The potential benefits, risks and costs of genetic use restriction technologies

The potential benefits, risks and costs of genetic use restriction technologiesThe potential benefits, risks and costs of genetic use restriction technologies
Rene C. Van Acker1, Anthony R. Szumgalski2, and Lyle F. Friesen2
1Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada N1G 2W1; 2Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (e-mail: [email protected]).
Received 27 October 2006, accepted 19 April 2007.
Van Acker, R. C., Szumgalski, A. R. and Friesen L. F. 2007. The potential benefits, risks and costs of genetic use restriction technologies. Can. J. Plant Sci. 87: 753–762. Genetic use restriction technologies (GURTs) are designed to restrict access to genet- ic materials and their associated phenotypic traits. Originally GURTs were developed to ensure that new crop varieties could be protected against unauthorized use, but recently there has been interest in the use of GURTs to facilitate novel trait confinement. There is controversy over the potential use of GURTs in food and feed plant varieties. Considerable discourse exists amongst many groups representing both public and private, and government and non-government interests, about whether GURTs should be adopted based on the potential benefits versus the potential risks and costs. Potential benefits include intellectual property rights protection, stimulation of private crop breeding research and development, enhancement of genetic diversity in breeding programs, and novel trait confinement. Potential risks and costs associated with GURTs include intra- and interspecific escape of the tech- nology, reduced access and increased cost of genetic material for breeders, increased regulation, liability risks in the event of GURT failure or escape, increased seed costs for farmers, further limits on access to novel genetic material for farmers, greater industrial control over agriculture, and a further decrease in agro-biodiversity. Although topical and controversial, the potential benefits versus the potential risks and costs of implementing GURTs are difficult to adequately assess because they are in the developmental stage and there has been no known field-based testing to-date. Until the results of peer-reviewed research on the environmental, social, economic and political impacts of GURTs are publicly available, no fair and useful assessment for the com- mercial release of the technology can occur.
Key words: Genetic use restriction technology, plants with novel traits, genetically modified, genetically engineered, plant breeding
Van Acker, R. C., Szumgalski, A. R. et Friesen L. F. 2007. Avantages et risques potentiels, et coût des technologies génétiques restrictives. Can. J. Plant Sci. 87: 753–762. Les technologies génétiques restrictives (GURT) sont conçues pour limiter l’accès au matériel génétique et aux caractères phénotypiques qui s’y associent. Au départ, elles avaient été développées pour qu’on ne puisse utiliser les nouvelles variétés sans autorisation, mais depuis peu, on s’y intéresse parce qu’elles pourraient faciliter l’expression de nouveaux caractères. L’application éventuelle de ces technologies aux variétés vivrières et fourragères suscite néanmoins la con- troverse. De nombreux groupes défendant des intérêts à la fois publics et privés, gouvernementaux et non gouvernementaux s’in- terrogent à savoir si l’on devrait les adopter, compte tenu de leurs avantages, de leurs risques de leur coût potentiels. Parmi les avantages, mentionnons la protection de la propriété intellectuelle, la stimulation des travaux de recherche et de développement privés en amélioration végétale, une meilleure diversité génétique dans les programmes d’hybridation et le confinement des nou- veaux caractères. Du côté des risques, on parle de fuite intra et interspécifique de la technologie, d’un accès réduit au matériel génétique et de son coût accru pour les agriculteurs, d’une réglementation plus sévère, de la responsabilité éventuelle advenant l’échec ou la fuite de la technologie, du coût supérieur des semences pour les producteurs, d’un accès plus difficile au nouveau matériel génétique pour les agriculteurs, d’un plus grand contrôle de l’industrie sur l’agriculture et d’une diminution encore plus grande de la biodiversité. Quoique particuliers et controversés, il est difficile de comparer les avantages de l’utilisation des tech- nologies GURT à leurs risques et à leurs coûts potentiels de manière adéquate car leur développement n’est pas terminé et aucun essai sur le terrain n’a encore été effectué. Tant que les résultats des recherches sur les retombées environnementales, sociales, économiques et politiques des technologies GURT n’auront pas été rendus publics après une évaluation confraternelle, on ne pour- ra évaluer correctement et utilement l’usage de telles technologies à des fins commerciales.
