A study of crop-to-crop gene flow using farm scale sites of fodder maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) in the UK

From 2000 to 2003 a range of Farm Scale Evaluation (FSE) trials were established in the UK to assess the effect of the release and management of herbicide tolerant (HT) crops on arable weeds and invertebrates. The FSE trials for maize were also used to investigate crop-to-crop gene flow and to develop a statistical model for the prediction of gene flow frequency that can be used to evaluate current separation distance guidelines for GM crops. Seed samples were collected from the non-GM half of 55 trial sites and 1,055 were tested for evidence of gene flow from the GM HT halves using a quantitative PCR assay specific to the HT (pat) gene. Rates of gene flow were found to decrease rapidly with increasing distance from the GM source. Gene flow was detected in 30% of the samples (40 out of 135) at 150 m from the GM source and events of GM to non-GM gene flow were detected at distances up to and including 200 m from the GM source. The quantitative data were subjected to statistical analysis and a two-step model was found to provide the best fit for the data. A dynamic whole field model predicted that a square field (150 m x 150 m in size) of grain maize would require a separation distance of 3 m for the adjacent crop to be below a 0.9% threshold (with <2% probability of exceeding the threshold). The data and models presented here are discussed in the context of necessary separation distances to achieve various possible thresholds for adventitious presence of GM in maize.     

Pollen-mediated intraspecific gene flow from herbicide resistant oilseed rape (<Emphasis Type="Italic">Brassica napus</Emphasis> L.)

The cultivation of genetically modified (GM) herbicide resistant oilseed rape (Brassica napus) has increased over the past few years. The transfer of herbicide resistance genes via pollen (gene flow) from GM crops to non-GM crops is of relevance for the realisation of co-existence of different agricultural cultivation forms as well as for weed management. Therefore the likelihood of pollen-mediated gene flow has been investigated in numerous studies. Despite the difficulty to compare different experiments with varying levels of outcrossing, we performed a literature search for world-wide studies on cross-fertilisation in fully fertile oilseed rape. The occurrence and frequency of pollen-mediated intraspecific gene flow (outcrossing rate) can vary according to cultivar, experimental design, local topography and environmental conditions. The outcrossing rate from one field to another depends also on the size and arrangement of donor and recipient populations and on the ratio between donor and recipient plot size. The outcrossing levels specified in the presented studies are derived mostly from experiments where the recipient field is either surrounding the donor field (continuous design) or is located as a patch at different distances from the donor field (discontinuous design). Reports of gene flow in Brassica napus generally show that the amount of cross-fertilisation decreases as the distance from the pollen source increases. The evidence given in various studies reveals that the bulk of GM cross-fertilisation occurs within the first 10 m of the recipient field. The removal of the first 10 m of a non-transgenic field facing a GM crop might therefore be more efficient for reducing the total level of cross-fertilisation in a recipient sink population than to recommend separation distances. Future experiments should investigate cross-fertilisation with multiple adjacent donor fields at the landscape level under different spatial distributions of rapeseed cultivars and different cropping systems. The level of cross-fertilisation occurring over the whole field is mainly important for co-existence and has not been investigated in agricultural scale experiments until now. Potential problems with herbicide resistant oilseed rape volunteers arising from intraspecific gene flow can be largely solved by the choice of suitable cultivars and herbicides as well as by soil management.     

EU biotech crop regulations and environmental risk: a case of the emperor's new clothes?

European Union Commissioner for the Environment Stavros Dimas recently hailed 'upgraded' non-genetically modified (GM) crops as an alternative to GM crops. A comparative analysis of the environmental risks associated with such non-GM herbicide-resistant crops and GM herbicide-resistant crops is presented here. The analysis highlights serious weaknesses in the European Union (EU) regulatory framework, and the contradictory policy of the EU Commission on the precautionary principle is also shown. The continued political stance of ignoring these regulatory and policy inconsistencies is examined and found to be flawed. It is postulated that, even in the face of these flaws and coupled with recent statements from the UK drawing attention to inconsistencies in the EU regulatory framework, the EU will continue to ignore the real and present environmental risks associated with upgraded non-GM crops for biopolitical reasons.     

Assessment of Real-time PCR Based Methods for Quantification of Pollen-mediated Gene Flow from GM to Conventional Maize in a Field Study

Maize is one of the main crops worldwide and an increasing number of genetically modified (GM) maize varieties are cultivated and commercialized in many countries in parallel to conventional crops. Given the labeling rules established e.g. in the European Union and the necessary coexistence between GM and non-GM crops, it is important to determine the extent of pollen dissemination from transgenic maize to other cultivars under field conditions. The most widely used methods for quantitative detection of GMO are based on real-time PCR, which implies the results are expressed in genome percentages (in contrast to seed or grain percentages). Our objective was to assess the accuracy of real-time PCR based assays to accurately quantify the contents of transgenic grains in non-GM fields in comparison with the real cross-fertilization rate as determined by phenotypical analysis. We performed this study in a region where both GM and conventional maize are normally cultivated and used the predominant transgenic maize Mon810 in combination with a conventional maize variety which displays the characteristic of white grains (therefore allowing cross-pollination quantification as percentage of yellow grains). Our results indicated an excellent correlation between real-time PCR results and number of cross-fertilized grains at Mon810 levels of 0.1–10%. In contrast, Mon810 percentage estimated by weight of grains produced less accurate results. Finally, we present and discuss the pattern of pollen-mediated gene flow from GM to conventional maize in an example case under field conditions.     

