Ecological Impacts of Genetically Modified Crops
- Experiences from Ten Years of Experimental Field Research and Commercial
The global area planted with genetically modified (GM) crops has consistently increased each year since GM crops were first commercially cultivated in 1996 reaching 90 million hectares in 2005. GM crops are currently grown by 8.5 million farmers in 21 countries, where 90% of the farmers using the GM technology live in developing countries.
Five countries (USA, Argentina, Brazil, Canada and China) are growing nearly 95% of the total area of these crops and there are four main GM crops that are grown worldwide. Soybean is the principal GM crop occupying most of the global area, followed by maize, cotton and oilseed rape. Herbicide tolerance is the dominant trait that is deployed in all four crops, while maize and cotton are the only two insect resistant GM crops commercialized. Concerns have been raised that the commercial cultivation of GM crops could result in adverse effects on the environment.
Agroscope Reckenholz Tänikon Research Station ART was commissioned by the Swiss Expert Committee for Biosafety to review the scientific knowledge on environmental impacts of GM crops deriving from ten years of worldwide experimental field research and commercial cultivation. The sources of information included peer-reviewed scientific journals, scientific books, reports from countries with extensive GM crop cultivation, as well as reports from international organizations.
For some of the questions addressed only limited information was available from commercial cultivation. Therefore most chapters of the study include to some extent scientific data deriving from large-scale experimental field research. The authors recognize that results from large-scale cultivation systems, as often characteristic in the countries growing GM crops, have to be transferred with care to small-scale agricultural systems like in Switzerland.
However, we believe that the worldwide scientific knowledge and the existing practical experiences should be taken into account for future decision making when discussing potential risks of field releases of GM crops in Switzerland.
Transgenic Plants: Facts and Stakes
The public at large will find the book's discussion of all problems related to the development of transgenic plants
Scientists get free access to environment journals
Agricultural Input Traits: Past, Present and Future
For thousands of years farm practices have evolved as new innovations have become available. Farmers want more value per unit of land, clean fields, and high yields with less input. Plants with incorporated pest resistance and herbicide resistance help meet these needs through increased yield, reduced chemical use, and reduced soil impacts.
Although researchers have developed useful traits for a wide variety of plant species, only a few traits are available commercially; however, global adoption of these traits has and continues to increase rapidly. Availability of future traits will be dependent on input not only from researchers, but from governments, interest groups, processors, distributors and ultimately consumers, in addition to the farmers that drive demand for transgenic seed.
Study Shows GM OK to Environment
Data available so far provides no scientific evidence that the commercial cultivation of genetically modified (GM) crops has caused environmental harm. This was the conclusion of a study "Ecological impacts of GM crops: Experiences from 10 years of experimental field research and commercial cultivation", commissioned by the Swiss Expert Committee for Biosafety. The study focused on insect resistance maize, herbicide tolerant soybean and soilseed rape, three of the major GM crops of significance for Swiss agriculture. Dr. Joerg Romeis of the Agroscope Reckenholz-Tanikan Research Station which conducted the study said that a number of issues related to the interpretation of scientific data on effects of GM crops on the environment were brought up. The study highlights these scientific debates and discusses the effects of GM crop cultivation on the environment considering the impacts caused by cultivation practices of modern agricultural systems. Email Dr. Romeis at firstname.lastname@example.org for additional information and how to obtain a copy of the report.
Environmental Risks of Genetic Engineering
Before release into commerce, genetically engineered organisms are first assessed for possible risks, including risks to the environment. The present paper first identifies the environmental risks recognized by regulators, and reviews the parameters considered predictive of risk. Recent field-scale studies suggest opportunities for improvement of the environmental risk assessment process. Risks unique to genetically engineered crops - if any - could pertain to the specific traits chosen for commercialization and to unintended trait expression caused by the process of transgene insertion itself. Both the standard against which to compare genetically engineered traits and the scale of exposure need to be considered when assessing environmental impact.