Mots clés: Technologies génétiques restrictives (GURT), plantes à caractères nouveaux, organismes génétiquement modifiés (OGM), manipulation génétique, hybridation des plantes
Genetic use restriction technologies (GURTs) are designed to restrict access to genetic materials and their associated phenotypic traits. Originally GURTs were developed to ensure that new crop varieties could be protected against “unauthorized” use (Oliver et al. 1998; Pendleton 2004).
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Abbreviations: D&PL, Delta and Pine Land; IPP, intel- lectual property protection; PMGF, pollen mediated gene flow, R&D, research and development; T-GURT, trait- based GURT; USDA, United States Department of Agriculture; V-GURT, variety-based GURT
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However, as the nature of genetically engineered traits in plants evolves (Elbheri 2005) and traits are introduced with known human health and environmental risks (Marvier and Van Acker 2005), GURTs may prove useful for preventing trait escape via intra- and interspecific trait movement. Although originally designed for use in arable crops (Oliver et al. 1998), GURTs theoretically could be applied to any organism type, including trees, livestock or fish, making the implications of GURT implementation very broad (Visser et al. 2001). There is substantial global controversy over the potential use of GURTs in food and feed plant varieties, and many groups, public, private, governmental and non-gov- ernmental, are considering whether GURTs should be adopted based on the potential benefits versus potential risks and costs (Service 1998; Mahajan 1999; Pendleton 2004). Strong arguments can be made both in favour and against the utilization of GURTs, depending on the socio-econom- ic, political and environmental context.
The purpose of this paper is to review current technical and related literature on GURTs, with particular emphasis on sterile seed technologies, in order to characterize poten- tial benefits, risks and costs associated with the adoption of GURTs in arable crops. This review also includes a com- parison of new GURTs to hybrid seed technology, a type of GURT that has been widely used commercially for many decades. The potential benefits, risks and costs vary by soci- etal group and so this review is structured to determine potential impacts of GURTs on farmers, plant breeders, governments and society. The paper is intended to inform scientists, students, administrators and policy advisors in various organizations as an aid in understanding GURTs and potential implications associated with their adoption.
CURRENT STATUS OF GENETIC USE RESTRICTION TECHNOLOGIES
There are currently two main classes of GURTs: variety- based and trait-based (Visser et al. 2001; Eaton et al. 2002; Pendleton 2004). Variety-based GURTs (V-GURTs) restrict the use of the variety as a whole by blocking its reproduc- tion. Trait-based GURTs (T-GURTs) regulate the expres- sion of a particular trait.
Variety-based GURTs (Sterile Seed Technology) The original patent for V-GURTs (Oliver et al. 1998 - US Patent 5,723,765) entitled “Control of plant gene expres- sion” was granted jointly to the United States Department of Agriculture (USDA) and Delta and Pine Land (D&PL) Company of Mississippi in March 1998 (Oliver et al. 1998). Although this patented technology was originally developed for tobacco (Nicotiana tabacum L.) and cotton (Gossypium hirsutum L.), it could potentially be applied to all seed-prop- agated crops (Lehmann 1998). This technology is based on a genetic change whereby plants will develop non-viable seeds, which will not germinate in the next generation. Therefore, farmers who use seeds protected by this technol- ogy will be able to grow and harvest an initial crop, but will not be able to save (“brown bag”) seeds from this crop to plant in the future. Although there originally were plans for a corporate merger between D&PL and Monsanto following
this patent, this merger eventually failed (Pilger 2002), largely in response to public pressure on Monsanto not to introduce this seed germination control technology (Masood 1998; Niiler 1999). However, the USDA decided to pursue the commercialization of this technology (Kaiser 2000), and in 2006, Monsanto purchased D&PL giving them ownership over a primary patented GURT (Anonymous 2006).
