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1.
Ecotoxicol Environ Saf ; 203: 110961, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888621

RESUMO

Cadmium (Cd), which seriously affects plant growth and crop production, is harmful to humans. Previous studies revealed ryegrass (Lolium multiflorum Lam.) exhibits Cd tolerance, and may be useful as a potential hyperaccumulator because of its wide distribution. In this study, the physiological and transcriptional responses of two ryegrass cultivars [i.e., high (LmHC) and low (LmLC) Cd tolerance] to Cd stress were investigated and compared. The Cd tolerance of LmHC was greater than that of LmLC at various Cd concentrations. The uptake of Evans blue dye revealed that Cd-induced root cell mortality was higher in LmLC than in LmHC after a 12-h Cd treatment. Furthermore, the content and influx rate of Cd in LmLC roots were greater than in LmHC roots under Cd stress conditions. The RNA sequencing and quantitative real-time PCR data indicated that the Cd transport regulatory genes (ABCG37, ABCB4, NRAMP4, and HMA5) were differentially expressed between the LmLC and LmHC roots. This expression-level diversity may contribute to the differences in the Cd accumulation and translocation between LmLC and LmHC. These findings may help clarify the physiological and molecular mechanisms underlying ryegrass responses to Cd toxicity. Additionally, ryegrass may be able to hyperaccumulate toxic heavy metals during the phytoremediation of contaminated soil.


Assuntos
Adaptação Biológica , Cádmio/metabolismo , Lolium/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Poluentes do Solo/metabolismo , Transcrição Genética/efeitos dos fármacos , Adaptação Biológica/efeitos dos fármacos , Adaptação Biológica/genética , Biodegradação Ambiental , Cádmio/análise , Cádmio/toxicidade , Genes de Plantas , Lolium/química , Lolium/genética , Raízes de Plantas/química , Raízes de Plantas/genética , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
2.
Sci Total Environ ; 741: 140439, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887003

RESUMO

Hydrophobic pollutants have become widely distributed across the world. From an agricultural perspective, their accumulation in crops from contaminated soil threatens food security and quality, leading to many diseases in humans. The Cucurbitaceae family can accumulate high concentrations of hydrophobic pollutants in their aerial parts. The Cucurbitaceae family contains major latex-like proteins (MLPs) as transporting factors for hydrophobic pollutants. MLP genes are expressed in the roots in which the MLPs bind hydrophobic pollutants. MLPs transport these hydrophobic pollutants to the aerial parts of the plant through the xylem vessels. As a result, hydrophobic pollutant contamination occurs in the Cucurbitaceae family. In this study, we suppressed the expression of MLP genes in the roots and reduced the amounts of MLPs with pesticide treatments. First, the fungicides Benlate and Daconil that deceased the hydrophobic pollutant, perylene, concentration in the xylem sap of zucchini plants were selected. Daconil suppressed the transcription activity of MLP in the roots. In the Daconil treatment, the amount of MLPs in the roots and xylem sap of zucchini plants was decreased, and the concentrations of the hydrophobic pollutants, pyrene and dieldrin, were significantly decreased. Our research contributes to the production of safer crops.


Assuntos
Cucurbita , Poluentes Ambientais , Poluentes do Solo/análise , Produtos Agrícolas , Dieldrin , Raízes de Plantas/química
3.
Environ Monit Assess ; 192(10): 651, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32964290

RESUMO

Cadmium (Cd) pollution in plastic shed soils has become increasingly severe, posing a great threat to human health and social stability. Phytoremediation of cadmium pollution is an environmentally friendly and inexpensive remediation method. In this study, maize (Zea mays L.) was selected as the phytoremediation crop by a potted method, and the bioavailability of cadmium was investigated by adding exogenous elemental sulfur. The relationships among the sulfur content, maize growth, cadmium accumulation, and soil parameters were systematically studied. The results showed that, with the supplement of sulfur, the soil pH and activities of soil enzymes (urease, catalase, and sucrase) decreased gradually, and the available heavy metals (Cd, Cr, Zn, and Cu) in soil showed an upward trend. The optimal cadmium enrichment was achieved under T2 by increasing both the biomass of the maize plant and the cadmium concentration in roots and stems. However, T3 and T4 significantly inhibited the growth of maize roots and shoots, leading to a much lower plant biomass compared with that of CK (sulfur-free treatment) and T2. In addition, the cumulative cadmium was not increased because of the low accumulation of cadmium in some parts of the plant. Correlation analyses showed that the sulfur content was negatively correlated with soil pH and maize biomass (P < 0.01), and the cadmium content of whole maize was positively correlated with the dry weight of maize (P < 0.05) and the cadmium content in roots and stems (P < 0.01). In summary, to optimize cadmium phytoremediation of the plastic shed soil, an appropriate concentration of sulfur should be selected in practical applications to ensure that the biomass of the maize is maximized, and the cadmium concentration in different parts of the maize is increased or stabilized.


