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1.
Food Chem X ; 22: 101289, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38544933

RESUMEN

Oligosaccharides are low-molecular-weight carbohydrates between monosaccharides and polysaccharides. They can be extracted directly from natural products by physicochemical methods or obtained by chemical synthesis or enzymatic reaction. Oligosaccharides have important physicochemical and physiological properties. Their research and production involve many disciplines such as medicine, chemical industry, and biology. Functional oligosaccharides, as an excellent functional food base, can be used as dietary fibrer and prebiotics to enrich the diet; improve the microecology of the gut; exert antitumour, anti-inflammatory, antioxidant, and lipid-lowering properties. Therefore, the industrial applications of oligosaccharides have increased rapidly in the past few years. It has great prospects in the field of food and medicinal chemistry. This review summarized the preparation, structural features and biological activities of oligosaccharides, with particular emphasis on the application of functional oligosaccharides in the food industry and human nutritional health. It aims to inform further research and development of oligosaccharides and food chemistry.

2.
Sci Total Environ ; 744: 140793, 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-32688002

RESUMEN

Owing to its sustainability and low cost, direct revegetation (DR) has been considered a promising alternative to capped revegetation (CR) for dealing with the serious environmental problem derived from various types of mine wastelands that are widespread in the world. However, a direct comparison of the performance of these two revegetation approaches for reclamation of extremely acidic mine wastelands and the underlying mechanisms is still lacking. To bridge this critical knowledge gap, we established 5000 m2 of vegetation on a highly acidified (pH < 3) Pb/Zn mine tailings pond employing both CR and DR schemes (2500 m2 for each scheme). We then profiled the structure, ecological network and function of soil microbial communities associated with two dominant plant species of the vegetations via high-throughput sequencing. Our results showed that CR and DR achieved a vegetation coverage of 59.7% and 90.5% within two years, respectively. This pattern was accompanied by higher concentrations of plant nutrients and lower acidification potentials in topsoils of the rhizospheres of the vegetation established by DR compared to those of CR. Revegetation approach, rather than plant identity, mostly affected the structure, ecological network and function of soil microbial community in the mine tailings pond. Rhizosphere soils of the vegetation established by DR generally had higher microbial diversity, higher relative abundances of dominant microbial phyla (e.g. Nitrospirae) that can aid plant uptake of nutrients, more complicated microbial interactive networks and more microbial genes responsible for nutrient cycling than those by CR. As the first report on a direct comparison of CR and DR schemes for reclamation of an extremely acidic mine wasteland, our study has important implications for not only the understanding of microbial ecology in revegetated mine wastelands but also the further development of sustainable revegetation schemes.


Asunto(s)
Microbiota , Contaminantes del Suelo/análisis , Biodegradación Ambiental , Estanques , Suelo , Microbiología del Suelo
3.
Ecotoxicology ; 29(6): 691-697, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32472470

RESUMEN

A short term pot trail was employed to evaluate the exposure of mixed heavy metals (Cu, Pb and Zn) on growth, radial oxygen loss (ROL) and root anatomy in Bruguiera gymnorrhiza. The possible function of BgC4H, a cytochrome P450 gene, on root lignification was also discussed. The exposures of mixed Cu, Pb and Zn directly reduce O2 leakage at root surface. The reduced ROL inhibited by heavy metals was mainly ascribed by the changes in root anatomical features, such as decreased root porosity together with increased lignification within the exodermis. BgC4H was found to be up-regulated after 0.5-day metal exposure, and remained higher transcript levels within 3-day metal exposure when compared to control roots. Besides, the inhibited photosynthesis may also result in less oxygen can be transported to the underground roots. In summary, the mangrove B. gymnorrhiza appeared to react to external mixed metal contaminants by developing a lignified and impermeable exodermis, and such a root barrier induced by mixed Cu, Pb and Zn appeared to be an adaptive response to block metal ions enters into the roots.


