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February 1998 | |
NEWS FOR THE AGRICULTURAL AND ENVIRONMENTAL BIOTECHNOLOGY COMMUNITY
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February 1998 | |
NEWS FOR THE AGRICULTURAL AND ENVIRONMENTAL BIOTECHNOLOGY COMMUNITY
FUNDING AVAILABLE FOR RISK ASSESSMENT RESEARCH
Applications are invited for competitive grant awards under the Biotechnology Risk Assessment Research Grants Program for fiscal year 1998. The Program is administered by USDA's Cooperative State Research, Education, and Extension Service (CSREES) and the Agricultural Research Service (ARS). The purpose of the Program is to assist Federal regulatory agencies in making science-based decisions about the safety of introducing into the environment genetically modified organisms, including plants, microorganisms, fungi, bacteria, viruses, arthropods, fish, birds, mammals and other animals.
The Program's research emphasis is on risk assessment and not risk management. Risk assessment research is defined as the science-based evaluation and interpretation of factual information in which a given hazard, if any, is identified, and the consequences associated with the hazard are explored. Risk management is defined as (1) research aimed primarily at reducing risks of biotechnology-derived agents and (2) a policy and decision-making process that uses risk assessment data in deciding how to avoid or mitigate the consequences identified in a risk assessment.
Proposals addressing the following topics are requested:
Proposals are due March 24, 1998. Subject to the availability of funds, the anticipated amount available for 1998 is $1.5 million. For further information contact Dr. Edward K. Kaleikau, USDA/CSREES (202-401-1901), Dr. Daniel D. Jones, USDA/CSREES (202-401-6854), or Dr. Robert M. Faust, USDA/ARS (301-504-6918).
The full text of the announcement is available on the internet (http://www.reeusda.gov/crgam/biotechrisk/biotech.htm). Forms and instructions for preparing and submitting applications for funding may be obtained either by calling 202-401-5048, or by sending email to psb@reeusda.gov. Specify the FY 1998 Biotechnology Risk Assessment Research Grants Program and include your name, postal address and telephone number. The materials will then be mailed (not e-mailed) to you.
WORLD BANK PANEL REPORTS ON USE OF BIOTECHNOLOGY TO ENHANCE FOOD SECURITY
World population has increased by 2.3 billion people in the past 40 years; by the year 2040, another 3.6 billion will be added. Most of this increase will be in the developing countries where already one billion people live in abject poverty and go hungry every day. The African nations of Ethiopia, Nigeria and Egypt each add more people than all of Western Europe combined, notes the World Watch Institute based in Washington, D.C. It is thus a daunting task to feed the ever increasing population in resource-poor countries where agriculture is already constrained by a lack of new arable land, small-sized farms, and destructive agricultural practices that contribute to soil degradation and salination.
With this stark scenario in mind, the World Bank and the Consultative Group on International Agricultural Research (CGIAR) convened in October 1997 a panel of top scientists to review the status of world food supplies, identify the prospects and needs of the developing world and to examine the role of crop biotechnology in improving the food security in these countries. The panel's findings are now published in "Bioengineering of Crops: Report of the World Bank Panel on Transgenic Crops." The report contends that the sensible use of biotechnology in developing countries can substantially increase food yields while promoting sustainable agriculture. Nobel Prize winner Henry W. Kendall, Professor of Physics at MIT and chair of the Union of Concerned Scientists chaired this panel which included Roger Beachy, Thomas Eisner, Fred Gould, Robert Herdt, Peter H. Raven, Jozef S. Schell and M.S. Swaminathan.
In an interview with Diversity, a news journal devoted to genetic resources, Ismail Serageldin, CGIAR chief and Vice President at the World Bank, said "Biotechnology will be a crucial part of expanding agricultural productivity in the 21st century," and "if safely deployed, could be a tremendous help in meeting the challenge of feeding an additional three billion human beings, 95 percent of them in the poor developing countries, on the same amount of land and water currently available."
The concise (30 pages) but thought-provoking report boldly outlines the present and future problems of world population and discusses the problems of food scarcity and malnutrition along with pressures on agriculture systems. It describes current technologies and major research efforts, then discusses various potential contributions that transgenic crops can make to alleviate problems of food security in the developing world. These include prevention of crop damage and losses through the use of disease and pest resistant varieties, decreased reliance on chemicals, enhanced stress tolerance, improved food quality, applications for bioremediation of environmental problems, and applications to human health problems through transgenic production of therapeutic drugs and edible vaccines.