Assuntos
Cádmio/análise , Poluentes do Solo/análise , Biodegradação Ambiental , Biomassa , Monitoramento Ambiental , Humanos , Raízes de Plantas/química , Plásticos , Solo , Enxofre , Zea mays
4.
Cochrane Database Syst Rev ; 9: CD004448, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32977351

RESUMO

BACKGROUND: Sickle cell disease, a common recessively inherited haemoglobin disorder, affects people from sub-Saharan Africa, the Middle East, Mediterranean basin, Indian subcontinent, Caribbean and South America. It is associated with complications and a reduced life expectancy. Phytomedicines (medicine derived from plants in their original state) encompass many of the plant remedies from traditional healers which the populations most affected would encounter. Laboratory research and limited clinical trials have suggested positive effects of phytomedicines both in vivo and in vitro. However, there has been little systematic appraisal of their benefits. This is an updated version of a previously published Cochrane Review. OBJECTIVES: To assess the benefits and risks of phytomedicines in people with sickle cell disease of all types, of any age, in any setting. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, the International Standard Randomised Controlled Trial Number Register (ISRCTN), the Allied and Complimentary Medicine Database (AMED), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). Dates of most recent searches: Cochrane Cystic Fibrosis and Genetic Disorders Haemoglobinopathies Trials Register: 17 March 2020; ISRCTN: 19 April 2020; AMED: 18 May 2020; ClinicalTrials.gov: 24 April 2020; and the WHO ICTRP: 27 July 2017. SELECTION CRITERIA: Randomised or quasi-randomised trials with participants of all ages with sickle cell disease, in all settings, comparing the administration of phytomedicines, by any mode to placebo or conventional treatment, including blood transfusion and hydroxyurea. DATA COLLECTION AND ANALYSIS: Both authors independently assessed trial quality and extracted data. MAIN RESULTS: Three trials (212 participants) of three phytomedicines: Niprisan® (also known as Nicosan®), Ciklavit® and a powdered extract of Pfaffia paniculata were included. The Phase IIB (pivotal) trial suggests that Niprisan® may be effective in reducing episodes of severe painful sickle cell disease crisis over a six-month period (low-quality evidence). It did not appear to affect the risk of severe complications or the level of anaemia (low-quality evidence). The single trial of Cajanus cajan (Ciklavit®) reported a possible benefit to individuals with painful crises, and a possible adverse effect (non-significant) on the level of anaemia (low-quality evidence). We are uncertain of the effect of Pfaffia paniculata on the laboratory parameters and symptoms of SCD (very low-quality of evidence). No adverse effects were reported with Niprisan® and Pfaffia paniculata (low- to very low-quality evidence). AUTHORS' CONCLUSIONS: While Niprisan® appeared to be safe and effective in reducing severe painful crises over a six-month follow-up period, further trials are required to assess its role in managing people with SCD and the results of its multicentre trials are awaited. Currently, no conclusions can be made regarding the efficacy of Ciklavit® and the powdered root extract of Pfaffia paniculata in managing SCD. Based on the published results for Niprisan® and in view of the limitations in data collection and analysis of the three trials, phytomedicines may have a potential beneficial effect in reducing painful crises in SCD. This needs to be further validated in future trials. More trials with improved study design and data collection are required on the safety and efficacy of phytomedicines used in managing SCD.


Assuntos
Anemia Falciforme/tratamento farmacológico , Antidrepanocíticos/uso terapêutico , Fitoterapia , Extratos Vegetais/uso terapêutico , Adolescente , Adulto , Amaranthaceae/química , Anemia/induzido quimicamente , Anemia Falciforme/sangue , Antidrepanocíticos/efeitos adversos , Criança , Pré-Escolar , Ensaios Clínicos Fase II como Assunto , Feminino , Humanos , Lactente , Masculino , Fitoterapia/efeitos adversos , Extratos Vegetais/efeitos adversos , Raízes de Plantas/química , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Nat Commun ; 11(1): 4897, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994415

RESUMO

Soil microbial respiration is an important source of uncertainty in projecting future climate and carbon (C) cycle feedbacks. However, its feedbacks to climate warming and underlying microbial mechanisms are still poorly understood. Here we show that the temperature sensitivity of soil microbial respiration (Q10) in a temperate grassland ecosystem persistently decreases by 12.0 ± 3.7% across 7 years of warming. Also, the shifts of microbial communities play critical roles in regulating thermal adaptation of soil respiration. Incorporating microbial functional gene abundance data into a microbially-enabled ecosystem model significantly improves the modeling performance of soil microbial respiration by 5-19%, and reduces model parametric uncertainty by 55-71%. In addition, modeling analyses show that the microbial thermal adaptation can lead to considerably less heterotrophic respiration (11.6 ± 7.5%), and hence less soil C loss. If such microbially mediated dampening effects occur generally across different spatial and temporal scales, the potential positive feedback of soil microbial respiration in response to climate warming may be less than previously predicted.


