvement performed better in the topsoil (0-5 cm) than in the subtop-soil (5-15 cm). Moreover, the soil properties were affected significantly by microsites around S. cupularis, resulting in regular changes of SWC, nutrients and enzyme activities in different microsites (Shrub center > Middle of canopy radius > Bare land). In addition, there are significant regression relationships between emergence rates and enriching soil water, C and N nutrients, so the emergence rates of native forages under canopy may be improved significantly with the enriched soil resources, especially for E. nutans. As a result, S. cupularis is a suitable pioneer shrub for the vegetation restoration of desertified alpine meadow on the Tibetan Plateau, because it could not only shape the enrichment of soil resources under canopy, but also facilitate emergence of companion forages in the process of vegetation restoration.


Assuntos
Pradaria , Salix , Ecossistema , Humanos , Ilhas , Nitrogênio/análise , Plântula/química , Solo , Tibet
2.
Bull Environ Contam Toxicol ; 106(3): 528-535, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33661312

RESUMO

Phytoremediation is a green, simple, eco-friendly, sustainable, and cost-effective remediation technology to remove and degrade contaminants from soil. In this study, a germination experiment and a pot experiment were performed in greenhouse to evaluate cadmium toxicity and phytoremediation capacity. The results showed that there was the highest membership function value of cadmium (MFVC) in KFJT-3 than that of KFJT-CK and KFJT-1, the value being 0.473, 0.456 and 0.413, respectively. Furthermore, the highest biomass was discovered in KFJT-3 compared to the other genotypes under 50 mg/kg cadmium stress. Physiological analysis showed that proline content significantly increased in KFJT-3, the value being 31.88%. In addition, Bioaccumulation factor (BAF) and Translocation factor (TF) value were 3.80 and 1.02 for KFJT-3, respectively. In conclusion, BAF and TF values showed that the cadmium tolerance of KFJT-1 and KFJT-3 could be higher than that of KFJT-CK, which could be the genotype for phytoremediation of cadmium contaminated soil.


Assuntos
Poluentes do Solo , Sorghum , Biodegradação Ambiental , Cádmio/análise , Cádmio/toxicidade , Raízes de Plantas/química , Prolina , Plântula/química , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
3.
Bull Environ Contam Toxicol ; 106(3): 545-556, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33638675

RESUMO

Heavy metals pollution and salinization of soils are widely distributed in agricultural soils. This study investigated the effects of five heavy metals and five heavy metals-contaminated salt on seed germination and seedling growth of halophyte Halogeton glomeratus (H. glomeratus). The results showed that seed germination, fresh weight (FW), dry weight (DW), radicles relative viability and ion contents (Cu2+, Ni2+, Zn2+, Cd2+ and Pb2+) of H. glomeratus were affected by different heavy metals and heavy metal-polluted 100 mM NaCl treatments. Ion contents in plumules increased with the increase of heavy metal concentrations with or without NaCl addition. Moreover, the accumulation levels of metals in the concentrations of Cu2+, Zn2+ and Pb2+ supplying 100 mM NaCl were higher than that without NaCl treatment. This can provide new insights into the value of H. glomeratus for phytoremediation of soil affected by heavy metals and also in combination with salinity.


Assuntos
Chenopodiaceae , Metais Pesados , Poluentes do Solo , Germinação , Metais Pesados/análise , Metais Pesados/toxicidade , Plantas Tolerantes a Sal , Plântula/química , Sementes/química , Cloreto de Sódio , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
4.
Sci Total Environ ; 772: 145023, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33581544