Evidence of environmental risk in the recognized areas of weediness on agricultural land, invasiveness of unmanaged systems, and non-target impacts from Bacillus thuringiensis (Bt) maize is presented. Targeted, statistically sound, rigorously conducted, multi-trophic studies analogous to the Field Scale Evaluation trials recently completed in the UK are needed to clarify the many questions which remain unanswered.
Biosafety of Genetically Modified Plants
Does genetically modified maize have an impact on beneficial insects? How does genetically modified oilseed rape affect pollen-collecting bees? How can transgenic pollen and seeds be prevented from spreading in the environment? These are just some of the questions being investigated in biological safety research worldwide. Answers and research findings, which are otherwise usually made public only at scientific conferences and congresses, are accessible to the public at www.gmo-safety.eu.
The information portal was commissioned by the German Federal Ministry of Education and Research (BMBF) and over recent years has become the central information hub for everything to do with biological safety research in Germany. Now the website is also available in English. At www.gmo-safety.eu interested laymen, journalists and politicians can find out what effect the modification of plant DNA has on the ecological interaction between plants and their environment.
The primary focus of the site is on crops - maize, oilseed rape, potatoes and cereals. Other topics include the development of more accurate tools for plant genetic engineering and concepts for post-market monitoring. A comprehensive database provides clear information about current and completed research projects, their aims and results. The research information is supplemented by background reports, interviews and insights into the day-to-day work of researchers. The site also presents major international studies on the environmental safety of GM plants.
The website accompanies the BMBF's support programme for biosafety research into genetically modified crops, which was launched in 2001. The ministry's aim is to create greater transparency and to offer the public the opportunity to form an informed opinion about the opportunities and threats of transgenic plants.
'GM products will continue to be marginalized in
Europe as long as industry remains silent.'
Organic baby spinach: could anything be more wholesome? According to the website of Earthbound Farm, the largest US grower of organic produce, "delicious organic salads, fruits and vegetables are grown with a concern for the things you value most-your family's health, the air you breathe, the water you drink and your children's future." Of course, "organic produce is never genetically engineered or modified" and "encourages an abundance of species living in balanced, harmonious ecosystems."
One of the species it encourages appears to be the food pathogen Escherichia coli O157:H7. As Nature Biotechnology went to press E. coli O157:H7 from fresh-picked spinach had caused 150 people in 23 US states to get sick, around 75 hospitalizations, including over 20 cases hemolytic uremic syndrome, one confirmed death (a 77-year-old woman) and two deaths that were suspected of being connected with 'fresh' spinach. In mid-September, the US Food and Drug Administration (FDA) advised consumers not to eat bagged fresh spinach and urged anyone who had and who felt ill to contact their physician.
A month earlier, the FDA and the US Department of Agriculture (USDA) held a joint press conference to announce that they had been notified by Bayer CropScience that trace amounts of an herbicide-resistant genetically engineered rice, LL Rice 601, had been detected in commercial long-grain rice. Before the resultant media furor died down, Greenpeace and Friends of the Earth followed up with the news that they had found the Bacillus thuringiensis toxin gene in rice products imported into Europe from China.
Patrick Moore - Going Nuclear
The co-founder of Greenpeace, Patrick Moore, left the prominent environmental organization in 1986 because it began "abandoning science and logic." Now the director of Greenspirit, Moore speaks out for the nuclear industry, the forest industry and supports genetically engineered crops. Is he still an environmentalist?
Edward Weinman: What are the most serious environmental problems facing us today?
Patrick Moore: Poverty, deforestation in the tropics, micronutrient deficiency (malnutrition), urban sprawl, population growth and air pollution.
EW: You left Greenpeace in 1986. Why leave what was perhaps the first environmental organization with clout?
PM: I left because I saw my colleagues abandoning science and logic and adopting zero-tolerance policies that made no sense. In many ways, Greenpeace is now promoting policies that are environmentally negative. Genetically modified crops reduce pesticide use; nuclear energy reduces greenhouse gas emissions; sustainable forestry produces the most abundant renewable material; aquaculture produces healthy oils and protein, and takes pressure off the wild stocks.