The report recognizes that investment so far in biotechnology research in developing countries has been meager. Rockefeller Foundation support of rice biotechnology research, though, should begin to pay off in two to five years, and rice production in Asia may increase by 25 percent over the next ten years.
Bioengineered crops are not in principle more injurious to the environment than traditionally bred crops, notes the report. Nevertheless, it underscores the need to evaluate potential problems or risks that have been raised by scientists and environmentalists, such as weediness, gene flow, development of new viruses, and unintended effects of plant-produced insecticides on non-target organisms.
The report concludes that "Transgenic crops that are developed and used wisely can be very helpful, and may prove essential, to world food production and agricultural sustainability." The panel then makes some concrete recommendations to the World Bank, urging it to:
To obtain a copy of the report, contact: The Secretariat, CGIAR, tel: 202-473-8949; fax: 202-473-8110, or http://www.worldbank.org/html/cgiar/HomePage.html.
C. S. Prakash
Center for Plant Biotechnology Research
Tuskegee University
prakash@tusk.edu
COMING SOON: A WIDER SELECTION OF SEEDLESS FRUIT
How many times have you picked up a piece of fruit, anticipating the first flavorful bite, only to be faced with the tedious task of picking out the seeds? The commercial success of seedless oranges and grapes shows consumers' eagerness for such easy-to-eat produce, but currently few fruits come in seedless varieties, and when available they may be more expensive. The higher cost reflects the difficulties of making a marketable seedless fruit, which requires either mutant lines, infertile hybrids, or costly and labor-intensive treatment of flowers with phyto-hormones. But consumers should take heart, as Italian researcher Angelo Spena and colleagues in Italy and Germany have developed a new and elegant method for tricking plants into making fruits with no seeds.
In normal plant reproduction, a fruit is formed only after successful fertilization of the ovule in the flower ovary. Levels of auxin, a plant hormone, rise in response to fertilization, and stimulate seed growth and formation of fruit tissue surrounding the seed. In some cases fruit development can occur in the absence of fertilization, but this is the exception to the rule. Spena and coworkers produced transgenic eggplant and tobacco plants that set seedless fruit by engineering them to produce auxin in the unfertilized ovary.
To do this, the researchers took advantage of two unique genes. The first, isolated from the plant pathogenic bacterium Pseudomonas syringae pv. savastanoi, is the coding region of the iaaM gene which leads to the production of auxin in plant tissue. The second gene sequence is the promoter region of DefH9, a gene from snapdragons which is expressed specifically in ovules. They linked the two together and transformed tobacco and eggplant, thinking that localized expression of the auxin-producing gene in the ovule would mimic auxin synthesis in fertilized ovules, and thus lead to fruit development. Indeed, this is exactly what seems to happen.
Transgenic tobacco plants that expressed the new gene construct grew normally, but in the absence of fertilization produced smaller-than-normal capsules that contained only aborted seeds. However, if flowers of these plants were self-pollinated, they set normal capsules and fertile seeds. Similarly, transgenic eggplants showed vegetative development identical to that of untransformed control plants, but when emasculated to prevent fertilization, they set fruit that was equal in size and shape to fruit of fertilized flowers, yet contained no seeds. The weight of a typical fertilized eggplant fruit was about 250g. Fruits of transgenic, unfertilized eggplants were indistinguishable from this, while those few fruits that formed from unfertilized, untransformed plants weighed only 60g. The transgenic seedless fruits were therefore of marketable size and quality.
Transgenic plants had an additional important advantage over untransformed plants - they produced fruit under unfavorable weather conditions.Fertilization of most plants is dependent on favorable environmental conditions such as temperature, light intensity, and wind, and the absence of an optimal environment may result in incomplete fertilization. Eggplant is a warm weather crop and does not set fruit well under cool, short-day conditions. However, when grown under such unfavorable conditions the transgenic plants produced fruit where none was obtained from untransformed control plants. The ability to set fruit under conditions adverse for pollination adds a significant agronomic advantage to these plants and offers hope of extended growing seasons and increased yields along with the value of a seedless product.
It is also significant that seedless fruit is only obtained from flowers that have not been fertilized. Pollination of transgenic plants results in fruit with viable seed through which the genes for seedlessness may be passed to subsequent generations of plants. However, this means that seedless fruits may only be obtained when flowers are not pollinated. Incorporation of a male sterility gene will be required in most crops before seedless fruit can be produced under large-scale field conditions. Nevertheless, the results of these experiments are very encouraging and one can only hope that Spena and coworkers quickly turn their attention to cherries, plums, raspberries, pomegranates . . .