Asunto(s)
Metales Pesados/toxicidad , Oxígeno/metabolismo , Raíces de Plantas/efectos de los fármacos , Rhizophoraceae , Contaminantes Químicos del Agua/toxicidad , Humedales , Cobre , Plomo , Raíces de Plantas/fisiología , Zinc
4.
World J Clin Cases ; 7(21): 3407-3418, 2019 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-31750325

RESUMEN

BACKGROUND: Mental health is one of the important dimensions of health, while depression is an important indicator of mental health evaluation. AIM: To investigate the association between intergenerational emotional support and depression of non-cohabiting parents (≥ 45 years old) in China. METHODS: We used the fourth wave data from the China Health and Retirement Longitudinal Study (2015). The data was made up of ten main modules, the associated two datasets, and five constructed datasets. The first step is to select the corresponding module data according to the purpose of this study. Moreover, the data of the six modules are integrated by the unique ID code and we choose depression and non-cohabiting items as the selection conditions. 4810 samples were selected, which mainly included data on intergenerational emotional support and the individual scores on depressive symptoms. RESULTS: The average age of 4810 respondents was (60.56 ± 14.613) years old. Females were accounted for more than half of the samples (52.6%). 74.0% respondents from rural areas and approximately 63.3% of the participants had a chronic disease. The mean value of the CESD-10 score was 13.06 (SD5.225). Both faces to face and phone contacts were protective factors on depression symptoms in the mid-aged and seniors in China (P < 0.05). In terms of the frequency of face to face contact, the more frequently you met your parents, the lower your parents' depressive score was. Also, phone contact variable results are displayed as a positive correlation completely between inter-generational contacts from children and depressive symptoms in non-cohabiting parents in China. Children's education level and income level were also reducing the risk of depression in non-cohabiting parents. However, gender, children's numerous, chronic disease and chronic disease number were the risk factors. CONCLUSION: Intergenerational emotional support is associated with depressive symptoms in non-cohabiting parents in China. However, the relationship was also affected by other variables.

5.
Environ Pollut ; 242(Pt B): 1921-1929, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30072222

RESUMEN

Microbial methylmercury (MeHg) production in contaminated soil-rice systems and its accumulation in rice pose health risks to consumers, especially those in Asia. However, the mechanism responsible for microbial MeHg production in paddy soils is far from clear. While previous studies examined the effect of soil and microbial factors on soil MeHg levels, in this work we explored the impact of rice cultivation itself on microbial MeHg production, focusing on the root exudate organic matter as a potential source of electron donors for microbial methylators. Effects of the cultivation of two rice cultivars, Heigu246 (H-rice) and Neiwuyou8015 (N-rice), on MeHg production in soils were therefore investigated in pot and batch incubation experiments. Soil MeHg levels measured in H-rice treatment during the heading and harvest stages were 18-49% higher than in the control and 23-108% higher than in N-rice treatment. Consequently, MeHg levels in grain, straw, and root were 38%, 81%, and 40% higher in H-rice than those in N-rice, which was mainly attributed to cultivar-specific MeHg production in soils. Results of the batch experiments suggested that root exudate organic matter could be responsible for MeHg production in soils during rice cultivation, by increasing the abundances of potential microbial methylators. For instance, root exudate organic matter increased copy numbers of Hg methylation genes (hgcA) in soils 4.1-fold. Furthermore, the 211% higher concentration of acetate (a key electron donor for microbial methylators) in the root exudate of H-rice could account for the higher MeHg production under H-rice than N-rice cultivation. Our results suggest that root exudate organic matter, especially acetate, as its key component, contributes to the elevated soil MeHg concentrations during rice cultivation. The proposed mechanism provides new insights into the elevated risk of MeHg production in contaminated soil-rice systems, as well as cultivar-specific MeHg bioaccumulation.