EW: How do we reconcile global needs to exploit natural resources for food and energy with the need to protect the environment? Are these needs incompatible?
PM: There are many ways to reconcile human needs with environmental protection. Sustainability is about continuing to satisfy civilization's need for food, energy, and materials while at the same time reducing negative environmental impact. This can be done through changes in behaviour (e.g., energy conservation) and technological change (e.g., using nuclear energy and renewable energy instead of fossil fuel).
Genetically Modified Foods Are Safe, Weizmann Head
Ilan Chet, president of the Weizmann Institute of Science and a professor of soil microbiology, said in Montreal recently that the benefits of such foods far outweigh the "very small risk" that harmful genes might be introduced into a plant. He acknowledged that there is a "marginal risk" to wild vegetation if an introduced gene spreads beyond cultivated crops.
He was firm that genetically modified foods should be labelled as such, and he said it was a mistake not to have done so from the beginning, because that has contributed to fear about these products. Chet noted that he is environmentally conscious: much of his career has been devoted to developing the use of micro-organisms as a replacement for chemical pesticides.
Chet scolded Europeans, in particular, for being unnecessarily alarmist about genetically modified foods, a phenomenon he attributes mainly to the influence of various national Green parties and Britain's Prince Charles.
Green Activists Board Ship in Protest
Three activists from the international environmental organization Greenpeace on Monday chained themselves to a cargo ship carrying more than 5,000 tons of genetically modified soya en route from Amsterdam to St. Petersburg.Greenpeace has been campaigning in the past several years for a complete ban on production of GM soya.
The three activists, who got on board of "Rusich-1" on Sunday to take samples of soya - tests have already revealed the soya is GM - were detained by the police. Greenpeace's boat "Arctic Sunrise" caught up with "Rusich-1" on Sunday in the Baltic Sea, about 200 miles away from St. Petersburg.
Russian legislation does not require any products made with GM ingredients to be marked with an appropriate label. According to Greenpeace, 77 percent of the imported GM soya arrives to Russia by sea via the Amsterdam-St. Petersburg route.
Genetically Modified Grapevine Field Trail in Stellenbosch, South Africa
The grapevine biotechnology research programme of the IWBT focuses on
understanding and ultimately improving disease resistance in grapevine in
support of environmentallyfriendly production practices. The South African
wine and grapevine industries have supported this research since 1998 for
its strategic potential and prospective economic importance. The research
has established the IWBT as one of the major centers internationally where
grapevine transformations and biotechnology research are conducted.
The Commission on Green Biotechnology
The InterAcademy Panel (IAP), a worldwide network of 92 Academies of Sciences, with its Secretariat in Trieste/Italy, advises citizens and politicians in their home countries on current problems of global relevance. The 'Berlin Group' are the participants of a workshop on 'Genetically modified crops in developing countries', jointly conducted by UGASH and IAP in Berlin (May 27-29, 2006). The Berlin Group has now issued a Statement that is being circulated for adoption by various academies in Europe and elsewhere.
The Berlin Group has taken the position that 'Molecular engineering of crops has brought revolutionary advances in agriculture. In just ten years since their introduction, many GM crop varieties have been grown on about 5 per cent of all global arable cropland in 21 countries by 8.5 million farmers, 90 per cent of them being resource-poor. Some developing countries have benefited from GM crops and are now in position to affirm their need and their will to adopt GM crops'. Based on this assertion, the Berlin Group states that:
The Berlin Statement denounces the unsupported arguments used against
GM crops and calls upon governments and environmental NGOs to end unjustified
campaigns against GM crops.
