* Decoding the GM Debate
* Officials Don't Plan to
* Public Biotech Research Towards Food Security and Sustainable Ag
* Substantial Equivalence
* Uganda Starts ‘Historic’ Trials on GM Staple Crops
* Communal Benefits of Transgenic Corn
* Using cassava to address vitamin A deficiency
* Scientists Silence Genes to Produce Hypoallergenic Carrots
* Strengthening Ag Biotech Regulation in India
* Democs for Schools: GM Food
Decoding the GM Debate
- Emma Young, G Magazine (Australia), Sept/Oct 2010. Full story at http://www.gmagazine.com.au/features/2284/decoding-gm-debate
‘G weighs up the evidence behind the claims made for and against GM crops.’
If you're looking for a topical issue that polarises opinion, you can't go past genetic modification (GM). At one end of the spectrum, GM food is the answer to world hunger, at the other, it's a ticking time bomb set to wreak havoc on human health and the natural world.
For thousands of years, people have been altering the genetic make-up of plants and animals by crossbreeding closely related organisms with desirable characteristics. Genetic modification, which involves copying genes from one species into another, provides a way to fast track this process - and also to massively expand the possibilities. Supporters say GM can make agriculture greener by enabling farmers to use less pesticide and switch to safer herbicides, for example. Critics say GM crops pose threats to human health and the environment.
The debate is highly charged, to say the least, and environmental groups, such as Greenpeace, frequently find themselves pitted against not only the big seed companies, like Monsanto, but scientists from organisations such as the CSIRO.
As far as Australians are concerned, generally, we're not comfortable with GM foods - and our attitudes haven't changed much in the past five years, according to surveys by Swinburne University in Melbourne. People lack trust in the institutions responsible for commercialising GM crops, the researchers found.
But some scientists in favour of GM worry that what they see as unfounded scare stories are helping to drive unnecessary fear and lack of trust. Establishing what's fact and what's hype on both sides of the debate is vital - not least because the number of GM crops being planted is on the increase worldwide.
Since the first commercialisation of GM crops in 1996 there's been a steady nine million hectare increase in their production each year, according to the latest figures from the International Service for the Acquisition of Agri-biotech Applications. In 2009, 134 million hectares of GM crops were planted worldwide, with the US accounting for nearly 1/2 of that total. Soybeans are the most popular GM crop, but maize takes a big share. In Australia, just over 20 per cent of our main GM crop, canola, is now genetically modified. And that figure is set to increase - in January this year Western Australia joined New South Wales and Victoria in permitting the commercial planting of the GM variety.
By far the most popular GM trait worldwide is herbicide resistance - the ability of a plant to survive a poison that doesn't differentiate between crops and weeds. The primary benefit is that farmers can spray crops with a herbicide and kill only the weeds. And in many cases, it has allowed farmers to switch to using safer herbicide. Take, for example, canola. US seed giant Monsanto added a bacterial gene that makes the GM crop resistant to a herbicide called glyphosate (Roundup), which is much less toxic than atrazine, the one commonly used with conventional canola.
"Mounting evidence of the environmental risks of atrazine really won me over to GM canola," says Rick Roush, a pest expert and dean of the Faculty of Land and Food Resources at the University of Melbourne. The soils in which herbicide-resistant crops are grown also need less tilling, which is better for the soil. The second most common GM trait is pest-resistance. GM cotton plants, for example, have been modified to produce a bacterial toxin (commonly called 'Bt') that kills a common caterpillar pest - massively reducing the amount of insecticide needed to protect the crop.
When Roush first heard about the genetically modified Bt cotton, in the 1980s, he thought it sounded like a terrible idea. "What really changed my mind was when I went to Mississippi to look at some of the field trials of Bt and non-Bt cotton, and the results were spectacular. At that time, 49 per cent of all insecticide sprays in the world were for cotton. I saw that they were essentially growing cotton crops without spraying for the major caterpillar pest - and I thought, this could tremendously reduce pesticide use."
In Australia, a CSIRO study found that Bt cotton needed between only 11 and 40 per cent of the amount of pesticide required for conventional cotton. This "has major benefits for the environment and human health," says John Manners, deputy chief of the CSIRO Plant Industry in St Lucia, Queensland.
