While conventional breeding speeds up the evolution of plants and skews it gradually to fit human needs, genetic engineering forces abrupt and disruptive changes in genome structure and function. The artificial gene (or edit) functions as it's designed to within the highly uniform genetic and environmental context of a modern commercial crop. How does it function in any other genome and ecosystem?
Risk assessment of GM plants has always focused on the intended artificial trait coupled to an assumption that if the altered bit of DNA 'escaped' into other plant populations it would fizzle out over time unless it conferred a clear, identifiable, risk-assessable fitness advantage. Now that we've grown GM crops in various environments for over two decades and there's been time for gene contamination incidents to inform the science, this trait-centred risk assessment is proving shaky.
Many commercialised GM crops, including rice, oilseed rape, cowpeas, beet and maize, have weedy relatives they can inter-breed with somewhere in the world.
Commercial GM crops grown in areas where there are related weeds are only one of the possible sources of gene pollution. Persistent populations of GM plants have been established due to seed spillage along transport routes in both exporting and importing countries [1]. Poor post-trial monitoring has led to experimental GM plants emerging in fields years after field tests [2,3]. GM crops are also grown illegally in some areas.
A study published in 2018 noted that:
"Examples of transgenes gone astray are increasingly commonplace. Transgenic individuals have been identified in more than a thousand free-living plant populations".
Does it really matter if a few artificial bits of DNA end up in some weeds?
The discovery that the artificial gene most commonly inserted into GM crops, (intended only to make them resistant to glyphosate-based herbicides) has a real potential to create superweeds outside of its home-crop should be a lesson [4]. In that instance, the cause of the increased reproductive talents of the GM weeds could be identified as hormone disruption arising from the novel trait. However, in other accidental GM scenarios, whether the forced metabolic change leads to a collapse of the weed (zero fitness) or domination over everything around it (super-fitness) or anything in between, depends on the weedy background genetics in which the artificial gene has landed. In the natural environment, this is a very diverse background indeed, with very diverse and unpredictable consequences.
A review of the real-life GM crop-weed hybrids identified so far has revealed a wide range of changes with no obvious connection to the introduced trait. These have included larger plant size, faster photosynthesis, increased seed-weight, -numbers and -germination, altered life-cycle characteristics such as earlier flowering, better overwintering, or a switch from annual to perennial. Alternatively, the expression of the artificial gene can be enhanced in its new background, for example leading to a super-insecticidal Bt-generating weed. These acquired features could have significant impacts on the natural environment where the interlocked cycles of food availability and reproduction are dependent on biodiversity and life-stage timing. The bigger picture is that the changes in a single weedy GM plant population may disrupt the fitness of multiple organisms dependent on it for food or reproduction which, in turn, may disrupt all the organisms dependent on them, risking ecosystem collapse.
As if this wasn't enough, it's also been found that GM crop-weed hybrids characteristically evolve over the first few generations. This means that any ecosystem disruption caused by the artificial DNA won't be an easily studied, one-off shift but will progress over the years.
In a nutshell, the trait-based risk assessment used by the biotech industry and regulators is a nonsense: each trait must be risk assessed as a new event when it's bred into any new genetic background, whether deliberately or accidentally. Also, risk assessment must include the environmental effects of novel GM weed hybrids over several generations.
The precautionary principle dictates that where there is insufficient knowledge of the likely outcomes, a GMO should not be approved for release into the environment.
Point out these glaring holes in the GMO risk assessment to your regulators.
The bottom line is that trait-based risk assessment, which the biotech industry is clinging to, is simple and incurs a minimal cost, while tracking country- and even world-scale environmental effects would be seriously complex, time-consuming and expensive. This is not a reason to avoid acknowledging there could be a problem: it's a reason not to engineer crop plant DNA in the first place!
You might mention to your regulators in Westminster that there's an environmental risk assessment minefield they will have to tread if they push the UK down the GM agriculture path.
