Environmental Effects of Transgenic Plants The Scope and Adequacy of Regulation (2002) / Chapter Skim
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7 The Future of Agricultural Biotechnology
7 The Future of Agricultural Biotechnology
Pages 220-259
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From page 220... ...
As such, our experience with the few herbicidetolerant and insect- and disease-resistant varieties that have been commercialized to date provides a very limited basis for predicting questions needed to be asked when future plants with very different phenotypic traits are assessed for environmental risks. 1 J This chapter is divided into three major sections.
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From page 221... ...
As discussed in Chapter 2, it is not possible to characterize the environmental hazards that may be associated with all such crops in advance of knowledge about their phenotypic characteristics and the agricultural ecology of the settings in which they will be grown. However, the second part of this section offers a preliminary discussion of some representative environmental risk issues that may be associated with these new transgen~c crops.
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From page 222... ...
It seems safe to assume, though, that genetically complex traits will require additional years of research to understand, let alone express and regulate in a genetically engineered crop species. Nevertheless, complex traits, including those controlling adaptation to abiotic stresses, such as drought and salinity, flowering and reproduction, and hybrid vigor, are being actively investigated, and it would not be surprising if some of these could be regulated in crop plants by genetic engineering within the next 5 to 10 years.
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From page 223... ...
Over the long term, new knowledge regarding the physiology and development of plants and their interaction with microorganisms could eventually provide the foundation to modify plant structure and reproduction. It may become possible to genetically engineer crop plants that are more tolerant to drought, salinity, and other abiotic stresses (see below)
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From page 224... ...
There is also interest in using genetic engineering technology to turn annual crop plants into factories that produce valuable chemicals (for a recent review, see Somerville and Bonetta 2001) and antibodies (Daniel!
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From page 225... ...
, the stability and nutritional value of corn oil could be improved by increasing the proportion of monounsaturated fatty acid, and there are efforts under way to do so by genetic engineering. Natural soybean oil contains a significant proportion of di- and triunsaturated fatty acids (linoleic and linolenic)
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From page 226... ...
However, the problem can be approached through genetic engineering by altering the activity of the enzymes that synthesize methionine and cysteine or by overproducing a protein that contains them. A complementary approach is to block expression of the major soy proteins that lack methionine and cysteine, thereby increasing the percentage of these amino acids in the remaining proteins.
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From page 227... ...
Folic acid deficiency increases the risk of birth defects, heart disease, and stroke. Much remains to be learned about the uptake and accumulation of minerals and the synthesis of vitamins in plants, but significant progress is being made in some areas of research, such that transgenic plants producing increased levels of several micronutrients have been created.
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From page 228... ...
Preliminary research has demonstrated that several types of plant tissues, including seeds and leaves, have the capacity to express genes encoding the protein subunits of monoclonal antibodies and assemble them into functional complexes (Daniel!
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From page 229... ...
Finding 7.1: For predicting environmental risks of future plant varieties and their novel traits, currently commercialized transgenic crops offer only limited experience and understanding. Finding 7.2: The production of nonedible and potentially harmful compounds in crops such as cereals and legumes that have traditionally been used for food creates serious regulatory issues.
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From page 230... ...
However, a brief discussion of the general issues associated with some new crops currently being developed will help frame the context in which environmental risks from commercialization of the next generation of transgenic crops may be discussed. Tolerance to Abiotic Stresses Abiotic stresses significantly limit crop production worldwide.
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From page 231... ...
Despite this uncertainty regarding the nature of stress-tolerant transgenic plants, they have raised concerns about environmental risks. Abiotic conditions, such as soil nutrient levels, water, cold, heat, salt, and metal toxicity, combined with their seasonal variations have strong determining effects on plant community structure worldwide, and the geographic distribution of many plant species is influenced strongly by these factors (Whittaker 1975~.
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From page 232... ...
For example, certain transgenic salt-tolerant plants can also tolerate other stresses including chilling, freezing, heat, and drought (Zhu 2001~. Phytoremediation In the future, transgenic plants may be grown to remove or detoxify pollutants from soils ("phytoremediation"~.
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From page 233... ...
The environmental risks associated with this strategy may be less scale dependent and have the additional benefit of potential harvest for extraction of their heavy metal content. Combinations of Transgenic Traits Risk assessments of transgenic crops have focused on the impacts of single traits (e.g., herbicide tolerance)
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From page 234... ...
Under the Federal Plant Pest Act and the Federal Plant Quarantine Act, however, APHIS may not be able to make such an evaluation. At the field or farming systems level, interaction of traits in transgenic plants could involve complex indirect causal pathways.
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Based on past experience, such interactions must be examined on a case-by-case basis. Chapter 3 includes a review of the environmental risk determinations made in connection with the U.S.
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From page 236... ...
Third, the need for involving the public to democratize decision making and the increasing role that communicating environmental risk will likely play in the future development of biotechnology are discussed. Finally, the focus is shifted back to regulatory policy issues, with a comment on the precautionary principle and drawing particular attention to some of the opportunities that the 2000 Plant Protection Act provides APHIS.
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From page 237... ...
farmers to capture a price premium for nontransgenic crops. At the same time, the existence of a market for nontransgenic crops creates a new kind of environmental risk from transgenics: If they cannot be environmentally isolated, pollen and residues from transgenic crops can affect/influence the economic value of nontransgenic crop production.
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From page 238... ...
The Nuffield Council on Bioethics report (1999) on ethical issues associated with biotechnology notes that there is an apparently persuasive argument for accepting environmental risks in order to increase the availability and reduce the cost of food for hungry people and poor farmers.
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From page 239... ...