Assuntos
Carbono/análise , Metagenoma/genética , Microbiota/fisiologia , Microbiologia do Solo , Solo/química , Aclimatação/genética , Archaea/genética , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Carbono/metabolismo , Ciclo do Carbono , Celulose/metabolismo , DNA Ambiental/genética , DNA Ambiental/isolamento & purificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Aquecimento Global , Pradaria , Temperatura Alta/efeitos adversos , Metagenômica , Modelos Genéticos , Raízes de Plantas/química , Poaceae/química
6.
PLoS One ; 15(8): e0231805, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760118

RESUMO

Boron (B) is required during all growth stages of cotton crop, especially during boll formation. However, Typic Haplocambid soils of cotton growing belt in Pakistan are B-deficient, which results in low yield and economic returns. Foliar application of B improves cotton productivity; however, information is limited on the role of soil applied B in improving cotton growth and yield. The current study investigated the role of soil applied B in improving growth, yield and fiber quality of cotton crop. Five different B doses (i.e., 0.00, 2.60, 5.52, 7.78 and 10.04 mg kg-1 of soil) and two cotton cultivars (i.e., CIM-600 and CIM-616) were included in the study. Soil applied B (2.60 mg kg-1) significantly improved growth, yield, physiological parameters and fiber quality, while 10.04 mg kg-1 application improved B distribution in roots, seeds, leaves and stalks. Significant improvement was noted in plant height (12%), leaf area (3%), number of bolls (48%), boll size (59%), boll weight (52%), seed cotton yield (52%), photosynthesis (50%), transpiration rate (10%), stomatal conductance (37%) and water use efficiency (44%) of CIM-600 with 2.60 mg kg-1 compared to control treatment of CIM-616. Similarly, B accumulation in roots, seeds, leaves and stalk of CIM-600 was improved by 76, 41, 86 and 70%, respectively compared to control treatment. The application of 2.60 mg kg-1 significantly improved ginning out turn (6%), staple length (3.5%), fiber fineness (17%) and fiber strength (5%) than no B application. The results indicated that cultivar CIM-600 had higher ginning out turn (1.5%), staple length (5.4%), fiber fineness (15.5%) and fiber strength (1.8%) than CIM-616. In crux, 2.60 mg kg-1 soil B application improved growth, yield, physiological and fiber quality traits of cotton cultivar CIM-600. Therefore, cultivar CIM-600 and 2.60 mg kg-1 soil B application is recommended for higher yield and productivity.


Assuntos
Boro/metabolismo , Gossypium/crescimento & desenvolvimento , Gossypium/metabolismo , Biomassa , Fibra de Algodão/análise , Fertilizantes , Paquistão , Fotossíntese , Folhas de Planta/química , Raízes de Plantas/química , Sementes/química , Solo/química , Água
7.
PLoS One ; 15(8): e0230089, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760138

RESUMO

Ecological stoichiometric should be incorporated into management and nutrient impacted ecosystems dynamic to understand the status of ecosystems and ecological interaction. The present study focused on ecological stoichiometric characteristics of soil, and leaves, stems, and roots of different macrophytes after the banning of seine fishing in Shengjin Lake. For C, N, and P analysis from leaves, stems, roots, and soil to explore their stoichiometric ratio and deriving environmental forces, four dominant plant communities (Vallisneria natans, Zizania latifolia, Trapa natans and Carex schmidtii) were collected. The concentration of C, N, P and C: N: P ratio in leaves, stems, roots, and soil among the plant communities varied significantly. Along the depth gradient high C: N was measured in C.schmidtii soil (7.08±1.504) but not vary significantly (P >0.05). High C: P result was found in T.natans (81.14±43.88) and in V.natans soil (81.40±42.57) respectively with no significant difference (p>0.05). Besides, N: P ratio measured high in V. natans (13.7±4.05) and showed significant variation (P<0.05). High leaf C: N and N: P ratio was measured in C. schmidtii and V. natans respectively. Nevertheless, high leaf C: P ratio was measured in Z. latifolia. From the three studied organs, leaf C: N and N: P ratio showed high values compared to root and stems. The correlation analysis result showed that at 0-10cm depth soil organic carbon (SOC) correlated negatively with stem total phosphorus (STP), and root total nitrogen (RTN) (P<0.05) but positively strongly with leaf total phosphorus (LTP) and leaf total nitrogen (LTN) (P<0.01) respectively. Soil total nitrogen (STN) at 0-10cm strongly positively correlated with leaf total phosphorus (LTP) (P<0.01) and positively with RN: P and leaf total carbon (LTC) (P<0.05). Soil basic properties such as soil moisture content (SMC), bulky density (BD) and pH positively correlated with soil ecological stoichiometric characteristics. Redundancy analysis (RDA) result showed available nitrogen (AN), soil total nitrogen (STN), and available phosphorus (AP) were the potential determinants variables on plants stoichiometric characteristics.