Reference
Rotino, GL, E. Perri, M. Zottini, H. Sommer, and A. Spena. 1997. Genetic engineering of parthenocarpic plants. Nature Biotechnology 15:1398-1401.
Jim Westwood
Dept. of Plant Pathology, Physiology and Weed Science
Virginia Tech
westwood@vt.edu
GENETICALLY DECAFFEINATED COFFEE
Some day, you may notice that decaffeinated brews in your favorite coffee shop have a deep, full flavor normally found only in regular coffees. Researchers in Hawaii are working to develop coffee plants that are genetically engineered to have only a fraction of the normal caffeine content, thus the beans are, in essence, genetically decaffeinated. This means that they do not have to be subjected to the harsh physical and chemical decaffeination processes used now.
Coffee, the world's third largest traded commodity after petroleum and precious metals, is worth $25 billion annually. Health-conscious consumers increasingly prefer decaffeinated coffee, which accounts for more than a quarter of the coffee market. Excessive and chronic caffeine intake is known to result in restlessness, nervousness, insomnia, heartburn and even bone loss. Caffeine also has as a therapeutic agent to stimulate heart and respiratory systems and as a diuretic.
Decaffeinated coffee typically has 2 mg of caffeine per cup in contrast to about 120 mg in regular coffee. The caffeine is removed from coffee beans either by a chemical process or the "Swiss" hot water method. In the chemical method, steamed beans are rinsed in methylene chloride to extract the caffeine. Although the process is considered safe, there has been a recent controversy on the use of this chemical. In the Swiss method, beans are soaked in hot water to extract the caffeine through activated charcoal. Both procedures affect the taste and aroma of the resultant brew. The beans treated with hot water further lose their protective wax coating and thus become sensitive to molds. Decaffeination is an expensive process and adds about $2.00 per kilogram to the cost of coffee, resulting in more than a billion dollars in extra costs in the U.S. alone.
The coffee biotechnology team, led by John Stiles of the University of Hawaii and funded by Integrated Coffee Technologies Inc., is engineering 'decaf coffee plants' by turning off a gene involved in caffeine production. The group began by isolating the enzyme xanthosine-N7-methyl-transferase, which catalyzes the critical first step in caffeine production in coffee leaves and berries. They cloned the gene encoding this enzyme, and used Agrobacterium-mediated transformation to insert an antisense version into Arabica coffee cells growing in tissue culture.
Transgenic callus was analyzed, and some lines were found to have only 2% of the normal level of caffeine found in regular plants. Thus, expression of the caffeine gene appears to have been silenced by the introduction of the antisense gene. In another approach, transgenic plants are being produced using the gene gun by Dr. Chifumi Nagai at the Hawaii Agricultural Research Center.
There is still a long way to go before you can have genetically engineered coffee in your cup. First, plants need to be regenerated from the transformed cell cultures; Stiles hopes to have such full-grown coffee plants soon. As coffee is a perennial plant, it may take another few years of testing to verify that the trait is stable and to determine whether the plants are ecologically and agronomically sound.Caffeine is suspected to play a role in protecting coffee plants against attacks by insects and fungi. "We do not foresee that as a problem because caffeine may have been useful to coffee plants in the wild in its native state, but under modern agronomic conditions, far removed from the wild, caffeine does not appear to have any protective role," says Stiles.
The research team is also using genetic engineering to control the ripening process in coffee plants by targeting ethylene biosynthesis in berries. Integrated Coffee Technologies Inc. and ForBio, an Australian biotechnology company which owns 21% of the ICTI, have licensed both projects for commercialization.
C. S. Prakash
Center for Plant Biotechnology Research
Tuskegee University
prakash@tusk.edu
MORE SHEEP CLONES, BY GOLLY
First there was Dolly, the sheep cloned from an adult mammary cell, and now come Polly and Molly. The same group of researchers at the Roslin Institute in Scotland report in the Dec 19, 1997 issue of Science the successful production of transgenic sheep from nuclei of genetically modified fetal sheep cells.
A DNA construct containing the human coagulation factor IX gene under the control of a sheep mammary-specific gene promoter was introduced into fetal sheep cells. This DNA construct directs high level expression of human factor IX in sheep milk. To isolate cells that have incorporated the factor IX gene into their genome, the factor IX gene is cotransformed along with a selectable marker gene that confers resistance to the antibiotic gentamycin. Cells that can grow in the presence of gentamycin due to incorporation of the selectable marker gene also frequently incorporate the factor IX gene.