UK: PM Attacks 'Irrational Arguments' on GM Food
Tony Blair yesterday risked infuriating opponents of genetically modified food - who include Prince Charles - by suggesting that their arguments are not "rational." The Prime Minister was making a keynote speech on science, in which he called for Britain to discuss technological innovations in a more "scientifically literate" fashion. "Government must show leadership and courage in standing up for science and rejecting an irrational public debate around it," he said, attacking those who had "distorted" facts to oppose developments such as GM food. Mr Blair said he was encouraged by the public debate about stem-cell research: whereas the US has largely banned the practice, Britain is a world leader in the field. The Prince of Wales has frequently questioned the value and safety of GM crops, which has irritated some government figures. Asked if Mr Blair's remarks were a criticism of the prince, the Prime Minister's spokesman said only: "We believe the debate has not been as rational as it should have been."
13th European Congress on Biotechnology
In line with the European Federation of Biotechnology's mission, the 13th European Congress on Biotechnology will focus on addressing the great challenges to humanity through the crucial theme of Symbiosis, applying cutting-edge Science and Industry in support of Society. The Scientific Programme Committee chaired by Prof. Mathias Uhlen is putting together a world-class programme. See the Congress website for more details and regular updates at www.ecb13.eu
OECD Forum 2007 will be held on 14th and 15th May in Paris.
It will address a range of topics under the theme of "Innovation for growth and equity: A new agenda for globalisation"
The World Congress on Industrial Biotechnology &
Conference in Alexandria met at November 15 to discuss how to boost research and development in the Arab world.
About 50 Arab and non-Arab scientists, technologists and science policymakers attended the conference. Stressing the importance of science and technology for development, they noted the importance of building scientific capacity to produce technology locally, rather than relying on imported technology.
Arab states must adopt more innovative ways of teaching science, they said.
For this they suggested introducing new information and communication technologies in schools, setting up special schools for gifted children and including the basics of science and technology in their national curricula at all educational levels.
To reform the Arab science and technology sector, the conference recommendations must be put into a broad strategic plan for science development that is adopted and financially supported by Arab governments."
EU Biotech Crop Regulations and Environmental Risk:
A Case of the Emperor's New Clothes?
European Union Commissioner for the Environment Stavros Dimas recently hailed 'upgraded' non-genetically modified (GM) crops as an alternative to GM crops. A comparative analysis of the environmental risks associated with such non-GM herbicide-resistant crops and GM herbicide-resistant crops is presented here. The analysis highlights serious weaknesses in the European Union (EU) regulatory framework, and the contradictory policy of the EU Commission on the precautionary principle is also shown. The continued political stance of ignoring these regulatory and policy inconsistencies is examined and found to be flawed. It is postulated that, even in the face of these flaws and coupled with recent statements from the UK drawing attention to inconsistencies in the EU regulatory framework, the EU will continue to ignore the real and present environmental risks associated with upgraded non-GM crops for bio political reasons.
Influence biosafety and biosecurity practices
An invitation to contribute to the coordination, harmonisation and exchange of biosafety and biosecurity practices within a pan-European network (BIOSAFETY-EUROPE)
BIOSAFETY-EUROPE is a Coordination Action funded through the European Commission's Sixth Framework Programme which started on April 1st 2006. The project has 19 partners from 11 European countries and an overall aim of promoting European harmonisation and the exchange of practices relating to biosafety and biosecurity management of biological containment facilities. The project will assess the cost-effectiveness of methods and practices used, develop a programme for training and seminars and result in recommendations that may be used for future policy making within the EU.
The project aims to ask three broad questions:
EFB members wishing to contribute can contact the project Coordinator Kathrin Summermatter (email@example.com) or visit the project web site (available end of October: www.biosafety-europe.eu). The Task Group on Safety in Biotechnology of the EFB fully supports this initiative as way to facilitate harmonization and to influence regulatory developments.
Patrick Rüdelsheim, Chairman EFB Task Group Safety in Biotechnology
Despite the fact that the Nobel Prize was awarded for the prion hypothesis, there remains the possibility that the infectious agent behind diseases such as mad cow, scrapie and variant Creutzfeldt-Jakob disease might not necessarily be rogue prion protein. The findings of the SC GUT project, funded for five years via the European Commission’s Fifth Framework Programme, show that there is a need to remain diligent and open minded when investigating the causes of this group of diseases.