Assuntos
Plantas/química , Solo/química , Carbono/análise , Carex (Planta) , China , Ecossistema , Eleocharis , Hydrocharitaceae , Lagos , Nitrogênio/análise , Fósforo/análise , Folhas de Planta/química , Raízes de Plantas/química , Caules de Planta/química , Poaceae , Áreas Alagadas
8.
Environ Pollut ; 266(Pt 1): 115385, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32798984

RESUMO

Bioaccumulation and toxicity of per-and polyfluoroalkyl substances and metal in plants have been confirmed, however their contamination in soil and plants still requires extensive investigation. In this study the combined effects of chlorinated polyfluoroalkyl ether potassium sulfonate (F53B) and chromium (Cr) on water spinach (Ipomoea aquatica Forsk) were investigated. Compared with each single stress, the combination of F53B and Cr (VI) reduced the biomass and height and increasingly accumulated in the roots and destroyed the cell structure. Besides, the co-contamination led to the immobilization of F53B and Cr (VI) in soil, which affected their migration in soil and transfer to plants. The antioxidant response and photosynthesis of the plant weakened under the single Cr (VI) and enhanced under the single F53B treatment; however the contamination of F53B and Cr (VI) could also reduce this effect, as confirmed by the gene expression of MTa, psbA and psbcL genes. This study provides an evidence of the environmental risks resulting from the coexistence of F53B and Cr (VI).


Assuntos
Ipomoea , Poluentes do Solo/análise , Cromo , Éter , Raízes de Plantas/química , Potássio , Spinacia oleracea , Água
9.
Bull Environ Contam Toxicol ; 105(3): 428-432, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32740744

RESUMO

The accumulation of Cd and Pb in rice grains poses a potential threat to human health, which is a subject of increasing concern across the globe. We examined the effect that foliar spraying of Zn-ethylenediaminetetraacetate (Zn-EDTA) (0.3% and 0.5% w/v) during the early-grain filling stage has on rice grain yield and Cd, Pb, Zn and Fe contents in rice tissues via a field experiment. The grain yield significantly decreased with the foliar application of 0.5% Zn-EDTA. In rice grain, foliar spraying of 0.5% Zn-EDTA significantly decreased the Cd and Pb contents, but increased the Zn and Fe contents. The main reasons for the decrease in the Cd and Pb content in grain were the inhibition of Cd and Pb by roots and the increased Fe content in grain via Zn-EDTA application. The foliar spraying of Zn-EDTA decreased the grain yield and Cd and Pb contents, while increased the Zn and Fe contents in grains.


Assuntos
Cádmio/análise , Ácido Edético/química , Chumbo/análise , Oryza/fisiologia , Poluentes do Solo/análise , Grão Comestível/química , Humanos , Oryza/efeitos dos fármacos , Folhas de Planta/química , Raízes de Plantas/química , Solo , Zinco/análise
10.
Bull Environ Contam Toxicol ; 105(3): 405-410, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32776280

RESUMO

The accumulation of zinc (Zn) in Cichorium intybus and effects of phytotoxicity during 90 days of growth on (natural) non-contaminated and Zn-contaminated soils were studied. The phytotoxicity effects were monitored by evaluating the leaf area, leaf biomass, leaf length and root length of the vegetable. The Zn concentrations ranged from 5.35 ± 1.05 to 37.5 ± 3.89 mg kg-1 in leaves of plants grown on natural soil, and from 334.0 ± 25.6 to 2232 ± 16.7 mg kg-1 when grown on Zn-contaminated soils. Zn accumulation caused a decrease in growth on contaminated soils and an increase in phytotoxicity. These effects were associated to high metal concentration, mobility and bioavailability in the soil as well as changes in the translocation mechanism from the roots to the leaves. Then, it must be avoided the organic fertilization of soils with either animal manure or other agricultural inputs containing high zinc concentrations.


