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1.
Integr Environ Assess Manag ; 14(5): 586-591, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30489025

RESUMO

A conceptual framework was developed by a working group of the Scientific Committee of the European Food Safety Authority (EFSA) to guide risk assessors and risk managers on when and how to integrate ecological recovery and resilience assessments into environmental risk assessments (ERA). In this commentary we advocate that a systems approach is required to integrate the diversity of ecosystem services (ES) providing units, environmental factors, scales, and stressor-related responses necessary to address the context dependency of recovery and resilience in agricultural landscapes. A future challenge in the resilience assessment remains to identify the relevant bundles of ecosystem services provided by different types of agroecosystem that need to be assessed in concert. Integr Environ Assess Manag 2018;14:586-591. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).


Assuntos
Agricultura , Ecossistema , Monitoramento Ambiental , Inocuidade dos Alimentos , Ecologia , Ecotoxicologia , Medição de Risco , Gestão de Riscos
2.
Front Plant Sci ; 5: 391, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25161661

RESUMO

A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab) maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize or by the produced Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies.

3.
Transgenic Res ; 23(6): 1025-41, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24733670

RESUMO

It is commonly held that confined field trials (CFTs) used to evaluate the potential adverse environmental impacts of a genetically engineered (GE) plant should be conducted in each country where cultivation is intended, even when relevant and potentially sufficient data are already available from studies conducted elsewhere. The acceptance of data generated in CFTs "out of country" can only be realized in practice if the agro-climatic zone where a CFT is conducted is demonstrably representative of the agro-climatic zones in those geographies to which the data will be transported. In an attempt to elaborate this idea, a multi-disciplinary Working Group of scientists collaborated to develop a conceptual framework and associated process that can be used by the regulated and regulatory communities to support transportability of CFT data for environmental risk assessment (ERA). As proposed here, application of the conceptual framework provides a scientifically defensible process for evaluating if existing CFT data from remote sites are relevant and/or sufficient for local ERAs. Additionally, it promotes a strategic approach to identifying CFT site locations so that field data will be transportable from one regulatory jurisdiction to another. Application of the framework and process should be particularly beneficial to public sector product developers and small enterprises that develop innovative GE events but cannot afford to replicate redundant CFTs, and to regulatory authorities seeking to improve the deployment of limited institutional resources.


Assuntos
Qualidade de Produtos para o Consumidor , Exposição Ambiental/prevenção & controle , Plantas Geneticamente Modificadas/efeitos adversos , Medição de Risco/métodos , Estatística como Assunto , Humanos
4.
Transgenic Res ; 23(6): 995-1013, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24633599

RESUMO

Worldwide, plants obtained through genetic modification are subject to a risk analysis and regulatory approval before they can enter the market. An area of concern addressed in environmental risk assessments is the potential of genetically modified (GM) plants to adversely affect non-target arthropods and the valued ecosystem services they provide. Environmental risk assessments are conducted case-by-case for each GM plant taking into account the plant species, its trait(s), the receiving environments into which the GM plant is to be released and its intended uses, and the combination of these characteristics. To facilitate the non-target risk assessment of GM plants, information on arthropods found in relevant agro-ecosystems in Europe has been compiled in a publicly available database of bio-ecological information during a project commissioned by the European Food Safety Authority (EFSA). Using different hypothetical GM maize case studies, we demonstrate how the information contained in the database can assist in identifying valued species that may be at risk and in selecting suitable species for laboratory testing, higher-tier studies, as well as post-market environmental monitoring.


Assuntos
Artrópodes/fisiologia , Bases de Dados Factuais , Monitoramento Ambiental/métodos , Controle Biológico de Vetores/métodos , Plantas Geneticamente Modificadas/toxicidade , Medição de Risco/métodos , Zea mays/parasitologia , Animais , Exposição Ambiental/prevenção & controle , Plantas Geneticamente Modificadas/parasitologia
5.
Chemosphere ; 90(3): 901-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23062830

