DANBURY, Texas -- Nearly 5 million pounds of genetically modified rice -- the first of its kind -- is to be buried in a landfill next week under orders from the company that had it grown in Brazoria County.
Aventis, which took a public relations hit when its bioengineered StarLink corn was mistakenly released to consumers, apparently has decided to destroy its first crop of genetically altered rice rather than risk its being shipped outside the United States, where it has not been approved.
The company won't release the rice for famine relief even though the U.S. Food and Drug Administration has approved it, said Jacko Garrett, the farmer who grew the rice under contract with Aventis.
Garrett, who formed the nonprofit Share The Harvest foundation, through which Texas farmers donate rice to the needy, is frustrated that the food won't be given away.
Trucks will start hauling the rice to a landfill near Alvin on Monday, he said.
"It just bothers me so bad when I'm sitting here trying to find food to feed people and I've got to go bury 5 million pounds of rice when we know it won't hurt a soul," Garrett said Thursday. "That's 40 million people you can feed with that 5 million pounds of rice."
Aventis officials have said they don't want to risk the liability that could result if some of the rice should reach markets outside the United States, he said.
"If it does, it's going to bring them more negative publicity than they would want to handle," said Garrett, who said he understands the company's legal concerns.
Because he grew the rice under contract to Aventis, he said, he is obligated to follow the company's wishes to dump it.
Officials at Aventis CropScience in Research Triangle Park, N.C., did not return calls for comment.
Aventis, a publicly traded company with headquarters in Strasbourg, France, has been caught in the middle of the debate over biotech food.
The company was sued last year after its genetically engineered StarLink corn was discovered in taco shells by a coalition of environmental and consumer groups. Government regulators had approved StarLink only for animal feed and industrial uses because of unresolved questions about whether it can cause allergic reactions.
The corn has not been proven to cause allergic reactions, but Aventis has not been able to track where all of it was sent.
Known by the trade name Liberty rice, the grain that was grown in Brazoria County for the company marked the first time that conventional rice had been genetically modified and grown for commercial use.
Because it is resistant to one particular herbicide, farmers can eliminate the use of others that usually are needed to control weeds and grasses.
At Garrett Farms, between Alvin and Angleton, Liberty rice was the highest-yielding, most-weed-free rice that was planted last year, Garrett said.
"I had no expectation that it would do the way it did," he said.
Genetically altered corn, soybeans and cotton have been grown in the United States for more than five years and the Grocery Manufacturers of America estimate that 60 to 70 percent of all processed foods may contain biotech soy or corn.
While Americans do not have strong opinions about genetically modified food, according to a recent poll, opposition is strong in Europe and Japan.
Aventis, formed in 1999 by a merger between French and German companies, announced in November that it intends to divest itself of its agricultural interests and focus on pharmaceuticals. The company had $22.3 billion in sales last year.
Unless the company changes its mind, Garrett said, it will take 95 truckloads to take all of the Liberty rice from seven bins at his farm to the landfill.
"And here I could be sending it to USA food banks or foreign countries in famine," he said. "They're dying because there's no food and here we are burying food, simply because it's genetically modified.
"I have to wonder when people will accept these technologies for the good they bring and allow us to better feed the world and reduce exposure to pesticides and herbicides."
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EARLIER NLPWESSEX POST 12 DECEMBER 2000
"Results indicate that excessive injury and yield reduction of glufosinate-resistant rice lines can occur if glufosinate is applied too early or too late in the growing season."
NATURAL LAW PARTY WESSEX nlpwessex@bigfoot.com www.btinternet.com/~nlpwessex ---------------------------------------------------------------------------- Weed Science Society of America Abstracts, Vol 39, 1999
(11) Tolerance of glufosinate-resistant rice lines to glufosinate. D. Y. Lanclos*, E. P. Webster, J. L. Griffin, S. D. Linscombe, and W. Zhang, Louisiana State Univ. Agric. Center, Baton Rouge.