Other GM crops currently in development could have different environmental benefits. Researchers in the US are working on GM varieties that need between 1/2 and 1/3 less nitrogen fertiliser than standard varieties, which could have significant environmental benefits. GM critics, however, see such promises as pipedreams in the same category as "clean coal" technologies.
Soybeans engineered to produce health-boosting omega-3 oils, which are currently extracted from fish, also have the potential to help the environment by taking the pressure off global fish stocks.
An additional benefit of some GM crops is that they produce bigger yields - though this doesn't hold across the board. As far as Roush and other scientists are concerned, the health and environmental benefits of GM are the most important to date. And some new strains of GM crops, such as those designed to grow better in drought conditions, look more promising in terms of increasing yields into the future in the developed world, including Australia. Finding effective ways to boost yields globally will be vital if we're to meet the estimated 50 per cent increase in demand for food by 2030, John Beddington, the UK's chief scientific adviser, told a food summit in London last year. GM certainly won't achieve this alone, he said.
Manners agrees: "It's but one technology that may help us to meet these challenges." But GM crops will be necessary to boost yields and help crops survive in harsher climates as the global population rises and global warming worsens, concluded a recent report from the UK's national academy of science, the Royal Society.
Concerns have also been raised about Bt crops, such as soybeans, which produce the bacterial toxin. "The plant is engineered to make an insect's gut explode when it eats it, which makes me a tad nervous," says Kelly.
Needlessly so, counters Roush. The toxin genes were chosen because receptors for them exist only in certain insects, including the caterpillars that eat the beans. They won't affect beetles or honeybees or anything else, including us, because human physiology is vastly different - we just don't have the receptors these toxins can bind to, he says. People have been eating Bt for a long time, he adds, because it has been widely used as an insecticide spray.
What about the claims that GM foods cause allergies, and could be behind the increase in allergies in the developing world? There is just no good evidence for this at all, says David Tribe, who teaches food safety, food allergy and food biotechnology at the University of Melbourne.
Of course, that's not to say that every GM food is safe. For example, a pea modified by CSIRO to contain a brazil nut gene was found during its development to trigger an unexpected immune response in mice. So CSIRO dropped the project, well before the pea got close to people.
Clearly, GM foods cannot all be lumped together as either 'safe' or 'unsafe'. Each has to be tested. Then the data has to be evaluated, on a case-by-case basis. However, the way GM foods are tested and evaluated has come under fire by GM critics.
Recently, India put the commercial release of a GM eggplant on hold after criticisms that the country's biotechnology regulator had not had data from the company that created it (a joint venture between a local firm and Monsanto) independently analysed.
Among her main concerns about the possible health effects of GM foods, says nutritionist and GM critic Rosemary Stanton is "the fact that testing has been done by the companies marketing the products. I would like FSANZ to insist on independent tests."
Important independent work is done, points out Tribe. "About 30 per cent of all publications of GM food safety are independent of commercial interests," he says.
Clearly, there are some legitimate environmental concerns about some GM crops - such as weed resistance and damage to farmland diversity. Proponents believe these aren't unmanageable. And, they say, whether crops are altered using GM or conventional breeding techniques, many of the risks are the same. After all, weeds resistant to Roundup appeared long before GM crops.
As for health risks, there's no good evidence that any GM food on the market today has any. Greenpeace says current animal feeding trials, which often last 90 days, aren't long enough - it would like to see two-year feeding studies on animals. A 2008 scientific review published in the Journal of the Royal Society of Medicine noted that GM foods had been eaten by millions of people worldwide for 15 years, with no reports of ill effects.
Roush and Tribe, among others, think the ongoing concern that GM foods somehow might have long-term health effects is holding back the development and spread of GM crops that can have significant health and environmental benefits. "I was initially a sceptic of GM crops," says Roush. "But they have reduced the environmental footprint of agriculture in lots of areas in the world. And there are technologies that will be much more important that any of the ones we've seen so far - like efficiency in the use of nitrogen fertiliser. To be able to reduce that is going to be spectacularly important."
Officials Don't Plan to Restrict Biotech Crops
- Philip Brasher, Des Moines Register, Oct. 9, 2010 http://www.desmoinesregister.com
Washington, D.C. — As the government wrestles with what to do about the growing problem of herbicide-resistant weeds, one idea apparently is off the table: restricting how farmers can use the biotech crops that are linked to the problem.