Commercializing genetically modified crops under EU regulations: objectives and barriers

Agriculture faces serious problems in feeding 9 billion people by 2050: production must be increased and ecosystem services maintained under conditions for growing crops that are predicted to worsen in many parts of the world. A proposed solution is sustainable intensification of agriculture, whereby yields are increased on land that is currently cultivated, so sparing land to deliver other ecosystem services. Genetically modified (GM) crops are already contributing to sustainable intensification through higher yields and lower environmental impacts, and have potential to deliver further significant improvements. Despite their widespread successful use elsewhere, the European Union (EU) has been slow to introduce GM crops: decisions on applications to import GM commodities are lengthy, and decision-making on applications to cultivate GM crops has virtually ceased. Delayed import approvals result in economic losses, particularly in the EU itself as a result of higher commodity prices. Failure to grant cultivation approvals costs EU farmers opportunities to reduce inputs, and results in loss of agricultural research and development from the EU to countries such as the United States and China. Delayed decision-making in the EU ostensibly results from scientific uncertainty about the effects of using GM crops; however, scientific uncertainty may be a means to justify a political decision to restrict cultivation of GM crops in the EU. The problems associated with delayed decision-making will not improve until there is clarity about the EU's agricultural policy objectives, and whether the use of GM crops will be permitted to contribute to achieving those objectives.     

Potential for the environmental impact of transgenic crops

In recent years, there has been increasing interest in how changes in agricultural practice associated with the introduction of particular genetically modified (GM) crops might indirectly impact the environment. There is also interest in any effects that might be associated with recombinant and novel combinations of DNA passing into the environment, and the possibility that they may be taken up by microorganisms or other live biological material. From the current state of knowledge, the impact of free DNA of transgenic origin is likely to be negligible compared with the large amount of total free DNA. We can find no compelling scientific arguments to demonstrate that GM crops are innately different from non-GM crops. The kinds of potential impacts of GM crops fall into classes familiar from the cultivation of non-GM crops (e.g., invasiveness, weediness, toxicity, or biodiversity). It is likely, however, that the novelty of some of the products of GM crop improvement will present new challenges and perhaps opportunities to manage particular crops in creative ways.     

Surveying of pollen-mediated crop-to-crop gene flow from a wheat field trial as a biosafety measure

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.     

Regulating coexistence of GM and non-GM crops without jeopardizing economic incentives

The ongoing debate about the coexistence of genetically modified (GM) and non-GM crops in the European Union (EU) mainly focuses on preventive measures needed to keep the adventitious presence of GM material in non-GM products below established tolerance thresholds, as well as on issues covering questions of liability and the duty to redress the incurred economic harm once adventitious mixing in non-GM products has occurred. By contrast, the interplay between the economic incentives and costs of coexistence has attracted little attention. The current overemphasis on the technical aspects and cost of coexistence over its economic incentives might lead EU policy-makers to adopt too stringent and rigid regulations on coexistence. Therefore, we argue for flexible coexistence regulations that explicitly take into account the economic incentives for coexistence. Our arguments provide a timely and important framework for EU policy-makers, who are currently struggling to implement coherent coexistence regulations in all member states.     

Detection of gene flow from GM to non-GM watermelon in a field trial

Gene flow from genetically modified (GM) crops to conventional non-GM crops is a serious concern for protection of conventional and organic farming. Gene flow from GM watermelon developed for rootstock use, containing cucumber green mottle mosaic virus (CGMMV)-coat protein (CP) gene, to a non-GM isogenic control variety “Clhalteok” and grafted watermelon “Keumcheon” was investigated in a small scale field trial as a pilot study. Hybrids between GM and non-GM watermelons were screened from 1304 “Chalteok” seeds and 856 “Keumcheon” seeds using the duplex PCR method targeting theCGMMV- CP gene as a marker. Hybrids were found in all pollen recipient plots. The gene flow frequencies were greater for “Chaiteok” than for “KeumcheonD; with 75% outcrossing in the “Chaiteok” plot at the closest distance (0.8 m) to the GM plot. A much larger scale field trial is necessary to identify the isolation distance between GM and non-GM watermelon, as the behaviors of insect pollinators needs to be clarified in Korea.     

Heterogeneity in the distribution of genetically modified and conventional oilseed rape within fields and seed lots