Assuntos
Chicória/efeitos dos fármacos , Poluentes do Solo/toxicidade , Zinco/toxicidade , Animais , Disponibilidade Biológica , Chicória/metabolismo , Fertilizantes , Metais , Folhas de Planta/química , Raízes de Plantas/química , Plantas , Solo , Poluentes do Solo/análise , Verduras , Zinco/análise
11.
PLoS One ; 15(8): e0237567, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797097

RESUMO

Distinct morphological MgO nanoparticles (MgONPs) were synthesized using biomasses of Saussurea costus roots. The biomass of two varieties of Saussurea costus (Qustal hindi and Qustal bahri) were used in the green synthesis of MgONPs. The physical and chemical features of nanoparticles were confirmed by spectroscopic and microscopic techniques. The surface morphology of the obtained nanoparticles was detected at different magnifications by SEM and TEM microscopy and the size of nanoparticles were found to be 30 and 34 nm for Qustal hindi and Qustal bahri, respectively. The antimicrobial activity of the prepared MgONPs was screened against six pathogenic strains. The synthesized nanoparticles by Qustal bahri biomass exerted significant inhibition zones 15, 16, 18, 17, 14, and 10 mm against E. coli, P. aeruginosa, C. tropicalis and C. glabrata, S. aureus and B. subtilis as compared to those from Qustal hindi 12, 8 and 17 mm against B. subtilis, E. coli and C. tropicalis, respectively. MgONPs showed a potential cytotoxicity effect against MCF-7 breast cancer cell lines. Cellular investigations of MgONPs revealed that the prepared nanoparticles by Qustal bahri exhibited high cytotoxicity against MCF-7 cancer cell lines. IC50 values in MCF-7 cells were found to be 67.3% and 52.1% for MgONPs of Saussurea costus biomasses, respectively. Also, the photocatalytic activity of MgONPs of each Saussurea costus variety was comparatively studied. They exhibited an enhanced photocatalytic degradation of methylene blue after UV irradiation for 1 h as 92% and 59% for those prepared by Qustal bahri and Qustal hindi, respectively. Outcome of results revealed that the biosynthesized MgONPs showed promising biomedical potentials.


Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Óxido de Magnésio/farmacologia , Azul de Metileno/química , Saussurea/química , Anti-Infecciosos/química , Antineoplásicos/química , Bactérias/efeitos dos fármacos , Biomassa , Catálise , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Fungos/efeitos dos fármacos , Química Verde , Humanos , Células MCF-7 , Óxido de Magnésio/química , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Processos Fotoquímicos , Extratos Vegetais/química , Raízes de Plantas/química
12.
Chemosphere ; 260: 127668, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32758779

RESUMO

A series of pollutants can be removed from soil using a Fenton-like oxidation and biological treatment. As a natural mineral, tourmaline has been used for as a material of Fenton-like reaction. In the present study, the risks of remediation technology tourmaline catalyzed Fenton-like reaction (TCFR) combined with Phanerochaete chrysosporium (TCFR + P) were assessed through measuring soil properties, physiological response of plant, and PBDEs migration from soil to plant. Batch pot experiments showed that the silicon contents, specific surface area and soil pore size of soil in TCFR and 5%TCFR + P groups increased obviously. TCFR and TCFR + P treatments promoted the lettuce growth compared to control. Moreover, chlorophyll content of lettuce in 2%TCFR + P and 5%TCFR + P group increased by 46.74% and 44.57% than that in the CK, respectively. The treatment of 2%TCFR decreased the total concentration of PBDEs in rhizosphere soil and non-rhizosphere soil by 52.0.2% and 64.17%, respectively, after 60 days compared to the soil of CK, and did not prompt the uptake of lower-brominated PBDEs by lettuce. TCFR and TCFR + P can alter the migration of BDE isomers from soil to plant, the ratio of BDE99/BDE100 in lettuce shoots decreased slightly. BDE-99/BDE-100 ratios in the shoots were lower than those in the roots, while BDE153/BDE154 ratios were higher than 1.0 and ratios in shoots were higher than those in roots. Therefore, our findings illustrated that the TCFR could be applied to remediate the agricultural soil, considering the appropriate doses of tourmaline.


