Bt gene harms GM plant: New answers to old questions on biosafety of GM crops

Issue: Jun 30, 2011

G V Ramanjaneyulu
Entomopathogenic bacterium Bacillus thuringiensis (Bt) and its toxins have been extensively used for pest control in agriculture and forestry and in public health programmes since the 1930s. At the core of such application are protein crystals that get synthesised when Bt cells develop spores. The proteins called Cry (from Crystal) are inimical to certain insect groups.

Transgenic plants containing Bt genes, commercially available since the 1990s, are developed by transferring genes to produce specific Cry proteins like CryIAc and Cry2AB. It is presumed the genes perform the same function of producing the toxin in the plant as they were doing in the bacterium and hence are safe for the environment.

However, field experiences show various problems: allergenicity, toxicity to non-target organisms and effects on soil fertility. Industry and pro-GM scientists dismiss such problems, asserting that Bt toxins have no unintended effects and claiming that GM and non-GM crops are substantially equivalent. Latest studies have raised questions about such claims. In an article in the June 2011 issue of Journal of Biosciences, Delhi University scientists reported that the expression of the Cry1Ac endotoxin has detrimental effects on the development of transgenic plants. The plants that showed appreciable CryIAc expression were phenotypically abnormal: they were malformed. This suggests preferential selection is at work while transgenic plants mature: those that express low level of Cry1Ac have better chances of coming through compared with ones expressing appreciable levels of the gene.

Deepak Pental, one of the authors of the paper, is a member of the Genetic Engineering Approval Committee (GEAC) and was the chairperson of the Expert Committee-I on Bt Brinjal.

Several researchers, including Kesavraj Kranti, director of the Central Institute of Cotton Research and member of GEAC, have observed that the expression of the Cry1Ac gene is not uniform during the life cycle of the Bt cotton. Kranti has also observed that the expression of Cry1Ac protein is highly variable in different parts of eight Bt cotton Bollgard hybrids and—more importantly—the expression declined progressively over the plant’s life cycle. He observed the lowest expression in the ovary of flowers and rind of the young green bolls—the sites most preferred by the bollworm—implying the crop could be most vulnerable to insect attack during flowering. This could hugely reduce crop yield.

Low expression of the Cry1AC gene will also negate the Insect Resistance Management strategy, which dictates the toxin level be several-fold higher than that required to kill all target insects. The low expression militates against development of plants bearing high levels of the toxin. Bt cotton in Gujarat and other areas in the country where the pink bollworm has become Bt-resistant are most likely plants with low levels of CryIAc expression. Bt Brinjal is likely to meet the same fate because the brinjal and fruit shoot borer it targets is a monophagous pest like the pink bollworm—it feeds only on brinjal.

The reason for the detrimental effects of Cry1Ac on plant growth and development is not known. However, the finding gives leads to understanding several problems about Bt genes.

Phenotypical abnormality in plants with high levels of CryIAc expression could be a result of a metabolic aberration during the process of gene transfer or gene itself. Such metabolic abnormality can also cause allergies and produce toxins detrimental to non-target organisms like friendly insects, soil microbes, cattle or other mammals, including humans, feeding on the plants or its products. Earlier reports on toxicity to monarch butterflies, reduced soil fertility and the controversial phenomenon of animal morbidity/mortality could be explained with more research along these lines.

The authors suggest that targeting of Cry1Ac into chloroplasts rather than nuclei can lead to plants expressing higher levels of Cry1Ac and better insect resistance. However, the finding that expression of a Bt toxin per se is detrimental to plants is significant since the toxin was thought to harm only certain insects. The findings reveal large knowledge gaps and actual problems associated with Bt crops. Bt crops should be banned till further research shows the technology can be precise, predictable and controllable in addition to being safe.