The implementation of co-existence in the commercialisation of GM crops requires GM and non-GM products to be segregated in production and supply. However, maintaining segregation in oilseed rape will be made difficult by the highly persistent nature of this species. An understanding of its population dynamics is needed to predict persistence and develop potential strategies for control, while to ensure segregation is being achieved, the production of GM oilseed rape must be accompanied by the monitoring of GM levels in crop or seed populations. Heterogeneity in the spatial distribution of oilseed rape has the potential to affect both control and monitoring and, although a universal phenomenon in arable weeds and harvested seed lots, spatial heterogeneity in oilseed rape populations remains to be demonstrated and quantified. Here we investigate the distribution of crop and volunteer populations in a commercial field before and during the cultivation of the first conventional oilseed rape (winter) crop since the cultivation of a GM glufosinate-tolerant oilseed rape crop (spring) three years previously. GM presence was detected by ELISA for the PAT protein in each of three morphologically distinguishable phenotypes: autumn germinating crop-type plants (3% GM), autumn-germinating 'regrowths' (72% GM) and spring germinating 'small-type' plants (17% GM). Statistical models (Poisson log-normal and binomial logit-normal) were used to describe the spatial distribution of these populations at multiple spatial scales in the field and of GM presence in the harvested seed lot. Heterogeneity was a consistent feature in the distribution of GM and conventional oilseed rape. Large trends across the field (50 x 400 m) and seed lot (4 x 1.5 x 1.5 m) were observed in addition to small-scale heterogeneity, less than 20 m in the field and 20 cm in the seed lot. The heterogeneity was greater for the 'regrowth' and 'small' phenotypes, which were likely to be volunteers and included most of the GM plants detected, than for the largely non-GM 'crop' phenotype. The implications of the volunteer heterogeneity for field management and GM-sampling are discussed.     

REVIEW ARTICLE: Transgenic plants and the environment

With a continued increase in the range of transgenes, and plantspecies for which genetic modification is possible, this reviewattempts to bring together some of the factors that will influencethe eventual fate of transgenes in the environment, and theeffects that such a dispersal may have. The review is developedfrom papers presented at the SEB Swansea meeting (April, 1994). Using experiments with GM (genetically modified) plants, andmarkers in non-GM plants, as well as observations on naturaland crop populations, it is possible to predict isolation distancesrequired for limiting the unintentional release from GM crops,and the probable fate of both GM pollen and seed if it is releasedbeyond the GM plot. Knowledge of wild relatives of crop plants,and ecological mechanisms can also give insights into the possibleeffects of different transgenes on native plants, and otheragricultural crops. A large number of limited scale releasesof GM plants have now taken place from which we can gain informationon the performance of GM crops in an agricultural environment,and the stability of the GM phenotype. All this information,can help to form a sound basis for regulations on the releaseof GM plants, an assessment of the need for, and scope of monitoring,and the best way in which to use GM crops. Key words: Transgenic releases, genetically-modified plants, molecular ecology, transgene stability     

Adaptation of crops to environment

Adaptability is defined as the ability of a crop (or variety) to respond positively to changes in agricultural conditions. The trait is genetically controlled and provides an ability to exploit environmental attributes, both natural and agronomic. Values of relative adaptability can be determined by the regression of the yield of the tested crop over the average yield of compared crops from several environments. We evaluated relative adaptability of 12 staple crops in 12 European countries and compared the yield data over a 43-year period from 1961 to 2003. An additional set of average yield data was also available for the 15 European Union (EU15) member countries. A wider range of 26 crop species was investigated that allowed comparisons between Europe and the USA between 1961 and 2003. Adaptability was closely related to the annual yield increases of the crops studied (r ²=0.999 both in the EU15 and the USA). However, the adaptability of certain crops differed between the two regions. Pulse, maize, millet, wheat and sorghum showed the highest adaptability in the EU15 region, whereas strawberry, pear, tomato, walnut and maize were highest in the USA. The lowest adaptability was found for walnut, pear, apple, cauliflower and hop in the EU15 and for mustard, hop, sugar beet, millet and oat in the USA. In European countries, crops with similar biology, environment and agronomical practices (like the amount of fertilizers and pesticides applied) tended to have similar adaptability values. The data indicate that high adaptability is an important prerequisite for continued yield gains in the best environments.     

Gene flow in genetically modified wheat

Understanding gene flow in genetically modified (GM) crops is critical to answering questions regarding risk-assessment and the coexistence of GM and non-GM crops. In two field experiments, we tested whether rates of cross-pollination differed between GM and non-GM lines of the predominantly self-pollinating wheat Triticum aestivum. In the first experiment, outcrossing was studied within the field by planting "phytometers" of one line into stands of another line. In the second experiment, outcrossing was studied over distances of 0.5-2.5 m from a central patch of pollen donors to adjacent patches of pollen recipients. Cross-pollination and outcrossing was detected when offspring of a pollen recipient without a particular transgene contained this transgene in heterozygous condition. The GM lines had been produced from the varieties Bobwhite or Frisal and contained Pm3b or chitinase/glucanase transgenes, respectively, in homozygous condition. These transgenes increase plant resistance against pathogenic fungi. Although the overall outcrossing rate in the first experiment was only 3.4%, Bobwhite GM lines containing the Pm3b transgene were six times more likely than non-GM control lines to produce outcrossed offspring. There was additional variation in outcrossing rate among the four GM-lines, presumably due to the different transgene insertion events. Among the pollen donors, the Frisal GM line expressing a chitinase transgene caused more outcrossing than the GM line expressing both a chitinase and a glucanase transgene. In the second experiment, outcrossing after cross-pollination declined from 0.7-0.03% over the test distances of 0.5-2.5 m. Our results suggest that pollen-mediated gene flow between GM and non-GM wheat might only be a concern if it occurs within fields, e.g. due to seed contamination. Methodologically our study demonstrates that outcrossing rates between transgenic and other lines within crops can be assessed using a phytometer approach and that gene-flow distances can be efficiently estimated with population-level PCR analyses.     

