Director, Food Security
Rockefeller Foundation, New York, USA
| Gary is the visionary who initiated the quest for a solution to the vitamin A deficiency problem, an initiative which culminated in the assembly of the Potrykus-Beyer team and the achievement of the grand goal, which was to generate rice plants producing beta-carotene in the endosperm, an achievement we all now know as Golden Rice. |
Vita
Studies in Microbiology at the University of North Carolina
Postdoctoral fellow funded by the Rockefeller Foundation to conduct research on plant-microbe interactions at the Boyce Thompson Institute for Plant Research
Rockefeller Foundation - Program Officer responsible for developing and implementing funding programs to help address environmental problems associated with agricultural development. This included work on alternatives to persistent pesticides and improved management of the agricultural resource base.
Since 1985 - responsible for the development and implementation of the Foundation's International Program on Rice Biotechnology, a $100 million investment to date, designed to bring the benefits of biotechnology to poor rice producers and consumers in developing countries.
Gary has authored or co-authored several articles relevant to agricultural biotechnology including "Plant Biotechnology and Developing Countries" (Trends in Biotechnology) and "Feeding the world in the Twenty-first Century" (Nature). He is currently leading the Foundation's work aimed at improving food security in Africa.
In Gary's own words (from the Rockefeller Foundation website):
Seeds of Hope
In the early 1980s, advances in plant molecular biology offered the promise of achieving genetic improvements in crops that could not be accomplished with conventional plant breeding. For the most part, however, such advances in crop biotechnology were not being applied to rice or other food crops of primary importance in developing countries. To help make sure the benefits of this powerful new technology would be available to poor farmers and consumers, the Rockefeller Foundation, beginning in 1985, committed roughly half of its agricultural funding to an international program on rice biotechnology. The primary objective of this program was to build rice biotechnology capacity in Asia, and an important part of it was funding the training of Asian scientists at advanced Western laboratories, where they invented techniques and worked on traits important for genetic improvement of rice - skills and knowledge which they then brought back home. About two dozen high-priority traits were targeted by the program, selected because they 1) would benefit poor farmers and consumers, and 2) were not readily achievable through conventional breeding. Beta-carotene production in rice endosperm was one of these targeted traits.
The Missing Phytoene. Foundation funding for research on this trait initially focused on two things: understanding genetic control of the carotenoid biosynthetic pathway in yellow maize, and biochemical analysis of rice endosperm. In a laboratory at Iowa State University, the dominant Y1 gene of maize — known to cause carotenoid production in the endosperm of yellow maize — was cloned. The Y1 gene was shown to code for phytoene synthase — an enzyme that combines two molecules of twenty-carbon geranylgeranyl diphosphate to form phytoene, the first forty-carbon compound on the carotenoid pathway. In another laboratory, analysis of rice endosperm showed that it contained geranylgeranyl diphosphate — but not phytoene.
In the early 1990s, two European scientists who were also interested in using rice biotechnology to benefit poor people in developing countries approached the Foundation. They too had identified yellow endosperm as a target trait. Dr. Ingo Potrykus of the Swiss Federal Institute of Technology in Zurich was a specialist in plant genetic transformation, and his lab was one of the first to genetically engineer rice. Dr. Peter Beyer of the University of Freiburg in Germany specialized in the biochemistry and genetics of the carotenoid biosynthetic pathway, using daffodil plants as a model system. These two scientists proposed to genetically engineer rice with daffodil genes to produce nutritionally significant levels of beta-carotene in the rice endosperm. At a Foundation-sponsored workshop, other scientists agreed that this task was difficult but achievable, and the effort was funded.
