Cultivation Of Transgenic Crops Research Articles

Engineering Abiotic Stress Tolerance in Crop Plants through CRISPR Genome Editing.

Environmental abiotic stresses challenge food security by depressing crop yields often exceeding 50% of their annual production. Different methods, including conventional as well as genomic-assisted breeding, mutagenesis, and genetic engineering have been utilized to enhance stress resilience in several crop species. Plant breeding has been partly successful in developing crop varieties against abiotic stresses owning to the complex genetics of the traits as well as the narrow genetic base in the germplasm. Irrespective of the fact that genetic engineering can transfer gene(s) from any organism(s), transgenic crops have become controversial mainly due to the potential risk of transgene-outcrossing. Consequently, the cultivation of transgenic crops is banned in certain countries, particularly in European countries. In this scenario, the discovery of the CRISPR tool provides a platform for producing transgene-free genetically edited plants-similar to the mutagenized crops that are not extensively regulated such as genetically modified organisms (GMOs). Thus, the genome-edited plants without a transgene would likely go into the field without any restriction. Here, we focused on the deployment of CRISPR for the successful development of abiotic stress-tolerant crop plants for sustaining crop productivity under changing environments.

Gene flow from herbicide resistant transgenic soybean to conventional soybean and wild soybean

Gene flow from transgenic crops to conventional cultivars or wild relatives is a major environmental and economic concern in many countries. South Korea is one of the major importer of transgenic crops for food and feed, although commercial cultivation of transgenic crops is not yet allowed in this country. This study evaluated gene flow from the herbicide glyphosate- and glufosinate-resistant transgenic soybean (Glycine max) to five non-transgenic soybean cultivars and three accessions of wild soybean (Glycine soja). Field trials were conducted over 2 years, and gene flow was monitored up to 10 m distance from the pollen source. The results indicated that the detectable rate of gene flow from transgenic to conventional soybeans varied between 0 and 0.049% in both 2014 and 2015 field trials, while no hybrids were detected among wild soybean progenies. The highest rate of gene flow was found in the progenies of the Bert cultivar, which exhibited the longest period of flowering synchronization between the pollen donor and the recipient. In addition, overall gene flow rates declined with increased distance from the transgenic soybean plot. Gene flow was observed up to 3 m and 8 m from the transgenic soybean plot in 2014 and 2015, respectively. Our results may be useful for developing measures to prevent gene flow from transgenic soybean.

The Romanian experience and perspective on the commercial cultivation of genetically modified crops in Europe.

Romania was the third country in Europe and the tenth in the world, to commercially adopt genetically modified crops in 1999, only 3years after they were first marketed globally. Half a million hectares of transgenic herbicide resistant soybean and insect resistant maize were grown in Romania during an uninterrupted 17-year period. After several years of continued declining area, the commercial cultivation of transgenic plants recently ended. The commercial cultivation of transgenic crops in Romania remains legally and technically possible, according to the EU and national regulations. However, the declining area cultivated with these crops in Romania seems to be the result of farmers' conscious decision, while waiting for more profitable genetically modified crops to become available that better fit their needs. This expectation would be a logical result of the EU GMO opt-out Directive 2015/412 and the advent of the new plant breeding techniques. The GMO opt-out mechanism is still expected to unblock the EU authorization process after the large majority of the EU member states have already prohibited the cultivation of genetically modified organisms in their territory. As the new plant breeding techniques offer significant technical and economic advantages, they could be rapidly adopted by commercial breeders and farmers outside Europe. The Court of Justice of the European Union ruled that plants obtained with the new gene editing techniques must go through the same authorization procedure as transgenic plants. This decision is expected to delay the approval and availability of these new plant varieties on the EU market and their commercial cultivation.

The Effect of the Different Transgenic BT Cotton Technology on the Fiber Quality

Transgenic crops that contain Cry genes from B. thuringiensis (Bt) were commercialized in many countries and widely adopted by farmers over the last 17 years. The cultivation of transgenic crops expressing B. thuringiensis (Bt) toxins to control insect pests provides both economical and environmental benefits from reductions in chemical insecticide use, effective control of pests and minimal impact on non-target organisms. The objective of this research was to know the effect of different transgenic Bt cotton on the fiber quality of different Bt cotton varieties. Three transgenic Bt cotton varieties CCR141, CCRI79 and Bollgard II were planted in the field of Institute of Cotton Research Chinese Academy of Agricultural Sciences during 2012 and 2013. Randomly 50 bolls lint sample were collected from top, middle and bottom of the cotton plants. The fiber obtained from the boll samples was used to measure the cotton fiber staple length (mm), staple elongation (%), staple micronaire value, staple strength (cN/tex) and staple uniformity (%) by using HVI equipment at Supervision, Inspection and Testing Center of cotton Quality, China. The result shows that lint quality characters of transgenic cotton varieties were not significantly affected compared with conventional non Bt variety during 2012 and 2013 but fiber strength is significantly affected during 2013. In conclusion there was no effect of transgenic Bt cotton on the fiber quality of cotton during 2012 and 2013.