A study was conducted in 1998 at the Rice Research Station near Crowley, LA to evaluate rice injury and yield in glufosinate-resistant rice lines, associated with glufosinate applications throughout the growing season. Glufosinate-resistant rice lines 'CPRS PB-13' and 'BNGL HC-11', were drill seeded in a Crowley silt loam soil. Glufosinate was applied at a rate of 0.84 kg ai/ha in single weekly applications starting 2 d after emergence (DAE) and continuing through 56 DAE. A weekly treatment of glufosinate at 0.42 kg/ha was added for comparison. Injury for the two lines consisted of chlorosis with some necrosis in the BNGL HC-11 at the first two application timings. At 5 d after the 2 DAE application, rice injury was 14 and 33% for CPRS PB-13 and BNGL HC-11, respectively. 'BNGL HC-11' was injured 71% at 14 d after the 7 DAE application compared with 14% for CPRS PB-13. Yield for CPRS PB-13 ranged from 6674 kg/ha treated 56 DAE to 7382 kg/ha treated 21 DAE, with no differences compared with the nontreated. BNGL HC-11 yielded 8596 kg/ha treated 35 DAE, which was greater than any other treatment; however, when treated 56 DAE yield was 5865 kg/ha which was lower than any other treatment. Weekly applications of glufosinate at 0.42 kg/ha did not reduce CPRS PB-13 yield compared to the nontreated; however, BNGL HC-11 yield was reduced 49% compared to the nontreated. Results indicate that excessive injury and yield reduction of glufosinate-resistant rice lines can occur if glufosinate is applied too early or too late in the growing season. =============================================================== 3. EARLIER NLPWESSEX POST 4 January 2001
As shown in this paper from the University of Texas the use of the CaMV viral promoter in transgenic plants is still continuing to cause considerable problems in transgenic plants.
It is clear from this and other papers that the behaviour of this viral promoter is not properly understood and that a great deal of research is still needed. All the more remarkable, therefore, that so many GM crops including the CaMV promoter have already been approved for use in world agriculture:
"...we have used physical (electroporation, microprojectile bombardment) techniques to transform rice cells or tissues and have developed reliable procedures for regenerating fertile rice plants. ...we became concerned by the frequent insertion of multiple copies of the transgene and by the fact that many of these copies were found to be rearranged....
In one set of experiments, we recovered a large number of rice transformants in which a CaMV 35S promoter was used to drive expression......Detailed analysis of these plants revealed that they contained multiple copies and rearranged inserts that frequently displayed non-Mendelian segregation of transgene expression....
...the 35S and mubi1 promoters were extensively methylated and transcriptionally inactivated in the silenced lines(2,3). The silenced state was stably transmitted to the next generation as indicated by the lack of expression of the bar gene in R2 progeny derived from the silenced lines.....Analysis of progeny of selfed plants homozygous for herbicide resistance revealed that silencing can arise in later (R2 and R3) generations, resulting in bialaphos-sensitive plants that showed no bar transcripts....
The evolution of sensitive systems for protecting self DNA from non-self DNA perhaps parallels that of the immune system and accounts for the ability of plants and other organisms to inactivate transgenes.....although full insight to these interactions remains to be uncovered".
Tim Hall, Institute of Developmental and Molecular Biology, Texas A&M University
For more information on the hazards associated with the use of the CaMV promoter in transgenic plants see: www.btinternet.com/~nlpwessex/Documents/camv.htm
NATURAL LAW PARTY WESSEX nlpwessex@bigfoot.com www.btinternet.com/~nlpwessex -----------------------------------------------------------------
CAN "STEALTH" APPROACHES DEFEAT GISMOS?
Tim Hall and his research group helped pioneer plant transformation by expressing the bean seed protein phaseolin in tobacco, a dicot plant. In seeking to broaden the scope of his research to include monocot transformation, he became aware of the difficulty in obtaining reliable expression using naked DNA in physical transformation techniques for rice. His group is currently gaining insight to silencing mechanisms and ways to avoid them.
The beneficial application of recombinant biotechnology to improve agronomic properties of major crops is well exemplified by advances made in rice. In a recent article in ISB News Report (December, 2000), Swapan Datta provided important insight to the ways in which gene cloning can be allied with innovative sexual breeding strategies to provide higher-yielding varieties to meet the ever-increasing global need for food. My research group is interested in the use of Bt (Bacillus thuringiensis) protein toxins to combat insect pests in rice. Our target insect is the rice water weevil (Lissorhoptrus oryzophilus), the most damaging and ubiquitous insect pest of rice in the US, and a serious pest worldwide.
With support from The Rockefeller Foundation, the Texas Advanced Technologies Program, and other sources, we have used physical (electroporation, microprojectile bombardment) techniques to transform rice cells or tissues and have developed reliable procedures for regenerating fertile rice plants. From examining genomic blot analysis of numerous gene constructs, we became concerned by the frequent insertion of multiple copies of the transgene and by the fact that many of these copies were found to be rearranged. Although early (callus-stage) screening of easily-detected resistance marker or reporter (e.g., GUS) genes can facilitate the recovery of plants expressing the gene of interest, we noted that primary and progeny plants not thus screened frequently failed to yield the expected expression of the transgene constructs, suggesting that silencing had occurred. Whereas important insight to gene silencing and cosuppression had been reported in dicot plants(1), no such reports existed for monocots and we decided to undertake a detailed analysis of our transgenic rice lines.
In one set of experiments, we recovered a large number of rice transformants in which a CaMV 35S promoter was used to drive expression of a Bt cryIIIA coding region and the maize ubiquitin promoter (mubi) to drive the bar gene as a selectable marker for bialaphos herbicide resistance. Detailed analysis of these plants revealed that they contained multiple copies and rearranged inserts that frequently displayed non-Mendelian segregation of transgene expression.