RESUMO

UNLABELLED: Arthropods form a major part of the biodiversity in agricultural landscapes. Many species are valued because they provide ecosystem services, including biological control, pollination and decomposition, or because they are of conservation interest. Some arthropods reduce crop yield and quality, and conventional chemical pesticides, biological control agents and genetically engineered (GE) crops are used to control them. A common concern addressed in the ecological risk assessment (ERA) that precedes regulatory approval of these pest control methods is their potential to adversely affect valued non-target arthropods (NTAs). A key concept of ERA is early-tier testing using worst-case exposure conditions in the laboratory and surrogate test species that are most likely to reveal an adverse effect. If no adverse effects are observed in those species at high exposures, confidence of negligible ecological risk from the use of the pest control method is increased. From experience with chemical pesticides and biological control agents, an approach is proposed for selecting test species for early-tier ERA of GE arthropod-resistant crops. Surrogate species should be selected that most closely meet three criteria: (i) Potential sensitivity: species should be the most likely to be sensitive to the arthropod-active compound based on the known spectrum of activity of the active ingredient, its mode of action, and the phylogenetic relatedness of the test and target species; (ii) RELEVANCE: species should be representative of valued taxa or functional groups that are most likely to be exposed to the arthropod-active compound in the field; and (iii) Availability and reliability: suitable life-stages of the test species must be obtainable in sufficient quantity and quality, and validated test protocols must be available that allow consistent detection of adverse effects on ecologically relevant parameters. Our proposed approach ensures that the most suitable species are selected for testing and that the resulting data provide the most rigorous test of the risk hypothesis of no adverse effect in order to increase the quality and efficiency of ERAs for cultivation of GE crops.


Assuntos
Artrópodes/fisiologia , Produtos Agrícolas/genética , Produtos Agrícolas/parasitologia , Controle Biológico de Vetores/métodos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/parasitologia , Animais , Ecologia/métodos , Medição de Risco
6.
GM Crops Food ; 3(2): 115-22, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22538226

RESUMO

Outcrosses from genetically modified (GM) to conventional crops by pollen-mediated gene flow (PMGF) are a concern when growing GM crops close to non-GM fields. This also applies to the experimental releases of GM plants in field trials. Therefore, biosafety measures such as isolation distances and surveying of PMGF are required by the regulatory authorities in Switzerland. For two and three years, respectively, we monitored crop-to-crop PMGF from GM wheat field trials in two locations in Switzerland. The pollen donors were two GM spring wheat lines with enhanced fungal resistance and a herbicide tolerance as a selection marker. Seeds from the experimental plots were sampled to test the detection method for outcrosses. Two outcrosses were found adjacent to a transgenic plot within the experimental area. For the survey of PMGF, pollen receptor plots of the conventional wheat variety Frisal used for transformation were planted in the border crop and around the experimental field up to a distance of 200 m. Although the environmental conditions were favorable and the donor and receptor plots flowered at the same time, only three outcrosses were found in approximately 185,000 tested seedlings from seeds collected outside the experimental area. All three hybrids were found in the border crop surrounding the experimental area, but none outside the field. We conclude that a pollen barrier (border crop) and an additional isolation distance of 5 m is a sufficient measure to reduce PMGF from a GM wheat field trial to cleistogamous varieties in commercial fields below a level that can be detected.


Assuntos
Fluxo Gênico , Plantas Geneticamente Modificadas/genética , Pólen/genética , Triticum/genética , Aminobutiratos/toxicidade , Cruzamentos Genéticos , Resistência à Doença/genética , Fungos/fisiologia , Resistência a Herbicidas/genética , Herbicidas/toxicidade , Interações Hospedeiro-Patógeno , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/microbiologia , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/microbiologia , Sementes/genética , Suíça , Triticum/efeitos dos fármacos , Triticum/microbiologia
7.
Environ Entomol ; 41(6): 1687-93, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23321119

RESUMO

Early-tier studies are the initial step in the environmental risk assessment of genetically engineered plants on nontarget arthropods. They are conducted in the laboratory where surrogate species are exposed to higher concentrations of the arthropod-active compound than those expected to occur in the field. Thus, early-tier tests provide robust data and allow to make general conclusions about the susceptibility of the surrogate to the test substance. We have developed an early-tier test for assessing the toxicity of orally-active insecticidal compounds to larvae of the ladybird beetle Coccinella septempunctata L. (Coleoptera: Coccinellidae). Using potassium arsenate and the protease inhibitor E-64 as model compounds, we validated the bioassay set-up for C. septempunctata. Sucrose solution containing the test compound was offered to larvae for 24 h on the first day of each of its four larval instars. Subsequently, larvae were fed ad libitum with Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs. Both compounds negatively affected C. septempunctata larval survival and development, and adult weight, indicating that the bioassay setup was able to detect dietary effects of insecticidal substances on the ladybird. Power analyses revealed that sample sizes of 20 or 45 per treatment are sufficient to detect 50 or 20% differences between the control and treatment groups, respectively, for the various measurement endpoints.


