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Commercial Success of ECLAIR Programme
AGRE-0003: Insect resistant transgenic plants with improved performance |
AGRE-0003: Insect resistant transgenic plants with improved performance
Science Background
Conventional plant breeders try to produce seeds and other propagation material, such as potato tubers, that carry natural resistance towards pests and diseases. However, the extensive use of agrochemicals remains the main method of control in agriculture, horticulture and the garden. An alternative is the use of materials of biological origin as biopesticides. At the time the project started there was a growing market for biopesticides based on proteins, produced by strains of the bacterium Bacillus thuringiensis (Bt), that are active against pests such as the caterpillars of many Lepidoptera (moths and butterflies). Attempts to produce plants with increased insect resistance using genetic engineering techniques to introduce the genes coding for the toxic proteins had been successful for several plant species (tobacco, tomato, potato). Whilst trials had shown that this could be an effective means of controlling damage to crops by caterpillars, expression levels were low.
Objectives
The primary objective was to produce transgenic plants, of commercially important species, conferring resistance to insect attack by introduction of genes encoding the insecticidal (Cry) proteins produced by Bt. Various approaches were suggested in order to overcome perceived problems associated with development of resistance in insect population, levels of expression and the spectrum of insects controlled. The project also aimed to increase the basic understanding of the mode of action of Bt proteins, as well as establish procedures for transformation of other plant species.
Significant changes and result since end of ECLAIR
At the time the project was funded PGS was a research-orientated biotechnology company based at the University of Gent. Five years later (1996), by then described as one of the major plant biotechnology companies in the world, PGS was acquired (100%) for a reputed $US 800 million, by the Hoechst/Schering joint venture now known as AgrEvo. The present value of the company no doubt reflects, to some extent, the knowledge, genes, transformation systems and patents concerning Bt that developed from work funded under ECLAIR.
Results
At the end of this ECLAIR project
Potato, Brassica and tomato plants selected as model plants for transformation had been transformed with combinations of genes (CryIAb, CryIC and CryIB) designed in order to broaden the insecticidal spectrum. A number of different promoter sequences and vectors, as well as techniques to increase gene copy number, had been used to increase the level of expression of protein (toxicity of the plants to the pests). In addition, studies on gut physiology as well as the mechanisms and genetics of insect resistance had been carried out using a number of species of Lepidoptera (Heliothis virescens, Plutella xylosella, Leptinotarsa decemlineata and Phthorimaea operculella). Progress had been made in assessing the potential of the concept, both in areas of molecular characterization and field evaluation of potatoes, tomatoes and Brassicas and in gaining a better understanding of the mode of action of Bt. The project had generated a number of insect resistant plant lines that were ready to be integrated into the commercial breeding programmes of he partners and other commercial organisations with which commercial relationships had been initiated. Initial trials with potatoes, including insect and herbicide resistance, in the early 1990s, came to an end when the potato company concerned was taken over. The methods developed were then applied to corn.
Current position
To a large extent, the current capabilities of PGS in plant genetic engineering evolved from the initial demonstration of the incorporation of a Bt gene into tomato and subsequent studies. These included investigations of the antigenic structures and insecticidal spectrum, mapping functional domains of the Bt protein and characterizing receptor sites in the target insects. This work has led to a number of patents on novel strains of Bt, as well as on methods of transforming plants with Bt. Commercial licensing of genes and methods of transformation of other crops such, as maize, cotton and rape have been extended to a number of companies in the US in particular. This includes use of a patented method that applies to all crops susceptible to transformation by Agrobacterium. In 1996, PGS was awarded a US patent, covering genes Bt under control of a plant promoter, which encodes truncated CryIA(b) proteins, used in control of the European corn borer in transgenic maize.
Impact
Commercial
PGS has been involved in several hundred field trials of genetically modified organisms (GMOs) and clearly made a significant contribution to the current extensive cultivation of transformed corn in the USA, that now cover millions of hectares.
Associated
PGS has subsequently participated in the AIR programme ( AIR1-CT92-0205: Engineering Stress Tolerance in Maize - ESTIM) as well as coordinating FAIR-0364. The aim of this project is to promote: Familiarisation with and acceptance of crops incorporating transgenic technology. The overall objective of the demonstration project is to run workshops, demonstration sites and field days as well as produce publications supporting GMO crops. It includes examination of the technical viability of transgenic hybrid and transgenic herbicide tolerant oilseed rape as a case study with agronomic trials comparing transgenic and non-transgenic characteristics to demonstrate, communicate and disseminate agronomic practices to farmers and direct interest groups. This second project is particularly apposite at the time of writing this report, with the evolution of a mounting resistance to GMO crops in the UK and elsewhere in Europe. Public opinion, fuelled by the media and conservation groups as well as increased legislation (EC Directives) covering labeling, has led to a moratorium on planting Bt-transformed crops in some countries, as well as the banning of foods containing products derived from GMO crops by several large supermarket chains. This has crossed to the US, where farmers are now reluctant to plant Bt varieties of corn, that are not recognized by the EU since gluten by-products from US wet-millers may not be imported. The demonstration that pollen from Bt-maize may be a real threat to the Monarch butterfly and other rare Lepidoptera has added to the concern of the impact of this technology on the environment.
Further information
Details of trials of GMO plants can be obtained via the internet from the website of the OECD: http://www.oecd.org
Contacts
Author
Plant Genetic systems
© Copyright 2006 Policy Statements
Updated
by CPL Press:
03/07/2007
- biomatnet@biomatnet.org
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