Evaluation of potential risks associated with recombination in transgenic plants expressing viral sequences

Turturo, C.; Friscina, Arianna; Gaubert, Stéphane; Jacquemond, Mireille; Thompson, Jeremy R.; Tepfer, Mark

doi:10.1099/vir.0.83339-0

Cited by 24 publications

(26 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 39-NCR can serve as an initiation site for the viral replicase (Teycheney et al, 2000), thus making it possible for full-length recombinant RNA3 that can potentially be replicated to be produced by a single crossover. Turturo et al (2008) showed clearly that the populations of recombinant viral RNAs were similar in the transgenic plant system when infected with a subgroup I CMV (I17F-CMV) and in the non-transgenic plants infected simultaneously with both CMV strains. However, the populations were, in both cases, completely dominated by recombinants at a single hotspot.…”

Section: Introductionmentioning

confidence: 98%

“…Tobacco (Nicotiana tabacum Xanthi XHFD8) plants were maintained in greenhouse conditions of 25±2 uC and 75±10 % relative humidity with a 16 h day length. Transgenic line 40.5 expresses the CP and entire 39-NCR of R-CMV RNA3 (subgroup II) (Turturo et al, 2008), and is not resistant to I17F-CMV (subgroup I). Cloned cDNAs of RNAs 1, 2 and 3 (pI1T7, pI2T7 and pI3T7, respectively) of I17F-CMV (Jacquemond & Lot, 1981) (kindly provided by M. Jacquemond, INRA, Avignon, France) were linearized and plants were inoculated as described previously .…”

Section: Methodsmentioning

confidence: 99%

“…Moreover, when the hotspot recombinant was tested alone by inoculation onto tobacco plants, it was found to be non-viable (Pierrugues et al, 2007). IP: 54.191.190.102 On: Sat, 12 May 2018 06: 14:05 Considering that in other experimental systems using cucumoviruses, aberrant recombinants were frequently reported (de Wispelaere et al, 2005;Fernandez-Cuartero et al, 1994;Masuta et al, 1998;Shi et al, 2007;Suzuki et al, 2003), it was surprising that none were observed by Turturo et al (2008), suggesting that the predominance of the hotspot masked the presence of other recombinant molecules. In order to test this hypothesis, plants of the same transgenic line were inoculated with an attenuated mutant of I17F-CMV, so that recombinants that restore the viral genome would be favoured by selection pressure.…”

Section: Introductionmentioning

confidence: 99%

“…The preferred strategy to evaluate this potential risk is to compare the populations of recombinants in transgenic and non-transgenic plants under conditions of minimal selection pressure in favour of the recombinants (Aaziz & Tepfer, 1999), but this has proved to be difficult to achieve. In a recent study, Turturo et al (2008) were the first to succeed, using transgenic plants expressing the coat protein (CP) and the 39-non-coding region (39-NCR) of RNA3 of a subgroup II strain of cucumber mosaic virus (R-CMV). The 39-NCR can serve as an initiation site for the viral replicase (Teycheney et al, 2000), thus making it possible for full-length recombinant RNA3 that can potentially be replicated to be produced by a single crossover.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analysis of recombination between viral RNAs and transgene mRNA under conditions of high selection pressure in favour of recombinants

Morroni

Thompson

Tepfer

2009

Journal of General Virology

Self Cite

View full text Add to dashboard Cite

One possible environmental risk related to the utilization of virus-resistant transgenic plants expressing viral sequences is the emergence of new viruses generated by recombination between the viral transgene mRNA and the RNA of an infecting virus. This hypothesis has been tested recently for cucumber mosaic virus (CMV) by comparing the recombinant populations in transgenic and non-transgenic plants under conditions of minimal selection pressure in favour of the recombinants. Equivalent populations were observed in transgenic and non-transgenic plants but, in both, there was a strongly dominant hotspot recombinant which was shown recently to be nonviable alone in planta, suggesting that its predominance could be reduced by applying an increased selection pressure in favour of viable recombinants. Partially disabled I17F-CMV mutants were created by engineering 6 nt deletions in five sites in the RNA3 39-non-coding region (39-NCR). One mutant was used to inoculate transgenic tobacco plants expressing the coat protein and 39-NCR of R-CMV. A total of 22 different recombinant types were identified, of which 12 were, as expected, between the transgene mRNA and the mutated I17F-CMV RNA3, while 10 resulted from recombination between the mutated RNA3 and I17F-CMV RNA1. Twenty recombinants were of the aberrant type, while two, including the dominant one detected previously under conditions of minimal selection pressure, were homologous recombinants. All recombinants detected were very similar to ones observed in nature, suggesting that the deployment of transgenic lines similar to the one studied here would not lead to the emergence of new viruses.

show abstract

Section: Introductionmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Analysis of recombination between viral RNAs and transgene mRNA under conditions of high selection pressure in favour of recombinants

Morroni

Thompson

Tepfer

2009

Journal of General Virology

Self Cite

View full text Add to dashboard Cite

show abstract

“…This includes studies such as those described in the previous section in the area of the impact of modified fitness of crops and crop relatives, but generic research can be equally important in other areas to GMO risk assessment. For instance, it took nearly 10 years to come to a point of completion regarding the potential impact of recombination in virus-resistant transgenic plants (Aaziz and Tepfer, 1999;de Wispelaere et al, 2005;Turturo et al, 2008). …”

Section: Conclusion and Recommendationsmentioning

confidence: 99%

Fitness and beyond: Preparing for the arrival of GM crops with ecologically important novel characters

Wilkinson

Tepfer

2009

Environ. Biosafety Res.

