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  Plant Genetic Systems
By
Jos Bijman
 
 
 
Keywords:  Plant Genetic Systems; Private industry; Hybridization; Disease/pest resistance; Technology transfer.
Correct citation: Bijman, J. (1994), "Plant Genetic Systems." Biotechnology and Development Monitor, No. 19, p. 19-20.

The Belgian plant biotechnology company Plant Genetic Systems is one of Europe's most successful biotechnology companies. Established more than ten years ago, Plant Genetic Systems has remained independent and has shown a steady growth of research and commercial activities. Over 90 per cent of its research and development budget is allocated to hybridization and insect­tolerance technology. While most of its research is targeted at developed countries crops, Plant Genetic Systems is also involved in technology transfer projects for developing countries.

In 1983, researchers directed by Marc Van Montagu and Jeff Schell at the University of Ghent, Belgium, were among the first to assemble a practical system for genetic engineering of plants. As a vector system for transferring foreign genes into the plant genome, they used the Ti plasmid of Agrobacterium tumefaciens. At the same time they had made plant cells resistant to the antibiotic kanamycin by transferring a bacterial neomycin phosphotransferase gene into the plant genome.
This experiment showed not only that foreign genes could be expressed in plants, but also provided a widely­used selectable marker gene for cells and tissues into which genes have been introduced. Today, Ti plasmid­derived vectors and marker genes are used routinely in laboratories around the globe for transforming dicotyledonous plant species.
In order to commercialize the inventions, the plant biotechnology company Plant Genetic Systems (PGS) was founded in 1983. In its eleven years' existence, PGS has developed many genetically engineered plants. Research is targeted at developing hybrids, insect control, disease resistance and stress tolerance in plants. In the 1980s PGS has conducted genetic engineering research on herbicide tolerance. Using herbicide detoxification genes from bacteria, PGS has developed plants that are tolerant to the broad­spectrum herbicide 'Basta', produced by the German agrochemical company Hoechst.

Research and business strategy
PGS' research strategy is to target technologies that have broad application to several crops. Research is pursued only where patent protection appears possible and where PGS anticipates it will have the freedom to apply that technology in its commercial target crops. Currently, most of the research effort is put into hybridization technology and insect­tolerance technology.
In commercializing its research findings PGS follows three different routes: (1) it selective licenses agreements to several seed companies, and receives royalties from sales of seed developed with PGS technology, (2) it establishes joint ventures with seed and other companies to collaborate in the production and marketing of hybrid crops, and
(3) it is building its own breeding operation for the development and marketing of hybrid seeds.

Insect tolerance
In 1985, PGS was the first to obtain genetically engineered (tobacco) plants with insect tolerance by expressing genes encoding for insecticidal proteins from Bacillus thuringiensis (Bt). As lepidopteran pests (for example caterpillars) attack virtually every major agricultural crop and account for the largest portion of all insecticide costs, PGS research focuses on these insect pests.
The insect­tolerance technology development programme involves screening for insecticidal Bt strains, gene identification, gene expression in crops and insect­tolerance management. For the screening activities, PGS has built up a Bt collection with over 12,000 isolates collected from diverse geographical areas and biotopes.
While several research groups around the world are working on insect tolerance, PGS has established its own proprietary position. Researchers in Ghent discovered that in order to produce insecticidally effective amounts of Bt protein in crops, only a portion of the full­length gene corresponding to the toxic part of the protein had to be used. Plant transformation with truncated Bt genes resulted in greater insecticidal effect than was obtained with full­length genes. In 1991, PGS issued a patent in Europe on plants made tolerant to insects using truncated Bt genes. In 1993, PGS was granted a patent in the USA, covering its Bt truncation technology for plants and seeds containing Bt proteins toxic to caterpillars.
Wide­scale use of Bt­induced insect­tolerant plants, however, could result in insects becoming resistant. PGS has devised a multiple Bt gene strategy to prevent or delay insects from becoming resistant to Bt proteins. PGS determined the specific binding capacity of Bt proteins to receptors in the insect's midgut and identified Bt proteins that bind to different receptors in the same insect. The resistance­management technology involves the combined expression of two or more different Bt genes encoding different non­competitively binding proteins.

Hybridization technology
PGS has, in collaboration with researchers at the University of California (USA), developed a genetically engineered pollination system, called SeedLink. This system inhibits pollen development in the female parent during hybrid seed production while restoring fertility in the F1 hybrid generation, the commercial crop grown by the farmer. SeedLink comprises of two main components: a male­sterility component and a fertility­restoration component. While male sterility is required for hybrid seed production, fertility restoration is also required for crops that are both (1) largely self­pollinated, such as canola/oilseed rape (OSR) or tomatoes, and (2) harvested for their grain or fruit. In the farmer's field such crops must be pollinated to ensure growth of a harvestable crop. In contrast, for crops such as lettuce or broccoli, harvested only for their vegetative parts before flowering and setting seed, fertility restoration and pollination are not necessary.
PGS is targeting its hybridization research at canola/OSR, maize, rice and various vegetables.