RESUMO

The individual impacts of elevated CO2 and heavy metals on soil nitrification have been widely reported. However, studies on the combined effects of elevated CO2 and heavy metals on soil nitrification are still limited. Here, a 135-day growth chamber experiment was conducted to investigate the impacts of elevated CO2 and cadmium (Cd) levels on soil nitrification in the rhizosphere of Robinia pseudoacacia L. seedlings. Elevated CO2 combined with Cd pollution generally stimulated ammonia monooxygenase (AMO), hydroxylamine oxidase (HAO), and nitrite oxidoreductase (NXR) activities. Compared to the control, the abundance of ammonia-oxidizing bacteria (AOB) at day 135 and ammonia-oxidizing archaea (AOA) increased significantly (p < 0.05) and the abundance of AOB at days 45 and 90 and that of the nitrite-oxidizing bacteria (NOB) decreased under elevated CO2 + Cd. Elevated CO2 mostly led to a significant (p < 0.05) decrease in soil nitrification intensity in the rhizosphere of R. pseudoacacia exposed to Cd. The effects of Cd, CO2, and their interaction on HAO and NXR activities were significant (p < 0.01). Soil pH, the C/N ratio, water-soluble organic carbon, water-soluble organic nitrogen (WSON), and total carbon were the dominant factors (p < 0.05) affecting nitrifying enzyme activities and nitrification intensity in rhizosphere soils. Elevated CO2 clearly affected AOA, AOB, and NOB community structures and dominant genera by shaping C/N ratio, pH, and Cd and WSON contents in rhizosphere soils under Cd exposure. Overall, the responses of pH, C/N ratio, WSON, and Cd to elevated CO2 led to changes in rhizosphere soil nitrification under the combination of elevated CO2 and Cd pollution.


Assuntos
Robinia , Poluentes do Solo , Amônia , Archaea , Cádmio/análise , Dióxido de Carbono/análise , Nitrificação , Oxirredução , Rizosfera , Plântula/química , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
5.
Environ Pollut ; 276: 116719, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33640652

RESUMO

Arsenic (As) is a ubiquitous environmental carcinogen that enters the human food chain mainly through rice grains. In the present study, we evaluated the potential of thiourea (TU; non-physiological reactive oxygen species scavenger) in mitigating the negative effects of arsenic (As) stress in indica rice variety IR64, with the overall aim to reduce grain As accumulation. At seedling stage, As + TU treatment induced the formation of more numerous and longer crown roots compared with As alone. The As accumulation in main root, crown root, lower leaf and upper leaf was significantly reduced to 0.1-, 0.14-, 0.16-, 0.14-fold, respectively in As + TU treated seedlings compared with those of As alone. This reduced As accumulation was also coincided with light-dependent suppression in the expression levels of aquaporins and photosynthesis-related genes in As + TU treated roots. In addition, the foliar-supplemented TU under As-stress maintained reducing redox conditions which decreased the rate of As accumulation in flag leaves and, eventually grain As by 0.53-fold compared with those of As treatment. The agronomic feasibility of TU was validated under naturally As contaminated sites of Nadia (West Bengal, India). The tiller numbers and crop productivity (kg seed/ha) of TU-sprayed plants were increased by 1.5- and 1.18-fold, respectively; while, grain As accumulation was reduced by 0.36-fold compared with those of water-sprayed control. Thus, this study established TU application as a sustainable solution for cultivating rice in As-contaminated field conditions.


Assuntos
Arsênico , Oryza , Poluentes do Solo , Arsênico/análise , Grão Comestível/química , Humanos , Índia , Raízes de Plantas/química , Plântula/química , Poluentes do Solo/análise
6.
Ecotoxicol Environ Saf ; 214: 112019, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33639494

RESUMO

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.


Assuntos
Cádmio/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Biomassa , Cádmio/análise , Grão Comestível/química , Recuperação e Remediação Ambiental , Genótipo , Humanos , Fenótipo , Desenvolvimento Vegetal , Folhas de Planta/química , Plântula/química , Solo , Poluentes do Solo/análise , Sorghum/crescimento & desenvolvimento
7.
Ecotoxicol Environ Saf ; 208: 111582, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396105

RESUMO

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.


Assuntos
Bombyx/fisiologia , Cádmio/toxicidade , Cadeia Alimentar , Chumbo/toxicidade , Morus/fisiologia , Poluentes do Solo/toxicidade , Solo/química , Animais , Biodegradação Ambiental , Cádmio/análise , Cádmio/metabolismo , Frutas/química , Metais Pesados/análise , Fotossíntese , Folhas de Planta/química , Plântula/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
8.
Sci Total Environ ; 768: 144983, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33454486