Asunto(s)
Monitoreo del Ambiente , Compuestos de Metilmercurio/química , Exudados de Plantas/química , Microbiología del Suelo , Contaminantes del Suelo/química , Agricultura , Asia , Contaminación Ambiental , Mercurio/análisis , Compuestos de Metilmercurio/análisis , Oryza/química , Suelo , Contaminantes del Suelo/análisis
6.
Patient Prefer Adherence ; 11: 853-860, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28507429

RESUMEN

OBJECTIVE: To examine factors that are associated with the apprehension levels of oncology nurses toward hospice care. Factors examined in this study included demographics, nursing experience, education levels, title and post, personal experiences, and attitudes toward end-of-life care. METHODS: Questionnaires were provided to nurses (n=201) from three first-tier hospitals in China. A quantitative scale, Professional End-of-life Care Attitude Scale (PEAS), was used to assess personal and professional apprehension levels toward hospice care. The PEAS was translated to Chinese with terms adapted to the cultural environment in China. Statistical analyses were performed to examine the relationships between the apprehension levels and various factors. RESULTS: The total PEAS scores exhibited internal consistency and reliability, with a Cronbach α=0.897 and Pearson's r=0.9030. Of the 201 nurses, 184 provided a valid response (91.5%). Education level was significantly correlated with personal (P<0.01) and professional apprehension levels (P<0.05). Higher apprehension level was found in nurses with less education. CONCLUSION: The PEAS quantitative survey is useful for evaluating apprehension levels of nurses toward hospice care. Nurses with more education experienced less anxiety when providing care for terminally ill patients. The findings suggested that education programs on hospice care could be strengthened to help nurses cope with negative attitudes toward end-of-life care.

7.
Sci Rep ; 6: 21805, 2016 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-26892768

RESUMEN

A greenhouse pot experiment was conducted to study the impact of arbuscular mycorrhizal fungi--Glomus versiforme (Gv) and Rhizophagus intraradices (Ri) on the growth, Cd uptake, antioxidant indices [glutathione reductase (GR), ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), ascorbate (ASA), glutathione (GSH) and malonaldehyde (MDA)] and phytochelatins (PCs) production of Lonicera japonica in Cd-amended soils. Gv and Ri significantly increased P acquisition, biomass of shoots and roots at all Cd treatments. Gv significantly decreased Cd concentrations in shoots and roots, and Ri also obviously reduced Cd concentrations in shoots but increased Cd concentrations in roots. Meanwhile, activities of CAT, APX and GR, and contents of ASA and PCs were remarkably higher in Gv/Ri-inoculated plants than those of uninoculated plants, but lower MDA and GSH contents in Gv/Ri-inoculated plants were found. In conclusion, Gv and Ri symbiosis alleviated Cd toxicity of L. japonica through the decline of shoot Cd concentrations and the improvement of P nutrition, PCs content and activities of GR, CAT, APX in inoculated plants, and then improved plant growth. The decrease of shoot Cd concentrations in L. japonica inoculated with Gv/Ri would provide a clue for safe production of this plant from Cd-contaminated soils.


Asunto(s)
Cadmio/metabolismo , Glomeromycota/fisiología , Lonicera/crecimiento & desarrollo , Micorrizas/fisiología , Contaminantes del Suelo/metabolismo , Cadmio/análisis , Cadmio/toxicidad , Peroxidación de Lípido , Lonicera/efectos de los fármacos , Lonicera/metabolismo , Lonicera/microbiología , Estrés Oxidativo , Fitoquelatinas/metabolismo , Suelo/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
8.
Zhong Yao Cai ; 39(3): 463-8, 2016 Mar.
Artículo en Chino | MEDLINE | ID: mdl-30088747

RESUMEN

Objective: To investigate the main morphological characters and interrelationship of Blumea bdsamifera, and to provide the guidance for selection and breeding of Blumea balsamifera. Methods: 19 main morphological characters and their interrelationship were analyzed by using correlation analysis,multiple stepwise regression analysis and factor analysis. Results: Variation coefficients of the morphological characters were big in Blumea balsamifera. Correlation coefficients for morphological characters were significant( P <0. 05 or P < 0. 01). Using factor analysis,19 morphological characters were classified into six principal divisors. Ten morphological characters, including length / wide of leaf,trunk diameter, leaf number of second branch, leaf number of first branch, number of trunk leaf, weight of strong leaf, weight of young leaf,weight of old leaf, number of first branch, leaf number of whole plant, were the main factors which influenced the weight of whole plant leaf. Conclusion: The variation of every morphological character of Blumea balsamifera is abundant in different population, and a certain correlation is existed among morphological characters. The morphological characters, length / wide of leaf, trunk diameter, number of first branch, number and weight of leaf, are the main factors which influenced the weight of whole plant leaf.