Briefly, this system, now known colloquially as “termi- nator technology”, is based on the transfer of a combination of three genes in one genetic construct (Fig. 1) (Gupta 1998; Lehmann 1998; Pendleton 2004; EcoNexus and the Federation of German Scientists 2006). These genes are: (1) a gene coding for a toxic substance (terminator or lethal gene), which is linked to a blocking sequence preventing its activation, (2) a recombinase gene containing information for a protein which cuts the blocking sequence linked to the toxic gene, and which is repressed by a repressing com- pound produced via the third gene (3) a repressor gene cod- ing for a protein which suppresses the recombinase gene. Without the application of an external stimulus (i.e., chemi- cal trigger such as the antibiotic tetracycline, which can block the repressor compound from its binding site) the repressor compound prevents the recombinase gene from being “switched on” so that the blocking sequence of the terminator gene remains intact. Thus, under normal condi- tions (absence of chemical trigger) the crop remains fertile and produces viable seed. However, once the chemical trig- ger is applied to seed, the recombinase gene is switched on, which in turn removes the blocking sequence from the ter- minator gene, resulting in lethal gene expression. Toxins produced by the activated terminator gene destroy the seed embryo, thereby rendering the seed non-viable. In this way, seed could be produced and increased commercially in the absence of the chemical trigger, but when sold to farmers the seed would be treated with the chemical triggering agent. All other aspects of plant growth would remain unaf- fected, because the toxic effects stimulated by chemical treatment only occur during the latter stages of embryo development, thus not adversely affecting crop yield (Lehmann 1998).
In addition to the mechanism described above for the original patent, there are a number of other variations of the same basic theme that can be applied to interfere with repro- duction in V-GURTs. The system described above pertains mainly to pure line seed production in self-pollinated crops, however, in the case of hybrid seed production an alternate strategy utilizing different gene components in each hybrid parent could be used (Gupta 1998; Lehmann 1998; Pendleton 2004). In this system, the first hybrid generation (the commercial crop grown by the farmer) would be sterile because the lethal and recombinase genes would be brought together in this generation and a chemical trigger would not be necessary (Gupta 1998; Lehmann 1998). In another sys- tem, tetracycline or another chemical trigger could be used to inactivate the terminator trait instead of being used to activate it (Visser et al. 2001; Pendleton 2004). Another strategy for V-GURTs pertains to vegetatively reproducing crops (e.g., roots, tubers and some ornamentals), whereby, unwanted growth during storage can be prevented by acti-
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vating a certain gene, and growth ability restored when needed by activating a second gene (Visser et al. 2001). Indeed, several companies have been pursuing a number of different patents on technology that is similar to the original V-GURT (Kaiser 2000).
Trait-based GURTs In the case of T-GURTs, one or more genes conferring a sin- gle trait are switched on or off through application of chem- ical inducers (Visser et al. 2001; Pendleton 2004). Therefore, T-GURTs are not intended to affect the viability of seeds, in contrast to V-GURTs, which result in sterile seeds. Traits of interest that could be controlled by T- GURTs include male sterility, pest resistance, stress toler- ance, nutrient production, seed germination or flower development (Gupta 1998; Pendleton 2004). The goal of T- GURTs is to protect the intellectual property (i.e., the “value-added” transgenic trait of interest) of plant breeders in newly developed varieties by restricting access through a biological mechanism (Eaton et al. 2002). These traits could be activated when needed by induction chemicals. For example, insecticidal genes (e.g., Bt) under the control of an
inducible promoter could remain inactivated until an insect pest outbreak justified the application of a chemical to induce the formation of gene products toxic to insects. The inducer chemical would probably be under the control and licensing of the seed company, however, the ultimate “trig- ger” of this technology could be controlled by farmers (Pendleton 2004).
In the literature there is often little distinction made between the two types of GURTS and the molecular mech- anism employed in both is very similar (Federation of German Scientists and EcoNexus 2006). Although this review will focus primarily on V-GURTs (sometimes referred to as sterile seed technology and colloquially as “terminator technology”), both types of technologies will be considered and reference will often be made to GURTs in general.
POTENTIAL BENEFITS OF GURTS There are a range of potential benefits, costs and risks asso- ciated with the release and use of GURTs in agriculture (Table 1). Potential benefits include intellectual property rights protection, stimulation of private research and devel-
Fig. 1. Depiction of one possible form of a varietal genetic use restriction technology (V-GURT) patterned after the Delta and Pine Land design and adapted from a figure developed by ExoNexus and the Federation of German Scientists (2006). This V-GURT design includes three genes in which the seed viability is maintained by a blocker sequence on the terminator gene (in scenario A) and seed sterility is trig- gered by the addition of an external chemical to parent seeds after harvest (in scenario B). This allows for the production of a recombinase which acts to remove the blocking sequence from the terminator gene.
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opment, genetic diversity enhancement, transgene contain- ment and increased agricultural productivity (Gupta 1998; Lehman 1998; Visser et al. 2001; Eaton et al. 2002; Goeschl and Swanson 2003; Lence et al. 2005). The degree of poten- tial benefits derived from GURTs depends on the social group involved (i.e., private companies, farmers, govern- ment or society in general), recognizing of course that these groups are not necessarily mutually exclusive.