The author is a scientist with the Centre for Sustainable Agriculture in Hyderabad

Bayer’s GM rice defeat

Nature Biotechnology, 29, 473 (2011)

In a lawsuit over genetically modified (GM) modified rice, jury members in an Arkansas circuit court ruled in March in favor of Riceland Foods of Stuttgart, Arkansas, a rice milling and exporting company, and against Bayer CropScience of Research Triangle Park, North Carolina, and Monheim, Germany. The jury recommended that Bayer pay Riceland $136.8 million—$125 million in punitive damages and $11.8 million in compensatory damages—calling Bayer negligent for allowing traces of its genetically engineered Liberty Link, herbicide-tolerant experimental rice to mix with commercial lots of long grain rice in 2006. Back then, Mike Johans, then secretary of the US Department of Agriculture, said: “There are no human health, food safety or environmental concerns associated with this [GM Liberty Link] rice.” Nonetheless, Riceland brought suit, claiming “loss of the European Union market,” which cost it $380 million in potential sales. Bayer counters that rice then destined for Europe “accounted for less than 5% of US-grown rice,” and “quickly was diverted and sold in other markets.” The company, which also points out that the jury-recommended award “exceeds what is permitted by Arkansas law and will therefore be limited to the statutory cap of $1 million,” says it will consider whether to appeal after the court issues its final rulings. Meanwhile, Liberty Link rice, which was not commercialized, is no longer being developed. Jeffrey L Fox