SCAR net: Web site on Agricultural research
Both for economic and environmental reasons, Europe needs to find alternatives to its current dependence on fossil fuels. An EU conference in Helsinki (FI) explored one of the alternatives: bio-refineries.
Has the traditional procedure of scientific peer review reached the level of its own incompetence? That was the focus of a recent conference in Prague organised by the European Science Foundation (ESF), the Czech Science Foundation (GACR), and the European Heads of Research Councils (EuroHORCs).
French Activist Farmer Bove Held in Custody
Bordeaux - Police detained radical farmer Jose Bove, a possible candidate for France's 2007 presidential election, on Saturday after a demonstration against genetically modified food (GMO) on private property.
Bove and some 50 other farmers went to the police to file a complaint of attempted murder against a corn producer. The owner, who was also held, had fired a gun in the air to disperse the demonstrators, police said. Between 100 and 150 protesters went to the farm in the southern Gironde region and poured water over what they said was genetically modified corn stocked in a silo in the town of Lugos. When the owner arrived, he fired his gun and ran his car into four vehicles before the demonstrators overpowered him. Bove, a prominent protester against globalisation and fast food, said in June he would run for president next year, hoping to rally voters on the far left. In 2003 he spent six weeks in jail for smashing up a McDonald's restaurant and was sentenced to four months in prison last year for destroying a field of genetically modified corn in southern France.
The New York Academy of Sciences Announces Launch
of Scientists Without Borders
The New York Academy of Sciences (NYAS) today announced the launch of Scientists Without Borders (SM), http://www.nyas.org/borders a groundbreaking project that will help link scientists worldwide to address health and other pressing problems in the developing world. The program, created in collaboration with the United Nations Millennium Project and guided by the Millennium Development Goals, will create a Web portal designed as a global dissemination and reference point for scientific knowledge. The portal will help to align efforts of the many public and private organizations already working toward the Millennium Goals, which are to eradicate extreme poverty and hunger; achieve universal primary education; promote gender equality and empower women; reduce child mortality; improve maternal health; combat HIV/AIDS, malaria, and other diseases; ensure environmental sustainability; and develop a global partnership for development.
Genetically Engineered Rice Wins USDA Approval Grain,
The Department of Agriculture declared safe for human consumption yesterday an experimental variety of genetically engineered rice found to have contaminated the U.S. rice supply this summer. The move by the Animal and Plant Health Inspection Service to deregulate the special long-grain rice, LL601, was seen as a legal boon to its creator, Bayer CropScience of Research Triangle Park, N.C. The company applied for approval shortly after the widespread contamination was disclosed in August and now faces a class-action lawsuit filed by hundreds of farmers in Arkansas and Missouri.
The experimental rice, designed to resist Bayer's Liberty weed killer, escaped from Bayer's test plots after the company dropped the project in 2001. The resulting contamination, once it became public, prompted countries around the world to block rice imports from the United States, sending rice futures plummeting and farmers into fits. In approving the rice, the USDA allowed Bayer to take a regulatory shortcut and skip many of the usual safety tests by declaring that the new variety is similar to ones already approved, in this case two varieties of biotech rice that Bayer never commercialized because farmers did not want them in their fields. The department gave its preliminary approval Sept. 8. "The protein in the company's herbicide-tolerant rice varieties . . . is well known to regulators, who have affirmed the rice poses no human health or environmental concern," said Greg Coffey, a Bayer spokesman.
Most critics agree that the new rice is safe to eat. The bacterial gene that is in LL601 is also in several approved varieties of engineered corn, canola and cotton. Experts say the key gene in the new rice is sure to move via pollen into red rice, a weedy relative of white rice and the No. 1 plant pest for rice farmers in the South.
Brazil bans GMOs in indigenous territories
Brazil has banned transgenic crops from indigenous territories but reduced the buffer zone separating them from conservation areas. [Spanish Full Text]
India gives West Africa US$250m to develop biofuels
The Indian government has provided US$250 million to fund biofuel production in 15 West African countries.
