Use of Gmos Under Containment, Confined and Limited Field Trials and Post-Release Monitoring of Gmos
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In: Biosafety of Genetically Modified Organisms: Basic concepts, methods and issues. Chowdhury MKA, Hoque MI and Sonnino A (Eds.). pp. 157-220. © FAO 2009. Chapter 4: Use of GMOs Under Containment, Confined and Limited Field Trials and Post-Release Monitoring of GMOs K. V. Prabhu* FAO Consultant, Food and Agriculture Organization of the United Nations Introduction The Genetically Modified Organisms (GMOs) in the plant world are those plants which are produced in the laboratory by incorporating into the native DNA of the plant, a small DNA portion carrying a gene that is foreign to the native species. This foreign gene is a recombinant DNA construct (rDNA) with all other regulatory switches to help the foreign gene express in its new genetic environment. This expression can be different from its original expression to the extent of expression which may make the GMO overproduce, underproduce, differently produce or not produce the protein product it is known to produce. But, when rDNA is produced it is within the confines of a highly specialized laboratory with skilled scientists and people handling the product who are generally trained to deal with the positive output as well as the negative ones and the unperceived consequences which comprise the major amount of risk involved. However, when it gets out of the laboratory, the element of risk associated with it passes into the hands of those who may not be associated with the technology or who would not understand the technology at all. The commercial activities about the technology makes the exposure still wider confounded with the risk involved in its release into an environment. The direct use of DNA either from unrelated organisms or from synthetic sources through molecular biological techniques to manipulate the genetic make-up of organisms has provided a large number of alternative strategies in making agriculture productive. The potential is vast beyond the realms of the conventional (though scientific) approaches the breeders have been following ever since agriculture was domesticated as source of sustenance and livelihood. The genetically modified organism (GMO, also referred to as living modified organism or LMO or popularly, transgenic organism) follows the same evolution cycle like that followed by any other technology that a evolving society invents, develops, produces, markets a commodity followed by R & D by the producer involving the inventor after consumer feed- back. In our context, GMO mostly concerns the transgenic crops to a large extent and micro- organisms to a lesser extent. Ever since the discovery of the scientific fact that genes from a totally unrelated organism (virus, bacterium, plants or animals) to plant in mid 1980s came to light, when a gene from Bacillus thuringiensis was cloned into a plasmid vector and transferred into tobacco (a process known as genetic engineering), the brightness of the discovery enlightened scientists from public and private domains alike to the limitless scope the technology possessed. Since then, *Head, Division of Genetics & Officer-in-Charge, National Phytotron Facility, Indian Agricultural Research Institute, New Delhi 110012 India. E-mail: [email protected] 158 Prabhu genetic engineering of plants has gone from a new and largely untested technique to a common agricultural phenomenon in most developed countries and some developing countries like China and India. The first field trial of a GM organism went ahead in 1986. Frostban was a spray containing genetically modified bacteria. In the trials, Frostban was sprayed over a strawberry crop to protect them from frost damage. Frostban was designed to stop the growth of other bacteria that catalyse the formation of ice. Frostban was tested at a site in Brentwood, California. But this open-air experiment didn’t please the local population, who formed a protest group called The Strawberry Liberation Front – the first pressure group opposed to genetic modification. But in the US, opposition to GM agriculture was short-lived and small- scale. In 1993 the US Food and Drug Administration declared GM food was ‘not inherently dangerous’, clearing the way for biotech companies to begin marketing modified seed. Within a decade after the first of the commercial transgenic crops became available to farmers to cultivate the area, more than 70 million acres of transgenic crops are grown in 2002. In the case of crops such as soybean, cotton and canola put together, nearly 60% of the cultivars are transgenic in origin. Such has been the pace with which commercial agriculture adopted the new technology. Of these crops under transgenics, about 40% are those which carry the Bt toxin (crystal protein gene – cry in its variant forms) that provides the crop an ability to kill the lepidopteran (sap-sucking) insects, followed by about 25% carrying the herbicide resistance genes (RR gene) which can withstand a particular type of herbicide while the weeds cannot. The other transgenics are those that have been given resistance to particular viruses by having a gene from the virus inserted into their DNA. In nutshell, the transgenics have arrived and are more likely to stay than otherwise, despite the disfavors among consumers and ecological concerns of nature watching scientists. Rationale for post-release monitoring: In 1995, the Conference of the Parties (COP) to the Convention on Biological Diversity set up an open-ended ad hoc Working Group on Biosafety to draft a protocol. After several years of talks, the COP adopted the Cartagena Protocol on Biosafety in Montreal on 29 January 2000. The Protocol is named to honour the city of Cartagena, Colombia, which had hosted the COP’s first extraordinary meeting intended to finalize and adopt the Protocol in 1999.The Biosafety Protocol was finally adopted in January 2000 with a stated aim to “contribute to ensuring an adequate level of protection in the field of the safe transfer, handling and use of living modified organisms resulting from modern biotechnology that may have adverse effects on the conservation and sustainable use of biological diversity, taking also into account risks to human health, and specifically focusing on transboundary movements” . The need for a protocol to be followed before and after an introduction of a GMO came into focus as it was also realized that there could be unintended hazards and risks from the use of GMOs and products thereof, if the new technology was not properly assessed before use. A gene construct comprising a host compatible promoter, a gene of interest and a terminator sequence or a polyadenylation Chapter 4: Use of GMOs Under Containment, Confined and Limited Field Trials 159 sequence is integrated in a stable manner into the genome of the organism/cell line of the target gene to be expressed and stably inherited. A genetically modified (GM) organism can be safe but this can be unsafe too. This will depend upon the trans-genes, the host organism and the environment where the GMO is being tested. In case of GM plants, in laboratory experiment, viral disease resistant transgenic plants have given rise to newer viruses by recombination. Transgenic rape seed plants containing bar genes transferred the transgenic trait to near relatives of Brassica spp. Insect resistant Bt plants coding for specific Bt proteins developed bt protein resistant insects in laboratory experiments. Transgenic soybean genetically modified to increase its sulfur containing amino acids by incorporating Brazillian nut 2S gene was allergenic to serum of people who were allergenic to Brazillian nut 2S protein. Potatoes genetically modified with specific lectin genes protected attack from insects but such portatoes were not safe to rodents when they were fed with such potatoes. The transgenic pollens of corn coding for Bt proteins killed the monarch butterfly larvae when they were forcibly fed with such pollens. It is expected that transgenic pollens coding for Bt porteins would affect the silkworm larvae, as these are insects that are susceptible to Bt proteins. There are examples of microoganisms, especially genetically modified viruses that turned virulent after modification. Monitoring plays a central role in environmental risk assessment and management and is undertaken to gain continuous or periodic information about aspects of an intention before it starts, during its lifetime and after its completion. Information generated from monitoring programmes is integrated into environmental risk assessment and management in various ways: • as the baseline against which to compare actual and predicted impacts; • as an input to models, forecasts and quantification stages; • to provide information to feed back into the risk assessment in an iterative process; • to confirm that risk assessments and management options are meeting their desired aims; and • as an alert mechanism if adverse impacts are found The magnifying effect any possible post-release disaster may lead us to is not something that has not happened with the non-GMOs in the past. The effect could be as drastic as that is perceived as that can be caused due to the commercialization of a GM crop. Ever since the occurrence of such epidemics and ecological calamities, scientists have been very cautious by monitoring the varietal composition in geographical area, monitoring releases through multi- locational trials advising breeding communities to ensure diversity in the genotypic composition of the material being released for commercial cultivation. Organized pre- commercial