Background
[1] A CONSTANT SUPPLY OF GM CONTAMINATION - June 2015
[2] MINEFIELD OF RICE (Doc - GMFS Archive) March 2008
[3] GM WHEAT POLLUTION MARK III - October 2016
[4] SUPER-FIT GM SUPERWEEDS - June 2018
SOURCES:
Does it really matter if a few artificial bits of DNA end up in some weeds?
The discovery that the artificial gene most commonly inserted into GM crops, (intended only to make them resistant to glyphosate-based herbicides) has a real potential to create superweeds outside of its home-crop should be a lesson [4]. In that instance, the cause of the increased reproductive talents of the GM weeds could be identified as hormone disruption arising from the novel trait. However, in other accidental GM scenarios, whether the forced metabolic change leads to a collapse of the weed (zero fitness) or domination over everything around it (super-fitness) or anything in between, depends on the weedy background genetics in which the artificial gene has landed. In the natural environment, this is a very diverse background indeed, with very diverse and unpredictable consequences.
A review of the real-life GM crop-weed hybrids identified so far has revealed a wide range of changes with no obvious connection to the introduced trait. These have included larger plant size, faster photosynthesis, increased seed-weight, -numbers and -germination, altered life-cycle characteristics such as earlier flowering, better overwintering, or a switch from annual to perennial. Alternatively, the expression of the artificial gene can be enhanced in its new background, for example leading to a super-insecticidal Bt-generating weed. These acquired features could have significant impacts on the natural environment where the interlocked cycles of food availability and reproduction are dependent on biodiversity and life-stage timing. The bigger picture is that the changes in a single weedy GM plant population may disrupt the fitness of multiple organisms dependent on it for food or reproduction which, in turn, may disrupt all the organisms dependent on them, risking ecosystem collapse.
As if this wasn't enough, it's also been found that GM crop-weed hybrids characteristically evolve over the first few generations. This means that any ecosystem disruption caused by the artificial DNA won't be an easily studied, one-off shift but will progress over the years.
In a nutshell, the trait-based risk assessment used by the biotech industry and regulators is a nonsense: each trait must be risk assessed as a new event when it's bred into any new genetic background, whether deliberately or accidentally. Also, risk assessment must include the environmental effects of novel GM weed hybrids over several generations.
The precautionary principle dictates that where there is insufficient knowledge of the likely outcomes, a GMO should not be approved for release into the environment.
OUR COMMENT
Point out these glaring holes in the GMO risk assessment to your regulators.
The bottom line is that trait-based risk assessment, which the biotech industry is clinging to, is simple and incurs a minimal cost, while tracking country- and even world-scale environmental effects would be seriously complex, time-consuming and expensive. This is not a reason to avoid acknowledging there could be a problem: it's a reason not to engineer crop plant DNA in the first place!
You might mention to your regulators in Westminster that there's an environmental risk assessment minefield they will have to tread if they push the UK down the GM agriculture path.
Background
[1] A CONSTANT SUPPLY OF GM CONTAMINATION - June 2015
[2] MINEFIELD OF RICE (Doc - GMFS Archive) March 2008
[3] GM WHEAT POLLUTION MARK III - October 2016
[4] SUPER-FIT GM SUPERWEEDS - June 2018
SOURCES:
- Normal C. Ellstrand, 2018, "Born to Run"? Not Necessarily: Species and Trait Bias in Persistent Free-Living Transgenic Plants, Frontiers in Bioengineering and Biotechnology 6
- Andreas Bauer-Panskus, et al., 2020, Risk assessment of genetically engineered plants that can persist and propagate in the environment, Environmental Sciences Europe, 32:32
- Spreading the risks: When genetically engineered organisms go wild, GM Watch 4.03.20
- Jia Fang, et al., 2018, Overexpressing Exogenous 5-Enolpyruvylshikimate-3-Phosphate Synthase EPSPS) Genes Increases Fecundity and Auxin Content of Transgenic Arabidopsis Plants, Frontiers in Plant Science 9
- Julie Ingwersen, USDA investigates unapproved GMO wheat found in Washington state, Reuters, 8.06.19
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