Scientists say farmers' over-reliance on Roundup herbicide, which the biotech soybeans and other crops are immune to, has led to increased problems with weeds that are resistant to the weedkiller and can cut crop yields.
But the Agriculture Department, which regulates the crops, has no plans to impose controls on their use, and a leading expert on the herbicide resistance issue says it's too late for government restrictions anyway.
Ann Wright, a deputy undersecretary at the USDA, told a House oversight subcommittee last week that the Obama administration is committed to protecting the continued use of genetically engineered seeds and lacks authority to restrict herbicide-tolerant crops even if it wanted to. "This administration and USDA see biotechnology as being a very important tool for farmers to use in addressing some very important issues, globally and domestically," Wright said. "All the options we look at have to be supportive of that."
She said that limiting the use of herbicide-tolerant crops would force farmers to "return to older, often costly, and less environmentally friendly" ways of controlling weeds. Michael Owen, a weed scientist at Iowa State University, said restrictions on planting the Roundup-immune crops would only delay the development of resistant weeds, not prevent it.
He said the best solution is to persuade farmers to stop relying exclusively on Roundup, the trade name for glyphosate, and use additional herbicides and other measures, such as rotating crops and cultivating problem areas. But that's a hard sell, he acknowledged, because the Roundup-resistant crops became popular with farmers precisely because they could keep weeds out of their fields with less labor and the use of a single chemical. "Mother Nature will efficiently, effectively and inevitably move around anything that's done recurrently that's simple and convenient," he said.
Owen worked on a recent National Research Council study that warned that the weed problem was threatening to erase the environmental gains that the biotech crops had produced. The use of the crops has allowed farmers to reduce their tillage, which cuts down on erosion and protects the water quality in neighboring streams and ponds.
About 93 percent of the soybeans and 70 percent of the corn planted nationwide this year were herbicide-tolerant varieties. Wright told the House panel that the USDA can regulate herbicide-tolerant crops only to prevent them from becoming pests themselves, not to stop their use from leading to resistant weeds.
The department's stand didn't sit well with Rep. Dennis Kucinich, an Ohio Democrat and former presidential candidate who is chairing a series of hearings on the superweed issue. Kucinich told Wright the department could impose restrictions on herbicide-tolerant crops under its authority to control noxious weeds.
Wright admitted she wasn't familiar with the noxious-weed section of the law, prompting Kucinich to respond, "You're really not? If the regulatory agency is not fully aware of the full extent of its authority, then that may be why we're having a problem here."
An official of the Environmental Protection Agency, meanwhile, said under questioning by Kucinich that EPA personnel have raised concerns about the weed-resistance issue with the USDA. The USDA "said to us, 'You've raised some good points. Let's talk about that,' " said Jim Jones, the EPA's deputy assistant administrator for chemical safety and pollution prevention. "Those conversations continue to this day."
Owen and other members of the research panel are in discussions with the USDA and additional scientists about setting up a summit meeting next spring in Washington to address the issue. Kucinich said there would be additional hearings on the issue, but his power to pursue it is going to be limited if Democrats lose control of the House in next month's elections.
Public Biotechnology Research Towards Food Security and Sustainable Agriculture
- Public Research and Regulation Initiative http://www.pubres.org
Nagoya, Japan, 11 October 2010 - Today starts the Fifth Meeting of the Parties to the Cartagena Protocol on Biosafety. The Cartagena Protocol is an important instrument, because it can help international sharing of the benefits of modern biotechnology, to which Parties have agreed in article 19 of the Convention on Biodiversity. This same article is the legal basis of the Cartagena Protocol.
Tens of thousands biotechnology researchers in thousands of public research institutes in developing and developed countries strive towards alleviating poverty, sustainable agricultural production, assuring food safety and quality and conservation of the environment. However, these same public sector scientists express concern that these efforts will be futile if regulations such as the Cartagena Protocol are not implemented in a balanced and science-based manner. They call on the negotiating Parties at MOP5 to constantly assess how the implementation of the Protocol will affect crucially important public research, to ensure that the Protocol will indeed contribute to sharing the benefits of this technology.