Asunto(s)
Asteraceae , Hojas de la Planta
9.
PLoS One ; 10(7): e0132347, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26176959

RESUMEN

The plant growth, phosphate acquisition, Cd translocation, phytochelatins (PCs) production and antioxidant parameters [superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione (GSH), ascorbate (ASA) and malonaldehyde (MDA)] were investigated in Cd-hyperaccumulator Solanum photeinocarpum inoculated with Glomus versiforme BGC GD01C (Gv) in Cd-added soils (0, 5, 10, 20, 40 mg Cd kg-1 soil). Mycorrhizal colonization rates were generally high (from 77% to 94%), and hardly affected by Cd. Gv colonization significantly enhanced P acquisition, growth and total Cd uptakes in both shoots and roots of S. photeinocarpum at all Cd levels. Meanwhile, Gv symbiosis significantly increased Cd concentration in the roots, and decreased Cd concentration in the shoots at all Cd levels, which indicates that Gv could promote phytostabilization by enhancing Cd accumulation in the roots to inhibit its translocation to shoots and the "dilution effects" linked to an increase in plant dry matter yield and a reduced Cd partitioning to shoots. Moreover, the improvement of CAT, POD and APX activities in the leaves of mycorrhizal plants infers that Gv symbiosis helped S. photeinocarpum to relieve oxidative damage to biomolecules in Cd-contaminated soil. The evident decline of MDA content in the leaves of mycorrhizal plants indicates that Gv symbiosis evidently improved antioxidant activities, and the enhancement of PCs production in the leaves of mycorrhizal plants suggests that Gv-inoculated plant may be more efficient to relieve Cd phytotoxicity. Therefore, the possible mechanisms of Cd phytotoxicity alleviation by Gv can be concluded as the decline of Cd concentration in the shoots and the improvement of P acquisition, PCs production and activities of CAT, POD, APX in mycorrhizal plants.


Asunto(s)
Antioxidantes/metabolismo , Cadmio/metabolismo , Glomeromycota/fisiología , Fitoquelatinas/metabolismo , Solanum/metabolismo , Cadmio/química , Cadmio/toxicidad , Malondialdehído/metabolismo , Micorrizas/enzimología , Micorrizas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Oxidorreductasas/metabolismo , Hojas de la Planta/enzimología , Hojas de la Planta/metabolismo , Raíces de Plantas/metabolismo , Brotes de la Planta/metabolismo , Contaminantes del Suelo/química , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/toxicidad , Solanum/enzimología , Solanum/crecimiento & desarrollo , Simbiosis/efectos de los fármacos
10.
Ecotoxicology ; 24(7-8): 1650-8, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25956982

RESUMEN

Metal pollution has been widely reported in mangrove wetlands; however, the mechanisms involved in metal detoxification by mangroves are still poorly understood. This study aimed to investigate the possible function of root lignification/suberization on Pb uptake and tolerance in mangroves. Two mangroves, Acanthus ilicifolius and Rhizophora stylosa with different root lignification/suberization were selected as plant materials; the former exhibits a thin exodermis and low lignification/suberization, while the latter possesses a thick exodermis and high lignification/suberization. A pot trial with addition of Pb was conducted to investigate the differences in Pb uptake and tolerance between the two mangroves. The experiment of rhizobox was designed to explore Pb dynamics and availabilities in the rhizosphere soils, besides, the ability of Pb uptake by the excised roots and X-ray analysis for Pb distribution within roots were also detected. The results revealed that R. stylosa exhibited relatively higher Pb tolerance together with less Pb accumulations when compared to A. ilicifolius. For both species, lower proportion of exchangeable and Carbonate Pb and higher higher Fe-Mn oxides Pb were observed in the rhizosphere zone when compared to the respective non-rhizosphere zone. The results from metal uptake by the excised roots and X-ray analysis clearly showed that the thick lignified/suberized exodermis of R. stylosa could more efficiently delay Pb entering into the roots, leading to less Pb accumulation. In summary, the present study proposes a barrier property of the lignified/suberized exodermis in dealing with the stresses of Pb.