Effects of Bt-transgenic rice cultivation on planktonic communities in paddy fields and adjacent ditches

The non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. We conducted field experiments during two growing seasons to determine the effects of cultivating Bacillus thuringiensis (Bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. Bt toxin was detected in soil but not in water. Water quality was not significantly different between non-Bt and Bt rice fields, but varied among up-, mid- and downstream locations in the ditch. Cultivation of Bt-transgenic rice had no effects on zooplankton communities. Phytoplankton abundance and biodiversity were not significantly different between transgenic and non-transgenic rice fields in 2013; however, phytoplankton were more abundant in the transgenic rice field than in the non-transgenic rice field in 2014. Water quality and rice type explained 65.9% and 12.8% of this difference in 2014, respectively. Phytoplankton and zooplankton were more abundant in mid- and downstream, than upstream, locations in the ditch, an effect that we attribute to water quality differences. Thus, the release of Bt toxins into field water during the cultivation of transgenic crops had no direct negative effects on plankton community composition, but indirect effects that alter environmental conditions should be taken into account during the processes of management planning and policymaking.

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape GT73 for food and feed purposes in Austria

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape GT73 for food and feed purposes in Austria

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape Ms8, Rf3 and Ms8×Rf3 for food and feed purposes in Austria

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape Ms8, Rf3 and Ms8×Rf3 for food and feed purposes in Austria

Genetically modified crops a methodological proposal of indicators

The increase of cultivated areas with genetically modified crops (GM) poses a political challenge, both in terms of risk assessment as well as State regulation. To overcome this challenge, reliable, hierarchized and systematized information is required. Therefore, we present a methodology developed to select environmental impact indicators of these crops in four dimensions: ecosystemic, social, economic, and institutional. To obtain these indicators, two associated models were employed: Pressure–State–Response (OCDE, 2003) and Theme–Subthemes (Unite Nations, DESA, 2007). Then, the most significant components (or factors) were identified and valued in accordance with the background. In order to obtain the indicators, the variables to be measured were individualized within each component. Some indicators are directed to assess the pressures generated by the cultivation of transgenic crops on the ecosystem, and also its current status. The other indicators provide information about the State responses in terms of economic and regulatory actions. The proposed indicators have been adjusted for the Uruguay case, but the methodology has a global scope, although the reality of each country must be incorporated when applying them. Their purpose is to contribute to the cost-benefit analysis of public policies related to the agricultural sector based on new GM varieties. Currently, this methodology is being applied by the National Observatory of GM crops (under implementation) in Uruguay.

Adventitious presence of transgenic events in the maize supply chain in Peru: A case study

Cultivation and trade of transgenic or genetically modified organisms (GMO) and commodities has become widespread worldwide. In particular, production of transgenic crops has seen an accelerated growth along with a complex regulatory process. Current Peruvian legislation prohibits import of transgenic seeds and cultivation of transgenic crops in National territory but allows import of GMO-derived products and commodities. In addition, there is legislation that mandates the labeling of food products containing transgenic ingredients but the labeling threshold is still under discussion and the enforcement of this law is on hold. In this context, we evaluated adventitious presence of transgenic events in locally traded yellow maize using PCR- and immuno-based detection methods. Our results indicated that contamination during the distribution system of lots derived from non-transgenic maize was unavoidable and generally below 1.0% (w/w). Transgenic event MON810 was found in truck-loads of nationally grown maize. In general, frequencies of GMO-derived targets in whole-grain lots were 2.2% (GMO content≥1%), 16.4% (GMO content≤1%) and 81.3% (GMO content below our detection levels). When samples of de-germinated maize where evaluated, frequencies were 25.6% (GMO content>0.9%), 65.1% (GMO content≤0.9%) and 9.3% (GMO content below our detection levels). We believe this information will aid policy makers in establishing a suitable threshold for trade and product labeling as well as to conduct further investigation on other crops and scenarios.