Assuntos
Bioensaio , Besouros/efeitos dos fármacos , Inseticidas/toxicidade , Plantas Geneticamente Modificadas/química , Animais , Afídeos , Arseniatos/toxicidade , Besouros/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Leucina/análogos & derivados , Leucina/toxicidade , Mariposas , Óvulo , Compostos de Potássio/toxicidade , Medição de Risco/métodos
8.
Pest Manag Sci ; 67(9): 1049-58, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21710684

RESUMO

The European corn borer (Ostrinia nubilalis), the Mediterranean corn borer (Sesamia nonagrioides) and the western corn rootworm (Diabrotica virgifera virgifera) are the main arthropod pests in European maize production. Practised pest control includes chemical control, biological control and cultural control such as ploughing and crop rotation. A pest control option that is available since 1996 is maize varieties that are genetically engineered (GE) to produce insecticidal compounds. GE maize varieties available today express one or several genes from Bacillus thuringiensis (Bt) that target corn borers or corn rootworms. Incentives to growing Bt maize are simplified farm operations, high pest control efficiency, improved grain quality and ecological benefits. Limitations include the risk of resistance evolution in target pest populations, risk of secondary pest outbreaks and increased administration to comply with licence agreements. Growers willing to plant Bt maize in the European Union (EU) often face the problem that authorisation is denied. Only one Bt maize transformation event (MON810) is currently authorised for commercial cultivation, and some national authorities have banned cultivation. Spain is the only EU member state where Bt maize adoption levels are currently delivering farm income gains near full potential levels. In an integrated pest management (IPM) context, Bt maize can be regarded as a preventive (host plant resistance) or a responsive pest control measure. In any case, Bt maize is a highly specific tool that efficiently controls the main pests and allows combination with other preventive or responsive measures to solve other agricultural problems including those with secondary pests.


Assuntos
Bacillus thuringiensis/genética , Controle Biológico de Vetores , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas/parasitologia , Zea mays/genética , Zea mays/parasitologia , Animais , Bacillus thuringiensis/metabolismo , Mariposas/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Zea mays/metabolismo
9.
Transgenic Res ; 20(6): 1191-201, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21607784

RESUMO

The ability to decide what kind of environmental changes observed during post-market environmental monitoring of genetically modified (GM) crops represent environmental harm is an essential part of most legal frameworks regulating the commercial release of GM crops into the environment. Among others, such decisions are necessary to initiate remedial measures or to sustain claims of redress linked to environmental liability. Given that consensus on criteria to evaluate 'environmental harm' has not yet been found, there are a number of challenges for risk managers when interpreting GM crop monitoring data for environmental decision-making. In the present paper, we argue that the challenges in decision-making have four main causes. The first three causes relate to scientific data collection and analysis, which have methodological limits. The forth cause concerns scientific data evaluation, which is controversial among the different stakeholders involved in the debate on potential impacts of GM crops on the environment. This results in controversy how the effects of GM crops should be valued and what constitutes environmental harm. This controversy may influence decision-making about triggering corrective actions by regulators. We analyse all four challenges and propose potential strategies for addressing them. We conclude that environmental monitoring has its limits in reducing uncertainties remaining from the environmental risk assessment prior to market approval. We argue that remaining uncertainties related to adverse environmental effects of GM crops would probably be assessed in a more efficient and rigorous way during pre-market risk assessment. Risk managers should acknowledge the limits of environmental monitoring programmes as a tool for decision-making.