Asunto(s)
Acanthaceae/metabolismo , Plomo/metabolismo , Rhizophoraceae/metabolismo , Contaminantes Químicos del Agua/metabolismo , Acanthaceae/anatomía & histología , Raíces de Plantas/anatomía & histología , Raíces de Plantas/metabolismo , Rhizophoraceae/anatomía & histología , Rizosfera , Especificidad de la Especie , Madera/anatomía & histología
11.
Ecotoxicology ; 24(7-8): 1659-67, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25956983

RESUMEN

Mangrove is a special coastal forest along tropical and subtropical intertidal shores. However, how mangroves adapt to tidal flooding and the mechanisms involved in mangrove zonation are still poorly understood. In this study, a pot trial with different tide treatments was conducted to investigate the differences in root anatomy, porosity, radial oxygen loss, iron plaque formation and waterlogging tolerance among six mangroves along a continuous tidal gradient. The index of waterlogging tolerance illustrated that Sonneratia apetala possessed the highest index, followed by Aeguceras corniculatum/Kandelia, Rhizophora stylosa, Heritiera littorlis and Thespesia populnea. Waterlogging tolerances of the mangroves were found to be positively correlated with their root porosity, radial oxygen loss and iron plaque formation. Waterlogging-sensitive species such as landward semi-mangroves exhibited small root porosity and ROL, while waterlogging-tolerant species such as seaward pioneer and rhizophoraceous mangroves exhibited extensive porosity, ROL and iron plaque formation. Nevertheless, grater root porosity and iron plaque formation were detected in permanent waterlogged plants when compared to drained plants. In conclusion, The present study proposes a structural adaptive strategy to tidal flooding in mangroves, such that the mangroves with higher root porosity, ROL and iron plaque appeared to exhibit higher waterlogging tolerance and adaptability in anaerobic foreshores.


Asunto(s)
Hierro/metabolismo , Oxígeno/metabolismo , Raíces de Plantas/fisiología , Olas de Marea , Árboles/fisiología , Agua/fisiología , China , Raíces de Plantas/anatomía & histología , Porosidad , Especificidad de la Especie , Árboles/anatomía & histología , Humedales
12.
Tree Physiol ; 34(6): 646-56, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24965807

RESUMEN

Metal pollution has been widely reported in mangrove wetlands; however, the mechanisms involved in metal detoxification by mangroves are still poorly understood. This study aimed to investigate the possible function of root anatomy and lignification/suberization on metal uptake and tolerance in seedlings of six species of mangroves. The results revealed that the three rhizophoraceous species (Bruguiera gymnorrhiza (L.) Poir, Kandelia obovata Sheue, Liu & Yong and Rhizophora stylosa Griff) consistently exhibited higher metal tolerances than the three pioneer species (Aegiceras corniculatum (Linn.) Blanco, Acanthus ilicifolius L. and Avicennia marina (Forsk.) Viern.). Moreover, metal-tolerant species often exhibited a thick exodermis with high lignification and suberization. The tolerance indices of the mangroves were found to be positively correlated with the amounts of lignin and suberin deposition within the exodermal cell walls. The observed metal uptake by the excised roots further illustrated that a lignified/suberized exodermis directly delayed the entry of metals into the roots, and thereby contributed to a higher tolerance to heavy metals. In summary, the present study proposes a barrier property of the lignified/suberized exodermis in dealing with the stresses of heavy metals, such that the mangroves which possessed more extensive lignification/suberization within the exodermis appeared to exhibit higher metal tolerance.


Asunto(s)
Cobre/metabolismo , Plomo/metabolismo , Rhizophoraceae/fisiología , Zinc/metabolismo , Transporte Biológico , China , Lignina/análisis , Lignina/metabolismo , Lípidos/análisis , Microscopía Electrónica de Rastreo , Hojas de la Planta/anatomía & histología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/fisiología , Raíces de Plantas/anatomía & histología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/fisiología , Rhizophoraceae/anatomía & histología , Rhizophoraceae/efectos de los fármacos , Plantones/anatomía & histología , Plantones/efectos de los fármacos , Plantones/fisiología , Especificidad de la Especie , Humedales
13.
Environ Pollut ; 184: 179-86, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24056187

RESUMEN

A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk & leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants.