The Honesty of Science is Being Compromised at Every Turn

COLIN TUDGE / New Statesman ( UK ) Can we still rely on what scientists tell us? Alas, no. Their conferences and papers are sponsored by industry, their bad results are concealed, their jobs are threatened if they step out of line. Colin Tudge on the corruption of humanity’s most precious discipline Science—not science-based, “high” technology such as smart weapons or GM crops, but science itself—is losing its way. Since science is the most potent agent of change—the ultimately anti-conservative driver of world affairs—this concerns us all. Some scientists worry about the present turn of events. Some do their best to circumvent some of the secrecy and greed that are among its modern manifestations: Sir John Sulston, for example, who put his team’s contributions to the Human Genome Project straight on to the web; or Tim Berners-Lee, who invented the web in the first place, and could surely by now be Bill Gates-rich, but who instead made it free—a gift to humankind, like the ceramics of China. But scientists as a whole do not seem worried enough. Some are waxing fatter than their forerunners ever dreamt of—mere lucre, after all, had not used to be the natural reward of the intellectual. Some in the highest places feel that the present way of doing things is good enough. It is just the way of the world, they say, and we have to be “realistic”. Yet scientists of all ranks write to the newspapers and complain about lack of public “trust”, which they ascribe to “public ignorance”, to be remedied by “education”. They are right about the lack of trust, but not about the ignorance. People are not daft; and you don’t have to be a PhD to smell a rat that is, as colonels used to write from Tunbridge Wells, nibbling not simply at the fact but at the very idea of civilisation. Science draws upon, and one way or another impinges upon, the furthest reaches of philosophy. Science cannot decide what is right or wrong but it affects moral decisions in a whole range of ways. It has been entwined with theology since its outset—indeed can be seen as the scion of religion—and the present public spats so often staged between the more dyed-in-the-wool clerics and the more aggressive scientists tend to be crude in the extreme. In normal times, these ramifications are fun. To be sure, there has been the odd burning. But on the whole, the nature and the limits of science have been cosily contained in donnish debate. What has changed things is modern, ruthless, vicious, crude economics: not capitalism per se, which has many benign faces, but the neo-monetarist, globalised, corporatised, no-holds-barred version of it. Science in its beginnings, and in essence as conceived by Pythagoras, is a divine invention. But even divinity is now deemed to be for sale and science, in effect, has been bought. Politicians and corporate bosses often argue that globalisation is good because it will bring unity to humankind. But it is hard to conceive of anything more able to disrupt humanity than the privatisation of science, with all its power to change minds and things. Patenting is necessary. But the widgets that are granted temporary licence derive from a corpus of knowledge put together by the genius of all humankind over at least 3,000 years. The sequestration of that knowledge is theft. Conversations with many scientists over many years have given me some insight into why so many of them seem content to put up with what to onlookers seems so foul. First, scientists say, science at its core is not as badly served as outsiders think. Most “basic” science—the really fundamental ideas, such as natural selection and the theory of relativity—is still paid for out of the public purse, and its course is still decided by intellectuals, who follow the ideas where they will lead. Only the applications—the translation of basic ideas into technologies—are in private hands. Despite appearances, core science maintains its Pythagorean purity. Second, some point out that input from commerce is not all bad. It provides much-needed cash, and science is a lot more expensive in these days of linear accelerators and PCR analysers than it was when Archimedes mused and sketched in the sand. And the particular problems posed by industry have often prompted the most profound insights. The laws of thermodynamics arose from study of the steam engine. Louis Pasteur founded modern microbiology in the 19th century on research undertaken for makers of wine and breeders of silkworms. Gregor Mendel set out to solve problems of interest to plant breeders and founded the science of genetics. It is fun and creative to turn a good wheeze into something that actually works, and perhaps does some good, as a new vaccine may do. Third, and more crudely, academic salaries are low. It is hard to raise a family in a university town on GBP30,000 a year. Professors knocking on the door for Nobel prizes may be paid less than supermarket managers, even without the free car. With a foot in industry, they can be rich, or at least be up there with the solicitors and estate agents. Why not? Do they deserve less? Beyond any doubt, academe and commerce can work very well together to everybody’s benefit, and often have. Many scientists, like most of us, just muddle along as best they can and, if a drug company will pay them and nobody else will, well, what should a poor post-doc do? But a lot can go wrong, and does. It is good for science that taxes pay for core research. But why, the taxpayers may reasonably ask, do the material fruits of that research then pass into private hands? If we believe that the world as a whole must be run by corporations—that they alone have the competence and that corporations survive only by doing what people want and need—then it is fine and dandy that people at large should give them a head start. Otherwise, the present arrangement seems like a bad deal. In truth, industry and science are locked in a positive feedback loop: good for both, in a way, but nothing much to do with the outside world. Industry provides the wealth that finances the science that produces the high technologies that enable the industry to make more wealth, and so on and so on. But industry cannot afford to be altruistic, as its executives are wont to point out. It cannot finance science that does not increase its own wealth. So we have the situation so well recognised in medicine—of drugs developed for western diseases, which are often minor irritations, while the biggies of the world, such as malaria and all the other still rampant tropical infections, are largely neglected. With Aids, the drugs developed primarily for the rich have been made available to (some) poor people only after up-to-the-wire protesting. Last year in the Lancet, Dr Bernard Dixon asked whether Sars might be treated by the well-tried, century-old technique of “passive immunity”—injecting antibodies originally derived from infected patients and multiplied in some neutral organism. This method can be greatly improved by modern biotechnology. Would it not work? Later a drug company executive told him: “Of course it would. But we’ve looked at it and there’s no money in it.” Goodness me. In agriculture the conflict is even more stark. The real threat of genetically modified crops is not that they will poison us but that they are designed to place all agriculture, including that of the developing world, in the hands of a few companies. If the developing world takes its farming down the western industrial route that those companies follow, half of its enormous population will be permanently out of work. All in all, anyone who believes that big corporations do work in the interests of all humanity is living on another planet. Yet I have met many people in high places who do believe this. More pernicious still is the way that privatisation has corrupted the fabric of science itself. Science