Current agricultural practices need to become more sustainable. Modern biotechnology has shown relevant benefits that need to be integrated in agricultural practices to address the giant challenges that the world community faces:
1. Develop new agricultural technologies to feed the 1 billion undernourished people, of the currently 6.8 billion global population
2. Double the food production by 2050 to meet the needs of an expected world population of 9.2 billion, and meet the higher demand for protein-rich meals, using more efficiently resources, such as water, fossil fuel and nitrogen
3. Reduce the environmental footprint caused by agriculture, such as the massive loss of topsoil, soil and water pollution by agrochemicals, and deforestation
4. Mitigate climate change and provide well adapted crops to cope with its effects on agricultural production.
Executive Secretary of PRRI, Dr. Stefan Rauschen, says it is a daunting task for public researchers to bring the results of their research to the farmers if regulations require millions of dollars to get GM crops approved, which is unaffordable for public research institutes.
Dr. Behzad Ghareyazie, President of the Biosafety Society of Iran emphasizes that governments in developing nations, including Muslim countries, should assist the access to modern biotechnologies. “Biased, excessive regulation is one of the barriers to access the benefits of advanced technologies. Iran was the first country to commercialize an insect resistant rice to lower the need for intensive use of environmentally harmful insecticides”.
Dr. Margaret Karembu, Director of ISAAA Africenter strongly believes that Africa should not be deprived of modern biotechnology. “Africa is the only continent in the world where food production per capita is decreasing and where hunger and malnutrition afflicts at least one in three people. Modern biotechnology can make a decisive contribution to improve harvest and alleviate hunger and poverty in Africa.
The adoption of Bt cotton in Burkina Faso for example, is expected to bring an income gain of over US$100 million per year and at least 50% reduction in insecticide sprays. Burkinabe women farmers are already experiencing additional benefits from saved time and labour used in fetching water for spraying to increasing their acreage on food crops during the cotton season, which was a big challenge before. Priority crops in Africa such as cowpea, cassava, sorghum, and banana are being developed by African public researchers, with the potential to increase c rop productivity by resisting devastating plant diseases and to alleviate human malnutrition through biofortification. African countries are concentrating efforts to properly regulate all of these GM crops”.
“The Philippines benefitted hugely from GM adoption and there is not one verifiable report that suggests harm to human health and the environment after more than 7 years of cultivation of GM maize in a cumulative area of more than 1 million hectares, says Dr. Desiree Hautea, from the Institute of Plant Breeding at University of the Philippines Los Banos”. Dr. Hautea is looking forward to the commercialization of the first public sector-developed GM crop in the Philippines, the insect resistant Bt eggplant, to shrink the excessive use of pesticides, and to improve income and productivity of resource-poor farmers. She is optimistic that the science and evidence based decision-making that has been established in her country, will continue to be upheld.
Dr. Lúcia de Souza from the Brazilian Biosafety Association (ANBio) says that GM crops in Brazil were estimated to have already spared 12.6 billion liters of water and 104.8 million liters of diesel, resulting in a reduction of 270.4 thousand tons of CO2 emissions. More needs to be done to increase the number of improved crops available to farmers such as cassava and beans, to extend benefits to developing countries. Latin American scientists from institutions of excellence in Brazil, Colombia, Costa Rica and Peru have joined in the Regional Project LAC Biosafety (GEF/WB/CIAT) to strengthen their capacities and maximize the benefits for sustainable agriculture.
Around the world, GM crops contributed US$ 51.9 billion during the period 1996-2008 due to substantial yield gains and reduction in production costs. Environmental benefits include savings on pesticides, water, fossil fuels and decreased emissions of green house gases. It is unacceptable to see that millions of people go to bed hungry every day. Researchers and regulators around the world should make it their common goal to promote a sustainable approach in agriculture that ensures every person is adequately fed and poverty is alleviated in the world.
- Anastasia Bodnar, Biofortified, Oct. 11, 2010. Full blog at http://www.biofortified.org/2010/10/substantial-equivalence/
One important concept that is used in most countries to regulate products of genetic engineering is substantial equivalence. The way to determine substantial equivalence is comparative assessment. What do substantial equivalence and comparative assessment mean? Depending on the source we use, we might find different definitions and different opinions of how useful they are in determining the safety of products of genetic engineering. The USDA provides information on Food Safety Assessment and Considerations as part of their Focus on Food Biotechnologypage at the Food Safety Research Information Office.