China signs science deals with Egypt and Algeria
China has signed deals with Egypt and Algeria to boost scientific cooperation, just days after the China-Africa summit concluded.
African science to benefit from China trade deal
Agricultural science in Africa will be boosted by a trade and aid deal that African countries agreed with China at a summit meeting this weekend.
Experts Vow to Push Biotech In Agriculture and Save
Experts in the field of biotechnology late last week ended a week long
workshop on biotechnology with the resolve to adopt biotechnological advances
in agriculture and expand the propagation of transgenic plants and trees
and solve problems related to food security, treatment of incurable diseases
and global reforestation.
Korea's Kim Donghern, the lead shepherd of the event, the 10th Asia-Pacific Economic Cooperation (APEC) Agricultural Technical Cooperation Working Group-Research, Development and Extension of Agricultural Biotechnology, cited the need to harness the potentials of biotechnology, not only for food, but for the environment, as well.
Korea is now stepping up the development of transgenic trees and expressed willingness to share information and technology to come up with fast-growing trees that can replenish the world's already bald forest with trees.
Biotechnology experts are now rushing to respond to some of these scientific findings and they are feverishly working on developing transgenic fish that reproduce quicker and in bigger volumes. A. R. Kapuscinski discussed the production of transgenic fish, which was originally developed, only for the aquarium market, with GloFish as the first transgenic fish that glows due to the action of a fluorescent protein that affects the skeletal muscle of the fish.
Now, the trend is for the development of fish species that grow quickly and provide abundant food for humans. Many types of shellfish are also being developed, even as Kapuscinski says environmental biosafety concerns have cropped up over the control of these fish species.
IRRI Official Cites Golden Rice Program
Los Ba?os, Laguna - The country has a better chance of reducing the Vitamin A deficiency of more than a third of its young if it pursues the expansion of hectarage devoted to the cultivation of the RC82 rice variety. This was the assessment made by Dr. Gerard Barry, chief of the Intellectual Property Management (IPM) unit of the International Rice Research Institute (IRRI) here, during the workshop of biotechnology experts from the Asia-Pacific Economic Cooperation (APEC) at the Diamond Hotel in Manila from Nov. 5-12. Barry also wants all member-nations of the APEC to support the Golden Rice Program to battle the prevalent Vitamin A and other micronutrient deficiencies in Third World Countries.
The IRRI official told participants at the 10th APEC Agricultural Technical Core Working Group (ATCWG) Research, Development, Extension of Agricultural Biotechnology workshop that it is not only logical but absolutely necessary to enhance the nutritional value of rice if developing countries want to defeat the scourge on health posed by vitamin deficiency, especially among children.
Aside from the Philippines, South Korea and China have joined the campaign for biofortification of rice as other companies like HarvestPlus have been breeding crops that are rich in iron, zinc, and pro-vitamin A. Among these crops are wheat, maize, sweet potato, beans, and cassava.
Barry foresees the further development of these rice strains to combat nutritional problems in many countries. Fortified rice is better than distributing supplements that eventually do not reach the target public, he admitted.
Costa Ricans Willing to Try GM Banana
Costa Rica is the second largest exporter of banana worldwide. Results of an exploratory study of the consumption and adoption of transgenic bananas in the country indicated that farmers are willing to adopt transgenic varieties because of potential savings in pest management costs. "This situation could be similar in other developing countries. any developments that could reduce management costs would be welcome by producers", wrote Francisco Aguilar and Bert Kohlmann in their paper published by the International Journal of Consumer Studies. The research has determined that a majority of Costa Rican consumers are also willing to buy and consume transgenic bananas. Those consumers that are young, have a small household, and higher levels of education and income, were found to be more likely to try the product. Aguilar and Kohlmann recommend that consumers be informed about transgenic products, their benefits, and associated risks. Only 35% of the consumers in their research were aware of the technology. The complete paper is at http://www.blackwell-synergy.com/doi/full/10.1111/j.1470-6431.2006.00527.x
Tomatoes Against Drought
Recently, a research team under the lead of Dr. Roberto Gaxiola, from the University of Connecticut managed to engineer a drought resistant crop plant by enabling the plants to produce more of a specific enzyme called H+-pyrophosphatase (H+-PPase). To achieve this, the research team first tested if genetically modifying plants so that they produced an increased amount of a specific enzyme, the H+-pyrophosphatase (H+-PPase) AVP1, would result in salt and water stress tolerant Arabidopsis plants. Arabidopsis is commonly used as model organisms. They found that the increased production of enzyme rendered the Arabidopsis plants more resistant to drought.