Daffodils Bearing Phytoene. Potrykus and Beyer initially confirmed that rice endosperm was capable of synthesizing geranylgeranyl diphosphate but not phytoene. Hence, to produce beta-carotene in the rice endosperm would require adding four enzymatic steps. The first task was to introduce the daffodil gene for phytoene synthase under the control of a rice promoter that would assure expression of the gene only in the rice endosperm. (A promoter is the regulatory portion of a gene that controls where and when the gene is expressed.) This was done, and the results were encouraging. The engineered rice plants produced phytoene in the endosperm at levels that would be nutritionally significant if converted to beta-carotene. Potrykus and Beyer then worked to introduce daffodil genes for the three remaining enzymatic steps required to convert phytoene to beta-carotene. One of these daffodil genes turned out to be unusually complex and difficult to work with, so they also tried a bacterial gene coding for an enzyme that could catalyze two steps in the pathway, including the step that was causing the problem. While initially intending to introduce the genes independently and combine them by crossing, they also tried adding them together in one sophisticated transformation experiment. The later approach provided the breakthrough they needed. Resulting rice plants containing two daffodil genes and the one bacterial gene carried out all four steps in the pathway and produced beta-carotene in the endosperm. The plants were normal, except that after milling, their grain was a beautiful golden yellow. Some of these plants produced amounts of beta-carotene, which at a daily intake of about 300 grams of rice could make a significant contribution toward meeting Vitamin A requirements.
Dissemination: IP Constraints and Testing
From the beginning of their research on Golden Rice, Dr. Potrykus and Dr. Beyer had intended to share it at no cost with public-sector rice-breeding programs for use by poor farmers in developing countries. However, as with nearly all academic research in crop biotechnology today, Golden Rice was produced using techniques that are patented in some countries and materials obtained under legal agreements that restrict further dissemination. As the inventors sought permission to share Golden Rice, a number of intellectual property (IP) constraints surfaced that appeared difficult to resolve. An additional concern was testing. Both the inventors and the Foundation wanted thorough testing for biosafety and nutrition, but such testing is expensive. They eventually concluded that the best and quickest way to overcome the IP constraints and test the product was to enter into a partnership with a company, Zeneca, that already had strategic and research interest in both rice and nutritional enhancement of food and consequently access to a large IP portfolio relevant to modifying the carotenoid biosynthetic pathway in plants, plus extensive experience in biosafety testing of crops and foods. This partnership arrangement required patenting their results.
Under the partnership agreement, Zeneca will help the inventors further modify their research product to produce a commercially viable variety of Golden Rice for dissemination to breeding programs, and will also facilitate biosafety testing and nutrition studies. It is known that the genes that have been added to the rice endosperm affect a small portion of the complex isoprenoid pathway in plants, and it will be important to analyze their effect on other metabolites to determine if there are health or environmental hazards — or, possibly, additional benefits. The allergenicity of the new gene products also needs to be assessed. It is possible that daffodils are responsible for what has been called "daffodil pickers' rash," and while it is unlikely, it needs to be confirmed that neither the daffodil genes nor the bacterial gene have introduced a new allergen to rice.
Drs Potrykus and Beyer have the rights under this agreement to share Golden Rice with public-sector rice breeding programs to generate new Golden Rice varieties for use by resource-poor farmers in developing countries, defined as farmers generating less than US$10,000/yr. income from Golden Rice. This is known as the Humanitarian Project. Zeneca has retained all commercial rights in all countries and will donate support to the inventors in the Humanitarian Project. This agreement seemed to be the best all-around way to speed dissemination to public-sector rice-breeding institutions, and thus to poor farmers in developing countries, while assuring that all appropriate health and nutritional studies are conducted. Field testing for potential environmental impacts will still need to be done at the national and local level with all regulatory decisions being the responsibility of the relevant national authorities.
When Golden Rice becomes widely available, it will complement home gardening and Vitamin A fortification and supplementation programs, particularly in rural areas difficult to reach via these other mechanisms. Other genetic improvements of rice have proven to be a highly effective way to deliver benefits to literally billions of people, including the rural poor. The mechanism as it works in relation to poor farmers is that international centers such as the International Rice Research Institute in the Philippines and national rice breeding programs produce new breeding lines and varieties and release them free, or at minimal cost. Since the new rice varieties are true-breeding, farmers can save and share a portion of their harvest as seed for subsequent plantings. The varieties that are profitable spread rapidly and broadly via farmer-to-farmer trade. If genes for beta-carotene production in rice endosperm are incorporated into new varieties along with genes for increased productivity and profitability, a powerful force will exist for disseminating a new dietary source of pro-Vitamin A to the people who most sorely need it. Combined with expanded Vitamin A supplementation programs — which will continue to be important — Golden Rice is expected to make a major contribution to improving the health of millions of the world's poorest children. The Rockefeller Foundation will continue to support efforts aimed at helping to make this a reality.