Assuntos
Biodegradação Ambiental , Éteres Difenil Halogenados/metabolismo , Silicatos/química , Poluentes do Solo/metabolismo , Catálise , Éteres Difenil Halogenados/análise , Alface , Minerais , Phanerochaete , Raízes de Plantas/química , Bifenil Polibromatos , Rizosfera , Solo , Poluentes do Solo/análise
13.
Int J Phytoremediation ; 22(9): 916-930, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32677841

RESUMO

This review article focuses on lead (Pb), one of the most ubiquitous and harmful toxicants found in soil. Our objective is to address misconceptions regarding the ability of plants to uptake Pb through their roots and translocate it to above-ground tissues, and their ability to act as hyperaccumulators and thereby phytoextract Pb. In accordance with a number of cited definitions, we suggest that species capable of Pb phytoextraction can be rated with the following three criteria: (1) root uptake above a nominal threshold of 1,000 mg Pb/kg, (2) bioconcentration factor (BCF or shoot/soil concentration) >1, and (3) translocation factor (TF or shoot/root concentration) > 1. We review the literature in the updated USDA Phytoremediation Database and conclude that without amendments: no plant has met all three criteria; no plant has been confirmed as a Pb hyperaccumulator. Our analysis suggests that Pb phytoextraction is not a viable remediation option. Pb phytostabilization, however, may be an effective remediation tool in a variety of settings. Planting some of the many species capable of tolerating soil Pb exposure and sequestering it in or around the root zone will limit Pb movement into other ecosystems, prevent resuspended dusts, and mitigate Pb exposure.


Assuntos
Poluentes do Solo/análise , Biodegradação Ambiental , Ecossistema , Chumbo , Raízes de Plantas/química , Solo
14.
Bull Environ Contam Toxicol ; 105(2): 270-276, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32661664

RESUMO

Marigold (Calendula calypso) is a multipurpose ornamental plant, but its cadmium (Cd) tolerance and phytoremediation potential is unknown. The proposed study was carried out to unravel Cd partitioning, physiological and oxidative stress responses of C. calypso grown under Cd stress. Plants were grown for four months in pots having different soil Cd levels: 0, 25, 50, 75, and 100 mg kg-1 soil. Plant growth, biomass, photosynthetic pigments, leaf water contents, stomatal conductance, and membrane stability index were not decreased at 25 mg kg-1 Cd. At higher levels of Cd stress, activities of antioxidant enzymes (SOD, APX, CAT, POD) increased to mitigate H2O2 and lipid peroxidation. Cadmium uptake in plants increased with increasing soil Cd levels, and roots accumulated a greater portion of Cd, followed by shoots and flowers, respectively. On the basis of Cd accumulation and its tolerance, it was determined that C. calypso can be successfully grown for phytostabilization of Cd contaminated soils.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Calendula/fisiologia , Poluentes do Solo/metabolismo , Antioxidantes , Biomassa , Cádmio/análise , Peróxido de Hidrogênio , Neonicotinoides , Estresse Oxidativo , Fotossíntese , Folhas de Planta/química , Raízes de Plantas/química , Solo , Poluentes do Solo/análise , Tiazinas
15.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2168-2174, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715678

RESUMO

Allelopathy is a plant-plant interaction mediated by the allelochemicals, which directly or indirectly influence plant growth. As the major part in response to allelochemicals, root morphological traits play an important role in allelopathy research. The global pattern of effects of exogenous allelochemicals on root morphology is not well known. We carried out a meta-analysis based on 61 studies to assess the effects of allelochemicals, including phenols, terpenoids, nitrogen-containing allelochemicals, on root morphology, especially on root length. We found that the allelochemicals significantly inhibited root length, but had little effect on root biomass, root surface area, and root volume. Phenols exhibited the most inhibitory effects on root length, while the allelochemicals had more inhibitory effect on root length of herbs than woody species as well as crops and other species. There was a linear relationship between phenols concentrations and their effect size. We quantified the dose-effect relationship of four phenolic acids, ferulic acid, p-hydroxybenzoic acid, vanillic acid and cinnamic acid. The inhibitory effect of flavonoids on root length was significantly higher than that of phenolic acids. Together, these findings suggested that the responses of target plant root traits to allelochemicals depended on allelochemicals type and dose, species identity, and culture conditions. Future studies need to decipher the mechanism underlying the allelochemicals on root traits of morphology, physiology and architecture under soil environment.