is dead without honesty, which should be judged as the lawyers judge it: the truth, the whole truth, and nothing but the truth. As things are, this most fundamental principle is compromised at every turn. Bad results are concealed; apparently favourable results are bruited in the spirit of PR; people are bought and/or threatened so that they comply, and even that once final guarantor of honesty, “peer review”, is now routinely circumvented. A cause celebre, described in a book out this year from Sheldon Krimsky of Tufts University School of Medicine, Massachusetts (Science in the Private Interest), is that of Dr Nancy Olivieri, who in the 1990s worked at the University of Toronto and Toronto’s Hospital for Sick Children. She was sponsored by the Canadian Medical Research Council and the drug company Apotex to test the company’s new treatment for thalassaemia, an inherited form of anaemia very common in the Mediterranean and south-east Asia though not so much in Canada. She found the drug did not work as well as Apotex hoped, and had worse side effects than the company had expected. She prepared to publish, as scientists should, and Apotex threatened to sue her. Then the university sacked her. Apotex was preparing to donate $12.7m to the university, and its president was lobbying the Canadian government on the firm’s behalf. Olivieri was finally exonerated and reinstated. But her case leaves a permanent stain, not on her but on academe; and as university vice-chancellors struggle to keep their institutions alive in a world that apparently regards academe as a luxury, it is naive in the extreme to suppose that it was, or is, a one-off. I have seen what I think comes close to perjury many a time—and often on public platforms—in the name of corporate science. What makes it worse is the piety that envelops it: the appeal to “evidence”, which for scientists is the sine qua non. Detractors are not simply derided, but shamed for their sloppy-mindedness. However, the “evidence” typically presented is anything but. There are graphs and statistics—the trappings of science—yet often they signify nothing. I remember a recent defence of golden rice, genetically engineered to be rich in Vitamin A, and hence to save the lives and sight of millions in the developing world. There were pictures of molecules and of poor blind children, and rows of figures to show how many could be helped, were it not for the tiresome non-governmental organisations. But the speaker did not point out that Vitamin A is, in effect, carotene, one of the commonest molecules in nature. It is the yellow pigment that is present (masked by the chlorophyll) in green leaves, and in yellow roots such as carrots and cassava as well as fruits such as papaya and mango. If people practise horticulture, they have Vitamin A aplenty, and traditional farming always included horticulture. Problems start when traditional mixed farms are replaced by monocultural commodity crops for export to make cash for the owners of the new estates. Golden rice is not the antidote to old-fashioned inadequacy, as the speaker implied. It merely solves (partially) a problem created by modernity. Then there is the new spectre of “confidentiality”, a long name for secrecy. Trials to test the safety of innovations, from toothbrushes to GM crops, used to be carried out by government scientists. Now, increasingly, they are by law in the hands of the producers themselves who—again protected by law—are not obliged to reveal all their results and methods. We must just take their word for it. Often the “evidence” presented in defence of, say, GM crops runs to thousands of pages, apparently covering many hundreds of trials, all of them carefully designed at great expense in the public interest. When Saddam Hussein presented the UN with a 10,000-page apologia for the weapons he apparently did not have, he was greeted with scepticism. The plausibility, diplomats felt, was inversely related to the bulk. Indeed so. Peer review? Well, it has never been quite what it was made out to be. There has always been bias. Much worse, however, is the state described by Richard Horton, editor of the Lancet, in the New York Review of Books last month. Drug companies now pay academics to give papers at international conferences, reporting favourable results from trials. (The companies also pick up all the other delegates’ expenses, including evening concerts and day trips, and generally shower them with gifts. I have picked up the odd diary myself over the years.) These papers are then published, and commonly appear as supplements in respectable scientific journals, often with little or no peer review and with no direct input from the editor. This is PR, but it is solemnised by the reputation of the journal, in turn built up by the honesty of others. There is one final twist, an abstract one but perhaps most damaging of all. Science, since its outset, has been fostered as a rational pursuit. It is the ultimate cerebration. Scientists sometimes appear as cold fish even though they are driven by passion. They suppress their passions as a matter of strategy, to keep their thoughts clearer. Yet all serious scientists, from the Greeks onwards, have recognised the limitations of their cerebrations. First, they acknowledge that the human ability to find out, and to understand, is limited. Second, they recognise that however hard they try, they can never eliminate subjectivity or mistakes. Science is often presented as a seamless edifice of certainty, “rational” all the way through, where in reality it has the texture of Dundee cake: currants of “fact” and raisins of well-tried theory contained in a dough of rhetoric and supposition. It relies far more on untried dogma than is commonly admitted. Third, scientists with a taste for philosophy—as the best ones have—recognise that “rationality” is not all there is. It is only half of being human This idea is expressed in many ways—the Greeks pitting Apollo against Dionysus; Thomas Aquinas insisting that understanding requires both the empiricism of science and divine revelation; David Hume proclaiming that we cannot derive “ought” from “is”; and the entire Romantic movement, emphasising the absolute need for emotional response as a guide to human action. Now, in the debased discussions that pass for critical debate, science is flaunted as if it had in fact achieved its own ideal, as if it really is as “rational” as its best exponents aspire to be. That is a mistake in itself. To compound matters, rationality is increasingly equated with expediency, and expediency with profit. So it is “rational” to seek to make as much money as possible out of farming, say, and “irrational” to bang on about employment, and ways of life, and autonomy, and suchlike abstractions. As the coup de grace, policy is increasingly decided on the basis of what is “rational”, which is equated both with what is commercially expedient and with what science says should happen. So it is that GM crops are being wished upon us on the grounds that there are no “scientific” reasons for not growing them. Anyone who cares about science—as well as anyone who cares about humanity, and good thinking—should be appalled by such nonsense. But it has become the norm, and is presented with all the pompous piety for which we deride the worst of clerics. Scientists and politicians are forever banging on about the need for “public debate” on the various manifestations of science, albeit with the implication that the status quo is basically fine and that the net flow of ideas should be de haut en bas. Well, we do need a public debate, but not the kind usually proposed. To put things right we need to dig very deep indeed, back to Pythagoras, and on from there, taking in most branches of moral philosophy, economics and theology. Otherwise the future life of humanity is going to be both more brutal and far shorter than it needs to be.

