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31.
Leonardo Cesar Ferreira Ana Catarina Cataneo Natália Corniani Yara Andréo de Souza Bruno José Aparecido Soares 《Pesticide biochemistry and physiology》2010,97(1):47-54
Nitric oxide (NO) is a molecule able to directly scavenge ROS and end chain reactions, which can be generated by some herbicides. This study aimed to evaluate whether the pretreatment of soybean plants with sodium nitroprusside (SNP) solution, a NO-donor substance, provides protection against oxidative stress generated by lactofen. Soybean plants were pretreated with SNP before lactofen application. The levels of lipoperoxides and photosynthetic pigments were quantified, and the activity of the antioxidant enzymes glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) was assessed. Although lipid peroxidation was not completely prevented, NO was able to scavenge ROS generated by the lactofen action, avoiding the photosynthetic pigment breakdown. Consequently, ROS scavenging by NO leads to a decrease in the available substrate for the antioxidant enzymes SOD, CAT, and POD, which are essential to protect plants under oxidative stress situations such as absence of GST induction by H2O2. 相似文献
32.
The root-feeding nematode community of wild plants may vary throughout their natural range. Little is known about how the variation of wild plants along their range affects their relationship with root-feeding nematodes. In the present study, we examined local and non-local combinations of host plants and root-feeding nematodes to test the hypothesis that nematode reproduction is favoured by local hosts. In two indoor experiments, we exposed populations of the wild dune grass Ammophila arenaria from northern and southern European coastal sand dunes to plant parasitic nematode species (Helicotylenchus spp.) from those same geographical origins. First, we used the southern nematode species to determine whether the effect of a local versus a non-local host may depend on nematode density. Then, in a cross-inoculation experiment we investigated how both nematode species performed with their local, as compared to the non-local hosts.
In both experiments, plant biomass and ontogenetic characteristics were not significantly different between the northern and southern populations. The applied nematode densities did not have a negative impact on plant performance. This allowed us to consider the response of the two different nematode species and their host plants without co-varying differences in plant responses. Reproduction of the nematode species differed according to host origin, but contrary to what we expected, nematode species did not perform better on their local hosts. Helicotylenchus n. sp., the southern species originating from Portugal, performed better on the non-local than on the local host. Male to female ratios were significantly different between the two nematode populations and were lowest in Helicotylenchus pseudorobustus from The Netherlands. Female and juveniles percentages were also quite distinct, with more females in the nematode species from The Netherlands and more juveniles in the nematode species from Portugal.
We concluded that ectoparasitic root-feeding nematodes Helicotylenchus spp. do not necessarily perform best on their local host population of the foredune grass A. arenaria. Our results imply that the natural distribution of Helicotylenchus spp. along the European coast is determined by other factors than host populations. These other factors that could be abiotic, e.g. water availability, or biotic, e.g. local natural enemies adapted to Helicotylenchus spp. Introducing plant genotypes from other parts of the natural range will, therefore, not necessarily lead to reduced abundance of semi-endo or ectoparasitic root-feeding nematodes. 相似文献
33.
Ana Rita Neves Daniela Pereira Catarina Gonalves Joana Cardoso Eugnia Pinto Vitor Vasconcelos Madalena Pinto Emília Sousa Joana R. Almeida Honorina Cidade Marta Correia-da-Silva 《Marine drugs》2021,19(12)
Marine biofouling is a natural process that represents major economic, environmental, and health concerns. Some booster biocides have been used in biofouling control, however, they were found to accumulate in environmental compartments, showing negative effects on marine organisms. Therefore, it is urgent to develop new eco-friendly alternatives. Phenyl ketones, such as benzophenones and acetophenones, have been described as modulators of several biological activities, including antifouling activity (AF). In this work, acetophenones were combined with other chemical substrates through a 1,2,3-triazole ring, a strategy commonly used in Medicinal Chemistry. In our approach, a library of 14 new acetophenone–triazole hybrids was obtained through the copper(I)-catalyzed alkyne-azide cycloaddition “click” reaction. All of the synthesized compounds were evaluated against the settlement of a representative macrofouling species, Mytilus galloprovincialis, as well as on biofilm-forming marine microorganisms, including bacteria and fungi. The growth of the microalgae Navicula sp. was also evaluated after exposure to the most promising compounds. While compounds 6a, 7a, and 9a caused significant inhibition of the settlement of mussel larvae, compounds 3b, 4b, and 7b were able to inhibit Roseobacter litoralis bacterial biofilm growth. Interestingly, acetophenone 7a displayed activity against both mussel larvae and the microalgae Navicula sp., suggesting a complementary action of this compound against macro- and microfouling species. The most potent compounds (6a, 7a, and 9a) also showed to be less toxic to the non-target species Artemia salina than the biocide Econea®. Regarding both AF potency and ecotoxicity activity evaluation, acetophenones 7a and 9a were put forward in this work as promising eco-friendly AF agents. 相似文献
34.