Assuntos
Alelopatia , Fenóis/análise , Produtos Agrícolas , Feromônios , Raízes de Plantas/química , Solo
16.
J Med Microbiol ; 69(8): 1049-1061, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32602832

RESUMO

Introduction. Metal exposure is an important factor for inducing antibiotic resistance in bacteria. Dandelion extracts have been used for centuries in traditional Chinese and Native American medicine.Aim. We assessed the effects of dandelion water extracts and taraxasterol on heavy metal-induced antibiotic resistance in Escherichia coli as well as the underlying mechanisms.Methodology. Dandelion extracts were obtained through 4 h of boiling in distilled water. Bacterial growth was monitored with a spectrophotometer. Biochemical assays were performed to assess the activities and gene transcriptions of ß-lactamase and acetyltransferase. Oxidative stress was determined using an oxidation-sensitive probe, H2DCFDA.Results. The present study demonstrated that higher concentrations of nickel (>5 µg ml-1), cadmium (>0.1 µg ml-1), arsenic (>0.1 µg ml-1) and copper (>5 µg ml-1) significantly inhibited the growth of E. coli. Lower concentrations of nickel (0.5 µg ml-1), cadmium (0.05 µg ml-1) and arsenic (0.05 µg ml-1) had no effect on bacterial growth, but helped the bacteria become resistant to two antibiotics, kanamycin and ampicillin. The addition of dandelion root extracts and taraxasterol significantly reversed the antibiotic resistance induced by these heavy metals. The supplements of antibiotics and cadmium generated synergistic effects on the activities of ß-lactamase and acetyltransferase (two antibiotic resistance-related proteins), which were significantly blocked by either dandelion root extract or taraxasterol. In contrast, oxidative stress was not involved in the preventative roles of dandelion root extracts and taraxasterol in heavy metal-induced antibiotic resistance.Conclusion. This study suggests that heavy metals induce bacterial antibiotic resistance and dandelion root extracts and taraxasterol could be used to help reverse bacterial resistance to antibiotics.


Assuntos
Resistência Microbiana a Medicamentos/efeitos dos fármacos , Metais Pesados/efeitos adversos , Extratos Vegetais/farmacologia , Esteróis/farmacologia , Taraxacum/química , Triterpenos/farmacologia , Resistência a Ampicilina/efeitos dos fármacos , Arsênico/efeitos adversos , Cádmio/efeitos adversos , Cobre/efeitos adversos , Escherichia coli/efeitos dos fármacos , Humanos , Índios Norte-Americanos , Resistência a Canamicina/efeitos dos fármacos , Medicina Tradicional Chinesa , Medicina Tradicional , Níquel/efeitos adversos , Raízes de Plantas/química
17.
Environ Sci Pollut Res Int ; 27(31): 39094-39104, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32638307

RESUMO

Two pot experiments were conducted to study the effects of intercropping cadmium (Cd) accumulator plants (Stellaria media (L.) Villars, Cardamine hirsuta, Cerastium glomeratum Thuill, and Galium aparine L.) and applying their straw on the growth and Cd accumulation of Brassica chinensis L. Intercropping with four accumulator plants reduced the biomass, water content, and photosynthetic pigment content of B. chinensis compared with monoculture. Intercropping with accumulator plants increased the Cd content in the roots and shoot of B. chinensis, and the translocation factor (TF), root bioconcentration factor (root BCF), and shoot bioconcentration factor (Shoot BCF) increased. The soil pH decreased and the soil available Cd content increased by intercropping. Thus, intercropping with four accumulator plants can promote the Cd uptake of B. chinensis. The straw of four accumulator plants reduced the biomass, water content, and photosynthetic pigment content of B. chinensis compared with the control. The straw of S. media and C. hirsute increased the Cd content in the roots and shoots of B. chinensis, TF, root BCF, and shoot BCF. The straw of C. glomeratum and G. aparine decreased the Cd content in the roots and shoots of B. chinensis, TF, root BCF, and shoot BCF. The soil pH increased and the soil available Cd content decreased by application of straw. Thus, the straw of C. glomeratum and G. aparine can reduce the Cd uptake of B. chinensis.


Assuntos
Brassica , Poluentes do Solo/análise , Biodegradação Ambiental , Cádmio/análise , Raízes de Plantas/química , Solo
18.
Environ Pollut ; 266(Pt 1): 115088, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32663676