RESUMO

The study presents results from 6 months of phytoremediation of sediments dredged from three urban retention tanks carried out in a mesocosm setup with the use of P. australis. Two kinds of P. australis seedlings were considered: seedlings originating from natural (uncontaminated - Suncont) and anthropogenically changed environments (contaminated - Scont); this distinction was reflected in the baseline concentrations of trace metals inside their tissues. The potentially toxic elements (PTEs) considered in this study were as follows: Zn, Cu, Cd, Ni, Cr, and Pb. The aim of the study was to compare the uptake, accumulation, and translocation properties of seedlings with different initial trace metal contents. The PTE concentrations were analyzed in sediments as well as in belowground and aboveground parts of plants in the middle (3rd month) and at the end of the investigation period using inductively coupled plasma mass spectrometry (ICP-MS), and the accumulation of PTEs in plant tissues was calculated. Phytoextraction efficiency was evaluated using the bioconcentration factor (BF) and translocation factor (TF). Plant morphology was assessed with scanning electron microscopy (SEM) to document plant stress due to PTE exposure. The results of our study indicated that P. australis seedlings originating from sites differing in the initial trace metal content exhibited different behavior when grown on sediments dredged from urban retention tanks. Suncont seedlings with low initial metal contents tended to adapt to the dredged sediments and showed phytoextraction ability, while Scont seedlings originating from sites with initial high contents of trace metals acted as phytoexcluders and tended to release PTEs from their tissues into the sediments. The morphological and structural effects caused by metal toxicity were observed in growth limitation, root tissue disturbance, root hair number decrease, and structural alterations in the epidermis and endodermis. Therefore, the Suncont seedlings presented better properties and adaptability for phytoremediation purposes.


Assuntos
Metais Pesados , Cádmio , Sedimentos Geológicos , Chumbo , Metais Pesados/análise , Plântula/química , Zinco
9.
Carbohydr Polym ; 255: 117494, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33436252

RESUMO

Hydrolysis of starch is key in several industrial processes, including brewing. Here, the activity and inactivation kinetics of amylases throughout barley malt mashing are investigated, as a prerequisite for rational optimisation of this process. Varietal differences were observed in the activity of α- and ß-amylases as a function of temperature for six barley and malt varieties. These differences were not reflected in the resulting wort composition after mashing, using three isothermal phases of 30 min at 45 °C, 62 °C and 72 °C with intermediate heating by 1 °C/min. Thermal inactivation kinetics parameters determined for α- and ß-amylases of an industrially relevant malt variety in a diluted system showed that enzymes were inactivated at lower temperatures than expected. The obtained kinetic parameters could predict α-amylase, but not ß-amylase inactivation in real mashing conditions, suggesting that ß-amylase stability is enhanced during mashing by components present or formed in the mash.


Assuntos
Hordeum/enzimologia , Proteínas de Plantas/metabolismo , Plântula/enzimologia , Amido/metabolismo , alfa-Amilases/metabolismo , beta-Amilase/metabolismo , Cerveja , Ensaios Enzimáticos , Estabilidade Enzimática , Fermentação , Hordeum/química , Temperatura Alta , Humanos , Hidrólise , Cinética , Proteínas de Plantas/química , Plântula/química , Amido/química , alfa-Amilases/química , beta-Amilase/química
10.
J Agric Food Chem ; 69(2): 638-645, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33398988

RESUMO

With widespread applications of the latest neonicotinoid in agriculture, dinotefuran has gradually become a hazardous contaminant for plants through the generation of excessive reactive oxygen species. However, the potential toxic mechanisms of oxidative damages to plants induced by dinotefuran are still unknown. As a core component of the glutathione antioxidant enzyme system, glutathione peroxidases have been used as biomarkers to reflect excessive oxidative stress. In this study, the hazardous effects of dinotefuran on AtGPX6 were investigated at the molecular level. The intrinsic fluorescence intensity of AtGPX6 was quenched using the static quenching mechanism upon binding with dinotefuran. Moreover, a single binding site was predicted for AtGPX6 toward dinotefuran, and the complex formation was presumed to be driven by hydrogen bonds or van der Waals forces, which conformed with the molecular docking results. In addition, AtGPX6 exhibited moderate binding affinity with dinotefuran based on the bio-layer interferometry assay. In addition, the loosening and unfolding of the protein skeleton of AtGPX6 with the addition of dinotefuran were explored along with the increase of hydrophobicity around tryptophan residues. Lastly, the toxic effects of dinotefuran on the root growth of Arabidopsis seedlings were also examined. The exploration of the binding mechanism of dinotefuran with AtGPX6 at the molecular level would provide the toxicity assessment of dinotefuran on plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/enzimologia , Guanidinas/farmacologia , Inseticidas/farmacologia , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Arabidopsis/química , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Sítios de Ligação , Inseticidas/química , Simulação de Acoplamento Molecular , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/química , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Plântula/química , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/genética
11.
Sci Total Environ ; 759: 143943, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33340855