Fetal sheep cells that contain either the selectable marker gene alone or the selectable marker and factor IX genes were used for nuclear transfer. As shown previously, the key step for successful nuclear transfer in sheep is starvation of the cells. This treatment reprograms the nucleus in some unknown manner to allow the development of a whole organism. Six lambs were born after nuclear transfer, three from cells containing just the selectable marker gene and three from cells containing the selectable marker and factor IX genes. As expected the DNA of the liveborn lambs was identical to that of the cells used for nuclear transfer. Furthermore, nuclear transfer of cells derived from a female fetus produced only female progeny, as predicted.
The efficiency of nuclear transfer with these genetically-manipulated fetal sheep cells was approximately 1% (6 liveborn lambs for 525 nuclear transfers). This percentage is similar to the efficiency previously reported using nonmanipulated fetal cells. These results demonstrate that genetic manipulation of the donor nucleus does not adversely affect the efficiency of nuclear reprogramming.
The ability to genetically manipulate cultured cells while still retaining nuclear transfer capabilities will allow the application of powerful gene targeting methodologies that have been developed for mice. In the majority of gene transfer studies, DNA is inserted randomly into the host chromosomes. This is a potential problem because the foreign DNA frequently is not expressed as desired or it gets incorporated into an important host gene rendering that gene nonfunctional. Gene targeting methodology allows for the selection of cells which have the foreign DNA inserted at a precise location in the host genome and thus can avoid the aforementioned problems.
Nuclear transfer in livestock has a number of additional advantages over the standard method of producing transgenic animals by pronuclear microinjection. The key advantage to nuclear transfer is that no recipient ewes are wasted gestating nontransgenic lambs. About 51 animals are required to produce one transgenic lamb by microinjection whereas only 21 animals are needed for nuclear transfer. Furthermore, in cases where one sex is desired over the other, for example production of transgenic ewes to produce a foreign protein in milk, only cells of female origin can be used for nuclear transfer to ensure that all progeny are female.
Clearly the next logical step is to combine the successful experiment that produced Dolly with this experiment that produced Molly and Polly, that is, nuclear transfer from cells of an adult animal that has already been genetically modified. Success with this approach would lead to the production of a large herd or flock of desirable transgenic animals starting from a single transgenic animal with a proven production trait.
Eric A. Wong
Department of Animal and Poultry Sciences
Virginia Tech
ewong@vt.edu
UPCOMING MEETINGS
If you're thinking about attending a major international conference in 1998, here are three to consider. We'll list others as information arrives.
June 1-5: 3rd Latin-American Meeting on Plant Biotechnology (REDBIO'98), Havana, Cuba. The theme of the conference is Food Security and Biotechnology in Latin America and the Caribbean. The outstanding scientific program includes Plenary lectures, Symposia, Round Tables and Workshops addressing basic and applied technical advances as well as policy issues such as public perception and intellectual property.
Details regarding the program, the list of invited speakers from all over the world, fees, hotels, tours, and other relevant information can be found on the internet (http://www.cenargen.embrapa.br/~redbio), or by contacting the President of the Organizing Committee, Carlos G. Borroto (fax: +53-7335040; email: cborroto@ceniai.inf.cu) or the Technical Secretariat, María Cristina Pérez (fax +53-7249460; email: acyt@ceniai.inf.cu)
June 9-12: Agbiotech: The Science of Success (ABIC 98), Saskatoon, Saskatchewan, Canada. The theme highlights strategies for commercialization of agbiotech products. Presentation topics include:
The conference includes tours, a scientific poster session, and a trade show with more than 60 exhibits. For more information, contact Sharon Murray, ABIC '98 Conference Coordinator (tel: 306-934-1772; fax: 306-664-6615; email: siggroup@sk.sympatico.ca) or connect to http://www.lights.com/abic.
November 23-27: Biodiversity, Biotechnology and Biobusiness: 2nd Asia-Pacific Conference on Biotechnology, Perth, Australia. The conference will provide a blend of papers on basic scientific and conservation issues, and the application of new biotechnologies to these. It will also explore how the biotechnology industry can benefit from the unique biodiversity of the region and how this benefit can be realized. The social and legal issues such as access and ownership of biodiversity will also be discussed.
Contact the Conference Secretariat (fax: +61-8-9322-1734; email: biodiversity@science.murdoch.edu.au) for further information.
The material in this News Report is compiled by Information Systems for Biotechnology, a joint project of USDA/CSREES and the Virginia Polytechnic Institute and State University. It does not necessarily reflect the views of the U.S. Department of Agriculture or of Virginia Tech. The News Report may be freely photocopied or otherwise distributed without charge. P.L. Traynor, Editor.
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