Assuntos
Tomada de Decisões , Monitoramento Ambiental/legislação & jurisprudência , Política Ambiental/legislação & jurisprudência , Plantas Geneticamente Modificadas , Agricultura , Biodiversidade , Produtos Agrícolas , Meio Ambiente , Marketing , Medição de Risco/legislação & jurisprudência , Medição de Risco/organização & administração , Estatística como Assunto , Fatores de Tempo
10.
Rev. bras. entomol ; 55(1): 1-5, Jan.-Mar. 2011.
Artigo em Inglês | LILACS | ID: lil-586063

RESUMO

Will the Convention on Biological Diversity put an end to biological control? Under the Convention on Biological Diversity countries have sovereign rights over their genetic resources. Agreements governing the access to these resources and the sharing of the benefits arising from their use need to be established between involved parties. This also applies to species collected for potential use in biological control. Recent applications of access and benefit sharing principles have already made it difficult or impossible to collect and export natural enemies for biological control research in several countries. If such an approach is widely applied it would impede this very successful and environmentally safe pest management method based on the use of biological diversity. The International Organization for Biological Control of Noxious Animals and Plants has, therefore, created the "Commission on Biological Control and Access and Benefit Sharing". This commission is carrying out national and international activities to make clear how a benefit sharing regime might seriously frustrate the future of biological control. In addition, the IOBC Commission members published information on current regulations and perceptions concerning exploration for natural enemies and drafted some 30 case studies selected to illustrate a variety of points relevant to access and benefit sharing. In this article, we summarize our concern about the effects of access and benefit sharing systems on the future of biological control.


Poderá a Convenção em Diversidade Biológica por um fim no Controle Biológico? Baseando-se na Convenção sobre Diversidade Biológica, os países têm soberania sobre seus recursos genéticos. Acordos que governam o acesso a tais recursos e o compartilhamento dos benefícios provenientes do seu uso precisam ser estabelecidos de comum acordo com as partes envolvidas. Isto também é aplicável a espécies coletadas com uso potencial em controle biológico. Recentes aplicações dos princípios de introdução e compartilhamento dos benefícios têm tornado difícil, ou mesmo impossível, coletar e exportar inimigos naturais em muitos paises para pesquisas em controle biológico em muitos países. Como esta é uma medida amplamente utilizada, tais procedimentos poderão impedir este bem sucedido e ambientalmente seguro método de manejo de pragas, baseado no uso da diversidade biológica. A Organização Internacional para Controle Biológico de Plantas e Animais Nocivos (IOBC) criou a "Comissão em Controle Biológico e Introdução e Benefícios Mútuos" para estudar o assunto. Tal comissão está desenvolvendo atividades nacionais e internacionais para esclarecer como o regime de compartilhamento de benefícios pode prejudicar seriamente o futuro do controle biológico. Além disto, membros da Comissão da IOBC publicaram informações sobre regulamentos atuais e suas opiniões relacionadas à exploração de inimigos naturais, listando cerca de 30 casos para ilustrar os pontos relevantes para a introdução e compartilhamento de benefícios. No presente artigo, é sumarizado o ponto de vista dessa comissão na IOBC sobre os efeitos dos sistemas de introdução e compartilhamento para o futuro do Controle Biológico.

11.
Transgenic Res ; 20(3): 467-79, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20740377

RESUMO

Scientific studies are frequently used to support policy decisions related to transgenic crops. Schmidt et al., Arch Environ Contam Toxicol 56:221-228 (2009) recently reported that Cry1Ab and Cry3Bb were toxic to larvae of Adalia bipunctata in direct feeding studies. This study was quoted, among others, to justify the ban of Bt maize (MON 810) in Germany. The study has subsequently been criticized because of methodological shortcomings that make it questionable whether the observed effects were due to direct toxicity of the two Cry proteins. We therefore conducted tritrophic studies assessing whether an effect of the two proteins on A. bipunctata could be detected under more realistic routes of exposure. Spider mites that had fed on Bt maize (events MON810 and MON88017) were used as carriers to expose young A. bipunctata larvae to high doses of biologically active Cry1Ab and Cry3Bb1. Ingestion of the two Cry proteins by A. bipunctata did not affect larval mortality, weight, or development time. These results were confirmed in a subsequent experiment in which A. bipunctata were directly fed with a sucrose solution containing dissolved purified proteins at concentrations approximately 10 times higher than measured in Bt maize-fed spider mites. Hence, our study does not provide any evidence that larvae of A. bipunctata are sensitive to Cry1Ab and Cry3Bb1 or that Bt maize expressing these proteins would adversely affect this predator. The results suggest that the apparent harmful effects of Cry1Ab and Cry3Bb1 reported by Schmidt et al., Arch Environ Contam Toxicol 56:221-228 (2009) were artifacts of poor study design and procedures. It is thus important that decision-makers evaluate the quality of individual scientific studies and do not view all as equally rigorous and relevant.