RESUMO

This work aimed to investigate the metal accumulation characteristics as well as biogeochemical changes in the rhizosphere and root foraging strategies of this plant species. Previous reports suggested that Noccaea rotundifolia ssp. cepaeifolia is a Zn, Cd and Pb hyperaccumulator. We used hydroponic, rhizobox and split-pot experiments for studying metal accumulation and related rhizosphere processes. Although this species accumulated up to 1250 mg Pb kg-1 and 27,000 mg Zn kg-1 in shoots, translocation factors <1 do not meet the hyperaccumulation criteria. Substantial increases in Ca(NO3)2-extractable metals in the N. rotundifolia rhizosphere of a metal-spiked soil can be explained by proton release from N. rotundifolia roots to maintain the charge balance during excessive metal uptake; this was not observed for the non-spiked, moderately contaminated control soil. Specific rhizosphere mechanisms targeting the alleviation of metal toxicity in N. rotundifolia rhizosphere were not detected. Generally, N. rotundifolia had larger total root and shoot mass in soils with heterogeneous distribution of Zn and Pb relative to homogeneous treatments, associated with less root mass placed in metal-enriched patches. However, the avoidance strategy was not reflected by low shoot metal concentrations. Metal accumulation rates and translocation factors do not meet the criteria for hyperaccumulation. Changes of pH and DOC in N. rotundifolia rhizosphere were apparently not involved in targeted immobilisation or detoxification of Pb, Zn and Cd. Avoidance of metal-rich patches in soil is a major tolerance strategy of N. rotundifolia.


Assuntos
Rizosfera , Poluentes do Solo/análise , Biodegradação Ambiental , Metais , Raízes de Plantas/química , Solo
19.
Zhongguo Zhong Yao Za Zhi ; 45(14): 3407-3413, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32726056

RESUMO

In this study, HPLC was used to determine the content of the four isoflavones of Astragalus membranceus var. mongholicus from different regions(calycosin-7-glucoside, ononin, calycosin and formononetin), and gray correlation analysis and path analysis were used to explore the influence of climate factors on the content of isoflavone components in A. membranceus var. mongholicus. The results showed that there were significant differences in the content of the four isoflavones in different areas(P<0.05); grey correlation analysis showed that the highest temperature in July, the lowest temperature in January and the daily average temperature had a greater impact on the content of flavonoid glycosides, meanwhile precipitation and relative humidity were the more important factors for the accumulation of flavonoid aglycones. According to the general analysis, the direct positive effects of the lowest temperature in January and altitude on the contents of four isoflavones in A. membranceus var. mongholicus were significant. High altitude and extreme temperature conditions might be more adverse to the formation and accumulation of isoflavone components. Therefore, the religions of A. membranceus var. mongholicus with high contents of isoflavones should be chosen the low altitude region with higher minimum temperature in January. This study provides a reference basis for the quality evaluation of A. membranceus var. mongholicus, and basic data for the selection of suitable habitat, construction of planting standards and directional cultivation of medicinal materials in A. membranceus var. mongholicus.


Assuntos
Astrágalo (Planta) , Isoflavonas/análise , Astragalus propinquus , Cromatografia Líquida de Alta Pressão , Raízes de Plantas/química
20.
Huan Jing Ke Xue ; 41(5): 2398-2405, 2020 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608859

RESUMO

Tri-and hexavalent chromium have different chemical properties, and their levels of toxicity to plants are different. However, there is no limit set by the soil environmental quality risk control standard for Cr(Ⅲ) or Cr(Ⅵ). Therefore, studying the ecological toxicity of Cr has important implications for protecting the environment. Based on the dynamics of the Cr(Ⅲ) and Cr(Ⅵ) levels in soil solution collected from eight soils, the toxicity thresholds of the two Cr forms to barley roots were investigated through model calculation and correlation analysis under different soil properties. The results showed that both Cr forms and the soil properties had significant effects on the root length of barley. The effective concentrations of Cr(Ⅲ) added to the soils that led to 10% inhibition (EC10), 50% inhibition (EC50), and no-observed-effect concentrations (NOEC) were significantly higher than those of Cr(Ⅵ). The EC50 of Cr(Ⅲ) ranged from 298.8 to 2014.1 mg·kg-1 (6.7-fold variation); the EC50 of Cr(Ⅵ) ranged from 8.0 to 126.6 mg·kg-1 (15.8-fold variation). Under the same soil conditions, the EC50 of Cr(Ⅲ) was 2.8 to 101.7 times higher than that of Cr(Ⅵ), suggesting the higher phytotoxicity of Cr(Ⅵ) than Cr(Ⅲ). Correlation analysis showed that the pH and soil organic matter were the main factors that influenced the Cr toxicity thresholds, as indicated by the root length of barley. The concentration of chromium in the soil solution was below the detection limit of the TAS-990 when Cr(Ⅲ) was applied at 1280 mg·kg-1 (or less) to soils, whereas for Cr(Ⅵ), the level was 40 mg·kg-1 (or less). Cr(Ⅲ) adsorption to the soil was significantly stronger than that of Cr(Ⅵ). The toxicity of Cr(Ⅵ) was significantly higher than that of Cr(Ⅲ), which was also influenced by soil properties.


Assuntos
Poluentes do Solo/análise , Solo , Cromo , Hordeum , Raízes de Plantas/química
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