Thus, encouraged by these positive results they went one step further by testing whether AVP1 could be used to engineer a drought-resistant crop plant. By using a special biological technique they transferred the AVP-1 gene to tomato (Lycopersicon esculentum, a cultivar tomato). The results were astonishing: an increased root system and an enhanced ability to recover from water deficit stress. Due to a more robust root system, the transgenic tomatoes were able to increase their water uptake during drought periods.
Considering the results of this study, the team concluded that the overexpression of the AVP-1 gene could provide a general strategy to gain drought-resistant crop plants. When Checkbiotech asked Dr. Gaxiola whether his team is testing other plants as well, or is intending to study the effect in other plants, he answered, "Yes, we are currently working with rice and poplar trees and plan to work with legumes."
Engineering Edible Cottonseed
Researchers have genetically engineered toxin-free cottonseeds, potentially
unlocking a large source of nutrition.
Cotton fibre continues to be a globally vital textile crop. The leftover cottonseeds are a high source of protein, but the presence of the toxic chemical gossypol makes them unfit for human consumption.
To remove gossypol from cottonseeds, Keerti Rathore and colleagues used RNA interference to disrupt a key gene for synthesizing gossypol in developing seeds. The technique produced mature seeds with gossypol levels well below the safe level for human consumption. Gossypol levels remained high in other parts of the cotton plant, however, allowing the seeds to maintain their natural, chemical defences.
Considering that the 44 million metric tons of cottonseed produced annually could nutritionally support 500 million people, gossypol-free cotton may provide a boon for global malnutrition, the researchers say. Also, besides the potential of edible cottonseed, RNA interference could possibly be applied to other crops with toxic components, such as fava beans, to increase their utilization.
Organic Mystery: Bt Pesticide May Not Really be
an Insect Killer
According to the accepted model, Bt toxin punches holes in an insect's gut. These pores either allow the bacterium to infect the insect's blood, the so-called hemolymph, or cause the insect to starve.
Nichole Broderick the University of Wisconsin-Madison graduate student fed the pesticide to gypsy moth caterpillars that had been cleared with antibiotics of other gut bacteria, she expected it to become even more lethal. "Initially I was testing the hypothesis that the gut bacteria were actually protecting the moth from Bt," she recalls. "I found that once they did not have a gut community [of bacteria], I could no longer kill them with Bt."
Studies on Bt in the past decades have focused on the first steps of Bt's action. "Nobody has really focused on what happens after the toxin makes the holes and the cells die," comments entomologist Juan Jurat-Fuentes of the University of Tennessee-Knoxville. "Do the insects recover, or are the other bacteria taking over?" The Wisconsin researchers found, by reintroducing the gut bacteria one by one, that the Enterobacter species NAB3 reinstated Bt's deadliest impact, and subsequent tests showed that this bacterium thrived in the hemolymph, whereas B. thuringiensis quickly died. Further, Escherichia coli engineered to produce the Bt crystal proved equally effective in killing larvae, although not when the bacterium host was dead but still carrying the toxin.
The results may explain the variable effectiveness often seen in Bt; for example, gypsy moths feeding on willow are resistant to the toxin, Raffa notes. Some had argued that the tannins in the willow might be binding to the Bt protein and allowing it to be eliminated, but now Raffa wonders if other compounds in the tree might be affecting Enterobacter, which might be the true killer. "Where it gets to be important is in revisiting our interpretation of some of those earlier findings," he says. It also might help explain the mystery of corn pest Spodoptera frugiperda, more commonly known as the fall armyworm, which develops holes in its gut when exposed to Bt but fails to die. "People had a hard time explaining how this toxin binds and makes pores, but it's not killing the insects," Jurat-Fuentes says.