Álvarez R Carvalho CP Sierra J Lara O Cardona D Londoño-Londoño J 《Journal of agricultural and food chemistry》2012,60(3):774-781
Clementines are especially appreciated for their delicious flavor, and recent years have seen a great increase in the consumption of clementine juice. In previous decades, antioxidant compounds have received particular attention because of widely demonstrated beneficial health effects. In this work, the organoleptic, volatile flavor, and antioxidant quality of clementine juice were studied with regard to the influence on them by different juice extraction systems: plug inside fruit and rotating cylinders. The results showed that juice extracted by the former method presented higher yields and hesperidin content, which was related to higher antioxidant activity, demonstrated by ORAC and LDL assays. The organoleptic quality was not affected by the processing technique, whereas there were significant differences in the chemical flavor profile. There are important differences in chemical and functional quality between juice extraction techniques, which must be taken into account when employing processing systems to produce high-quality products. 相似文献
35.
Raphael Marichal Michel Grimaldi Jerome Mathieu George G. Brown Thierry Desjardins Mario Lopes da Silva Junior Catarina Praxedes Marlucia B. Martins Elena Velasquez Patrick Lavelle 《Pedobiologia》2012,55(5):233-240
Pontoscolex corethurus (Müller, 1857) is the most common invasive earthworm in disturbed lands in the tropics. Conditions required for its successful colonization of new plots are still not understood since some areas can be invaded while others, sometimes in the vicinity, are not. We kept newly hatched P. corethrurus in a wide range of Amazonian soils where population densities had been previously evaluated. We identified soil conditions that best sustain survival, soil ingestion and growth of P. corethrurus in controlled laboratory conditions and checked if presence/absence in the field was consistent with laboratory observations. While pH and Ca influenced survival; Mg and C content were the greatest determinants for growth and C:P, Mg and clay contents determined soil ingestion rates. Soil ingestion and growth rate were correlated. There were no differences in earthworm soil ingestion rates between invaded and non-invaded soils. However, growth rate and survival were higher in soils from invaded sites than in soils from non invaded sites, indicating that soil quality may play a role in the invasion process. We identified two cases where P. corethrurus did not occur: (1) unfavourable soil texture and chemical properties, but also some areas with and (2) favourable soil texture and chemical properties but no invasion. Other parameters, like vegetation cover (grass or trees), soil structure and compaction, soil hydrologic processes or biotic resistance of native earthworm communities could potentially also be key elements for understanding why P. corethrurus populations occur in some sites and not in others. 相似文献
36.
Sara C. Pé-Leve Santos Mariana Eloy Cruz António M. E. Barroso Catarina P. S. Fonseca Mauro Guerra Maria Luísa Carvalho José Paulo Santos 《Journal of Soils and Sediments》2014,14(4):778-784
Purpose
Mining activities represent a current source of pollution due to the large release of trace elements from mineral particles into the soil, atmosphere, and ecosystems. In active or abandoned metal-mining areas, direct discharge from mining deposits is one of the most common processes of contamination.Materials and methods
In this work, we calculated the elemental concentrations of plants, edible for cattle, which might contain high values of toxic elements, such as As, Cu, Zn, and W, originated from mining exploitation, especially wolframite. Several species of plants originating from the same contaminated place, close to the mine, were the subject of our study in order to compare the uptake of harmful elements, from the contaminated soils, in the different plants. We have used the energy-dispersive X-ray fluorescence technique to perform the analysis and quantification of the elements present in the collected samples. The quantification was based on the fundamental parameters method for plants and on the WinAxil compare mode using a standard reference material, for soils. Calibration against a series of standard samples has been carried out.Results and discussion
A comparison between contaminated and control samples, within the same species, was performed. The contamination of the two mining wash sites is assessed by comparing the elemental concentration of several plants in these places. Elemental content in soils was investigated, and a comparison between elemental levels in plants was performed.Conclusions
High concentrations of tungsten were found near the new wash site. Arsenic was found throughout the area in concentrations many times higher than those recommended by the World Health Organization. 相似文献37.