RESUMO

The emerging contaminants gallium (Ga) and indium (In) are extensively used in advanced industries and are considered as toxic to humans. Limited information is available on the dynamics of Ga and In in soil-upland crop systems. Therefore, this study aimed to investigate the effects of Ga and In on the growth and uptake of Ga and In by wheat plants grown in Ga- and In-contaminated soils. The wheat seedlings were planted in soils of different properties spiked with various Ga and In concentrations (50, 100, 200, and 400 mg kg-1). The plant-available Ga, In, and Al in the soils were extracted by 0.02 M CaCl2, and their concentrations in plant tissues of wheat seedlings and plant biomass were determined after harvesting. The results indicated that the Al toxicity of wheat seedlings increased with Ga and In concentrations in acidic soils. Indium phytotoxicity was found in both neutral and acidic soils. Plant analysis results indicated that the concentration of Ga and In in roots was approximately one order of magnitude higher than that in the shoots of wheat seedlings, and the capability for Ga translocation from roots to shoots was higher than for In. The results of this study suggest that the dynamics of Ga and In in soil-upland crop systems is strongly dependent on the soil properties, such as pH and Al availability.


Assuntos
Gálio , Poluentes do Solo , Gálio/toxicidade , Humanos , Índio/toxicidade , Raízes de Plantas/química , Plântula/química , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Triticum
12.
Int J Biol Macromol ; 168: 195-204, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33309659

RESUMO

Herein for the first time a novel acid phosphatase from the seedlings of Cichorium intybus was purified to homogeneity by using various chromatographic techniques (salt precipitation, ion exchange, size exclusion and affinity chromatography) and thermodynamically characterized. The molecular mass of purified enzyme (66 kDa) was determined by SDS-PAGE under denaturing and non-denaturing conditions and by gel-filtration confirmed as dimer of molecular mass 130 kDa. The Michaelis-Menten (Km) constant for -p-NPP (0.3 mM) and (7.6 µmol/min/mg) Vmax. The enzyme was competitively inhibited by phosphate, molybdate and vanadate. Phenyl phosphate, ɑ and ß-glycero-phosphate and-p-NPP were found to be good substrate. When temperature increased from (55 °C to 75 °C), the deactivation rate constant (kd) was increased (0.1 to 4.6 min-1) and half- life was decreased from 630 min to 15 min. Various thermal denaturation parameters; change in enthalpy (ΔH°), change in entropy (ΔS°) and change in free energy (ΔG°) were found 121.93 KJ·mol-1, 72.45 KJ·mol-1 and 98.08 KJ·mol-1 respectively, confirming that acid phosphatase undergoes a significant process of unfolding during deactivation. The biochemical properties of acid phosphatase from C. intybus on the behalf of biological activity and its relationship to pH variations, thermal deactivation and kinetics parameters provide an insight into its novel features.


Assuntos
Fosfatase Ácida/química , Fosfatase Ácida/isolamento & purificação , Chicória/química , Chicória/enzimologia , Chicória/metabolismo , Cromatografia em Gel/métodos , Eletroforese em Gel de Poliacrilamida/métodos , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Fosfatos , Plântula/química , Temperatura , Termodinâmica
13.
PLoS One ; 15(12): e0234893, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382695