B. thuringiensis is also rather mysterious: it remains unclear why the bacterium expends so much energy producing the crystals, as it delivers no clear benefit to the microbe. And after roughly 10 years of widespread use in transgenic crops--globally, at least 500,000 square miles of farmland bear plants that produce their own Bt toxin--almost none of the targeted insects have shown signs of immunity, unlike other pesticides. "There is still only one insect, the diamondback moth, that has evolved resistance," observes entomologist Bruce Tabashnik of the University of Arizona.
Although this study suggests that Bt works in conjunction with gut bacteria, perhaps to produce septicemia, the exact killing mechanism remains unknown. Resolving it could lead to ways that prevent Bt resistance or improve the effectiveness of the toxin. At least the research gives new appreciation of the crop pests. "More and more we're seeing that you can't just think of the insect as a single species," Tabashnik remarks. "You have to look at the community of the symbionts it harbors and how that affects how it interacts with its environment."
Rapid Trait Development System (RTDS)
Cibus, a San Diego company, which has been funded quietly for several years by a group of biotechnology investors in the US, believes there is huge potential in its non-transgenic technology for introducing "traits" such as herbicide resistance into plants. Cibus named after the Latin word for food will collaborate with the US National Grain Sorghum Producers Foundation to develop new traits for the cereal and also expects to hit the herbicide-resistant seed market with canola (oilseed rape) next year and rice in 2008.
The RTDS technology uses the plant's own genetic machinery to change its DNA, through a site-directed mutagenesis. This is standard practice for bacteria but Cibus is the first company to develop a fast and reliable way of applying it to plants. "Essentially they are directing and greatly speeding up natural selection," says Guy Cardineau, a professor at Arizona State University. He is one of several independent plant scientists who have evaluated RTDS and are enthusiastic about its potential.
Wheat gene discovery could fight malnutrition
New research revealing how to boost the nutrient content of wheat could help combat malnutrition in developing countries, say researchers.
Wheat Gene May Boost Foods' Nutrient Content
Researchers at the University of California, Davis; the U.S. Department of Agriculture; and the University of Haifa in Israel have cloned a gene from wild wheat that increases the protein, zinc and iron content in the grain, potentially offering a solution to nutritional deficiencies affecting hundreds of millions of children around the world.
Results from the study will be reported in the Nov. 24 issue of the journal Science. "Wheat is one of the world's major crops, providing approximately one-fifth of all calories consumed by humans, therefore, even small increases in wheat's nutritional value may help decrease deficiencies in protein and key micronutrients," said Professor Jorge Dubcovsky, a wheat breeder and leader of this research group. He noted that the World Health Organization estimates that more than 2 billion people are deficient in zinc and iron, and more than 160 million children under the age of five lack an adequate protein supply.
The cloned gene, designated GPC-B1 for its effect on Grain Protein Content, accelerates grain maturity and increases grain protein and micronutrient content by 10 to 15 percent in the wheat varieties studied so far. To prove that all these effects were produced by this gene, the researchers created genetically modified wheat lines with reduced levels of the GPC gene by a technique called RNA interference. These lines were developed by research geneticist Ann Blechl of USDA's Agricultural Research Service in Albany, Calif.
Dubcovsky leads a consortium of 20 public wheat-breeding programs known as the Wheat Coordinated Agricultural Project, which is rapidly introducing GPC-B1 and other valuable genes into U.S. wheat varieties using a rapid-breeding technique called Marker Assisted Selection. The resulting varieties are not genetically modified organisms, which will likely speed their commercial adoption. More information about the Wheat Coordinated Agricultural Project is available online at [ http://maswheat.ucdavis.edu/. ] http://maswheat.ucdavis.edu/.