Attitudes of European farmers towards GM crop adoption

This article analyses European Union (EU) farmers' attitudes towards adoption of genetically modified crops by identifying and classifying groups of farmers. Cluster analysis provided two groups of farmers allowing us to classify farmers into potential adopters or rejecters of genetically modified herbicide-tolerant (GMHT) crops. Results showed that economic issues such as the guarantee of a higher income and the reduction of weed control costs are the most encouraging reasons for potential adopters and rejecters of GMHT crops. This article also examines how putting in place measures to ensure coexistence between GM and non-GM crops may influence farmers' attitudes towards GMHT crop adoption. Results show that the implementation of a coexistence policy would have a negative impact on farmers' attitudes on adoption and consequently may hamper GMHT adoption in the EU.     

Testing Potential Effects of Maize Expressing the Bacillus thuringiensis Cry1Ab Endotoxin (Bt Maize) on Mycorrhizal Fungal Communities via DNA- and RNA-Based Pyrosequencing and Molecular Fingerprinting

The cultivation of genetically modified (GM) crops has increased significantly over the last decades. However, concerns have been raised that some GM traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (AMF), potentially leading to alterations in soil functioning. Here, we test two maize varieties expressing the Bacillus thuringiensis Cry1Ab endotoxin (Bt maize) for their effects on soil AM fungal communities. We target both fungal DNA and RNA, which is new for AM fungi, and we use two strategies as an inclusive and robust way of detecting community differences: (i) 454 pyrosequencing using general fungal rRNA gene-directed primers and (ii) terminal restriction fragment length polymorphism (T-RFLP) profiling using AM fungus-specific markers. Potential GM-induced effects were compared to the normal natural variation of AM fungal communities across 15 different agricultural fields. AM fungi were found to be abundant in the experiment, accounting for 8% and 21% of total recovered DNA- and RNA-derived fungal sequences, respectively, after 104 days of plant growth. RNA- and DNA-based sequence analyses yielded most of the same AM fungal lineages. Our research yielded three major conclusions. First, no consistent differences were detected between AM fungal communities associated with GM plants and non-GM plants. Second, temporal variation in AMF community composition (between two measured time points) was bigger than GM trait-induced variation. Third, natural variation of AMF communities across 15 agricultural fields in The Netherlands, as well as within-field temporal variation, was much higher than GM-induced variation. In conclusion, we found no indication that Bt maize cultivation poses a risk for AMF.     

Impact of gene stacking on gene flow: the case of maize

To respect the European labelling threshold for the adventitious presence of genetically modified organisms (GMOs) in food and feed, stakeholders mainly rely on real-time PCR analysis, which provides a measurement expressed as a percentage of GM-DNA. However, this measurement veils the complexity of gene flow, especially in the case of gene stacking. We have investigated the impact of gene stacking on adventitious GM presence due to pollen flow and seed admixture as well as its translation in terms of the percentage of GM-DNA in a non-GM maize harvest. In the case of varieties bearing one to four stacked events, we established a set of relationships between the percentage of GM kernels and the percentage of GM-DNA in a non-GM harvest as well as a set of relationships between the rate of seed admixture and the percentages of GM material in a non-GM harvest. Thanks to these relationships, and based on simulations with a gene flow model, we have been able to demonstrate that the number of events and the stacking structure of the emitting fields impact the ability of a non-GM maize producer to comply with given GM kernel or GM-DNA thresholds. We also show that a great variability in the rates of GM kernels, embryos and DNA results from seed admixture. Finally, the choice of a unit of measurement for a GM threshold in seed lots can have opposite effects on the ability of farmers to comply with a given threshold depending on whether they are crop or seed producers.     

Relevance of genetically modified crops in light of future environmental and legislative challenges to the agri-environment

A key challenge for countries like Ireland up to 2030 is to produce sufficient supplies of food, feed and fuel, without compromising on public health or negatively impacting the environment. As we progress through the technology era, certain agricultural technologies [e.g. genetically modified (GM) crops] have been championed to maximise production while minimising environmental impact. Yet, multiple arguments have been made to counter such a claim, which has led to a polarisation of opinions and a plethora of generic commentaries being made in regard to the impact of this technology. Yet, few studies within the European Union (EU) have conducted a critical needs analysis to assess the potential of specific GM traits in light of issues, such as climate change, increased environmental legislation (e.g. EU Water Framework, Nitrates Directive, proposed reform to the Pesticide Directive and Common Agricultural Policy reform), mitigating biodiversity loss and sustainable biofuel production. The goal of this study is to collate a register of GM traits such that a list of potential GM crops could be prioritised against the backdrop of the challenges facing the tillage sector. Clearly, the crops with the most significant potential for genetic modification are those that are grown widely and/or receive high applications of pesticides and fertilisers (e.g. potato, wheat, barley and maize). GM traits with significant agronomic potential include late blight resistant potato, Fusarium head blight resistant wheat and Septoria resistant wheat and herbicide‐tolerant winter oilseed rape and maize. Following on from these, crops with enhanced nitrogen‐use efficiency could provide significant input to the tillage sector in light of EU‐based restrictions on nitrogen usage, crops with elevated protein content could offset the costs of imported animal feed and crops with modified oil content/lignocellulose composition could assist in biodiesel/bioenergy production at a regional level. This study is relevant to other European countries that cultivate similar crops and like Ireland, are facing multiple challenges to their tillage sector in the near future.     

