Omics approach shows fewer changes from GE than breeding and environment

ResearchBlogging.orgRicroch AE, Bergé JB, & Kuntz M (2011). Evaluation of genetically engineered crops using transcriptomic, proteomic and metabolomic profiling techniques. Plant physiology PMID: 21350035

  • The authors conducted a literature survey on 44 recent “omic” comparisons between GE and non-GE crop lines. Those profiling techniques (transcriptomics, proteomics, and metabolomics) have been increasingly applied to the analysis of genetically engineered (GE) crop plants with regard to their food safety and nutritional equivalence. None of the published “omic” assessments has raised safety concerns about GE cultivars.
  • The results show that genetic engineering has less impact on the expression of RNA or on protein and metabolite levels than conventional breeding or environmental conditions (e.g. drought).
  • Differences between GE crops and their comparators should be analyzed in a wider context of natural variation. The most pronounced differences were consistently found between the various conventional varieties, a trend linked to the crop diversity maintained or created by plant breeders. This should be put in perspective taking into account that conventional breeding is generally regarded as safe, despite the fact that the nature of the changes in new conventional cultivars are usually unknown.
  • Metabolomics is becoming the prevalent approach but does not yet provide added value for food safety assessment compared to the currently used analytical methods. More basic research is required before non-targeted large-scale methodologies can be internationally certified and accepted.

The study concludes (emphasis added):

Today, the fast accumulating data from targeted approaches as well as non-targeted profiling, consistently indicating that transgenesis has less impact than conventional breeding, should lead at least to a convergence of regulations for various crop breeding methods. Obviously, on a scientific basis this should mean lowering the current regulatory burden for GE crops (Chassy, 2010). Considering that health problems have not been identified for GE crops after 15 years of commercialization, time may have come to simplify the risk assessment of modern biotechnology products, and therefore reduce cost. This would make risk assessment more affordable for small companies, academic institutions, or low-income countries.
However, considering that regulations ruling GE crop marketing have been strengthened continuously due to political pressure, especially in the European Union (see Morris and Spillane, 2010), it is more likely that the non-GE authorization, and firstly of mutagenized crops, will be brought in to line with the GE regulation. In addition, although there is no evidence that more food safety testing is necessary for GE crops, one can predict that a “whatever is possible should be done” policy will push for the use of “omics” technologies in their mandatory assessment.

Abstract:

Transcriptomic, proteomic, and metabolomic profiling techniques have been increasingly applied to the analysis of genetically engineered (GE) crop plants with regard to their food safety and nutritional equivalence. This literature survey is based on 44 recent “omic” comparisons between GE and non-GE crop lines with or without deliberate modification of metabolic pathways. Metabolomics is becoming the prevalent approach but does not yet provide added value for food safety assessment compared to the currently used analytical methods. All three “omic” approaches, on either crop plants or on Arabidopsis thaliana, a research model organism, converge in their conclusions when the effects of a genetic modification itself is compared to inter-variety variation or environmental effects. Transgenesis has less impact on the expression of genomes or on protein and metabolite levels than conventional breeding or plant (non-directed) mutagenesis when comparison is available. In addition, environmental conditions usually have a larger impact. The present update highlights the need to place pair-wise differences between GE crops and their comparators in a wider context of natural variation. None of the published “omic” assessments has raised new safety concerns about marketed GE cultivars. From a scientific point of view, these observations indicate that the current regulatory burden on GE crops should be lowered. Mandatory use of “omics” techniques in reglementary GE food safety assessment cannot be recommended. More basic research is required before non-targeted large-scale methodologies can be internationally certified and accepted.

Science, Syndicated,
David Tribe

Written by David Tribe

David Tribe’s research career in academia and industry has covered molecular genetics, biochemistry, microbial evolution and biotechnology. He has over 60 publications and patents. Dr. Tribe's recent activities focus on agricultural policy and food risk management. He teaches graduate programs in food science and risk management as a Senior Lecturer in the Department of Agriculture and Food Systems, University of Melbourne.

3 comments

  1. Excellent paper, which means it’s sure to attract the usual dubious negative commentary from the anti-people.
    Even so, the conclusions of the paper are nothing new — the novelty is the thoroughness of the research involved in reaching the conclusions.
    The anti-people will of course use the tired old trope: It’s favorable to GM crops, therefore it’s corrupted by Kapitalist mentalities, therefore it’s not independent or trustworthy, therefore, it’s pure propaganda and must be dismissed by anyone who cares about the planet, etc. and so forth.
    Statement of competing interests: I personally enjoy hearing the howls of pain and indignation from the anti-people as they confront the facts and discover, the facts are not on their side.

  2. So, the question has to be asked, is there any consensus around what the regulatory approach should be when transgenic approaches do have large metabolic, transcriptional or proteomic effects.
    In my line of research one might expect a more NUE corn plant to have pretty large differences in each of these (particularly when compared to the proper controls in similar conditions) simply by virtue of using nitrogen more efficiently and therefore acting differently – won’t necessarily be the case, but may be – likewise an gene, or set of genes, to increase intrinsic yield of a plant may well also have large systemic effects – do the omics offer a safety screening tool (ie should transgenics be looked at using the omics as a decision point as to the extent of safety testing required?) – you wouldn’t really expect relatively simple binary traits like HT and IR to have wide reaching metabolic, transcriptional or proteomic effects – but once you start really engineering metabolism and tweaking stuff to give real changes in end season yield (rather than simply allowing plants to realize their potential) I can’t imagine that there won’t be changes above and beyond the environmental and varietal differences on occasion (although given plants plasticity of metabolism to deal with various conditions (if only the poor little dears could run away from the elements…) perhaps this assumption is wrong) and to make such a play about there not being any differences in 1st gen transgenics may well come back and bite us on our ass later (and for traits more likely to have large impact outside of a commercial setting)

  3. Ewan,
    I would suggest that there might be a consensus around the notion that if the results fall within the range of natural variability — even if consistently on one end of the range — there should be no special scrutiny. The rationale would be an exercise in substantial equivalence, which is held by some to be analytically prior the precautionary principle. An excellent tool in this regard would be the ILSI Crop Composition Database, at
    http://www.ilsi.org/FoodBioTech/Pages/CropCompositionDatabase.aspx

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