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Effect of chromium species on phytochemical and physiological parameters in Datura innoxia 总被引:1,自引:0,他引:1
Vernay P Gauthier-Moussard C Jean L Bordas F Faure O Ledoigt G Hitmi A 《Chemosphere》2008,72(5):763-771
In soil, chromium can be found in two main valence states: hexavalent Cr(VI) and trivalent Cr(III). In this study, we investigated the impact of Cr on photosynthetic gas exchange, photosystem II (PSII) activity, Cr translocation and accumulation, proline content and alkaloids production, i.e. scopolamine and hyoscyamine, in Datura innoxia. Cr uptake was influenced by its oxidation state and its concentration in growth medium. The plant roots were determined as being the main organ of Cr accumulation. Cr(VI) was more toxic than Cr(III) as indicated by reduction in plant biomass and net photosynthesis. The stomatal conductance showed a similar trend to that of photosynthetic capacity. Cr(III) and Cr(VI) had a different impact on substomatal CO(2) concentration then Cr toxicity was related to its oxidation states. In plants stressed with a Cr(VI) excess, a down regulation of PSII activity was observed with an impairment of photochemical activity. Indeed, the maximum quantum yield of PSII (F(v)/F(m)), the quantum yield of PSII (PhiPSII) and the efficiency of excitation capture by open centers (F'(v)/F'(m)) decreased. Cr(III) had little effects on PSII primary photochemistry, whatever its form induces an increase of scopolamine content without changes in hyoscyamine content in leaves of D. innoxia. These results provide that chromium contamination can change the secondary metabolites composition of leaves, thereby, impacting the quality, safety and efficacy of natural plant products synthesized by D. innoxia plants. 相似文献
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Dalel Daâssi Lassaad Belbahri Armelle Vallat Steve Woodward Moncef Nasri Tahar Mechichi 《Environmental science and pollution research international》2014,21(3):1746-1758
The search for novel microorganisms able to degrade olive mill wastewaters (OMW) and withstand the toxic effects of the initially high phenolic concentrations is of great scientific and industrial interest. In this work, the possibility of reducing the phenolic content of OMW using new isolates of fungal strains (Coriolopsis gallica, Bjerkandera adusta, Trametes versicolor, Trichoderma citrinoviride, Phanerochaete chrysosporium, Gloeophyllum trabeum, Trametes trogii, and Fusarium solani) was investigated. In vitro, all fungal isolates tested caused an outstanding decolorization of OMW. However, C. gallica gave the highest decolorization and dephenolization rates at 30 % v/v OMW dilution in water. Fungal growth in OMW medium was affected by several parameters including phenolic compound concentration, nitrogen source, and inoculum size. The optimal OMW medium for the removal of phenolics and color was with the OMW concentration (in percent)/[(NH4)2SO4]/inoculum ratio of 30:6:3. Under these conditions, 90 and 85 % of the initial phenolic compounds and color were removed, respectively. High-pressure liquid chromatography analysis of extracts from treated and untreated OMW showed a clear and substantial reduction in phenolic compound concentrations. Phytotoxicity, assessed using radish (Raphanus sativus) seeds, indicated an increase in germination index of 23–92 % when a 30 % OMW concentration was treated with C. gallica in different dilutions (1/2, 1/4, and 1/8). Figure
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Polluted soils of former coking plants are characterized by multiple organic contributions, e.g. coal tar, coal, coke, soot,
and natural organic matter, that can either be sources of polycyclic aromatic hydrocarbons (PAHs) or act as sorption surfaces
for pollutants. The contamination level is usually based on the quantification of 16 PAHs but it does not provide any information
on PAH sources. We studied the aliphatic fractions of 25 soil samples from a former coking plant site by microscopy and gas
chromatography-mass spectrometry (GC-MS). The microscopic investigation allowed to identify four main organic contributions:
coal tar, coal, coke, and natural organic matter. These isolated sources were analyzed and considered as reference materials.
Although the PAH distributions were very similar in the 25 contaminated soils, alkanes and hopanes distributions were representative
from various contributions characterizing the relative enrichment in coal, coal tars, or natural organic matter. Two principal
component analyses based on n-alkanes and hopanes showed that three molecular indices, the carbon preference index, the low molecular weight/high molecular
weight n-alkanes ratio, and the 18α(H)-22,29,30-trisnorhopane/(18α(H)-22,29,30-trisnorhopane+17α(H)-22,29,30-trisnorhopane) ratio
allow to classify polluted soils according to various organic contributions. 相似文献
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The Lophogastrida are primitive Mysidacea and comprise only six genera. One of these, Eucopia is considered as highly specialized and constitutes the family Eucopiidae; the other genera constitute the Lophogastridae.