Stop worrying; start growing. Risk research on GM crops is a dead parrot: it is time to start reaping the benefits of GM

Opponents of genetically modified crops continue to raise concerns about risk, despite 20 years of research disproving their claims. Science should close the book on risk research and turn to studying the economic and environmental benefits of agricultural biotechnologyEver since the Asilomar Conference on ‘Recombinant DNA'' in February 1975, regulatory policies relating to recombinant DNA technology have focused on the idea that this technology implies threats to human health and the environment [1]. As a consequence, the explicit goal of these policies is to protect society and nature from an assumed hazard, or, if protection is not possible, at least to delay the implementation of the technology until scientific evidence shows it to be harmless. These policies were widely accepted at the time, as public concerns were, and still are, important. As time has gone by, the evidence for negative impacts of genetically modified (GM) crops has become weaker. However, the regulatory policies within the EU are still rigid enough to prevent most GM crops from leaving the confined laboratory setting; should some candidate occasionally overcome the hurdles posed by these policies, the precautionary principle is invoked in order to ensure further delaying in its use in the field. The reason for this over-cautious approach is widespread public resistance to GM crops, caused and amplified by interested groups that are opposed to the technology and invest heavily into lobbying against it.As time has gone by, the evidence for negative impacts of genetically modified (GM) crops has become weakerAgainst this background of political resistance, it is no surprise that the risks, costs and potential disadvantages of not growing GM crops have received little or no attention. These disadvantages become increasingly relevant as the scientific arguments for the prevailing resistance to GM crops become weaker. Twenty-five years of risk research on GM crops have established beyond reasonable doubt that biotechnology is not per se riskier than conventional plant breeding technologies [2]. The whole seemingly endless discussion about purported risks of GM crops is akin to the famous Monty Python sketch in which John Cleese is trying to return a dead parrot to shopkeeper Michael Palin, who, despite the evidence, insists that the bird is well, alive and “pining for the fjords”. Instead, we need to highlight the opportunities missed by not accepting GM crops. These include lost revenues for farmers, breeding companies and consumers, brain drain and lost technology innovations, reduced agricultural productivity and sustainability, foregone health benefits, especially reducing malnutrition, and many more realized or expected virtues of GM crops [3].In a report from 2010, the EC […]concluded that biotechnology is not per se riskier than conventional plant breeding technologiesRisk assessment and risk analysis of genetically modified organisms (GMOs) is governed by internationally accepted guidelines, developed by the Codex Alimentarius Commission (www.fao.org). One leading principle is the concept of substantial equivalence, which stipulates that any new GM variety should be assessed for its safety by comparing it with an equivalent, conventionally bred variety that has an established history of safe use [4]. Despite the fact that the Codex Alimentarius guidelines are globally endorsed, the authorization procedure for GMOs differs substantially between national jurisdictions. Europe stands out as being considerably more restrictive than countries in North and South America and parts of Asia, for example. Within the European Union (EU), a common regulatory legal framework such as Regulation (EC) No. 1829/2003, governs GM crops intended for human food and animal feed. Any party seeking approval for an edible GM crop must provide extensive scientific documentation that demonstrates that the food or feed derived thereof has no adverse effects on human and animal health or the environment, does not mislead the consumer, or does not differ from the food it is intended to replace to such an extent that its normal consumption would be nutritionally disadvantageous for the consumer.The risk assessment is conducted and compiled by the applicant, and is evaluated by the GMO Panel of the European Food Safety Authority (EFSA). The opinion of the panel should form the scientific basis when member states provide other legitimate arguments and cast their votes in the Standing Committee for Food and Animal Health of the European Commission. Thus, the decision to approve a particular GMO should be on the basis of scientific grounds. By the same logic, one might take for granted that only GMOs that have been shown to have adverse effects on animal or human health or the environment will not receive approval. In practice, however, the decision whether or not to approve a particular GMO is not solely a scientific issue. Several member states vote, in principle, against approval, irrespective of the scientific opinion delivered by the EFSA [5]. In recognition of this dead-lock, the European Commission (EC) has suggested that individual member states should have the right to restrict cultivation of a given GM crop even if there are no scientifically established risks, that is, to adopt restrictions on the basis of socio-economical or ethical grounds [6].In addition to the scientific documentation provided by the applicants who seek approval of a GM crop, public research has investigated the risks of GMOs during the past 15 years. The Directorate-General Research under the EC has spent €200 million during the past decade on such research, and several member states have initiated national research programmes specifically targeting the potential impact of the very same crops and traits that are in the European approval system [2]. A collaborative working group under the Standing Committee on Agricultural Research (SCAR) has estimated that the funds allocated to national risk research on GMOs in 13 European countries amount to at least €120 million during the past eight years (http://bmg.gv.at/home/Schwerpunkte/Gentechnik/Fachinformation_Allgemeines/SCAR_Collaborative_Working_Group_Risk_Research_on_GMOs).In a report from 2010, the EC summarized the results of 130 research projects involving more than 500 independent research groups and concluded that biotechnology is not per se riskier than conventional plant breeding technologies [2]. Further support for this position comes from the UK Farm-Scale Evaluation (FSE), which studied the potential impact of herbicide-tolerant crops on farmland biodiversity [7]. One insight from the study is that overall changes in agricultural management determine the impact of a crop on biodiversity, rather than the technology or breeding behind the crop itself [8].