Asunto(s)
Monitoreo del Ambiente , Mercurio/análisis , Compuestos de Metilmercurio/análisis , Minería , Oryza/química , Contaminantes del Suelo/análisis , China , Contaminación de Alimentos/análisis , Contaminación de Alimentos/estadística & datos numéricos , Mercurio/metabolismo , Compuestos de Metilmercurio/metabolismo , Oryza/metabolismo , Suelo/química , Contaminantes del Suelo/metabolismo
14.
Environ Pollut ; 164: 110-7, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22361050

RESUMEN

Effects of N deficiency and salinity on root anatomy, permeability and metal (Pb, Zn and Cu) translocation and tolerance were investigated using mangrove seedlings of Rhizophora stylosa. The results showed that salt could directly reduce radial oxygen loss (ROL) by stimulation of lignification within exodermis. N deficiency, oppositely, would reduce lignification. Such an alteration in root permeability may also influence metal tolerance by plants. The data indicated that a moderate salinity could stimulate a lignified exodermis that delayed the entry of metals into the roots and thereby contributed to a higher metal tolerance, while N deficiency would aggravate metal toxicity. The results from sand pot trail further confirmed this issue. This study provides a barrier property of the exodermis in dealing with environments. The plasticity of root anatomy is likely an adaptive strategy to regulate the fluxes of gases, nutrients and toxins at root-soil interface.


Asunto(s)
Metales/metabolismo , Nitrógeno/deficiencia , Raíces de Plantas/fisiología , Rhizophoraceae/fisiología , Contaminantes Químicos del Agua/metabolismo , Adaptación Fisiológica , Biodegradación Ambiental , Metales/toxicidad , Nitrógeno/metabolismo , Permeabilidad , Raíces de Plantas/anatomía & histología , Raíces de Plantas/efectos de los fármacos , Rhizophoraceae/anatomía & histología , Rhizophoraceae/efectos de los fármacos , Salinidad , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/toxicidad
15.
J Exp Bot ; 63(7): 2619-30, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22268157

RESUMEN

Root anatomy, radial oxygen loss (ROL), and tolerances to ferrous (Fe(2+)), sulphide (S(2-)), and zinc (Zn(2+)) ions were investigated in seedlings of eight species of mangrove, including three pioneer species, three rhizophoraceous and two landward semi-mangrove species. The results showed an interesting co-tolerance to Fe(2+), S(2-), and Zn(2+). The three rhizophoraceous species (Bruguiera gymnorrhiza, Kandelia obovata and Rhizophora stylosa), which possessed the thickest lignified exodermis and the 'tightest barrier' in ROL spatial pattern, consistently exhibited the highest tolerance to Fe(2+), S(2-), and Zn(2+). B. gymnorrhiza could directly reduce ROL by increasing lignification within the exodermis. Such an induced barrier to ROL is a probable defence response to prevent further invasion and spread of toxins within plants. The data also indicated that, in B. gymnorrhiza, Fe(2+) or S(2-), or both, induced a lignified exodermis that delayed the entry of Zn(2+) into the roots and thereby contributed to a higher tolerance to Zn(2+). This study provides new evidence of exclusive strategies of mangrove seedling roots in dealing with contaminations. The information is also important in the selection and cultivation of tolerant species for the bioremediation of contaminated waters or soils.


Asunto(s)
Compuestos Ferrosos/metabolismo , Radical Hidroxilo/metabolismo , Raíces de Plantas/metabolismo , Rhizophoraceae/metabolismo , Sulfuros/metabolismo , Zinc/metabolismo , Raíces de Plantas/anatomía & histología , Rhizophoraceae/anatomía & histología
16.
Crit Rev Environ Sci Technol ; 42(20): 2113-2152, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23335842

