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Juncus maritimus root biochemical assessment for its mercury stabilization potential in Ria de Aveiro coastal lagoon (Portugal) Texte intégral
2015
Anjum, Naser A. | Duarte, Armando C. | Pereira, Eduarda | Aḥmad, Iqbāl
Major endogenous biochemical properties can make plants ideal agents for metal/metalloid-contaminated site cleanup. This study investigates the biochemistry of Juncus maritimus (Lam) roots for its high mercury (Hg) stabilization potential in the sediments of the Ria de Aveiro coastal lagoon (Portugal), which received Hg-rich effluents from a chlor–alkali industry between 1950 and 1994. J. maritimus plants were collected at a reference (R) site and three sites with the highest (L1), moderate (L2), and the lowest (L3) Hg contamination levels. The highest Hg-harboring/stabilizing J. maritimus roots at L1, exhibited significantly elevated damage endpoints (H₂O₂; lipid peroxidation, LPO; electrolyte leakage, EL; protein oxidation, PO; proline) which were accompanied by differential changes in H₂O₂-metabolizing defense system components (ascorbate peroxidase, catalase, glutathione peroxidase, glutathione S-transferase), glutathione reductase and the contents of both reduced and oxidized glutathione. Trends in measured endpoints reached maximum levels at L1 followed by L2 and L3. Cross-talks on root–Hg status and the studied biochemical traits revealed (a) high Hg-accrued elevations in oxidative stress as an obvious response; (b) Hg-stabilization potential of J. maritimus roots as a result of a successful mitigation of elevated high Hg-induced H₂O₂, and its anomalies such as LPO, EL, and PO; and (c) the induction of and a fine synchronization between non-glutathione and glutathione-based systems. Overall, the study unveiled biochemical mechanisms underlying root tolerance to Hg burden-accrued anomalies which, in turn, helped J. maritimus during Hg-stabilization.
Afficher plus [+] Moins [-]A coordinated set of ecosystem research platforms open to international research in ecotoxicology, AnaEE-France Texte intégral
2015
Mougin, Christian | Azam, Didier | Caquet, Thierry | Cheviron, Nathalie | Dequiedt, Samuel | Le Galliard, Jean-François | Guillaume, Olivier | Houot, Sabine | Lacroix, Gerard | Lafolie, François | Maron, Pierre-Alain | Michniewicz, Radika | Pichot, Christian | Ranjard, Lionel | Roy, Jacques | Zeller, Bernd | Clobert, Jean | Chanzy, André
The infrastructure for Analysis and Experimentation on Ecosystems (AnaEE-France) is an integrated network of the major French experimental, analytical, and modeling platforms dedicated to the biological study of continental ecosystems (aquatic and terrestrial). This infrastructure aims at understanding and predicting ecosystem dynamics under global change. AnaEE-France comprises complementary nodes offering access to the best experimental facilities and associated biological resources and data: Ecotrons, seminatural experimental platforms to manipulate terrestrial and aquatic ecosystems, in natura sites equipped for large-scale and long-term experiments. AnaEE-France also provides shared instruments and analytical platforms dedicated to environmental (micro) biology. Finally, AnaEE-France provides users with data bases and modeling tools designed to represent ecosystem dynamics and to go further in coupling ecological, agronomical, and evolutionary approaches. In particular, AnaEE-France offers adequate services to tackle the new challenges of research in ecotoxicology, positioning its various types of platforms in an ecologically advanced ecotoxicology approach. AnaEE-France is a leading international infrastructure, and it is pioneering the construction of AnaEE (Europe) infrastructure in the field of ecosystem research. AnaEE-France infrastructure is already open to the international community of scientists in the field of continental ecotoxicology.
Afficher plus [+] Moins [-]Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites Texte intégral
2015
Simon-Delso, N. | Amaral-Rogers, V. | Belzunces, L. P. | Bonmatin, J. M. | Chagnon, M. | Downs, C. | Furlan, L. | Gibbons, D. W. | Giorio, C. | Girolami, V. | Goulson, D. | Kreutzweiser, D. P. | Krupke, C. H. | Liess, M. | Long, E. | McField, M. | Mineau, P. | Mitchell, E. A. D. | Morrissey, C. A. | Noome, D. A. | Pisa, L. | Settele, J. | Stark, J. D. | Tapparo, A. | Van Dyck, H. | Praagh, Jaap van | Van der Sluijs, J. P. | Whitehorn, P. R. | Wiemers, M.
Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.
Afficher plus [+] Moins [-]COST action TD1407: network on technology-critical elements (NOTICE)—from environmental processes to human health threats Texte intégral
2015
Cobelo-García, A. | Filella, M. | Croot, P. | Frazzoli, C. | Du Laing, G. | Ospina-Alvarez, N. | Rauch, S. | Salaun, P. | Schäfer, J. | Zimmermann, S.