… it is time to look at the other side of the equation and gauge the possible benefits of adopting and growing GM cropsBetween 2008 and 2009, the EFSA GMO panel evaluated a renewal to permit the continued import, processing and cultivation of maize variety MON810 for food and feed. MON810 expresses the Cry1Ab protein from the soil-borne bacterium Bacillus thuringiensis (Bt), which confers resistance to the European corn borer, and is one of two GM crops approved for cultivation in Europe; it was first approved in 1998. As a basis for its 2009 opinion, the EFSA GMO Panel summarized 48 peer-reviewed papers on the potential risks of MON810 on animal and human health and the environment, in addition to the documentation provided by the company [9]. It found no adverse effects and concluded that MON810 is comparable with its conventionally bred parental lines. The only difference reported was that MON810 has an increased variability in lignin content, in some studies it has been found to be higher and in some studies lower. Similarly, a review by Icoz & Stotzky [10] of studies on the effects of insect-resistant Bt crops on soil ecosystems found no notable detrimental effects on microbes and other organisms in below-ground soil ecosystems. Accordingly, the authors concluded that “…available funding would be better spent on studies of the potential risks associated with the release of transgenic plants genetically engineered to express pharmaceutical and industrial products that, in contrast to Cry proteins, are targeted primarily to human beings and other higher eukaryotic organisms.”If, as 15 years of intense research and risk assessment have shown, GM crops do not pose greater risks for human health or the environment than conventionally bred varieties, it is time to look at the other side of the equation and gauge the possible benefits of adopting and growing GM crops. To that end, Fagerström & Wibe [11] analysed the potential economic consequences for Sweden of farmers not growing GM crops—herbicide-tolerant sugar beet and canola, and late blight-resistant potato—and then extended the analysis to all of the EU. They considered two rough categories of impact: effects that could be evaluated by studying market prices that show impacts for producers on work-force and capital, and demand for fertilizers, pesticides and fuel, and factors related to the cost of keeping GM crops separated from conventionally or organically grown crops during cultivation, harvest, transport, storage and processing. The latter cost arises from the European attitude of regarding GM crops and products as contaminants—as if we were dealing with toxic substances.In 2008, Sweden produced almost 2 million tons of sugar beet grown on approximately 37,000 hectares and with a production value of €70 million. The authors calculated that a shift to herbicide-tolerant sugar beet could have led to a 5–10% increase in yield. Expenditure on seeds would increase from €180 to €210 per hectare, but the cost of herbicides would decrease from €180 to €55. Taken together, the cost of input goods would decrease by 27%.Analysis of the sugar beet shows that the economic value to producers and, by extension, to society is strategically dependent on two factors: the cost of keeping GM sugar separate from conventional sugar, and the public acceptance of GM sugar. The crucial limit was found to be a separation cost of 25% of the price; at this limit, the economic value to society vanishes even if all consumers buy GM products—if public acceptance is 100%. In a realistic scenario the separation cost is ∼10% of the price and the public acceptance is ∼25% of the consumers. Thus, the economic benefit would be €1.3 million, or ∼2% of the total value of sugar beet production. If GM crops enjoyed full public acceptance, and if there were accordingly no costs of separation, the economic gain to society would amount to €10 million; about 14% of the total value of sugar beet production. Approximately 3,000 hectares of arable land—8% of the acreage of sugar beet—would be available for other uses.Similar values apply for potato and canola, so introducing these three GM crops in Sweden would yield an economic value of €30 million annually. In addition, producers would regain 10,000 hectares (ha) of arable land; using official statistics on leasing costs for arable land in Sweden, this has an annual value of approximately €2 million. This adds up to a combined annual value to society of €32 million. The accumulated value of this annual revenue over many years—the so-called capitalized value—is €1–€1.6 billion at an interest rate of 2–3%. The annual gain amounts to approximately 14, 11 and 5% of the production value for sugar beet, canola and potato, respectively. EU-wide, a shift to these three GM crops would yield a gain of ∼€2 billion annually, and would save ∼645,000 ha, which corresponds to a capitalized value in the range of €80–€120 billion.These calculations presuppose full public acceptance of GM crops; that is, a world in which consumers perceive GM crops as equal to or better than non-GM varieties. In addition, the results rest on the assumption that the benefits to the environment such as decreased use of pesticides can be measured by the cost of the pesticides. Presumably, this is an underestimate of the environmental benefits, and the societal value is therefore probably greater than the figures presented above.Other studies address the problem of missed economic benefits, often using economic models similar to those used by Fagerström & Wibe [11]. Generally, they confirm the results discussed above: the magnitudes of the unrealized benefits are similar. Matin Qaim, an agricultural economist at Göttingen University, Germany, for example, presented figures for Bt cotton adoption that would entail global welfare gains in the range of €0.5–€1.0 billion per year [12]. The biggest impact occurs in China, but India, where the relevant technology was more recently commercialized, has been catching up rapidly. It is estimated that the widespread adoption of Bt cotton in India and other countries of South Asia will result in further regional welfare gains on the order of €1 billion per year.The benefits of adopting GM oilseeds and maize are amplified by the larger international markets on which they are traded. While the annual global welfare gains at the present moderate level of adoption are estimated at €3.5 billion [13], this figure could reach approximately €7.5 billion with widespread international adoption of herbicide-tolerance and insect-resistant crops [12]. However, it is also noted that a ban on production and imports by the EU could reduce these global gains by two-thirds owing to unrealized benefits for domestic consumers and the far-reaching influence of EU policies on international trade flows and production decisions in other regions.… not adopting modern breeding tools—including biotechnology—will probably hamper the European agricultural systems facing a warmer and more variable climateLarge global welfare gains are projected for GM rice as well. Assuming that there is moderate adoption of GM rice in rice-producing regions, the combined global welfare gains are estimated to be in the region of €5 billion per year for Bt-carrying, herbicide-resistant and drought-tolerant rice varieties, with India and China gaining the most. Projected welfare gains in China alone could reach more than €3 billion when first-generation GM rice technologies are widely adopted. Both studies [11,12] highlight that available analyses probably provide lower estimates of the global welfare effects of GM crops, because other environmental and health benefits have not been properly quantified.Agriculture is blamed frequently for biodiversity loss. Several recent studies, however, demonstrate that the design of the agricultural landscape, with refuges for non-crop species, intercropping and crop rotation, can counterbalance the effects of an intensified agriculture system [14]. Hence, one of the most important consequences of better yields from herbicide and pest-resistant GM crops in Europe would be that the surplus land could be used for refuges to promote biodiversity in the farming landscape and save natural forests from deforestation or wetlands from being drained to make way for farmland. However, regulations regarding cultivation distances, as well as other measures to keep GM crops separate from conventionally bred varieties, lock GM crops into large-scale agricultural practices and, in effect, prevent intercropping. Thus, the principle of non-coexistence limits the scope for farmers to take full advantage of the benefits of present and future GM crops to further reduce the need for pesticides and increase the productivity of farmland. This line of reasoning is supported by a recent study showing