Diogo F. N. Cardoso Ana Catarina Bastos Amadeu M. V. M. Soares Susana Loureiro 《Journal of Soils and Sediments》2014,14(9):1559-1567
Purpose
Ecotoxicological risk assessment of chemical compounds is considered more accurate when mixtures of chemicals and/or interactions between chemicals and natural stressors are considered. To further simulate natural conditions, under which organisms are often exposed to combinations of natural and anthropogenic stressors, the combined exposure of a widely used insecticide, carbaryl, under UV radiation was evaluated. It is more than likely that soil organisms are confronted with a combination of chemical exposure and increasing UV irradiance on the terrestrial habitat. Considering the heterogeneity of contamination in field soils and the probability of collembolan to avoid contaminated soil (less time under exposure), combined effects of carbaryl and ultraviolet radiation were evaluated, by using a short exposure to Folsomia candida.Materials and methods
Single exposures to carbaryl and UV radiation were performed, and adult mortality and number of laid and hatched eggs were reported. Following the results, a combined exposure was carried out, using the same conditions performed previously in the single tests. Organisms were exposed simultaneously to carbaryl (from 1 to 7 mg kg?1) and UV doses (from 1,121.29 to 3,795.26 J m?2), the last corresponds to 1 to 4 h of exposure. Mortality was reported, and organisms were left to lay eggs in culture boxes.Results and discussion
Both ultraviolet radiation and high concentrations of carbaryl as single stressors increased the number of produced eggs of F. candida, with significant differences at higher concentrations (4, 5.5, and 7 mg kg?1) of carbaryl and an EC50 of 5.93 mg kg?1. In the case of UV radiation, statistical differences were found at all concentrations compared with control, with an EC50 of 1,248.24 J m?2. In both cases, no significant mortality was observed. When combined, both stressors acted independently on egg production, showing additivity of effects (independent action (IA) model to data on laid eggs; SS?=?0.00056; r2?=?0.75; p?Conclusions This study highlights the importance of taking UV exposure conditions into account when assessing the impact of pesticides to soil biota and looking for more realistic scenarios while showing that soil sheltering occurs only up to a certain extent and that indirect effects can be observed. The opposite trends on responses obtained under standardized tests and short exposures to carbaryl provided some insight on the possible effects of carbaryl during collembolan life cycle. 相似文献38.
Catarina Passidomo 《Agriculture and Human Values》2014,31(3):385-396
Among critical responses to the perceived perils of the industrial food system, the food sovereignty movement offers a vision of radical transformation by demanding the democratic right of peoples “to define their own agriculture and food policies.” At least conceptually, the movement offers a visionary and holistic response to challenges related to human and environmental health and to social and economic well-being. What is still unclear, however, is the extent to which food sovereignty discourses and activism interact with and affect the material and social realities of the frequently low-income communities of color in which they are situated, and whether they help or hinder pre-existing efforts to alleviate hunger, overcome racism, and promote social justice. This research and corresponding paper addresses those questions by examining food justice and food sovereignty activism in the city of New Orleans since Hurricane Katrina as understood by both activists and community members. I argue, using post-Katrina New Orleans as a case study, that food projects initiated and maintained by white exogenous groups on behalf of communities of color risk exacerbating the very systems of privilege and inequality they seek to ameliorate. This paper argues for a re-positioning of food justice activism, which focuses on systemic change through power analyses and the strategic nurturing of interracial alliances directed by people residing in the communities in which projects are situated. 相似文献
39.
Fontes-Sousa AP Moura C Carneiro CS Teixeira-Pinto A Areias JC Leite-Moreira AF 《Veterinary journal (London, England : 1997)》2009,181(3):326-331
Limited data are available on the use of more recent echocardiographic parameters in the rabbit. Echocardiographic examination, including conventional echocardiography and tissue Doppler imaging (TDI), was performed on 26 male New Zealand white rabbits under ketamine–midazolam sedation. Particular emphasis was placed on the more recent systolic and diastolic parameters, such as myocardial performance index (Tei index) and mitral annular motion (from septal and lateral sides of the left ventricle) obtained using pulsed TDI.Parameters that assessed systolic and diastolic function (fractional shortening, Tei index, and maximal mitral E- and A-wave velocities) were comparable to those reported in the literature for rabbits in the awake state. The less cardiodepressive anaesthetic protocol could offer a good alternative in performing echocardiographic evaluation whenever such caution is necessary. TDI is feasible in healthy rabbits and potentially suitable for the investigation of left ventricle systolic and diastolic function. 相似文献
40.