Introduction: The End of the GMO?
There is no robust and parsimonious explanation for differences in diffusion of agricultural biotechnology across countries or across time. Variables that delineate common political rifts in international trade and politics fail to explain variation. The one constant is a risk-utility balance, filtered through structures of regulatory mechanisms and their associated political ecology: Agriculture vs Environment ministries, eg. This paper assesses in a preliminary way political prospects of new technologies for genetic engineering of agricultural plants, especially CRISPR-Cas9. The frontiers of plant breeding are moving away from transgenesis as dominant form of plant breeding and test of what requires special regulation -- a 'GMO' or 'LMO.' New regulatory constructs treat gene-edited plants more as mutagenized crops -- in a targeted rather than random way. Since the thousands of mutagenized agricultural plants have been immune to regulation as ‘GMOs’ – and can be ‘organic’ - this political battle for definition will shape the future diffusion of agricultural – and other – biotechnologies globally, marking the end of pointless battles over the ‘GMO.’ Because of the utility of new techniques for consumers and farmers alike – unlike transgenic plants for the most part – as well as for the environment and human health, the risk-utility balance is being fundamentally altered.
This past summer, possibly the world’s first meal consisting of genome-edited (CRISPR) foods was served up in Sweden by scientist Stefan Jannson (Zhang et al., 2016). The meal — ‘Tagliatelle with CRISPRy fried vegetables’ — was served with cabbage grown directly on Umeå University’s campus. The Swedish Board of Agriculture ruled that CRISPR-Cas genome-edited crops do not fall under the EU’s definition of a genetically modified organism (GMO); no special regulation was necessary. Similar rulings have occurred in the U.S. and Canada. If this trend continues, can we expect to see many more meals based on genome-edited crops across Europe and elsewhere in the future? This new and rapidly expanding form of technology, and impending public responses, will force a fundamental re-evaluation of how to regulate tomorrow’s food crops – and much else.
The genomics revolution that enabled modern agricultural biotechnology has been a source of optimism and controversy since its inception: suicide seeds and silver bullets. Social and political resistance has prevented adoption and diffusion in many countries, in law if not in farmer practice (Herring and Paarlberg, 2016). Innovations in crop genetic engineering have, where accepted, significantly increased the number and diversity of crop varieties and enhanced harvested yield, improved nutritional content and conferred resistance to biotic and physical stresses (Collinge et al., 2010; Deikman et al. 2012). Genomic techniques have proved valuable to complement conventional breeding methods. Genetically modified (GM) crops have also demonstrated potential to address malnutrition and to improve agronomic practices where other approaches fail: virus-resistance is a prominent example. Some biotech crops enable labor-saving strategies that allow farmers additional time for other activities. At the same time, labor displacement has not proved so detrimental to the rural poor as first hypothesized and there is even some evidence of potential for decreasing gender inequality under certain cropping conditions and village economy (Katage and Qaim 2012; Kouser et al., 2017). Crops with improved yield and improved resistance to pests, weeds and environmental stresses such as drought and flooding can assist farmers who lack access to public safety-net mechanisms or reliable markets. Resilience to certain environmental shocks that result from climate change is one possible outcome (Cominelli and Tonelli, 2010). While the first genetically modified crops were bred for improved agronomic traits, agricultural biotechnology has pursued as well crops with improved human health benefits (Bhutta et al., 2013).
As often in new technology, promises of potential have freqently outrun workable options on the ground for farmers. That situation may be changing dramatically. Over the past few years, a new technology known as genome editing has come to the forefront. Genome editing systems based on existing bacterial defense and repair pathways within cells are being developed with applications in crop science, livestock improvement and medicine (Montenegro, 2016). In general, the technology is rapid, precise and efficient, compared to other means of developing desired characteristics in plants: transgenesis, chemical or radiation-induced mutagenesis and conventional breeding. These attributes, coupled with relatively low cost and comparative freedom from regulatory encumbrances, have enabled genome editing to revolutionize basic molecular-biology research and take it to an entirely new level.
Genome editing systems based on clustered regularly interspaced short palindrome repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), for example, are now available in most research labs and exhibit forms of utility ranging from those as small as examining the function of a particular gene fragment to as large as the genome-wide mutagenesis screening of an entire crop for novel traits (Ding et al., 2016, Bortesi and Fischer, 2015, Sauer et al., 2016). Furthermore, genome editing provides a plethora of applications in the crop sciences. Unlike transgenic plants, genome editing allows plant breeders to know exactly where a change has been made in the genome, leaves no trace of that process, and enables all copies of a particular gene to be altered within a plant at the same time. Moreover, crop genome editing shows signs of proving more socially acceptable than GMOs – and thus subject to fewer regulatory barriers, though large ethical issues and property questions remain to be settled (Potrykus, 2010, Perez-Massof et al., 2013).
The following review illustrates how genome editing fits into the broader frame of agricultural development. It describes how genome editing differs from and builds upon earlier achievements in genomics. Next, it provides examples of how genome editing is being applied today to improve traits for the world’s major food crops. The use of ‘gene drive’ as a mechanism to spread newly edited genomes rapidly, as well as examples of the use of genome editing for livestock improvement and for medical breakthroughs in human health are provided. The review ends with a discourse regarding the future of genome editing as a tool to address some of humanity’s greatest challenges, and, reciprocally, some social, economic and ethical questions requiring coordinated responses to move forward.
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