The policy chicken and the science egg. Has applied ecology failed the transgenic crops debate?

Ecology has a long history of research relevant to and impacting on real-world issues. Nonetheless problems of communication remain between policy-makers and scientists because they tend to work at different levels of generality (policy deals with broad issues, science prefers specific questions), and complexity (policy-makers want simple answers, ecologists tend to offer multi-factorial solutions) and to different timescales (policy-makers want answers tomorrow, ecologists always seem to want more time). These differences are not unique to the debate about the cultivation of transgenic crops. Research on gene flow is used to illustrate how science and policy are intimately bound together in a value-laden, iterative and messy process unlike that characterised by the 'encounter problem-do science-make policy' model. It also demonstrates how the gap between science and policy is often characterised by value-laden language. Scientists involved in ERA for transgenic crops may find their engagement with policy- and decision-makers clouded by misunderstanding about what one should expect from the other. Not the least of these, that science can define harm, is explored in a discussion of the U.K. Farm Scale Evaluations of herbicide-tolerant GM crops. The varied responses to these extensive trials highlight the problems of linking specific scientific experiments with broad policy objectives. The problems of applied ecology in the transgenic crops debate are not unique but may differ from other areas of environmental policy in the intense politicisation of the debate, the emphasis on assessment of risk and the particularly broad policy objectives.

Environmental fate of glyphosate and aminomethylphosphonic acid in surface waters and soil of agricultural basins

Argentinian agricultural production is fundamentally based on a technological package that combines no-till and glyphosate in the cultivation of transgenic crops. Transgenic crops (soybean, maize and cotton) occupy 23million hectares. This means that glyphosate is the most employed herbicide in the country, where 180–200million liters are applied every year.The aim of this work is to study the environmental fate of glyphosate and its major degradation product, aminomethylphosphonic acid (AMPA), in surface water and soil of agricultural basins. Sixteen agricultural sites and forty-four streams in the agricultural basins were sampled three times during 2012. The samples were analyzed by UPLC-MS/MS ESI(+/−).In cultivated soils, glyphosate was detected in concentrations between 35 and 1502μgkg−1, while AMPA concentration ranged from 299 to 2256μgkg−1. In the surface water studied, the presence of glyphosate and AMPA was detected in about 15% and 12% of the samples analyzed, respectively. In suspended particulate matter, glyphosate was found in 67% while AMPA was present in 20% of the samples. In streams sediment glyphosate and AMPA were also detected in 66% and 88.5% of the samples respectively.This study is, to our knowledge, the first dealing with glyphosate fate in agricultural soils in Argentina. In the present study, it was demonstrated that glyphosate and AMPA are present in soils under agricultural activity. It was also found that in stream samples the presence of glyphosate and AMPA is relatively more frequent in suspended particulate matter and sediment than in water.

Uses and benefits of glyphosate in German arable farming

Glyphosate is world-wide seen as the most widely used herbicide ingredient. In Germany, from 1999 to 2010, the use of glyphosate based herbicides (GBH) increased by 100%. Many agronomical benefits are attributed to glyphosate, but there is also public criticism. To analyse current application patterns and to assess the agronomical importance of GBH in Germany, a survey was carried out among 896 arable farmers. The survey took place in early 2011, taking 2009 as a reference year. In Germany, cultivation of transgenic crops is generally not permitted and, therefore, herbicide resistance trait does not play any role in application patterns.Based on farmer's statements, a calculated application area of 4.3 million hectare arable land was estimated, representing 39% of total arable area. Three application modes receive major proportions of glyphosate use, these are: pre-sowing (20.7% of application area), pre-harvest (11.2%) and stubble application (68.1%). Among the field crops, oilseed rape (including oilseed rape stubbles) is treated with 27.5% of the nation-wide glyphosate amount followed by winter barley (20.1%) and winter wheat (15.8%). Without using glyphosate, farmers expect an increase in the share of ploughed arable land from 38.1% to 71.4%. Also, without glyphosate the use of cultivator on stubble land is expected to increase about 1.6 passes on average. If applied pre-sowing, glyphosate could save herbicide applications in the following crop. Saving one application of a post-emergence herbicide was estimated by farmers for corn and sugar beet (46% of pre-sowing applications), silage maize (40%), oilseed rape (27%), and winter wheat (22%). Most applications are applied on off-crop fields, so farmers did not quote any observation of yield savings due to glyphosate. The nation-wide economic benefit of glyphosate due to savings of other agricultural measures such as soil cultivation and post emergence herbicides is calculated between 79 and 202 million Euro per year, depending on glyphosate price.We conclude, that glyphosate offers large benefits to farmers, though some routine applications results in only moderate economic benefit compared to the non chemical practices being replaced. Developing decision rules for farmers might allow for an optimum allocation of glyphosate use.