Self Cite

View full text Add to dashboard Cite

The seemingly inexorable expansion of global human population size, significant increases in the use of biofuel crops and the growing pressures of multifunctional land-use have intensified the need to improve crop productivity. The widespread cultivation of high-yielding genetically modified (GM) crops could help to address these problems, although in doing so, steps must also be taken to ensure that any gene flow from these crops to wild or weedy recipients does not cause significant ecological harm. It is partly for this reason that new GM cultivars are invariably subjected to strict regulatory evaluation in order to assess the risks that each may pose to the environment. Regulatory bodies vary in their approach to decision-making, although all require access to large quantities of detailed information. Such an exhaustive case-by-case approach has been made tractable by the comparative simplicity of the portfolio of GM crops currently on the market, with four crops and two classes of traits accounting for almost all of the area under cultivation of GM crops. This simplified situation will change shortly, and will seriously complicate and potentially slow the evaluation process. Nowhere will the increased diversity of GM crops cause more difficulty to regulators than in those cases where there is a need to assess whether the transgene(s) will enhance fitness in a non-transgenic relative and thereafter cause ecological harm. Current practice to test this risk hypothesis focuses on attempting to detect increased fitness in the recipient. In this paper we explore the merits and shortcomings of this strategy, and investigate the scope for developing new approaches to streamline decision-making processes for transgenes that could cause unwanted ecological change.Keywords: environmental risk assessment / fitness / fitness parameters / GM crops / invasiveness / weediness THE CONTEXT OF ENVIRONMENTAL RISK ASSESSMENTThroughout the world, wherever transgenic crops are grown outside the confines of the laboratory, there is a regulatory system for governing and monitoring the conditions under which experimental field trials and/or commercial cultivation is sanctioned. There is considerable variation between individual countries in the legislative frameworks that dictate how decisions to permit, delay or halt the release of a particular transgenic event are made (Capalbo et al., 2003;Cardwell and Kerr, 2008;Guehlstorf and Hallstrom, 2005; Jepson et al., 2005;Kalaitzandonakes et al., 2007;Nasiruddin and Nasim, 2007;Ramjoue, 2007;Salleh, 2006;Zafar, 2007). Nevertheless, there appears to be a growing harmonization of the underlying process that governs decision-making, * Corresponding author: jjw@aber.ac.uk with all systems adopting a case-by-case approach in which large bodies of evidence are first presented and then evaluated in a reiterative fashion.The documents made in support of individual submissions are usually rather weighty and data-rich; they invariably include substantial information relating to the biology and agr...

show abstract

Environmental Impact of Genetically Modified Organisms ( GMOs )

Hails

2009

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

The intensification of agriculture has provided cheaper more plentiful food, but has also caused declines in farmland wildlife. The introduction of genetically modified (GM) crops may exacerbate this, or offer new ways of mitigating anthropogenic impacts. The potential consequences of the introduction of GM crops have been studied for over a decade, since commercialization. Although the specific issues depend on the crop and transgenes involved, one common theme that emerges is that the biggest effects will arise from the way in which the GM crop will be managed. Herbicide‐tolerant GM crops may allow better weed control, and this is a risk to biodiversity that should be mitigated. However, even herbicide‐tolerant crops have some environmental benefits through reduced production and application of herbicides. Insect and disease‐resistant crops will have fewer impacts on nontarget organisms than conventional crops and their management, and so may offer direct environmental benefits. Key concepts Farmland biodiversity has been enhanced and maintained by agricultural land management over hundreds of years. Changes in the intensity of farming since the 1970s have caused its decline, and any future change may exacerbate or ameliorate this impact. Global warming potential (GWP) is the potential of a gas produced by a product or a process to contribute to global warming. It is measured over a specific time period, and on a scale relative to carbon dioxide. Different agricultural practices will have different GWP. Life cycle assessment is defined as an objective process to evaluate the environmental burdens associated with a product or a process by identifying energy and materials used and wastes released to the environment. Meta‐analysis involves retrieving and combining data from a number of studies to obtain a quantitative estimate of the overall effect which can be statistically analysed. Refuge strategy is the strategy employed to delay or prevent the build up of pests resistant to the GM crop. It involves a ‘refuge’ of approximately 20% of the crop in which susceptible individuals may survive, in contrast to the 80% of the crop in which the majority of the pest individuals fail to reach maturity. Any rare resistant individuals that do survive are then likely to mate with a susceptible individual and produce susceptible offspring. Natural enemy release posits that natural enemies limit the growth or survival of plants. Resistance to these natural enemies could release a plant genotype from natural enemy regulation and lead to invasiveness. Comparative sustainability assessment is a matrix‐based approach to assess comparative sustainability, benefits and risks of the introduction of any novel agricultural products or practices. The purpose is to develop a more objective and comprehensive approach towards agricultural and rural policy.

show abstract

Evaluation of potential risks associated with recombination in transgenic plants expressing viral sequences

Cited by 24 publications

References 27 publications

Analysis of recombination between viral RNAs and transgene mRNA under conditions of high selection pressure in favour of recombinants

Analysis of recombination between viral RNAs and transgene mRNA under conditions of high selection pressure in favour of recombinants

Fitness and beyond: Preparing for the arrival of GM crops with ecologically important novel characters

Environmental Impact of Genetically Modified Organisms ( GMOs )

Contact Info

Product

Resources

About