The current socio-economic, environmental and public health challenges that countries are facing clearly need common-defined strategies to inform and support our transition to a sustainable economy. Here, the technology-critical elements (which includes Ga, Ge, In, Te, Nb, Ta, Tl, the Platinum Group Elements and most of the rare-earth elements) are of great relevance in the development of emerging key technologies—including renewable energy, energy efficiency, electronics or the aerospace industry. In this context, the increasing use of technology-critical elements (TCEs) and associated environmental impacts (from mining to end-of-life waste products) is not restricted to a national level but covers most likely a global scale. Accordingly, the European COST Action TD1407: Network on Technology-Critical Elements (NOTICE)—from environmental processes to human health threats, has an overall objective for creating a network of scientists and practitioners interested in TCEs, from the evaluation of their environmental processes to understanding potential human health threats, with the aim of defining the current state of knowledge and gaps, proposing priority research lines/activities and acting as a platform for new collaborations and joint research projects. The Action is focused on three major scientific areas: (i) analytical chemistry, (ii) environmental biogeochemistry and (iii) human exposure and (eco)-toxicology.
Afficher plus [+] Moins [-]Transfer of metal(loid)s in a small vineyard catchment: contribution of dissolved and particulate fractions in river for contrasted hydrological conditions Texte intégral
2015
Rabiet, M. | Coquery, M. | Carluer, N. | Gahou, J. | Gouy, V.
The use of inorganic pesticides in viticulture leads to the accumulation of metal(loid)s in soils which can be transferred to the hydro-systems (groundwater and surface water) via several processes. This study reports on the occurrence and behavior of metal(loid)s (Li, Al, Cr, Ni, Cu, Zn, As, Sr, and Ba), with a particular focus on Cu, Zn, and As, in a small stream draining a vineyard catchment. Base flow and flood events were monitored in order to assess the spatiotemporal variability of metal(loid) concentrations and to evaluate the contribution of the particulate fraction to the transfer of metal(loid)s according to the hydrological conditions. Results show that very different patterns of metal(loid)s were observed in the Morcille River according to the hydrological conditions. In base flow conditions, Cu and As were mainly transported in dissolved phase, which contributed to more than 70 and 80 %, respectively, of the total load during this period. On the contrary, during base flow, Zn was mainly transported as associated to particles (90 %). During the two storm events monitored, the particulate fraction was dominant, as its represented around 74–80 %, 97 %, and 50–70 % of the total Cu, Zn, and As load in the river, respectively. Thus, despite a weaker affinity for particles during floods (decrease of particulate content during floods), metal(loid)s were mainly brought as particles, given that high amounts of suspended particulate matter (up to 2031 mg/L) were mobilized. Finally, comprehensive fluxes estimations confirmed that floods were responsible for more than 90 % of the total Cu, Zn and 75 % for As load transiting in the Morcille River in August within a very short period of time (less than 17 %).
Afficher plus [+] Moins [-]Lipids and proteins—major targets of oxidative modifications in abiotic stressed plants Texte intégral
2015
Anjum, Naser A. | Sofo, Adriano | Scopa, Antonio | Roychoudhury, Aryadeep | Gill, Sarvajeet S. | Iqbal, Muhammad | Lukatkin, Alexander S. | Pereira, Eduarda | Duarte, Armando C. | Aḥmad, Iqbāl
Stress factors provoke enhanced production of reactive oxygen species (ROS) in plants. ROS that escape antioxidant-mediated scavenging/detoxification react with biomolecules such as cellular lipids and proteins and cause irreversible damage to the structure of these molecules, initiate their oxidation, and subsequently inactivate key cellular functions. The lipid- and protein-oxidation products are considered as the significant oxidative stress biomarkers in stressed plants. Also, there exists an abundance of information on the abiotic stress-mediated elevations in the generation of ROS, and the modulation of lipid and protein oxidation in abiotic stressed plants. However, the available literature reflects a wide information gap on the mechanisms underlying lipid- and protein-oxidation processes, major techniques for the determination of lipid- and protein-oxidation products, and on critical cross-talks among these aspects. Based on recent reports, this article (a) introduces ROS and highlights their relationship with abiotic stress-caused consequences in crop plants, (b) examines critically the various physiological/biochemical aspects of oxidative damage to lipids (membrane lipids) and proteins in stressed crop plants, (c) summarizes the principles of current technologies used to evaluate the extent of lipid and protein oxidation, (d) synthesizes major outcomes of studies on lipid and protein oxidation in plants under abiotic stress, and finally, (e) considers a brief cross-talk on the ROS-accrued lipid and protein oxidation, pointing to the aspects unexplored so far.
