Genetically Modified crops
Plant genetic transformation
2.8 Transformation', 'genetic modification', 'genetic engineering' and 'transgenesis' are all synonyms for the transfer of isolated and cloned genes into the DNA, usually the chromosomal DNA, of another organism. Transformation of micro-organisms was first achieved in 1973 and this was followed by the development of GM technology for animals. Plants, due to the dense nature of the plant cell wall, were more difficult to transform. It was another ten years before the first successful experiments were reported. These first examples involved the use of the crown gall-inducing bacterium, Agrobacterium tumefaciens, to transfer genes for antibiotic resistance into tobacco plants (paragraphs 2.14-15).
2.9 Since those early days, almost every significant crop species has been successfully transformed. The technology, initially in the hands of only a few advanced academic laboratories, has been established and refined in the laboratories of most major plant breeding companies. The international movement of research scientists between laboratories, the work of agencies such as the Department For International Development (DFID) in the UK, and initiatives such as the Rockefeller Rice Biotechnology Program have ensured that effective transformation technology is now practised in all major plant breeding research centres in both developed and developing countries.
2.10 Initially, transformation was developed in model broad-leaved plants such as tobacco and tomato. Narrow-leaved plants, which include all the major cereal crops, were more difficult and the first successful transformations, in rice and maize, were not reported until the late 1980s. Consistently successful transformations of the more recalcitrant cereals such as wheat and barley have only been achieved very recently.
Footnotes9 The Rockefeller Rice Biotechnology Program began in 1984, focusing on Asia. It concentrated first on developing tools of rice biotechnology such as gene-mapping, gene-tagging and genetic transformation. As these tools have been developed, greater emphasis has been placed on training, technology transfer and capacity-building within individual countries.
10 Gordon-Kamm W, Spencer T, Mangano M, Adams T, Daines R, Start W et al. (1990) Transformation of maize cells and regeneration of fertile transgenic plants, The Plant Cell, 2:603-618 and From M , Morrish F, Armstrong C, Williams R, Thomas J and Klein T (1990) Inheritance and expression of chimeric genes in the progeny of transgenic maize plants, BioTechnolgy, 8:833-839.