Genetically modified plants and plant protection problems: Progress and estimation of potential risks

In this review, the achievements and perspectives for the creation of transgenic plants are analyzed. Until now, virtually all commercially cultivated genetically modified plants have been developed for the purpose of getting a solution to the problem of plant protection: such plants carry transgenes conferring resistance to herbicides, pests, and viruses. Approaches used for the development of commercial genetically modified varieties resistant to herbicides, insects, and viruses were considered; strategic approaches and perspectives for the development of commercial genetically modified plants resistant to fungal and bacterial pathogens and nematodes were also examined. The ecological (including agronomic issues) and social risks connected with commercial cultivation of transgenic crops were discussed.

Can science justify regulatory decisions about the cultivation of transgenic crops?

Results of scientific studies are sometimes claimed to provide scientific justification for regulatory decisions about the cultivation of certain transgenic crops. A decision may be scientifically justified if objective analysis shows that the decision is more likely than alternatives to lead to the achievement of specific policy objectives. If policy objectives are not defined operationally, as is often the case, scientific justification for decisions is not possible. The search for scientific justification for decisions leads to concentration on reducing scientific uncertainty about the behaviour of transgenic crops instead of reducing uncertainty about the objectives of policies that regulate their use. Focusing on reducing scientific uncertainty at the expense of clarifying policy objectives may have detrimental effects on scientists, science and society.

Advances in effects of insecticidal crystal proteins released from transgenic Bt crops on soil ecology

With the large scale cultivation of transgenic crops expressing Bacillus thuringiensis (Bt) insecticidal crystal proteins in the world, the problem of environmental safety caused by these Bt crops has received extensive attention. These insecticidal crystal proteins can be released into the soil continuously in the growing period of Bt plants. If their accumulation of the insecticidal crystal proteins exceeds consumption by insect larvae and degradation by the environmental factors, these insecticidal crystal proteins could constitute a hazard to non-target insects and soil microbiota. There are three main ways to release insecticidal crystal proteins into soil for Bt plants: root exudates, pollen falling, and crop reside returning. The Bt insecticidal crystal proteins released into soil can be adsorbed rapidly by active soil particles and the absorption equilibrium attained within 1-3 h. The adsorption protects Bt insecticidal crystal proteins against soil microbial degradation or enzyme degradation, which leads to remarkable prolong of the persistence of insecticidal activity. The change of soil microorganism species is an important index for evaluating the effect of Bt plants on soil ecology. The research showed that these insecticidal crystal proteins released by the Bt plant root exudates or Bt organism had no toxicity to the soil earthworms, nematodes, protozoa, bacteria and fungi; however, it could reduce the mycelium length of the arbuscular mycorrhizal fungi (AMF) and restrain AMF to form invasion unit. The influencing degree of Bt protein on soil enzyme activity varied with the releasing modes or growth period of Bt crops. Bt Cry1Ab protein can be taken up from soil by parts of following crops; however, different results were obtained with different commercial kits. To better understand the soil ecological evaluation about the insecticidal crystal proteins released from transgenic Bt crops, this review provides a comprehensive overview about the release, adsorption and residue of Bt insecticidal crystal proteins in soil, as well as their effects on soil protozoa, soil microorganism, soil enzyme activity and following crops.

The impact of the EU regulatory constraint of transgenic crops on farm income

World population and the need for nutritious food continue to grow. For 14 years farmers from a range of countries across the globe have been accessing transgenic technologies either to reduce crop production costs, increase yield and/or to exploit a range of rotational benefits. In 2009 134 Mha of transgenic crops was grown. The arable area of the EU 27 is approximately 102 Mha; however, only about 0.1 Mha of transgenic crops, mainly maize in Spain, is grown in the EU. This is in part due to limited approvals before the establishment of a moratorium on the cultivation of transgenic crops. In this paper we estimate the revenue foregone by EU farmers, based on the potential hectarages of IR and HT transgenic crops that have been economically successful elsewhere if they were to be grown in areas of the EU where farmers could expect an overall financial benefit. This benefit would accrue primarily from reduced input costs. We estimate that if the areas of transgenic maize, cotton, soya, oil seed rape and sugar beet were to be grown where there is agronomic need or benefit then farmer margins would increase by between €443 and €929 M/year. It is noted that this margin of revenue foregone is likely to increase if the current level of approval and growth remains low, as new transgenic events come to market and are rapidly taken up by farmers in other parts of the world.