Assuntos
Proteínas de Bactérias/toxicidade , Besouros/fisiologia , Endotoxinas/toxicidade , Proteínas Hemolisinas/toxicidade , Plantas Geneticamente Modificadas/fisiologia , Zea mays/fisiologia , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Larva , Plantas Geneticamente Modificadas/genética , Projetos de Pesquisa , Medição de Risco , Tetranychidae/fisiologia , Zea mays/genética
14.
Nat Biotechnol ; 26(2): 203-8, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18259178

RESUMO

An international initiative is developing a scientifically rigorous approach to evaluate the potential risks to nontarget arthropods (NTAs) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is used internationally within regulatory toxicology and environmental sciences. The approach focuses on the formulation and testing of clearly stated risk hypotheses, making maximum use of available data and using formal decision guidelines to progress between testing stages (or tiers). It is intended to provide guidance to regulatory agencies that are currently developing their own NTA risk assessment guidelines for IRGM crops and to help harmonize regulatory requirements between different countries and different regions of the world.


Assuntos
Artrópodes/efeitos dos fármacos , Toxinas Bacterianas/toxicidade , Controle Biológico de Vetores , Plantas Geneticamente Modificadas/toxicidade , Medição de Risco/métodos , Animais , Toxinas Bacterianas/genética , Marcação de Genes/métodos , Plantas Geneticamente Modificadas/parasitologia , Fatores de Risco
15.
Transgenic Res ; 17(3): 317-35, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17562214

RESUMO

A major concern related to the adoption of genetically modified (GM) crops in agricultural systems is the possibility of unwanted GM inputs into non-GM crop production systems. Given the increasing commercial cultivation of GM crops in the European Union (EU), there is an urgent need to define measures to prevent mixing of GM with non-GM products during crop production. Cross-fertilization is one of the various mechanisms that could lead to GM-inputs into non-GM crop systems. Isolation distances between GM and non-GM fields are widely accepted to be an effective measure to reduce these inputs. However, the question of adequate isolation distances between GM and non-GM maize is still subject of controversy both amongst scientists and regulators. As several European countries have proposed largely differing isolation distances for maize ranging from 25 to 800 m, there is a need for scientific criteria when using cross-fertilization data of maize to define isolation distances between GM and non-GM maize. We have reviewed existing cross-fertilization studies in maize, established relevant criteria for the evaluation of these studies and applied these criteria to define science-based isolation distances. To keep GM-inputs in the final product well below the 0.9% threshold defined by the EU, isolation distances of 20 m for silage and 50 m for grain maize, respectively, are proposed. An evaluation using statistical data on maize acreage and an aerial photographs assessment of a typical agricultural landscape by means of Geographic Information Systems (GIS) showed that spatial resources would allow applying the defined isolation distances for the cultivation of GM maize in the majority of the cases under actual Swiss agricultural conditions. The here developed approach, using defined criteria to consider the agricultural context of maize cultivation, may be of assistance for the analysis of cross-fertilization data in other countries.


Assuntos
Agricultura/métodos , Contenção de Riscos Biológicos/métodos , Plantas Geneticamente Modificadas/fisiologia , Zea mays/fisiologia , Quimera/genética , Quimera/fisiologia , Produtos Agrícolas/fisiologia , Cruzamentos Genéticos , Estudos de Viabilidade , Fertilização/fisiologia , Geografia , Polinização/fisiologia , Suíça , Zea mays/genética
16.
Adv Biochem Eng Biotechnol ; 107: 235-78, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17522828