RESUMO

Breast cancer is the second leading cause of cancer-related mortality in women. Various nutritional compounds possess anti-carcinogenic properties which may be mediated through their effects on the gut microbiota and its production of short-chain fatty acids (SCFAs) for the prevention of breast cancer. We evaluated the impact of broccoli sprouts (BSp), green tea polyphenols (GTPs) and their combination on the gut microbiota and SCFAs metabolism from the microbiota in Her2/neu transgenic mice that spontaneously develop estrogen receptor-negative [ER(-)] mammary tumors. The mice were grouped based on the dietary treatment: control, BSp, GTPs or their combination from beginning in early life (BE) or life-long from conception (LC). We found that the combination group showed the strongest inhibiting effect on tumor growth volume and a significant increase in tumor latency. BSp treatment was integrally more efficacious than the GTPs group when compared to the control group. There was similar clustering of microbiota of BSp-fed mice with combination-fed mice, and GTPs-fed mice with control-fed mice at pre-tumor in the BE group and at pre-tumor and post-tumor in the LC group. The mice on all dietary treatment groups incurred a significant increase of Adlercreutzia, Lactobacillus genus and Lachnospiraceae, S24-7 family in the both BE and LC groups. We found no change in SCFAs levels in the plasma of BSp-fed, GTPs-fed and combination-fed mice of the BE group. Marked changes were observed in the mice of the LC group consisting of significant increases in propionate and isobutyrate in GTPs-fed and combination-fed mice. These studies indicate that nutrients such as BSp and GTPs differentially affect the gut microbial composition in both the BE and LC groups and the key metabolites (SCFAs) levels in the LC group. The findings also suggest that temporal factors related to different time windows of consumption during the life-span can have a promising influence on the gut microbial composition, SCFAs profiles and ER(-) breast cancer prevention.


Assuntos
Dieta/métodos , Ácidos Graxos Voláteis/sangue , Microbioma Gastrointestinal/efeitos dos fármacos , Neoplasias Mamárias Experimentais/prevenção & controle , Polifenóis/farmacologia , Plântula/química , Actinobacteria/efeitos dos fármacos , Actinobacteria/isolamento & purificação , Actinobacteria/fisiologia , Animais , Brassica/química , Clostridiales/efeitos dos fármacos , Clostridiales/isolamento & purificação , Clostridiales/fisiologia , Feminino , Microbioma Gastrointestinal/fisiologia , Expressão Gênica , Lactobacillus/efeitos dos fármacos , Lactobacillus/isolamento & purificação , Lactobacillus/fisiologia , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Experimentais/sangue , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Knockout , Polifenóis/química , Receptor ErbB-2/deficiência , Receptor ErbB-2/genética , Receptores Estrogênicos/deficiência , Receptores Estrogênicos/genética , Chá/química
14.
J Environ Qual ; 49(5): 1359-1369, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016446

RESUMO

Cadmium concentrations in cacao (Theobroma cacao L.) beans from South America often exceed trade limits. Liming soil is advocated as a remediation option, but amendments cannot be incorporated into the entire root zone without harming the trees. An experiment was set up to identify how Cd uptake varies within the root zone when surface and subsurface soil layers are either limed or not. The experiment used 22-cm-height pots with top and bottom layers using surface and subsurface soil samples from a cacao field. The potted soils were either surface limed or not or fully limed and layers spiked with stable 108 Cd isotope in various combinations to trace the plant Cd provenance. The root distribution was neither affected by liming nor by soil source; 70% of the root biomass was present in the top layer. Plants grown on the fully limed surface soil had 1.7 times lower Cd concentrations in leaves than the unlimed treatments, whereas this concentration was 1.2 times lower when only the top layer was limed (surface soil used in both layers). The isotope dilution data showed that surface soil liming enhanced Cd uptake from the unlimed bottom layer compared with the unlimed soil, suggesting compensating mechanisms. The pots containing surface soil over subsurface soil also showed that compensating effect but, due to lower phytoavailable Cd in the subsurface soil, surface liming still effectively reduced foliar Cd. We conclude that liming might be a feasible mitigation strategy, but its effectiveness is limited when Cd phytoavailability remains untreated in the subsurface layer.