What substantial equivalence can do is give us a starting point. We know that there is variation in amounts and types of proteins and metabolites, gene expression, and other parameters from variety to variety, from environment to environment, and from plant to plant. For example, if I use a microarray to find similarly and differently expressed genes in two genetically identical plants grown in slightly different environments, such as different temperatures, I will find some genes that have significantly different expression. Similarly, plants of different varieties grown in the same environment will have different gene expression profiles and even two identical plants in the same environment will have some differences.
The first step in a comparative assessment is to test and compare the genetically engineered variety to a genetically similar variety that doesn’t have the trans- or cis-gene. Tests can include gene expression, metabolic profiles, feeding studies, and more. If differences aren’t found in a reasonably wide panel of tests, then the genetically engineered variety can be called substantially equivalent to the genetically similar variety.
If differences are found, two questions need to be asked. First, does the change fall within the natural variation found among different varieties of the same species? For example, some varieties of corn with the Bt gene have been found to contain more lignin than genetically similar varieties without the Bt gene, but the amount of lignin falls within the normal range of lignin content for corn plants. Second, is there a scientific explanation for each change? For example, a transgene that causes higher calcium uptake from the soil is expected to result in higher amounts of calcium.
If there is a change that doesn’t fall within the natural variation for that species, especially if there isn’t an obvious scientific explanation for the change, then more testing needs to be done to determine safety with regard to environment and human health.
What substantial equivalence does not do is give license to make assumptions. The process of genetic engineering does have the potential to cause unintended changes in the resulting organism. That’s why a comparative assessment needs to be conducted before a plant, animal or microbe that has been genetically engineered can be deemed substantially equivalent to a non-genetically engineered but genetically similar organism.
One major problem with determining substantial equivalence is that it is hard to know which tests are appropriate. This problem has improved greatly as “omics” type tests have become more widely used. Tests for macronutrient content could be expected to miss small but significant changes but wide screens for changes in the transcriptome, proteome, or metabolome could be expected to find those small changes.
Another problem with comparative assessments is that each genetically engineered trait may require different types of testing, depending on what the trait is. For example, a drought tolerant crop may need to be tested under wet and dry conditions while a nutritional trait may not need to be tested under different environmental conditions.
An alternative view to substantial equivalence and comparative assessment is the precautionary principle. Instead of starting by looking for differences between a genetically engineered organism and a non-genetically engineered but genetically similar organism as we find in a comparative assessment, the precautionary principle requires us to start with the assumption that there are differences and enough studies must be conducted to determine that something is completely safe before release. The precautionary principle is an important enough idea that it deserves its own post, but I will say here that it has some problems, the biggest of which is that the amount of testing that is deemed to be “enough” is rarely defined, so the amount of tests that “need” to be conducted can always be made larger, which may actually be the point.
Uganda Starts ‘Historic’ Trials on GM Staple Crops
- Peter Wamboga-Mugirya, 5 October 2010 http://www.scidev.net/
Ugandan researchers will carry out a series of field trials on some of the major food crops that have been genetically modified (GM), following several recent approvals by the Uganda National Biosafety Committee, despite a lack of clear legislation on commercialising any such products within the country.
They will seek to develop both transgenic and conventional maize varieties tolerant to climate change-induced drought; GM cassava resistant to virulent cassava brown streak virus ravaging the starchy root crop across eastern and central Africa; GM bananas with engineered resistance to Xanthomonas bacterial infections; and cotton plants containing both Bt and ‘roundup-ready’ genes.
According to Yona Baguma, vice-chairman of the committee, the approvals — given in July and followed by planting that started last month (September) and will go on until November — are “historic”. They are clear signals that Uganda’s scientific community has built capacity in molecular biology and convinced the committee it can adhere to national and international guidelines on GM organisms, he said.
“It is also significant that the committee has matured with functional and competent systems to assess and evaluate applications, with rejections and approvals,” said Baguma.
Godfrey Asea, principal investigator for the maize trials and national project coordinator for Water Efficient Maize for Africa’s said: “Our confined field trial site is ready to plant the first transgenic maize in November 2010.
“This shall be a trial on efficacy for drought-tolerance by GM and conventionally-bred maize. When it succeeds, we expect to carry out more trials on starch content, taste, production outputs and to commercialise by 2017,” Asea told SciDev.Net.