Characterization of R1 progeny by methylation-sensitive isoschizomer restriction digestion, nuclear run-on, and RNase protection assays revealed that the 35S and mubi1 promoters were extensively methylated and transcriptionally inactivated in the silenced lines(2,3). The silenced state was stably transmitted to the next generation as indicated by the lack of expression of the bar gene in R2 progeny derived from the silenced lines. The epigenetic modification of the transgene sequences was further confirmed by the reactivation of the bar gene expression in R2 seedlings (from the silenced lines) germinated on medium containing 5-azacytidine (5azaC). Analysis of progeny of selfed plants homozygous for herbicide resistance revealed that silencing can arise in later (R2 and R3) generations, resulting in bialaphos-sensitive plants that showed no bar transcripts.
As in the case of our rice lines, DNA methylation is frequently associated with transgene silencing(4). However, in most instances, it is likely that silencing arises from heterochromatin formation resulting from the binding of proteins such as MeCP2 that recognize methylated DNA and that, in turn, recruit histone deacetylases to form a repressive chromatin architecture(5). DNA methylation can be stimulated in many ways. Although cruciform integration intermediates appear to be especially well-recognized by DNA methyltransferases(6), repeat sequences and perhaps certain features of sequence composition or structure of transgenes mark them as being invasive DNA. In accord with the concepts of Bestor and Tycko(6), we suggest that several "genome intruder surveillance and modulation systems" (GISMOS) exist to screen, detect, and modify both extra- and intra-genomic DNA parasites such as transposons(7). The evolution of sensitive systems for protecting self DNA from non-self DNA perhaps parallels that of the immune system and accounts for the ability of plants and other organisms to inactivate transgenes. Similar rationale exists for the development of post-transcriptional silencing systems that are very effective against viral invasion and aberrant RNA expression levels from transgenes [reviewed in (8)].
Is it reasonable to believe that the design of transgenes can be such that they evade recognition by GISMOS? Like aircraft that escape radar detection, we can envision such designs as "stealth" constructs, and we have speculated that this may be feasible as we gain better insight to the full spectrum of silencing mechanisms(7,8). Powerful approaches are now being employed to increase such understanding, landmark discoveries such as finding in Arabidopsis that plants with a deficient methylation system (the ddm1 mutation) were unable to maintain silencing and that plants with mutation of the MOM gene release transcriptional silencing(9). The fact that the ddm1 gene encodes a SWI2/SNF2-like protein(10) reinforces the connection between chromatin architecture, methylation, and silencing, although full insight to these interactions remains to be uncovered. The directed debilitation of plant genes conjectured to be involved in gene silencing, for example by RNAi approaches(11), promises to reveal the GISMOS' inner secrets. As the veils are removed, it appears certain that we will also obtain novel revelations concerning epigenetic regulation of plant development that will be helpful in developing stealth transgene strategies.
Sources
1. Matzke MA and Matzke AJM. 1990. Gene Interactions and Epigenetic Variation in Transgenic Plants. Developmental Genetics 11: 214-223.
2. Kumpatla SP and Hall TC. 1999. Organizational complexity of a rice transgene locus susceptible to methylation-based silencing. IUBMB Life 48: 459-467.
3. Kumpatla SP, Teng W, Buchholz WG, and Hall TC. 1997. Epigenetic transcriptional silencing and 5-azacytidine-mediated reactivation of a complex transgene in rice. Plant Physiology 115: 361-373.
4. Selker EU. 1999. Gene silencing: Repeats that count. Cell 97: 157-160.
5. Nan X, et al. 1998. Transcriptional repression by the methyl-CpG-binding protein MeCP2 involves a histone deacetylase complex. Nature 393: 386-389.
6. Bestor TH and Tycko B. 1996. Creation of genomic methylation patterns. Nature Genetics 12: 363-367.
7. Kumpatla SP, et al. 1998. Genome intruder scanning and modulation systems and transgene silencing. Trends in Plant Science 3: 97-104.
8. Iyer LM, et al. 2000. Transgene Silencing in Monocots. Plant Molecular Biology 43: 323-346.
9. Amedeo P, et al. 2000. Disruption of the plant gene MOM releases transcriptional silencing of methylated genes. Nature 405: 203-206.
10. Jeddeloh JA, Stokes TL, and Richards EJ. 1999. Maintenance of genomic methylation requires a SWI2/SNF2-like protein. Nature Genetics 22: 94-97.
11. Smith NA, et al. 2000. Total silencing by intron-spliced hairpin RNAs. Nature 407: 319-320.
Tim Hall Institute of Developmental and Molecular Biology Texas A&M University mailto:tim@idmb.tamu.edu
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