Novas Técnicas Genómicas: alegações duvidosas em matéria de produtividade, sustentabilidade e segurança 47 New genomic techniques: dubious claims on productivity, sustainability, and safety MICHAEL ANTONIOU1, CLAIRE ROBINSON2 1 Professor of Molecular Genetics and Toxicology, King’s College London, UK 2 Co-director, GMWatch, UK Genetic modification methods have been promoted as a way to address food production and farming problems since the mid-1990s, when “transgenic” genetically modified (GM) crops and foods (mostly soybeans and maize) were introduced on a wave of claims for their productivity and sustainability.1 However, they failed to deliver on their promises. They did not increase yields2 or reduce pesticide use – in fact, they increased it.3 And they did not make farming easier, as weeds became resistant to the herbicides (specifically glyphosate) that the GM crops were engineered to tolerate,4 and insect pests developed resistance to the insecticide Bt toxin that GM crops were engineered to produce.5 Now the new generation of GM crops, produced using so-called “new genomic techniques” (NGTs) such as gene editing, are touted to succeed where transgenics failed. Advocates claim that NGTs, particularly gene editing, make “precise” changes to the genome of an organism that mimic what can happen naturally through normal reproduction or natural mutation, enabling desirable traits to be reliably and safely engineered into plants. The outcomes, we are told, are predictable, so NGT plants will not harm health or the environment. But have things really changed with the arrival of NGTs? If we look closely at the evidence, there is sound scientific reason to doubt the claims made for NGT products. 1 https://www.isaaa.org/resources/publications/downloads/biosafety_bk.pdf 2 https://www.ers.usda.gov/publications/pub-details/?pubid=45182; https://www.ncbi.nlm.nih.gov/pubmed/28230933; http://www.tandfonline.com/doi/full/10.1080/14735903.2013.806408#.UrnaHfYnuUc 3 http://www.enveurope.com/content/24/1/24 4 http://www.enveurope.com/content/24/1/24; https://onlinelibrary.wiley.com/doi/10.1002/ps.4760; https://pubmed.ncbi.nlm.nih.gov/29024306/ 5 https://pubmed.ncbi.nlm.nih.gov/36610076/; http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169115; https://www.dtnpf.com/agriculture/web/ag/crops/article/2020/09/29/epa-proposes-phasing-dozens-bt-corn; https://www.nature.com/articles/s41477-020-0615-5 6 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5536862/; https://www.sciencedirect.com/science/article/pii/S0002929721002718 Productivity NGTs are claimed to be able to generate crops with higher yields. However, this claim is based on faith and marketing speak, not science. Agronomic traits such as higher yields, resistance to diseases and pathogens, and tolerance to environmental stresses are genetically complex – that is, they have the functioning of many gene families at their basis. They could be called “omnigenic” in nature.6 This type of massive, complex, and balanced combinatorial gene function is far beyond what GM approaches such as NGTs can provide, which is the manipulation of one or few genes. Accordingly, there is no “GM gene” for higher yield. Only conventional breeding, in some cases aided by the non-GM biotechnology tool of genetic “marker assisted selection” (MAS), can bring about the large combinations of genes to robustly confer complex traits such as increased yield. (See below for examples of conventional breeding successes augmented by MAS). Furthermore, any claim that we need to increase food crop yields to feed the hundreds of millions of people that go hungry every day and to provide for the world’s increasing population ignores three fundamental socioeconomic facts: i. As far back as 2011, advisors to the World Bank said enough food was being produced to feed 14 billion
RkJQdWJsaXNoZXIy MTgxOTE4Nw==