that the willingness of farmers to adopt GM crops is substantially hampered by the costs and uncertainties associated with coexistence regulations, despite lower costs for chemicals [15].Historically, cereal crop varieties have been replaced by new varieties on average every 5–10 years [16]. The reasons for this turnover vary, but one underlying drive for crop replacement is the rapid loss of resistance traits. In order to maintain yield levels, farmers must either increase their use of chemicals to kill pests, or change to a new crop variety; hence the continuous breeding for resistance traits. Imminent climate changes will put further constraints on agricultural production, including an increasing need for faster and more efficient plant breeding to adapt crops to more variable local conditions [17]. If breeders fail in this regard, agro-chemical use will increase and Europe will become more dependent on imports. In Europe, the spatial variation in rainfall is expected to increase: Northern Europe can expect a more humid climate, which will constrain crop production owing to the increased severity of biotic stresses such as insect pests, fungal pathogens and the invasion of alien, noxious species, whereas crop production in southern Europe will have to be adapted to drier conditions [18,19]. Thus, not adopting modern breeding tools—including biotechnology—will probably hamper the European agricultural systems facing a warmer and more variable climate [20].Legislation that determines what constitutes a GMO was ratified in 2001. In a legal sense, a GMO is defined as an organism in which the genetic material has been altered in a way that does not occur naturally by mating or natural recombination, and refers to both plants and animals, except humans. In practice, a GMO is defined by an addendum to the Directive 2001/18EC, which lists the techniques that give rise to a GMO. Since the Directive 2001/18EC was ratified, ten years have passed, and technology has progressed further. Many of the techniques listed in the addendum have been improved or are obsolete. A recent report to the EC by the Joint Research Centre [21] describes new methods, their possible applications for plant breeding and potential implications for agriculture. One common aspect of the new techniques is that many involve the use of recombinant DNA or RNA molecules in one phase of the breeding process; however, these recombinant molecules are not present in the final product and are commonly not transmitted to the next generation.… the burden of EU legislation for GM technologies is completely out of proportion compared with other science-based endeavoursInterestingly, European scientists at public and private institutions are at the forefront of technological development concerning new breeding. In this respect the situation is similar to the history of plant transformation technologies first developed at European universities [22], but now mainly used outside Europe [23]. By way of illustration, BASF, the company that developed the Amflora potato, announced recently that it is halting research on GM crops in Europe. Ultimately, the development and success of scientific know-how and new technology in Europe, as well as the adoption of new techniques and crops, will depend on the decisions made by European legislators who are discussing GM technologies and their ratification.As a comparison, other genetically engineered products, such as biopharmaceuticals, are approved for humans and food-producing animals after ordinary science-based safety assessments [23], without the ideological stigmatization and biased decision-making processes seen for GM crops.Our review of the state-of-affairs of GM crops in Europe raises several fundamental issues. First, the burden of EU legislation for GM technologies is completely out of proportion compared with other science-based endeavours. This is manifested by the substantially longer time required for a GM product to reach approval within the European legal framework (45 months), compared with GMO-exporting countries such as the USA, Canada or Brazil (27 months) [24]. In addition, these European approval times are only valid for importing commodities; approvals for cultivation in Europe take substantially longer. It took 14 years for the Amflora potato, for example, which is only the second GM crop to be approved in Europe. Not only are rules more restrictive in Europe, but only the largest companies in the seed and plant breeding business have the financial capacity to go through the lengthy and costly procedure required for approving a GM crop variety. This hampers small and medium business and prevents business spin-offs from plant research.Second, research priorities in regard to the environmental impacts of agriculture are not directed in a productive way; risk research in Europe is not helping to develop sustainable agriculture for the future. The paradigm that stipulates that biotechnology is inherently risky, and singles out one plant breeding technology as the basis for risk research, is putting a massive regulatory burden on a technology that could enhance sustainability. As a consequence, any future risk research on GMOs in Europe should address the costs of this burden and the risks of not using biotechnology. We conclude that the research programmes set up in the EU to address the potential risks of GM crops are no longer scientifically motivated inquiries. The scientific community has already settled the relevant questions regarding potential risks associated with GM crops approved under legislation; what is going on is a political game. In this game, the so-called precautionary principle is used, in absurdum, to delay any launch of a GM crop far beyond the limit of reasonable scientific doubts.Third, it is time to acknowledge the distinct imbalance with respect to the costs and benefits of GM crops: lobbyists who benefit from demonizing GM crops are not the ones who have to carry the costs. Hence, it is not the hyped risks of GM crops that are a problem in the EU, it is the submissive attitude of politicians and policy-makers towards organizations who insist that GM crops are risky. It is then ordinary consumers who pay the costs and do not receive the benefits. This submissiveness manifests in the prevailing policy that GM products should be kept separate from non-GM products, as well as the incessant calls for regulations about labelling and traceability. As shown above, the potential benefit to the European economy from adopting GM crops is substantial. But these potential benefits vanish altogether when the costs of maintaining separation and consumer resistance are brought into play as a result of misinformation campaigns.… research priorities in regard to the environmental impacts of agriculture are not directed in a productive way…Risk research on GM crops in Europe has to come to an end, as do futile battles about disasters that will not happen. A dead parrot is a dead parrot, both in Monty Python sketches and in science. The way to sustainable and productive agriculture is not by maintaining expensive, parallel production systems, using different sets of crop varieties, and relying on expensive regulations for their coexistence. Instead, agricultural systems should use the best available technology at all stages, including plant breeding. It is clear that the approval and decision process within the EU for GM crops is not science-based. The risk assessment and approval process, where the outcome is dominated by the opinions of a few self-interested stakeholder organizations with special interests is unique. It is alarming that decision-making bodies kow-tow to this non-science-based paradigm.? Open in a separate windowTorbjörn FagerströmOpen in a separate windowChristina DixeliusOpen in a separate windowUlf MagnussonOpen in a separate windowJens F Sundström     