RESUMEN

Cadmium (Cd) is one of the most toxic and widely distributed pollutants in the environment. Cadmium contamination of soils has posed a serious threat to safe food production in many parts of the world. The authors present a comprehensive review of present status of phytoextraction technology for cleaning up Cd-contaminated soils, based primarily on the data resulting from both laboratory and field-scale studies that have been conducted to assess or improve the Cd phytoextraction potential of various plant species in the past decade. The encouraging results of field-scale studies have provided a fundamental basis to usher phytoextraction technology into practical use to remediate slightly to moderately Cd-contaminated soils in Europe and Asia, although this technology is not yet ready for widespread application. Chelators and microorganisms tested so far seem not to contribute to the applicability of Cd phytoextraction. The major challenges for the large-scale application of Cd phytoextraction are (a) how to further improve the efficiency of Cd phytoextraction, (b) how to cut the overall costs of Cd phytoextraction, and (c) how to get greater stakeholders' acceptance of Cd phytoextraction as a reliable option.

17.
Int J Phytoremediation ; 12(4): 384-403, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20734915

RESUMEN

This study investigated the contributions of mixed arbuscular mycorrhizal fungi (AMF) inoculum-i.e., mixed populations of indigenous mycorrhiza (Glomus intraradices, Glomus geosporum, Glomus mosseae) (IM) isolated from arsenic (As) contaminated soil and non-indigenous mycorrhiza such as G. mosseae (GM), which possess metal tolerance characteristics-and the addition of phosphate rock (PR) towards the uptake and accumulation of As by Pteris vittata (As hyperaccumlator) grown in As-contaminated soil. Regardless of As levels added to soil, plant growth was substantially improved in amended treatments when compared with the control. In addition, root surface area (0 mg/kg As: 15.2 cm2; 150 mg/kg As: 16.9 cm2; 300 mg/kg As: 20.7 cm2), chlorophyll contents (0 mg/kg As: 1.16 mg/g; 150 mg/kg As: 1.46 mg/g; 300 mg/kg As: 1.81 mg/g) and As translocation factor (0 mg/kg As: 0; 150 mg/kg As: 4.29; 300 mg/kg As: 5.22) in P. vittata of PR+IM/GM were also increased. Such combination could further enhance plant growth (indicated by higher N, P and chlorophyll contents) and As uptake by P. vittata.


Asunto(s)
Arsénico/metabolismo , Arsénico/toxicidad , Micorrizas/fisiología , Fosfatos/aislamiento & purificación , Pteris/crecimiento & desarrollo , Pteris/microbiología , Contaminantes del Suelo/toxicidad , Biodegradación Ambiental/efectos de los fármacos , Biomasa , Clorofila/metabolismo , Recuento de Colonia Microbiana , Glomeromycota/efectos de los fármacos , Glomeromycota/crecimiento & desarrollo , Glomeromycota/fisiología , Micorrizas/efectos de los fármacos , Micorrizas/crecimiento & desarrollo , Nitrógeno/metabolismo , Fósforo/metabolismo , Pteris/anatomía & histología , Pteris/efectos de los fármacos , Suelo/análisis , Propiedades de Superficie/efectos de los fármacos
18.
Environ Geochem Health ; 29(6): 473-81, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17874190

RESUMEN

A greenhouse pot experiment was conducted to investigate the effects of the colonization of arbuscular mycorrhizal fungus (AMF) Glomus mosseae on the growth and metal uptake of three leguminous plants (Sesbania rostrata, Sesbania cannabina, Medicago sativa) grown in multi-metal contaminated soil. AMF colonization increased the growth of the legumes, indicating that AMF colonization increased the plant's resistance to heavy metals. It also significantly stimulated the formation of root nodules and increased the N and P uptake of all of the tested leguminous plants, which might be one of the tolerance mechanisms conferred by AMF. Compared with the control, colonization by G. mosseae decreased the concentration of metals, such as Cu, in the shoots of the three legumes, indicating that the decreased heavy metals uptake and growth dilution were induced by AMF treatment, thereby reducing the heavy metal toxicity to the plants. The root/shoot ratios of Cu in the three legumes and Zn in M. sativa were significantly increased (P<0.05) with AMF colonization, indicating that heavy metals were immobilized by the mycorrhiza and the heavy metal translocations to the shoot were decreased.


