Thirteenth report : the release of genetically engineered organisms to the environment / Royal Commission on Environmental Pollution ; Chairman Lord Lewis of Newnham.

  • Great Britain. Royal Commission on Environmental Pollution.
Date:
1989
Catalogue details

Licence: Open Government Licence

Credit: Thirteenth report : the release of genetically engineered organisms to the environment / Royal Commission on Environmental Pollution ; Chairman Lord Lewis of Newnham. Source: Wellcome Collection.

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    4.4 The range of organisms affected by a virus may be altered in less direct ways. For example, a laboratory study of a pathogenic plant virus showed that it was possible, by altering a single gene, to change the range of insects that could carry it(°). Since certain insects prefer certain plants, this could enable the virus to come into contact with previously unaffected plant species. Other ‘indirect mechanisms which widen the target range may also exist. Viruses are described in more detail in Appendix 4. The issues raised by the genetic manipulation of viruses are discussed further in paragraphs 5.31-5.34. 4.5 Projects intended to engineer plants to produce insect toxins have been referred to in paragraph 2.24. In such cases the possibility that the toxin may appear in a part of the plant that might be eaten by non-target animals or by people must be borne in mind. Many plants grown for human consumption contain toxins, however. For example, some kinds of beans need cooking to make them safe for humans to eat and potatoes and rhubarb are familiar examples of plants of which parts are poisonous whilst other parts can be eaten. It is important to be aware of the existence of these toxins and the preparation necessary to make them safe. 4.6 Another concern with insect resistant plants is that the cultivation of thousands of acres of the crop may encourage the development and spread of insects resistant to the toxin. This possibility would be increased if there were a strong likelihood of the gene which generates the toxin spreading to other plants by conventional means, for example by pollen transfer. Spread of the gene might also result in other, non-target insects falling victim to the toxin. 4.7 The converse of the example mentioned in paragraph 4.5 is that organisms might be engineered to remove or disable genes normally causing toxicity, pathogenicity or virulence, so that they could then be used in circumstances in which they would otherwise be undesirable. In such cases concern will focus on the possibility that these harmful genes may be unexpectedly reacquired or reactivated, perhaps under environmental condi- tions unlikely to occur during testing in the laboratory. 4.8 Different issues were raised by the release of ‘ice-minus’ bacteria in the USA, described in Appendix 5 paragraphs 18 and 19. These genetically engineered micro-organisms were sprayed experimentally onto strawberries and potatoes in California to compete with micro-organisms that induce ice formation and so to prevent frost damage. There was some concern that, if the use of such GEOs eventually became so widespread that they became prevalent in the atmosphere, their action might also lead to changes in local climate by preventing the formation of rain droplets. Following two studies commissioned by the US Congress Office of Technology Assessment (OTA) it was concluded that the likelihood of climatic change was negligible even in the event of large-scale agricultural use of this GEO(®). The example nevertheless emphasises the need for care to be taken about possible environmental consequences. 4.9 A number of elements, including nitrogen, are essential for life. The amounts that are biologically available can control the number of living organisms an environment can sustain. Some genetic engineering research is trying to produce plants and animals which use these essential elements more efficiently. For example, bacteria such as Rhizobium are being manipulated to enhance nitrogen fixation in the soil. Again the OTA commissioned a study of this work to investigate whether there might be any consequences for the nitrogen cycle. Their conclusion was that the probability of adverse conse- quences was very remote and that genetically engineered Rhizobium could be safely used in field tests to investigate the consequences of their release. They