Sequence-Based Analysis of the Intestinal Microbiota of Sows and Their Offspring Fed Genetically Modified Maize Expressing a Truncated Form of Bacillus thuringiensis Cry1Ab Protein (Bt Maize)

The aim was to investigate transgenerational effects of feeding genetically modified (GM) maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt maize) to sows and their offspring on maternal and offspring intestinal microbiota. Sows were assigned to either non-GM or GM maize dietary treatments during gestation and lactation. At weaning, offspring were assigned within sow treatment to non-GM or GM maize diets for 115 days, as follows: (i) non-GM maize-fed sow/non-GM maize-fed offspring (non-GM/non-GM), (ii) non-GM maize-fed sow/GM maize-fed offspring (non-GM/GM), (iii) GM maize-fed sow/non-GM maize-fed offspring (GM/non-GM), and (iv) GM maize-fed sow/GM maize-fed offspring (GM/GM). Offspring of GM maize-fed sows had higher counts of fecal total anaerobes and Enterobacteriaceae at days 70 and 100 postweaning, respectively. At day 115 postweaning, GM/non-GM offspring had lower ileal Enterobacteriaceae counts than non-GM/non-GM or GM/GM offspring and lower ileal total anaerobes than pigs on the other treatments. GM maize-fed offspring also had higher ileal total anaerobe counts than non-GM maize-fed offspring, and cecal total anaerobes were lower in non-GM/GM and GM/non-GM offspring than in those from the non-GM/non-GM treatment. The only differences observed for major bacterial phyla using 16S rRNA gene sequencing were that fecal Proteobacteria were less abundant in GM maize-fed sows prior to farrowing and in offspring at weaning, with fecal Firmicutes more abundant in offspring. While other differences occurred, they were not observed consistently in offspring, were mostly encountered for low-abundance, low-frequency bacterial taxa, and were not associated with pathology. Therefore, their biological relevance is questionable. This confirms the lack of adverse effects of GM maize on the intestinal microbiota of pigs, even following transgenerational consumption.     

Design of a decision support tool for managing coexistence between genetically modified and conventional maize at farm and regional levels

Over the last 15 years, several studies on coexistence have used simulation results of spatially explicit gene flow models. These models predict the adventitious presence (AP) of GM grains in non-GM fields at the landscape scale. However, result uncertainty is not quantified. Moreover, most of the models require an important amount of input data on climate, land use, and crop management practices which might not always be available. A comprehensive Bayesian statistical approach has been implemented in the case of gene flow. This approach makes it possible to inform the decision-maker on AP, whatever the amount of information available in a given situation, to provide information on the uncertainty of the predictions and to model the variability of AP within a field, which helps set up sampling strategies.The resulting decision-support tool (DST) can compute the expected AP and its probability distribution in non-GM maize fields at different times of the growing season and under different management scenarios. Integrated through a web interface, the DST is designed to be operationally helpful for managing coexistence between GM and non-GM maize crops for a wide range of stakeholders from farmers to policy makers.