Uganda has previously approved and carried out a field trial on banana to test black sigatoka disease resistance (2007 - 2009), two trials to evaluate Bt and roundup ready cotton (2009 - 2010), one trial to test cassava mosaic virus resistance (2009 - 2010), and one ongoing trial to test banana bio-fortified for vitamin A and iron.
But the country still lacks a national biotechnology legal framework for releasing such crops on the market. The 2008 National Biotechnology and Biosafety Bill has still not been approved by Parliament and, with elections expected in February next year, the date of its passage is still unsure.
But Godber Tumushabe, chief executive officer of the Advocates Coalition for Development and Environment — a policy think-tank — said Uganda is unnecessarily rushing to develop GM crops before it builds the critical scientific and
infrastructural capacity to ensure the products are safe.
Only three African countries are currently growing GM crops commercially: Burkina Faso, Egypt and South Africa. Several others are conducting research and field trials, including Ghana, Kenya, Malawi, Nigeria, Tanzania and Zimbabwe, mainly focusing on staple local crops such as cowpea.
Communal Benefits of Transgenic Corn
- Bruce E. Tabashnik, Science October 8, 2010:
Vol. 330. no. 6001, pp. 189 - 190
Genetically engineered crops represent one of the most controversial and rapidly adopted technologies in the history of agriculture. First grown commercially in 1996, transgenic crops covered 135 million hectares (ha) in 25 countries during 2009 . To reduce reliance on insecticide sprays, corn and cotton have been genetically engineered to make insecticidal proteins derived from the common bacterium Bacillus thuringiensis (Bt). These Bt toxins kill some devastating insect pests, but unlike broad-spectrum insecticides, they do little or no harm to most other organisms, including people. Many pests have rapidly evolved resistance to insecticides, however, spurring concerns that adaptation by pests could quickly reduce the efficacy of Bt crops and the associated environmental, health, and economic benefits. On page 222 of this issue, Hutchison et al. (below) rein in some of those concerns, documenting a landmark case in which Bt corn has remained effective against a major pest for more than a decade, yielding billions of dollars of estimated benefits to farmers in the midwestern United States.
Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers by W. D. Hutchison et al. Science. 2010. Vol. 330. p 222
Transgenic maize engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become widely adopted in U.S. agriculture. In 2009, Bt maize was planted on more than 22.2 million hectares, constituting 63% of the U.S. crop. Using statistical analysis of per capita growth rate estimates, we found that areawide suppression of the primary pest Ostrinia nubilalis (European corn borer) is associated with Bt maize use. Cumulative benefits over 14 years are an estimated $3.2 billion for maize growers in Illinois, Minnesota, and Wisconsin, with more than $2.4 billion of this total accruing to non-Bt maize growers. Comparable estimates for Iowa and Nebraska are $3.6 billion in total, with $1.9 billion for non-Bt maize growers. These results affirm theoretical predictions of pest population suppression and highlight economic incentives for growers to maintain non-Bt maize refugia for sustainable insect resistance management.
Using Cassava to Address Vitamin A Deficiency
- American Society of Plant Biologists, http://www.aspb.org
‘A natural variation shows promise for increasing provitamin A in cassava roots using transgenic or conventional methods’
Cassava is an important food source in many poverty-stricken regions of the world, including sub-Saharan Africa, but the low levels of micronutrients in commercial varieties do little to address hidden hunger. New research published in The Plant Cell shows that a single, naturally arising change in one gene leads to high provitamin A levels in cassava roots and opens the door to addressing vitamin A deficiency via biofortified cassava.
An article published in The Plant Cell this week describes the results of a collaborative effort led by Professor Peter Beyer from Freiberg University in Germany, together with researchers at the International Center for Tropical Agriculture (CIAT) in Colombia. These researchers studied a naturally arising variant of cassava with yellow roots in order to understand the synthesis of provitamin A carotenoids, dietary precursors of vitamin A. Beyer was also co-creator of Golden Rice, a biofortified crop which provides precursors of vitamin A not usually present in the rice that people eat.