Afficher plus [+] Moins [-]Exposure to vancomycin causes a shift in the microbial community structure without affecting nitrate reduction rates in river sediments Texte intégral
2015
Laverman, Anniet M. | Cazier, Thibaut | Yan, Chen | Roose-Amsaleg, Céline | Petit, Fabienne | Garnier, Josette | Berthe, Thierry
Antibiotics and antibiotic resistance genes have shown to be omnipresent in the environment. In this study, we investigated the effect of vancomycin (VA) on denitrifying bacteria in river sediments of a Waste Water Treatment Plant, receiving both domestic and hospital waste. We exposed these sediments continuously in flow-through reactors to different VA concentrations under denitrifying conditions (nitrate addition and anoxia) in order to determine potential nitrate reduction rates and changes in sedimentary microbial community structures. The presence of VA had no effect on sedimentary nitrate reduction rates at environmental concentrations, whereas a change in bacterial (16S rDNA) and denitrifying (nosZ) community structures was observed (determined by polymerase chain reaction–denaturing gradient gel electrophoresis). The bacterial and denitrifying community structure within the sediment changed upon VA exposure indicating a selection of a non-susceptible VA population.
Afficher plus [+] Moins [-]Ozone exposure and flux-based response functions for photosynthetic traits in wheat, maize and poplar Texte intégral
2015
Bagard, Matthieu | Jolivet, Yves | Hasenfratz-Sauder, Marie-Paule | Gérard, Joëlle | Dizengremel, Pierre | Le Thiec, Didier
Ozone exposure- and dose-response relationships based on photosynthetic leaf traits (CO2 assimilation, chlorophyll content, Rubisco and PEPc activities) were established for wheat, maize and poplar plants grown in identical controlled conditions, providing a comparison between crop and tree species, as well as between C3 and C4 plants. Intra-specific variability was addressed by comparing two wheat cultivars with contrasting ozone tolerance. Depending on plant models and ozone levels, first-order, second-order and segmented linear regression models were used to derive ozone response functions. Overall, flux-based functions appeared superior to exposure-based functions in describing the data, but the improvement remained modest. The best fit was obtained using the POD0.5 for maize and POD3 for poplar. The POD6 appeared relevant for wheat, although intervarietal differences were found. Our results suggest that taking into account the dynamics of leaf antioxidant capacity could improve current methods for ozone risk assessment for plants.
Afficher plus [+] Moins [-]Metabarcoding approach for non-indigenous species surveillance in marine coastal waters Texte intégral
2015
Zaiko, Anastasija | Samuiloviene, Aurelija | Ardura, Alba | Garcia-Vazquez, Eva
In this study, high-throughput sequencing (HTS) metabarcoding was applied for the surveillance of plankton communities within the southeastern (SE) Baltic Sea coastal zone. These results were compared with those from routine monitoring survey and morphological analyses. Four of five nonindigenous species found in the samples were identified exclusively by metabarcoding. All of them are considered as invasive in the Baltic Sea with reported impact on the ecosystem and biodiversity. This study indicates that, despite some current limitations, HTS metabarcoding can provide information on the presence of exotic species and advantageously complement conventional approaches, only requiring the same monitoring effort as before. Even in the currently immature status of HTS, this combination of HTS metabarcoding and observational records is recommended in the early detection of marine pests and delivery of the environmental status metrics of nonindigenous species.
Afficher plus [+] Moins [-]The dynamics of low-chlorinated benzenes in a pilot-scale constructed wetland and a hydroponic plant root mat treating sulfate-rich groundwater Texte intégral
2015
Chen, Zhongbing | Kuschk, Peter | Paschke, Heidrun | Kästner, Matthias | Köser, Heinz
A rarely used hydroponic plant root mat filter (PRMF, of 6 m²) and a horizontal subsurface flow constructed wetland (HSSF CW, of 6 m²), operating in continuous flow and discontinuous outflow flushing modes, were investigated for treating sulfate-rich and organic carbon-lean groundwater contaminated with monochlorobenzene (MCB); 1,2-dichlorobenzene (1,2-DCB); 1,4-dichlorobenzene (1,4-DCB); and 2-chlorotoluene. Whereas the mean inflow loads ranged from 1 to 247 mg m⁻²days⁻¹, the range of mean inflow concentrations of the chlorobenzenes recorded over a period of 7 months was within 0.04 and 8 mg L⁻¹. A hydraulic surface loading rate of 30 L m⁻²days⁻¹was obtained in both systems. The mean load removal efficiencies were found to vary between 87 and 93 % in the PRMF after a flow path of 4 m, while the removal efficiencies were found to range between 46 and 70 % and 71 to 73 % in the HSSF CW operating in a continuous flow mode and a discontinuous outflow flushing mode, respectively. Seasonal variations in the removal efficiencies were observed for all low-chlorinated hydrocarbons both in the PRMF and the HSSF CW, whereby the highest removal efficiencies were reached during the summer months. Sulfide formation occurred in the organic carbon-lean groundwater particularly in summer, which is probably due to the plant-derived organic carbon that fostered the microbial dissimilatory sulfate reduction. Higher redox potential in water was observed in the PRMF. In conclusion, the PRMF could be an option for the treatment of water contaminated with compounds which in particular need oxic conditions for their microbial degradation, such as in the case of low-chlorinated benzenes.
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