Assuntos
Cacau , Poluentes do Solo/análise , Cádmio/análise , Plântula/química , Solo
15.
J Environ Manage ; 276: 111328, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32932068

RESUMO

Phytoremediation enhanced by electrokinetic has been considered as a potential technology for remediating contaminated soils. However, the effects of electric fields on Cd accumulation and photosynthesis in Zea mays (as a cathode) is still unclear. In the present study, Zea mays seedlings were exposed to various doses of Cd2+ (10, 50, 100 µM) to explore the impact of electric fields on Cd accumulation and photosynthesis of Zea mays. Results showed that upon exposure to a concentration of 100 µM Cd, electric fields significantly altered the Cd contents in maize shoots, whereas the concentration of 50 µM Cd increased the Cd contents in maize roots as well as affected the Cd transport from roots to shoots. Uptake index (UI) increased by 1.34%-66.16% with the application of electric fields. The variation of photosynthetic rates attributed to the open or closure of stoma was similar to the change of shoot fresh weight, particularly in maize exposed to high Cd stress. This study proposes a new technology in Cd phytoremediation and provides important information on physiological processes in maize when exposed to Cd stress and electric fields.


Assuntos
Poluentes do Solo , Zea mays , Biomassa , Cádmio/análise , Fotossíntese , Raízes de Plantas/química , Plântula/química , Poluentes do Solo/análise
16.
Environ Sci Pollut Res Int ; 27(31): 39635-39650, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32651780

RESUMO

Past mining activities have left a legacy of abandoned mine tailing deposits whose metal contaminants poses serious risks to ecosystems and human health. While the development of a vegetated cover in mine tailings can help in mitigating these risks, the local factors limiting plant establishment in these sites are not well understood, restricting phytostabilization efforts. Here, we explore some of the barriers that limit seedling establishment of two species (Vachellia farnesiana and Prosopis velutina) in a mine tailing deposit located in Nacozari, Sonora, Mexico, and assess whether compost addition can help in overcoming these barriers in pot and field experiments. Our field observations found 20 times more carbon and at least 4 times more nitrogen concentration in areas under vegetated patches than in non-vegetated areas, while a previous study found no difference in metal concentrations and other physicochemical parameters. This suggests that organic matter and nutrients are a major limitation for plant establishment. In agreement with this, species failed to establish without compost addition in the field experiment. Compost addition also had a positive effect on biomass accumulation, pH and microbial activity, but increased the substrate soluble concentration of As, Cu, and Zn. Nonetheless, only Cu, K, and Mo in P. velutina accumulated in tissues at levels considered toxic for animal consumption. Our study documents that compost addition facilitated plant establishment for the phytostabilization of mine tailings and help to prevent the dispersion of most metal contaminants via animal consumption. We encourage the use of complementary strategies to minimize the risk of dispersion of metal contaminants.


Assuntos
Compostagem , Poluentes do Solo/análise , Ecossistema , Humanos , México , Plântula/química , Solo
17.
Int J Phytoremediation ; 22(14): 1448-1461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603186

RESUMO

Nama aff. stenophylla plants grow on mining waste abandoned 100 years ago, exposed to high concentrations of heavy metals. Accumulation of heavy metals in plant biomass has been related to the phyto-accessible fractions of these, so we assessed the effect of those heavy metals in different concentrations on the germination and development of seedlings. The seed traits were characterized with optical and scanning electron microscope. The seeds were assessed for dormancy by pre-germinative treatments, germination percentage, tolerance index regarding heavy metals, and the elongation of seedlings under three concentrations of arsenic (As), cadmium (Cd), Iron (Fe), lead (Pb), and zinc (Zn) (phyto-accessible [Ph], five times higher [Hi] and lower [Lo]). The seeds have no dormancy, and the heavy metals did not affect the embryo. Pb, Cd, and As, affected the germination percentage more (p < 0.005). The treatments that most affected seedling elongation were Zn [Hi], Cd [Hi], Pb [Lo], Zn [Ph], Pb [Hi], Zn [Lo] (p < 0.005). The seedlings cells alterations were associated with the reduction in length, although larger cortical cells may be due to heavy metal compartmentalization in vacuoles. The seeds and seedlings showed tolerance to high concentrations of Fe and As, and to phyto-accessible of As, Cd, Pb, and Fe.