In this work, the scientists compared different cassava cultivars with white, cream, or yellow roots - more yellow corresponding to more carotenoids - in order to determine the underlying causes of the higher carotenoid levels found in the rare yellow-rooted cassava cultivar. They tracked the difference down to a single amino acid change in the enzyme phytoene synthase, which functions in the biochemical pathway that produces carotenoids. The authors went on to show that the analogous change in phytoene synthases from other species also results in increased carotenoid synthesis, suggesting that the research could have relevance to a number of different crop plants. Furthermore, they were able to turn a white-rooted cassava cultivar into a yellow-rooted plant that accumulates beta-carotene (provitamin A) using a transgenic approach that increased the enzyme phytoene synthase in the root.
This work beautifully combines genetics with biochemistry and molecular biology to deepen our understanding of carotenoid biosynthesis. “It paves the way for using transgenic or conventional breeding methods to generate commercial cassava cultivars containing high levels of provitamin A carotenoids, by the exchange of a single amino acid already present in cassava” says Beyer. Thus, it has the potential be a big step the battle against vitamin A deficiency, which is estimated to affect approximately one third of the world’s preschool age children.
Scientists Silence Genes to Produce Hypoallergenic Carrots
- Crop Biotech Update, isaaa.org
Pathogens and abiotic stress could stimulate the production of a plant protein called pathogenesis-related protein-10 (PR10). This protein elevates the allergenic potency of numerous fruits and vegetables, such as carrots. Two similar genes (Dau 1.01 and Dau c 1.02) were found in carrots that code for PR10 forms. Susana Peters of Justus Liebig University, Germany, and colleagues conducted a study with the objective of producing hypoallergenic carrots by silencing either Dau 1.01 or Dau c 1.02 in transgenic carrots through RNA interference (RNAi).
Through quantitative polymerase chain reaction (qPCR) and immunoblotting, the presence of the genes and the protein was documented. Results showed that PR10 accumulation was highly reduced in the transgenic plants, compared with the untransformed samples. Both the transgenic and wild-type plants were treated with salicylic acid, a chemical that induces PR10. An accumulation of PR10 was observed in the wild-type carrots, but not in the transgenic plants. The decrease of the allergenic potency in Dau c1-silenced plants was enough to cause a reduced allergic reaction of patients with carrot allergy, verified by skin prick test. This study demonstrated the possibility of producing low-allergenic food through RNAi, and the scientists recommend for simultaneous silencing of multiple allergens to come up with hypoallergenic carrots for consumers.
Read more about this study at http://www.springerlink.com/content/5192893147177l34/fulltext.html.
Strengthening Agricultural Biotechnology Regulation in India
- Crop Biotech Updare, isaaa.org
The Energy and Resources Institute (TERI) has released the first in a series of policy briefs - 'Strengthening Agricultural Biotechnology Regulation in India'. This policy brief outlines the crucial elements of a strong biotechnology regulatory regime in India, namely, a process-based regulatory system, an autonomous regulatory body, transparent process and harmonization with international standards. The brief focuses on India's current regulatory system and lists policy recommendations for further strengthening the existing system. The new series of policy briefs is based on research work in specific areas and will be made available to members of parliament, policy-makers, regulators, experts, civil society and the media to encourage wider discussion.
The first policy brief is accessible at http://www.teriin.org/policybrief/docs/TERI_PolicyBrief_Sept2010.pdf Comments and suggestions can be sent to Dr. Vibha Dhawan, Executive Director, TERI at email@example.com
Democs for Schools: GM Food
A card game to facilitate a group discussion about genetically-modified food. The game you play to have your say
Democs conversation kits are an exciting way to hold your own debate on difficult scientific, political and ethical issues.
Each kit presents a range of key viewpoints on a particular issue in an easily accessible format and offers a simple, game-like structure to facilitate debate. The kits include a deck of cards representing key facts, opinions and examples about the topic. Participants uses the cards to identify the things that matter to them and as a starting point for discussion.
Genetically modified food is often touted as the answer to world food shortages. Plants can be modified to be more nutritious, grow in a wider range of conditions and need less fertilisers. But critics are concerned that the risks of genetic modification are not yet understood, that the new technologies give too much power to big corporations and that they risk undermining biodiversity. This kit explore key questions around GM food like:
What are the risks around GM?
Should big companies be allowed to patent genes?
Should we permit a new round of GM tests in the UK?
(Thanks to Prof. Chris Leaver for the tip)