RESUMO

The worldwide commercial cultivation of genetically modified (GM) crops has raised concerns about potential adverse effects on the environment resulting from the use of these crops. Consequently, the risks of GM crops for the environment, and especially for biodiversity, have been extensively assessed before and during their commercial cultivation. Substantial scientific data on the environmental effects of the currently commercialized GM crops are available today. We have reviewed this scientific knowledge derived from the past 10 years of worldwide experimental field research and commercial cultivation. The review focuses on the currently commercially available GM crops that could be relevant for agriculture in Western and Central Europe (i.e., maize, oilseed rape, and soybean), and on the two main GM traits that are currently commercialized, herbicide tolerance (HT) and insect resistance (IR). The sources of information included peer-reviewed scientific journals, scientific books, reports from regions with extensive GM crop cultivation, as well as reports from international governmental organizations. The data available so far provide no scientific evidence that the cultivation of the presently commercialized GM crops has caused environmental harm. Nevertheless, a number of issues related to the interpretation of scientific data on effects of GM crops on the environment are debated controversially. The present review highlights these scientific debates and discusses the effects of GM crop cultivation on the environment considering the impacts caused by cultivation practices of modern agricultural systems.


Assuntos
Produtos Agrícolas/genética , Ecossistema , Plantas Geneticamente Modificadas/genética , Produtos Agrícolas/efeitos dos fármacos , Resistência a Medicamentos/genética , Herbicidas/farmacologia , Resistência a Inseticidas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos
17.
FEMS Microbiol Ecol ; 59(3): 600-10, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17381517

RESUMO

In this study, the effects of the Bt-toxin Cry1Ab and a soybean trypsin inhibitor (SBTI) on intestinal bacterial communities of adult honeybees (Apis mellifera) were investigated. It was hypothesized that changes in intestinal bacterial communities of honeybees may represent a sensitive indicator for altered intestinal physiology. Honeybees were fed in a laboratory set-up with maize pollen from the Bt-transgenic cultivar MON810 or from the non-transgenic near isoline. Purified Cry1Ab (0.0014% w/v) and SBTI (0.1% or 1% w/v) represented supplementary treatments. For comparison, free-flying honeybees from two locations in Switzerland were analysed. PCR-amplification of bacterial 16S rRNA gene fragments and terminal restriction fragment length polymorphism analyses revealed a total of 17 distinct terminal restriction fragments (T-RFs), which were highly consistent between laboratory-reared and free-flying honeybees. The T-RFs were affiliated to Alpha-, Beta-, and Gammaproteobacteria, to Firmicutes, and to Bacteriodetes. Neither Bt-maize pollen nor high concentrations of Cry1Ab significantly affected bacterial communities in honeybee intestines. Only the high concentration of SBTI significantly reduced the number of T-RFs detected in honeybee midguts, a concentration that also increases bee mortality. Therefore, total bacterial community structures may not be a sensitive indicator for providing evidence for the impact of insecticidal proteins on honeybees at sublethal levels.


Assuntos
Bactérias/classificação , Abelhas/microbiologia , Abelhas/fisiologia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Toxinas Bacterianas/efeitos adversos , Intestinos/microbiologia , Intestinos/fisiologia , Plantas Geneticamente Modificadas/efeitos adversos , Pólen , Polimorfismo de Fragmento de Restrição , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Medição de Risco , Proteínas de Soja/efeitos adversos , Suíça , Inibidores da Tripsina/efeitos adversos , Zea mays
18.
Exp Appl Acarol ; 38(2-3): 125-39, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16596347

RESUMO

The investigation of Neoseiulus cucumeris in the context of the ecological risk assessment of insect resistant transgenic plants is of particular interest as this omnivorous predatory mite species is commercially available and considered important for biological control. In a multitrophic feeding experiment we assessed the impact of Bt maize on the performance of N. cucumeris when offered spider mites (Tetranychus urticae) reared on Bt (Bt11, Syngenta) or non-Bt maize (near isogenic line) and Bt or non-Bt maize pollen as a food source. Various parameters including mortality, development time, oviposition rate were measured. Spider mites were used as a prey for N. cucumeris, since these herbivores are known to contain similar levels of Cry1Ab toxin, when reared on Bt maize, as those found in the transgenic leaf material. In contrast, toxin levels in pollen of this transgenic cultivar are very low. No differences in any of the parameters were found when N. cucumeris was fed with spider mites reared on Bt and non-Bt maize. Pollen was shown to be a less suitable food source for this predator as compared to spider mites. Moreover, subtle effects on female N. cucumeris (9% longer development time and 17% reduced fecundity) were measured when fed with pollen originating from Bt maize as compared to non-Bt maize pollen. Our findings indicate that the predatory mite N. cucumeris is not sensitive to the Cry1Ab toxin as no effects could be detected when offered Bt-containing spider mites, and that the effects found when fed with Bt maize pollen can be assigned to differences in nutritional quality of Bt and non-Bt maize pollen. The significance of these findings is discussed with regard to the ecological relevance for risk assessment of transgenic plants.