Baba Ramdev’s plan for reviving agriculture

Tens of thousands of people had come to Delhi to support the fast of Swami Ramdev that began on June 4. In the early hours of June 5 (the midnight of June 4/5) Delhi police backed by Rapid Action Force sweeped on sleeping protestors using teargas and lathi-charge to evicted them.

Devinder Sharma

Standing on the dais and looking at the sea of humanity that braved the heat of the peak summer season in New Delhi, I wondered what these millions were here for. It had been almost ten hours since the indefinite fast that Swami Ramdev launched and I was trying to read the faces of some of those who I could see clearly from where I was sitting. This was in the afternoon of June 4.

The turn of events in the next few hours have put a permanent blot on the face of Indian democracy.

These were poor people. A majority of them came from the lower strata of the society. They were drenched in sweat. They had poured in from distant parts of the country. Some came in trains, some in public buses, some came as part of better organised bus loads. With their bags on their heads or slung on their shoulders, and quite a large number coming with their families, including small children, they thronged to Ramlila grounds in the heart of Delhi with a great sense of hope and determination which was clearly visible on their faces. Victim of continuous apathy, neglect and discrimination, they were born in misery and will probably live all through in misery. Treated like cattle, and shunned by the perfumed class who are more or less beneficiaries of the corrupt system, they had demonstrated their willingness to walk the extra mile knowing well it was going to be really hard and tough.

As I sat there on the stage, I could see clearly the mired expressions on some the faces I tried to scan. The Incredulous India, as the Shining India brigade would normally refer the million to, had arrived.

Besides the contentious issue of getting back the black money stashed in safe havens outside the country, Swami Ramdev had struck a common cord with the masses. Here is one person with whom I have interacted in recent times who I find has a finger on the real nerve of the nation. Rooted firmly on the ground, he has relentlessly called for changes in a manner that would have direct bearing on the deprived millions. He talked of providing technical and professional education in regional languages, he talked of repealing the draconian land acquisition provisions and also understood how dangerous it would be for not only country’s food security but also the national sovereignty by allowing indiscriminate transfer of agricultural land for non-agricultural purposes.