Canola/OSR: PGS believes that SeedLink will make the production of canola/OSR hybrids technically and economically feasible for the first time. Canola/OSR is grown for its oil, which is commonly used as a salad oil and in food processing and preparation. It has the lowest level of saturated fats of any commercial vegetable oil, and therefore demand has grown in cholesterol conscious consumer markets. PGS has decided to develop and market its own canola/OSR seed. Its worldwide breeding programme is carried out at its breeding stations in Belgium and Canada as well as through a joint venture in India.
No hybrid canola/OSR seed has been marketed yet, but extensive field tests are currently being carried out in Europe and Canada. According to a PGS spokesman, the 1993 field trials in Canada have demonstrated that its canola hybrids yield at least 20 per cent more than the highest­yielding non­hybrids that are used as controls in official government variety demonstration trials.

Maize: The male­sterility component of the PGS technology can greatly improve the efficiency of current methods to produce hybrid maize seed. Seed companies rely on manual and mechanical removal in the field of the tassel (the male part of the plant) for hybrid maize seed production. In the United States, the total costs of detasseling, including yield loss and labour costs, is estimated at approximately US$ 150­200 million each year, while in Western Europe the cost is estimated at approximately US$ 40 million a year. By licensing its SeedLink technology to seed companies, PGS expects to share in a substantial portion of the detasseling cost savings.

Rice: PGS' hybridization technology could also be an efficient tool for the production of hybrid rice. Current methods for producing hybrid rice seed are so labour­intensive that they are only economically feasible in countries where labour is amply available at low cost. In 1990, PGS entered a joint research, development and commercialization venture with Japan Tobacco. This company has exclusive rights to commercialize the hybrid rice technology within Japan, in return for royalties. Outside Japan the production and marketing rights will be held by a proposed joint venture to be owned equally by PGS and Japan Tobacco. In 1993, PGS has successfully transformed rice with its proprietary gene for the production of male­sterility, and also with the fertility­restoration component of its hybridization technology.

Vegetables: In the vegetable seed business PGS intends to pursue opportunities for its hybridization technology through broad licensing as well as forward integration for specific crops and territories. Brassica vegetables, which include broccoli, cabbage and cauliflower, are a primary licensing target. PGS has licensed SeedLink to several vegetable seed companies in Europe and Asia. Typically, such license agreements provide that the licensees supply PGS with their commercial germplasm to be transformed by PGS with its proprietary genes. The licensees then use the transformed germplasm in their commercial breeding programmes.
PGS has been field testing SeedLink cauliflower, chicory, broccoli and cabbage in the greenhouse. PGS stresses, however, that there is still no assurance that such breeding and testing will result in commercially successful products.

Technology transfer
Most of PGS' activities are aimed at the industrialized world, as that is where the large seed companies are located and where patent protection can be obtained. Still, PGS believes it has something to offer for developing countries.
PGS considers co­operation between private companies and International Agricultural Research Centres (IARCs) as the most effective method for technology transfer to developing countries. In order to attract private companies to this form of co­operation, financial support by donor agencies is required. PGS has been involved in a number of collaborative research programmes with public sector institutions in developing countries, supported by international development agencies.
In 1987, the Brazilian Agriculture Research Institute (EMBRAPA) and PGS started a four­year project, supported by the Inter­American Development Bank, on the engineering of plants that produce seeds containing proteins with the amino acid methionine. PGS provided scientific expertise and training for EMBRAPA personnel, as well as logistic support to EMBRAPA to initiate in­house research in Brazil. In the course of research, technology was developed which specifically promotes the expression of proteins with high levels of the essential amino acid methionine.
In 1988, International Rice Research Institute (IRRI), Philippines, and PGS began a two­year project on the isolation, identification and characterization of natural Bt strains with interesting insecticidal activities in rice pests. This project was supported by the Rockefeller Foundation, USA. As part of the project, IRRI personnel received training at PGS' laboratories.
In 1992, the International Potato Center (CIP), Peru, and PGS started a three­year collaboration on the production of transgenic potato clones with resistance to the potato tuber moth, supported by the Belgian AID Agency. Within this project, the potato germplasm is provided by CIP, while the Bt genes and gene technology is provided by PGS. CIP expects to hold the first field trials with transgenic potatoes with resistance to the potato tuber moth soon.
PGS feels that with these collaboration projects both parties may gain. On the one hand, the IARCs will gain access to expensive technology which it would otherwise have great problems obtaining. Also, all collaborative projects include training of scientific personnel from IARCs by PGS. On the other hand, PGS has an opportunity to apply its technology in broader germplasm than it would normally have access to. Moreover, the project with IRRI has been very favourable in extending PGS' Bt collection.

Contract requirements
The transfer of technology between PGS and IARCs has been subject to contractual agreements covering scientific and budget matters as well as issues of biosafety, ownership and exploitation of results. As to the ownership of results, project know­how is jointly owned by both partners. In the case of patentable technology being generated during the project, ownership of the patent would typically belong to the company since it is best qualified to prosecute its application. As to the exploitation of results, commercial rights are assigned on the basis of the 'classical' client countries of each partner. For the IARCs these are the developing countries, while the major clients of the private sector partner are the developed countries of the world.
Jos Bijman

Sources
Jan Leemans, "Ti to Tomato, Tomato to Market: A decade of plant biotechnology", Bio/Technology, vol. 11, March 1993.

Suri Sehgal (1992), "Developing World Seed Future in Need of Action". In: Seed World, May 1992.

B. Verachtert (1991), "Innovations in Biological Control". In: Proceedings of a Seminar on Crop Protection for Resource Poor Farmers. UK: 4­8 November 1991.



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