The bucket and the searchlight: formulating and testing risk hypotheses about the weediness and invasiveness potential of transgenic crops

The bucket and the searchlight are metaphors for opposing theories of the growth of scientific knowledge. The bucket theory proposes that knowledge is gained by observing the world without preconceptions, and that knowledge emerges from the accumulation of observations that support a hypothesis. There are many problems with this theory, the most serious of which is that it does not appear to offer a means to distinguish between the many hypotheses that could explain a particular set of observations. The searchlight theory proposes that preconceptions are unavoidable and that knowledge advances through the improvement of our preconceptions - our hypotheses - by continuous criticism and revision. A hypothesis is a searchlight that illuminates observations that test the hypothesis and reveal its flaws, and knowledge thereby increases through the elimination of false hypotheses. Research into the risks posed by the cultivation of transgenic crops often appears to apply the bucket theory; many data are produced, but knowledge of risk is not advanced. Application of the searchlight theory, whereby risk assessments test hypotheses that transgenic crops will not be harmful, seems to offer a better way to characterise risk. The effectiveness of an environmental risk assessment should not be measured by the size of the bucket of observations on a transgenic crop, but by the power of the risk hypothesis searchlights to clarify the risks that may arise from cultivation of that crop. These points are illustrated by examples of hypotheses that could be tested to assess the risks from transgenic crops and their hybrids becoming weeds or invading non-agricultural habitats.

Representativity of a mesoscale network for weather-related factors governing pollen dispersal

The cultivation of transgenic crops, such as maize, requires successful gene isolation in field environments. Five spatial statistical techniques are used to evaluate the use of a regional mesoscale observation network (Iowa Environmental Mesonet) as a means to drive field-scale pollen dispersion modeling. The Nearest Neighbor Index, Fractal Dimension, Morisita Index, Thiessen Polygons, and Coefficient of Representativity are computed showing the positive and negative impacts of sequential addition of observation networks into a mesonet framework (a collection of pre-existing networks). While it is shown that the arbitrary combination of disparate observing networks increases spatial resolution, this improvement is often at the expense of increased clustering due to co-location of observation sites near urban areas. Network composition in terms of density and degree of clustering was evaluated with a grid analysis using the Barnes scheme as a means to mitigate clustering and improve prediction accuracies when mesonet data are applied to modeling. This paper shows the importance of understanding and accounting for the spatial characteristics of an observational network before applying it to a modeling effort such as field scale pollen dispersion.

Comparison of herbicide regimes and the associated potential environmental effects of glyphosate‐resistant crops versus what they replace in Europe

While cultivation of transgenic crops takes place in seven of the EU member states, this constitutes a relatively limited part of the total acreage planted to these crops worldwide. The only glyphosate-resistant (GR) crop grown commercially until recently has been soybean in Romania. In addition, large-scale experimental European data exist for GR sugar and fodder beets, and, to a lesser extent, GR oilseed rape. These GR crops are likely to have an impact both on the use of herbicides and on the environmental impact of the latter. From the data on these GR crops, it appears that quantities of herbicides applied to GR beets are decreased while those on GR soybean are slightly increased compared with their conventional counterparts. Depending on the parameters used for prediction or measurement of environmental impacts of GR crops, generally similar or less negative impacts were observed compared with conventional crops. Favourable environmental effects of the glyphosate-containing herbicide regimes on GR crops appear feasible, provided appropriate measures for maintaining biodiversity and prevention of volunteers and gene flow are applied.

Crop-to-wild gene flow, introgression and possible fitness effects of transgenes

Crop-to-wild gene flow has received close attention over the past ten years in connection with the development and cultivation of transgenic crops. In this paper, we review key examples of crop/wild sympatry and overlapping flowering phenology, pollen and seed dispersal, the barriers to hybridisation and introgression, the evolution and fate of interspecific hybrids, their fitness, and the potential cost of transgenes. We pay particular attention to ways in which the evolution and divergence between crops and their wild relatives may interfere with these successive steps. Our review suggests that crop-to-weed gene flow is highly idiosyncratic and that crop gene dispersion will certainly be very difficult to preclude totally. Future directions for research should thus focus on the long-term establishment and effects of transgenes on natural communities.