Questions over USDA’s Role in Transgenic Contamination and Regulation. Prof. Joe Cummins and Dr. Mae-Wan Ho
This article was submitted to the USDA on behalf of I-SIS
Bayer CropScience has filed a request to the United States Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) for non-regulated status for rice with glufosinate herbicide-tolerant event LLRICE601 and any progeny derived from crosses of this event with traditional rice varieties [1]. It is seeking retroactive approval for a transgenic rice variety that has escaped from test plots into commercial rice in the United States and exported to the rest of the world. This has resulted in a virtual collapse of the US rice industry as bans and quarantines were promptly imposed by importing countries, while several lawsuits have been filed by rice farmers against Bayer in the US [2 3], and USDA has responded by announcing an expedited approval process for the rice strain.
USDA/APHIS has opened the Bayer proposal for public comment, and provided background documents on the proposal. In fact, USDA/AHIS has even prepared an environmental assessment on Bayer’s behalf [4], “for a preliminary decision to extend a determination of non-regulated status.”
Bayer CropScience’s request for the extension of LLRICE601 is “based on its similarity to previously deregulated rice lines, LLRICE62 and LLRICE06.”
All comments must be received on or before 10 October 2006, to be filed under APHIS-2006-0140, which can be accessed electronically at: http://www.regulations.gov/fdmspublic/component/main
About a third of the LLRICE601 petition was left blank under “confidential business information” (CBI). This is far from consistent with the scientific requirement for full and truthful reporting. None of the previous petitions for un-regulated status have such extensive designation of CBI, and apparently some of the CBI information has been openly reported previously, and it is clear that USDA/APHIS is not normally required to accept frivolous CBI designations.
Bayer wants to have the present petition considered an extension of its previous petition 98-329-01p for non-regulated status for events LLRICE62 and LLRICE06, which was granted in 1998. Bayer claims that the three rice transformation events yield “equivalent” modifications.
This extension, if granted, would make a mockery of the present event-specific regulation, which recognizes that the transgenic variety resulting from genetic modification technology is specific to the transformation event, and no two events - even in the same experiment using identical constructs, vectors and plant tissues - can be considered “equivalent”.
All three varieties LLRICE601 and LLRICE06 and LLRICE62 have the single bar gene (for glufosinate tolerance) driven by a CaMV promoter. But there the similarity ends. Although they all express the PAT protein that inactivates gufosinate, the protein probably differs in size and level of expression in different lines. The protein in LLRICE601 has an aspartic acid at position 2 where both those in LLRICE06 and LLRICE62 have a serine residue. USDA/APHIS claimed that the difference was insignificant because many other crops with similar variants have been designated unregulated. But past mistakes in regulation does not make the present one right. Moreover, the N-terminal amino acids are normally involved in important cellular transactions that are very likely to be affected by the amino acid substitution.
LLRICE06 and LLRICE62 were produced by a process described as “direct”gene transfer, while LLRICE601 was produced by Agrobacterium transformation. The CaMV promoter is longer in LLRICE601 than in LLRICE06 and LLRICE62. LLRICE601 uses the nos terminator while LLRICE06 and LLRICE62 use the 35S CaMV terminator. LLRICE601 also has a second CaMV promoter inserted somewhere in the genome during the transformation of the rice cells.
Above all, each transgenic rice variety has chromosomal inserts at different locations in the genome, and involved genetic modification of different rice varieties: LLRICE06 was created from medium grain variety M202, LLRICE62 from the medium grain variety Bengal, and LLRICE601 from the long grain variety Cocodrie.
Thus, there are many important differences between LLRICE601 and LLRICE06 or LLRICE62, and they can in no way be considered “equivalent” [1, 3-6].
LLRICE601 has been implicated in widespread pollution of rice grown in the United States. However, during the period that Bayer’s varieties LLRICE06 and LLRICE62 (both unregulated), and LLRICE601 (now seeking approval) were tested in open fields in Louisiana and Arkansas, other field trials were taking place. These were Liberty rice events developed jointly by the USDA, University of Arkansas and University of Louisiana, with DNA inserts similar to LLRICE601, LLRICE06 and LLRICE62, but have not yet been submitted for unregulated status.