The increasing nutritional and economic demands of the less developed regions of the world are expected to impact the more economically secure countries. Some people believe that such problems will require increases in productivity that far exceed what agricultural technology has achieved in the past and that these increases cannot be achieved without the use of transgenic crop plants (McGloughlin 1999, Borlaug 2000~.
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From page 240... ...
The potential for commercially grown transgenic crops to increase total world food supplies and to reduce the need for utilizing marginal lands for food production is thus an appropriate but highly contested dimension of the context in which environmental risks for the next generation of crops will be debated (Kalaitzandonakes 1999~. One driving factor in the debate is the suspicion that need-based arguments promoting transgenic crops are only a ruse for profit-seeking activities by the biotechnology industry.
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From page 241... ...
The context for evaluation of environmental risks must take account of the need-based argument for expanding food capacity and production. Both human and environmental dimensions of the need for increased food production are critical to any balanced evaluation of the risks from transgenic crops.
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Finding 7.8: In an era of globalization, applications of transgenic crops in developing countries will be an important component of the context in which environmental impacts from transgenic crops are evaluated. Involving the Public and Communicating Environmental Risk Members of the public express an interest in the environmental impacts of agriculture and a desire to be informed about the relative environmental risks and benefits of different production methods.
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From page 243... ...
Also, because biotechnology is controversial, participant involvement is becoming increasingly critical to the role of risk analysis in forming the basis for authority, believability, and public confidence in regulatory decision making and in the subsequent commercialization and widespread adoption of transgenic crops. As noted in Chapter 2, risk analysis should play at least two roles in the regulation of transgenic plants.
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. The question of whether genetically engineered crops involve environmental risks is thus not wholly a scientific one.
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From page 245... ...
Finding 7.9: Adequate risk management for future biotechnology products will depend on a regulatory culture that reinforces the seriousness with which environmental risks are addressed. Finding 7.10: Public confidence in biotechnology will require that socioeconomic impacts are evaluated along with environmental risks and that people representing diverse values have an opportunity to participate in judgments about the impact of the technology.
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From page 246... ...
If such a transgene moves into a wild relative, there could be widespread environmental dissemination of the pharmaceutical substance or other nonfood substances that could have impacts on wildlife as well as microbial populations. Provisions for regulation of such environmental risks are identified under the existing coordinated framework.
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From page 247... ...
Transgenic crop varieties that may be environmentally benign in this country might have a high risk of ecological disruption were they to be grown in some developing countries. For example, corn grown in southern Mexico and Guatemala and potatoes grown in the highlands of Peru will cross readily with wild relatives, which could lead to environmental risks.
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From page 248... ...
Consequently, unless there are additional negotiations, the regulatory impact of the precautionary principle will be determined by practice and only after its use will it be possible to articulate what it actually is. The European discussion of the precautionary principle has occurred in the context of attempts to harmonize grades, standards, and regulatory approaches among member states.
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From page 249... ...
Arguably, these approaches simply reflect the current regulatory philosophy in place for transgenic plants under the coordinated framework. However, other contributors explicitly advocate the use of nonscientific criteria, such as political solidarity or respect for life, to evaluate the possibility and potential for environmental hazards (Bernstein 1998, M'Gonigle 1998~.
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A comparison of the environmental risks from Green Revolution varieties
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From page 251... ...
on pestprotected plants cite a number of environmental risks that should be accounted for in the regulation of both current and future crop varieties. When these observations are combined, the possibility that nontransgenic crops may also pose environmental risks requiring a regulatory response becomes logically inescapable.
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This trigger captures all products of genetic engineering but excludes potentially hazardous products derived from conventional methods. This regulatory trigger is imperfect because it does not provide regulatory scrutiny for certain conventional crop plants that may have environmental risks.
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From page 253... ...
Finding 7.14: The committee finds that the Plant Protection Act of 2000 can be viewed as an opportunity to clearly define the types of novel plants, regardless of method of breeding, that trigger regulatory scrutiny. As explained in previous chapters, APHIS regulates transgenic plants under the authority of the Federal Plant Pest Act (FPPA)
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From page 254... ...
When evaluating transgenic crops for deregulation, it becomes increasingly difficult to defend the idea that these new nontransgenic crops should automatically be excluded from scrutiny for environmental impact. THE NEED FOR STRATEGIC PUBLIC INVESTMENT IN RESEARCH Perhaps more than anything else, the experience with commercialization of transgenic crops has revealed gaps in the knowledge base for understanding and measuring the environmental risks of crop production, irrespective of whether recombinant DNA technologies have been applied.
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From page 255... ...
Recently, the USDA's Initiative for Future Agriculture and Food Systems (IFAFS) program has included a competition for funding research, education, and extension on the management of environmental risks of agricultural biotechnology.
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(3) Research is needed to evaluate the environmental risks associated with conventionally produced crop plant varieties.
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From page 257... ...
For example, how should feedback loops be established between validation efforts and longterm monitoring efforts so as to clarify the adequacy of available ecological indicators for monitoring of ecological effects of transgenic crops? Finally, research is needed on processes for establishing long-term monitoring indicators in relation to transgenic crops as well as research to evaluate the efficacy and effectiveness of potential long-term indicators.
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From page 258... ...
In addition, tissue culture itself often introduces unwanted and unpredictable genetic and epigenetic variation to transgenic plants that such methods may avoid. Alternatively, different promoters could allow greater control of where in the plant the gene product is produced; tissue-specific promoters could preclude expression of pesticidal proteins, for example, in pollen and other tissues.
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From page 259... ...
Recommendation 7.3: Significant public-sector investment is called for in the following research areas: improvement in risk analysis methodologies and protocols; improvement in transgenic methods that will reduce risks and improve benefits to the environment; research to develop and improve monitoring for effects in the environment; and research on the social, economic, and value-based issues affecting environmental impacts of transgenic crops.
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