Assuntos
Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Germinação , Metais Pesados/análise , Metais Pesados/toxicidade , Plântula/química , Sementes , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
18.
PLoS One ; 15(5): e0231696, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32379784

RESUMO

The detection of direct archaeological remains of alcoholic beverages and their production is still a challenge to archaeological science, as most of the markers known up to now are either not durable or diagnostic enough to be used as secure proof. The current study addresses this question by experimental work reproducing the malting processes and subsequent charring of the resulting products under laboratory conditions in order to simulate their preservation (by charring) in archaeological contexts and to explore the preservation of microstructural alterations of the cereal grains. The experimentally germinated and charred grains showed clearly degraded (thinned) aleurone cell walls. The histological alterations of the cereal grains were observed and quantified using reflected light and scanning electron microscopy and supported using morphometric and statistical analyses. In order to verify the experimental observations of histological alterations, amorphous charred objects (ACO) containing cereal remains originating from five archaeological sites dating to the 4th millennium BCE were considered: two sites were archaeologically recognisable brewing installations from Predynastic Egypt, while the three broadly contemporary central European lakeshore settlements lack specific contexts for their cereal-based food remains. The aleurone cell wall thinning known from food technological research and observed in our own experimental material was indeed also recorded in the archaeological finds. The Egyptian materials derive from beer production with certainty, supported by ample contextual and artefactual data. The Neolithic lakeshore settlement finds currently represent the oldest traces of malting in central Europe, while a bowl-shaped bread-like object from Hornstaad-Hörnle possibly even points towards early beer production in central Europe. One major further implication of our study is that the cell wall breakdown in the grain's aleurone layer can be used as a general marker for malting processes with relevance to a wide range of charred archaeological finds of cereal products.


Assuntos
Arqueologia/métodos , Cerveja/história , Grão Comestível , Proteínas de Plantas/ultraestrutura , Cerveja/análise , Grão Comestível/química , Grão Comestível/ultraestrutura , Egito , Europa (Continente) , História Antiga , Humanos , Microscopia Eletrônica de Varredura , Plântula/química , Plântula/ultraestrutura
19.
Int J Phytoremediation ; 22(12): 1242-1248, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32393060

RESUMO

The contamination of orchard by cadmium (Cd) has recently increased in severity. To decrease the Cd content in fruit tree, a pot-based experiment was conducted to study the effects of intercropping with two Solanum species (Solanum alatum and Solanum diphyllum) on the growth and Cd accumulation of Cyphomandra betacea seedlings. The data revealed that intercropping with two Solanum species significantly increased the biomass, photosynthetic pigment contents, antioxidant enzyme activities, and soluble protein contents of C. betacea seedlings under Cd stress condition. The intercropping significantly decreased the Cd content in C. betacea seedlings. However, the intercropping significantly decreased the S. alatum and S. diphyllum biomasses, while increased the Cd content and accumulation in the roots and shoots of two Solanum species, and the Cd uptake by S. alatum was lower than that of S. diphyllum. Therefore, intercropping with these two Solanum species, especially S. diphyllum, may promote the growth and decrease the Cd content in C. betacea.


Assuntos
Poluentes do Solo/análise , Solanum , Biodegradação Ambiental , Cádmio/análise , Raízes de Plantas/química , Plântula/química
20.
Food Chem ; 321: 126716, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32278985

RESUMO

To explore functional food ingredients from green seedlings, the bioactive components (phenolic compounds and γ-aminobutyric acid) and antioxidant activities (DPPH radical scavenging ability, ABTS radical scavenging ability and reducing power) of three green seedlings, including coix seed seedling (CSS), highland barely seedling (HBS) and naked oats seedling (NOS) cultivars were respectively measured and deeply compared. Results indicated that CSS showed the highest contents of the total polyphenol (183.35 mg/100 g), total flavonoid (348.68 mg/100 g), and γ-aminobutyric acid (54.17 mg/100 g). As expected, CSS also exerted the highest level of antioxidant activity, followed by HBS and NOS. Moreover, CSS possessed the potential of stimulating immune responses, including promoting proliferation and strengthening phagocytosis function of RAW264.7 cells. Taken together, all results suggested that the three green seedlings, especially CSS could be used as natural ingredients for functional food.


Assuntos
Aminobutiratos/análise , Coix/química , Flavonoides/análise , Polifenóis/análise , Plântula/química , Aminobutiratos/farmacologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Camundongos , Extratos Vegetais/química , Polifenóis/farmacologia , Sementes/química
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