Among the latter family, the genus Gnathophausia is closely related to Eucopia, with two species (G. gracilis and E. sculpticauda) sharing similar morphological characteristics [i.e. ornamentation (spines) of the uropods, and the gastric mill]. This indicates
that these species are phylogenetically related. To test this hypothesis, the partial 16S mitochondrial ribosomal RNA gene
from various representative species of Gnathophausia and Eucopia were compared. The resulting phylogenetic tree suggests that each genus is monophyletic, and that Gnathophausia, which is the deepest-branching genus, is the most primitive, with the Eucopiidae originating from the Lophogastridae. The
molecular results support the morphological hypothesis, and suggest an early separation of the two genera or a rapid divergence
of Eucopia due to morphological specialization.
Received: 29 June 1997 / Accepted: 16 March 1998 相似文献
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A Spatially Explicit Resource-Based Approach for Managing Stream Fishes in Riverscapes 总被引:1,自引:0,他引:1
The article describes a riverscape approach based on landscape ecology concepts, which aims at studying the multiscale relationships
between the spatial pattern of stream fish habitat patches and processes depending on fish movements. A review of the literature
shows that few operational methods are available to study this relationship due to multiple methodological and practical challenges
inherent to underwater environments. We illustrated the approach with literature data on a cyprinid species (Barbus barbus) and an actual riverscape of the Seine River, France. We represented the underwater environment of fishes for different discharges
using two-dimensional geographic information system-based maps of the resource habitat patches, defined according to activities
(feeding, resting, and spawning). To quantify spatial patterns at nested levels (resource habitat patch, daily activities
area, subpopulation area), we calculated their composition, configuration, complementation, and connectivity with multiple
spatial analysis methods: patch metrics, moving-window analysis, and least cost modeling. The proximity index allowed us to
evaluate habitat patches of relatively great value, depending on their spatial context, which contributes to the setting of
preservation policies. The methods presented to delimit potential daily activities areas and subpopulation areas showed the
potential gaps in the biological connectivity of the reach. These methods provided some space for action in restoration schemes. 相似文献
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Sandra Vranic Ignacio Garcia-Verdugo Cécile Darnis Jean-Michel Sallenave Nicole Boggetto Francelyne Marano Sonja Boland Armelle Baeza-Squiban 《Environmental science and pollution research international》2013,20(5):2761-2770
Because of an increasing exposure to environmental and occupational nanoparticles (NPs), the potential risk of these materials for human health should be better assessed. Since one of the main routes of entry of NPs is via the lungs, it is of paramount importance to further characterize their impact on the respiratory system. Here, we have studied the uptake of fluorescently labeled SiO2 NPs (50 and 100 nm) by epithelial cells (NCI-H292) and alveolar macrophages (MHS) in the presence or absence of pulmonary surfactant. The quantification of NP uptake was performed by measuring cell-associated fluorescence using flow cytometry and spectrometric techniques in order to identify the most suitable methodology. Internalization was shown to be time and dose dependent, and differences in terms of uptake were noted between epithelial cells and macrophages. In the light of our observations, we conclude that flow cytometry is a more reliable technique for the study of NP internalization, and importantly, that the hydrophobic fraction of lung surfactant is critical for downregulating NP uptake in both cell types. 相似文献
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The paper presents a comparative analysis of the development and present state of compensation for victims of catastrophes in Belgium and the Netherlands. These two neighbouring countries have both seen legislative changes in this field in recent years, albeit with different outcomes. The paper thus analyses to what extent the two compensation scheme structures allow for conclusions as to the comparative benefits of a comprehensive insurance scheme for natural disasters. From the perspective of law and economics, the evolution of private insurance and public intervention through compensation funds, the preference for private or public solutions and the actual financing of these are examined. Drawing on practical experience, such as the case of flood risks, the solutions are tested in view of incentive-based financing. The paper concludes that the private insurance market is more developed in Belgium than it is in the Netherlands, where the reform process has not yet ended. 相似文献