At a time when the perfumed class chanted the mantra of development — by usurping the natural resources and by displacing the millions — Swami Ramdev talked of empowering the masses. And that is why Shining India in reality hated him, and in lot many ways feared him. Ever since the time I fist sat down with him to discuss what is going wrong with agriculture I found in him someone who was not only receptive but also wanting to understand the complexities and look for viable solutions. To me — and also for him — reviving agriculture and thereby empowering the masses is the key to true economic growth, progress and happiness. I could therefore see in him as an amplifier, someone who could carry the message loudly and clearly. He had the strength to demonstrate that another India is possible. He was keen to help provide viable alternatives.

At a time when the State was colluding with the Corporates to take over agriculture and push farmers out of farming, Swami Ramdev emerged as a strong voice in favour of self-reliance. The charter of demands that HRD Minister Kapil Sibal now frowns at actually had a number of such positive elements for transforming agriculture thereby effectively ensuring household food security and minimising hunger and poverty. It was after a lot of deliberations that Swami ji had narrowed down a vast plethora of issues to some salient features that needed immediate attention. These set of interventions were included in the list of demands that Swami Ramdev had sent to the Prime Minister.

The first set of demands pertained to land aacquisitions. Primarily, the demand was for not allowing agricultural land — whether it is mono-cropped or multi-cropped — to be diverted for non-farm purposes. Even where it is to be definitely acquired given the nature of public utility, permission has to be sought from the Gram Sabhas. It was pointed out very clearly that already the country is in the throes of a crisis given that the demand for food is requiring more area to be maintained under agriculture. For instance, it was pointed out that if India was to grow domestically the quantity of pulses and oilseeds (in the form of edible oil) that are presently imported, an additional 20 million hectares would be required.

Preserving productive agricultural land for cultivation therefore assumes utmost importance. In the United States, the US government is providing US $ 750 million for the the period 2008-13 under the Farm Bill 2008 to farmers to conserve and improve their farm and grazing lands so as to ensure they do not divert it for industrial and private use. On the contrary, India is in a hurry to divest its farm lands and turn them into concrete jungles in the name of development.

India is faced with a terrible agrarian crisis. The serial death dance across the country, with over 2.5 lakh farmers already committing suicide, shows no signs of ending. Much of the crisis is because of the unsustainable farming practices that have turned the Green Revolution to a Gray revolution. Reviving agriculture and restoring the pride in farming form the two most important planks of any nationwide strategy to revitalise the rural economy. The following are some of the key elements of the farm strategy and the immediate approach that needs to be followed:

a) Knowing that GM crops/foods pose serious environmental and health hazards, Swami Ramdev had asked for a 10-year moratorium on Bt-Brinjal and all field trials and commercial release of GM crops. The basic purpose is to ensure that the biotech industry is not allowed to contaminate the environment and thereby destroy the biodiversity that is available. He had also demanded that facilities for 29-biosafety tests that the Supreme Court nominee on the Genetic Engineering Assessment Committee (GEAC) Dr Pushpa Bhargava had called for be first ensured before any GM crop/food is allowed for commercial release.

b) Seed is emerging a major issue of contention for farmers. Over the years, the government has facilitated the takeover by private industry of the seed supply and trade. This has taken away the control of farmers over their seed. Although there were a number of suggestions and approaches that we discussed, finally Swami Ramdev included two major areas of focus in relation to seed. First was the need to regulate seed price considering that industry continues to fleece farmers by charging exorbitantly. Secondly, every district should have a community-controlled seed centre with a gene bank for traditional seeds. The local available seed diversity needs to be protected and conserved at any cost.