As field tests of the USDA-Universities Liberty rice events overlapped in time and location with the origins of the transgenic contamination of rice stocks (see below), one should expect USDA/APHIS to recuse (disqualify) themselves from the investigation of the genetic contamination of food crops by LLRICE601 on the basis of possible involvement or conflict of interest, and to allow a body of competent, independent investigators to conduct the investigations at “arms length”.
The USDA-University transgenic rice events field-tested alongside Bayer’s three LLRICE events were produced in Louisiana. Using biolistic methods, a number of rice lines were transformed with a plasmid delivering the bar gene (driven by the CaMV 35S promoter and maize alchohol dehydrogenase intron, and terminated by the nos terminator), accompanied by a hygromycin resistance gene and a GUS (enzymatic color marker), both also driven by the CaMV 35S promoter. Transformants containing low copy number of inserts failed to express the gus gene due to gene silencing [7]. Hybridization between the transformed transgenic rice lines (Cypress and Bengal) and the weed red rice was carried out to examine the spread of transgenes to weedy relatives and the dispersal and dormancy of weed hybrid seed. Seed dormancy and dispersal were about the same in transgenic and non-transgenic lines [8], while out-crossing frequency of glufosinate resistance to weedy red rice was about 0.3 percent [9]. USDA was involved in studying the spread of transgenes from rice; and hence must have been aware that extensive field-testing in the rice growing areas of Louisiana and Arkansas could only result in extensive transgene contamination of the commercial crop.
Even though field tests of transgenic rice have been done in Puerto Rico, Texas, California, Mississippi, Louisiana and Arkansas, the main impact of transgenic contamination ascribed to LLRICE601 appears to be centered around Arkansas and Louisiana. The USDA center of rice research and rice germplasm storage is located at the Dale Bumpbers National Research Laboratory in Stuttgart, Arkansas County. The University of Arkansas, too, has a rice research laboratory in Stuttgart. Both laboratories were involved in the development and testing of Liberty transgenic rice. Bayer’s LLRICE601 field test sites were located in Drew Crittenden County and Jackson County [1], all within less than an hour’s drive from the USDA laboratory in Arkansas County; and the USDA rice tests were located in Hempstead County [8, 9], within easy reach of the USDA laboratory.
LLRICE601 was transformed using the Agrobacterium vector system that integrates T-DNA from a disarmed Ti (tumour-inducing) plasmid. There is evidence of multiple complex patterns of T-DNA integration into the rice genome. About a third of transformation events are accompanied by DNA integrations extending beyond the T-DNA boundaries [10]. Furthermore, T-DNA insertions cause mutations by disrupting target genes in the chromosomal integration site [11]. There appears to be no attempts at identifying the mutated gene(s) in LLRICE601.
Will transgenic pollen introgression into red rice ultimately lead to the formation of a “super” weed? Will multiple-resistance appear in US rice creating super weed volunteers as more than one herbicide-tolerance traits have been used in rice? It seems likely that the multiple herbicide resistance encountered in canola [12] (What Lurks Behind Triple Herbicide-Tolerant Oilseed Rape?) will appear in rice if herbicide tolerant rice is grown on a large scale.
USDA is the final authority on organic certification in the US. But it is taking steps to undermine this standard, as is clear from the USDA/APHIS draft environment assessment of LLRICE601 on behalf of Bayer [4]: “The presence of a detectable residue of a product of excluded methods alone does not necessarily constitute a violation of the National Organic Standards.” In practice, planting genetically-modified seed would render the organic crop non-organic and require it to be sold as conventional. But the USDA/APHIS goes on to state: “The status of the organic operation depends on the operator’s foreknowledge of the origin and status of the seed planted.” In other words, what the operator does not know, does not count. So organic farmers are encouraged to maintain their ignorance. Unfortunately, their customers do not hold the same view.
USDA has not stipulated a requirement that rice fields contaminated with genetically modified rice should be identified, knowing full well that pollen flow will pollute neighboring organic fields, as well as non-organic fields. The polluted “organic” crop may be deemed organic in US but it is unlikely to be so considered in export markets. Approval of transgenic rice should be accompanied by a clear recognition of liability in case of contamination.
Bayer has failed to provide a case for retroactive designation of unregulated status for the LLRICE601, and a clarification is needed on the role of USDA /APHIS as regulator of transgenic contamination when it has all the appearance of being a potential perpetrator.
Article first published 29/09/06
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