Assuntos
Plantas Geneticamente Modificadas/parasitologia , Tetranychidae/crescimento & desenvolvimento , Zea mays/parasitologia , Animais , Bacillus thuringiensis , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Endotoxinas/metabolismo , Feminino , Proteínas Hemolisinas , Masculino , Oviposição , Controle Biológico de Vetores , Pólen/metabolismo , Tetranychidae/parasitologia
19.
Nat Biotechnol ; 24(1): 63-71, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16404399

RESUMO

The area devoted to growing transgenic plants expressing insecticidal Cry proteins derived from Bacillus thuringiensis (Bt) is increasing worldwide. A major concern with the adoption of Bt crops is their potential impact on nontarget organisms including biological control organisms. Regulatory frameworks should advocate a step-wise (tiered) approach to assess possible nontarget effects of Bt crops. Laboratory and glasshouse studies have revealed effects on natural enemies only when Bt-susceptible, sublethally damaged herbivores were used as prey or host, with no indication of direct toxic effects. Field studies have confirmed that the abundance and activity of parasitoids and predators are similar in Bt and non-Bt crops. In contrast, applications of conventional insecticides have usually resulted in negative impacts on biological control organisms. Because Bt-transgenic varieties can lead to substantial reductions in insecticide use in some crops, they can contribute to integrated pest management systems with a strong biological control component.


Assuntos
Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/efeitos adversos , Proteínas de Bactérias/metabolismo , Qualidade de Produtos para o Consumidor , Controle Biológico de Vetores/métodos , Plantas Geneticamente Modificadas/efeitos adversos , Plantas Geneticamente Modificadas/metabolismo , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Resistência a Inseticidas/fisiologia , Plantas Geneticamente Modificadas/genética , Medição de Risco/métodos , Fatores de Risco
20.
Environ Biosafety Res ; 5(4): 183-6, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17640503

RESUMO

The scientific organizers of the symposium put much emphasis on the identification and definition of hazard and the potential consequences thereof and three full sessions with a total of 13 presentations encompassing a wide range of related themes were planned for this topic. Unfortunately, one talk had to be cancelled because of illness of the speaker (BM Khadi, India). Some presentations covered conceptual approaches for environmental risk assessment (ERA) of GM plants (problem formulation in the risk assessment framework, familiarity approach, tiered and methodological frameworks, non-target risk assessment) and the use of models in assessing invasiveness and weediness of GM plants. Other presentations highlighted the lessons learned for future ERA from case studies and commercialized GM crops, and from monitoring of unintended releases to the environment. When the moderators of the three sessions came together after the presentations to align their summaries, there was an obvious need to restructure the 12 presentations in a way that allowed for a consistent summarizing discussion. The following new organization of the 12 talks was chosen: (1) Concepts for problem formulation and non-target risk assessment, (2) Modeling as a tool for predicting invasiveness of GM plants, (3) Case-studies of ERA of large-scale release, (4) Lessons learned for ERA from a commercialized GM plant, (5) Monitoring of unintended release of Bt maize in Mexico. The new thematic structure facilitates a more in-depth discussion of the presentations related to a specific topic, and the conclusions to be drawn are thus more consistent. Each moderator agreed to take responsibility for summarizing one or more themes and to prepare the respective report.


Assuntos
Produtos Agrícolas/genética , Meio Ambiente , Plantas Geneticamente Modificadas/toxicidade , Animais , Artrópodes/fisiologia , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas/virologia , Medição de Risco
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