c) The use and abuse of chemical pesticides has played havoc with human health, the food chain and also resulted in an unbalanced biological equilibrium in nature. It is now being realised that agriculture can perform much better without the use of chemical pesticides which are not only a drain on the farmers pockets but also is harmful for human health and environment. Following the decision to phase out dreaded chemical pesticide Endusulfan under the Stockholm Convention, the demand was to also ban 67 pesticides which are being used in India but are banned for use elsewhere.

d) A beginning could also be made by ensuring that in the proposed 12th Five Year Plan at least a target to convert 25 per cent of the total agriculture area be fixed for converting to zero pesticides use. Already 40 lakh acres in Andhra Pradesh has been brought under non-pesticidal management by under a government programme and this could be replicated across the country.

e) A National Sample Survey Organisation (NSSO) survey had concluded that the average monthly income of a farming family in India does not exceed Rs 2400. No wonder, more than 40 per cent farmers have expressed the desire to quit farming if given an alternative. Because of the dwinling farm incomes more and more agrarian distress is becoming visible. A Farmers Income Commission therefore needs to be setup and income guaranteed to the farmer under a Farmers Income Guarantee Act (FIGA)

f) It is strange paradox that while 32 crore people go to bed hungry every night foodgrains continue to rot in storage. A centralised procurement and distribution network has failed to ensure that food reaches those who need it most. Suggesting for local production, local procurement and local distribution, community grain storage banks need to be established in every panchayat. This will not only minimise grain wastage but also ensure that food reaches the hungry.

g) Education in the Agriculture, Health and Engineering Sectors should also be in Hindi and other State languages.

I don’t think any political party or the common minimum programme of the successive coalitions that ran the country have ever projected such a comprehensive agricultural and rural economy plan. Unfortunately, amidst the din and noise created over black money and corruption, the proposals to revitalise the rural economy by strengthening agriculture were simply ignored. The nation therefore lost a historic opportunity to debate and deliberate on some worthwhile approaches that could usher in self-reliance in agriculture and put an end to farmer suicides. #

Government’s response to Ramdev’s Demands

response to baba ramdev’s demands down load

Govt’s response as put up on the PIB home page. The very last paragraph is on Agriculture.

The govt is claiming that already many programmes are underway to promote organic farming, bio-pesticides and bio-fertilisers – they name RKVY, NPOP/NCOF, NHM amongst these. They claim that organic farming has reached 10.8 lakh hectares from 42000 hectares in 2004-05 because of all of this. “All these will be strengthened and expanded”.

On pricing support, the govt defends CACP and how things are based on cost data.

Microbial properties, enzyme activities and the persistence of exogenous proteins in soil under consecutive cultivation of transgenic cottons (Gossypium hirsutum L.)

PLANT SOIL ENVIRON., 57, 2011 (2): 67–74 67

Z.H. Chen, L.J. Chen, Y.L. Zhang, Z.J. Wu

Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, P.R. China


One Bacillus thuringiensis (Bt) and two stacked Bt and cowpea trypsin inhibitor (Bt + CpTI) cottons and their non-transgenic isolines were consecutively cultivated to investigate the soil persistence of Cry1Ac and CpTI pro­teins and their effects on microbial properties and enzyme activities involving C, N, P, and S cycling in soil. Results showed that there were the persistence of Cry1Ac and CpTI proteins in soil under 4-year consecutive cultivation of transgenic cottons. Cry1Ac proteins varied from 6.75 ng/g to 12.01 ng/g and CpTI proteins varied from 30.65 to 43.60 ng/g. However, neither of these two proteins was detected in soil under non-transgenic cottons. Soil micro­bial biomass carbon, microbial activities, and soil enzyme activities (except urease and phosphodiesterase) signifi­cantly decreased in soil under transgenic cottons. Correlation analysis showed that most of microbial properties and enzyme activities in soil had a negative relationship with Cry1Ac content, while most of them had a positive relationship with CpTI content. Our data indicate that consecutive cultivation by genetically modified cottons with Bt and CpTI genes can result in persistence of Cry1Ac and CpTI proteins and negatively affect soil microbial and biochemical properties.