Plant Breeders It has been suggested that the absence of robust intellectual property rights results in diminished private research and development (R&D) in plant breeding (Goeschl and Swanson 2003; Pendleton 2004; Lence et al. 2005). For example, more private research has traditionally been con- ducted on crops for which hybrids are practically feasible [e.g., corn (Zea mays L. and sorghum (Sorghum bicolor L.)] compared with those for which they are not [e.g., wheat (Triticum aestivum L.) and rice (Oryza sativa L.)] (Goeschl and Swanson 2003). Therefore, GURTs represent a novel mechanism for capturing returns from innovation in the plant breeding industry, in a similar manner to the more con- ventional technique of hybrid varieties. The GURT mecha- nism greatly improves the plant breeder’s capacity for “rent capture”, potentially increasing private investment into agri- cultural R&D resulting in a higher rate of innovation in the plant breeding industry (Goeschl and Swanson 2003). Breeding companies hope to protect their investments in improved varieties thus GURTs may provide a better form of insurance (i.e., a real biological barrier) against the free use of genetic innovations as compared with patents, plant breeders’ rights or licenses (Visser et al. 2001; Burk 2004; Pendleton 2004). Hence, GURTs would more effectively enforce property rights (Lence et al. 2005). Apart from the sterile seed technology of V-GURTs, it is also possible that T-GURTs protecting value-added traits in newly released commercial varieties could be applied to virtually all crops (Visser et al. 2001). Plant breeders and seed companies thus could be the beneficiaries of substantial financial gains through the implementation of GURTs.
The potential for transgene or novel trait escape may be reduced through sterile seed technology (Gupta 1998; Visser et al. 2001; Eaton et al. 2002). This would be benefi- cial for seed companies by decreasing the probability of cor- porate liability for environmental contamination or health risks due to escaped transgenes or novel traits (Pendleton 2004; Marvier and Van Acker 2005). It would also reduce the chances of competitors or farmers accessing proprietary genetic material through volunteer or feral crop plants. To police the unauthorized use of agro-biotechnology seed companies must currently send agents out into farmers’ fields, which along with ensuing lawsuits, can be costly (Burk 2004). With the facilitation of transgene or novel trait containment through GURTs, seed comapnies would save on costs of monitoring farmers’ fields for unauthorized use of genetic material or for transgene escapes that must be mitigated.
Farmers Potential benefits for farmers through implementation of GURTs may be related to improved yields as a result of increased R&D on crop varieties by private seed companies (Lehmann 1998; Eaton et al. 2002; Goeschl and Swanson 2003). If GURTs are available, private plant breeding com- panies will have greater motivation to develop new and improved varieties of crops for which hybrids are impracti- cal. For instance, with the use of GURTs, it is expected that R&D will increase for those crops which are primarily self- pollinated such as wheat, rice and cotton (Visser et al. 2001). Farmers thus may profit in the long-term from these innovations because more productive varieties and unique novel traits will become available as breeding efforts increase. For example, the vast majority of improved vari- eties have been from hybridized crops, with an average annual yield increase of 2.18% over the long-term for hybrid crops compared with 1.58% for non-hybrid crops in devel- oped countries (Goeschl and Swanson 2003). Thus, for many farmers increased crop yields compensate for having to purchase new hybrid seeds each year, provided that there is no downward response of prices to an increase in supply
Table 1. Genetic use restriction technology (GURT): potential economic benefits, costs and risks [modified from Eaton et al. (2002)]
Societal group Potential benefits Potential risks Potential costs
Farmers Increased productivity from Misuse of monopoly powers Increased input costs improved crop genetics due to by breeders from seed purchase increased research and Reduced seed security and development investment access to genetic improvements
Breeders Increased share of research Heightened regulations in response to Increased cost for (especially private sector) benefits from new products public pressure access to genetic
resources of other breeders
Society Increased agricultural productivity Reduced genetic diversity in fields Reduction in food (reduced sustainability of sovereignty
Reduced food costs agricultural systems)
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(Lehmann 1998). The utilization of GURTs could potential- ly allow non-hybrid crop yield increases to match those of hybrids. Furthermore, incentives to breed new varieties may enhance genetic diversity in…