Asunto(s)
Medicago sativa/crecimiento & desarrollo , Metales Pesados/metabolismo , Micorrizas/fisiología , Sesbania/crecimiento & desarrollo , Cobre/metabolismo , Medicago sativa/metabolismo , Medicago sativa/microbiología , Micorrizas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Brotes de la Planta/metabolismo , Brotes de la Planta/microbiología , Sesbania/metabolismo , Sesbania/microbiología , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo
19.
J Plant Physiol ; 164(11): 1489-98, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17207552

RESUMEN

Sedum alfredii has been reported to be a cadmium (Cd) hyperaccumulator. Phytochelatins (PCs) and other thiol (SH)-containing compounds have been proposed to play an important role in the detoxification and tolerance of some heavy metals, but it is not clear whether PCs are responsible for Cd hyperaccumulation and tolerance in S. alfredii. In this study, two geographically isolated populations of S. alfredii were studied: one population grew on an old Pb/Zn mine site, while the other on a non-mine site. The mine population of this species exhibited a stronger heavy metal tolerance than in the other population. Root-to-shoot transport of Cd was higher in population located at the mine site than at the non-mine site. Considerable amounts of Cd were accumulated in leaves and stems of mine plants, while most Cd was distributed in roots of non-mine plants. Non-protein SH in plant tissues of two populations were further investigated by a HPLC pre-column derivatization system. Upon exposure to Cd, no PCs were detected in all tissues of mine population, while an appreciable amount of glutathione (GSH) was observed in the descending order of stem>root>leaf. The concentrations of GSH consistently increased with the increase of exogenous Cd concentrations and time. On the contrary, Cd exposure strongly induced the production of PCs (mainly PC(2) and PC(3)) and GSH in plant tissues of non-mine population, and the concentrations of GSH showed an initial drop over the duration of 7-d exposure. The present results provided strong evidence that PCs are not involved in Cd transport, hyperaccumulation and tolerance in mine population of S. alfredii.


Asunto(s)
Cadmio/metabolismo , Cadmio/farmacología , Glutatión/metabolismo , Fitoquelatinas/metabolismo , Sedum/metabolismo , Adaptación Fisiológica , Relación Dosis-Respuesta a Droga , Minería , Sedum/efectos de los fármacos
20.
J Zhejiang Univ Sci B ; 7(10): 825-9, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16972325

RESUMEN

OBJECTIVE: Study blood vessel injury and gene expression indicating vascular endothelial cell apoptosis induced by mannitol with and without administration of anti-oxidative vitamins. METHODS: Healthy rabbits were randomly divided into four groups. Mannitol was injected into the vein of the rabbit ear in each animal. Pre-treatment prior to mannitol injection was performed with normal saline (group B), vitamin C (group C) and vitamin E (group D). Blood vessel injury was assessed under electron and light microscopy. In a second experiment, cell culture specimen of human umbilical vein endothelial cells were treated with mannitol. Pre-treatment was done with normal saline (sample B), vitamin C (sample C) and vitamin E (sample D). Total RNA was extracted with the original single step procedure, followed by hybridisation and analysis of gene expression. RESULTS: In the animal experiment, serious blood vessel injury was seen in group A and group B. Group D showed light injury only, and normal tissue without pathological changes was seen in group C. Of all 330 apoptosis-related genes analysed in human cell culture specimen, no significant difference was seen after pre-treatment with normal saline, compared with the gene chip without pre-treatment. On the gene chip pre-treated with vitamin C, 45 apoptosis genes were down-regulated and 34 anti-apoptosis genes were up-regulated. Pre-treatment with vitamin E resulted in the down-regulation of 3 apoptosis genes. CONCLUSION: Vitamin C can protect vascular endothelial cells from mannitol-induced injury.


Asunto(s)
Antioxidantes/farmacología , Apoptosis , Células Endoteliales/citología , Regulación de la Expresión Génica , Manitol/química , Animales , Células Endoteliales/patología , Humanos , Manitol/farmacología , Hibridación de Ácido Nucleico , Análisis de Secuencia por Matrices de Oligonucleótidos , Sondas de Oligonucleótidos/química , Oxidación-Reducción , Conejos , Vitaminas/metabolismo
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