Safety Assessment of YieldGard VT Rootworm/RR2
Transcription
Safety Assessment of YieldGard VT Rootworm/RR2
Safety Assessment of YieldGard VT Rootworm/RR2 ™ , MON 88017 Executive Summary Monsanto Company has developed the next generation biotechnology-derived corn product YieldGard VT Rootworm/RR2™ (MON 88017), which combines the benefits of corn rootworm protection of first-generation YieldGard ® Rootworm corn (MON 863) with glyphosate tolerance of Roundup Ready® Corn 2 (NK603). MON 88017 produces a modified Cry3Bb1 protein isolated from Bacillus thuringiensis (Bt) subspecies kumamotoensis that selectively controls the coleopteran insect pest corn rootworm (Diabrotica spp.). MON 88017 also produces the CP4 EPSPS protein from Agrobacterium sp. strain CP4, which confers tolerance to glyphosate, the active ingredient in the Roundup® family of agricultural herbicides. Thus, MON 88017 will provide growers with the combined benefits of insect and weed control. Corn (Zea mays L.) is grown in nearly all areas of the world and ranks third behind rice (Oryza sativa L.) and wheat (Triticum sp.) in total global production. In 2006, 31.7 million hectares (M ha) or 78.3 million acres of corn were planted in the U.S. The average yield of corn grain harvested was 9.4 metric tonnes per hectare (MT/ha) or 149 bushels per acre (bu/A), with a total production of 268 MMT (or 10.5 billion bushels). The corn crop is subject to feeding damage from insects and competition from weeds. Corn rootworm larvae are the major insect pest in the U.S. Corn Belt and cause significant damage by feeding on the roots of corn plants. In 2003, Monsanto commercialized the biotechnology-derived corn product MON 863, which provides an alternative to soil insecticides for the control of corn rootworm larvae. MON 863 produces a Cry3Bb1 protein that selectively controls or suppresses corn rootworm species. This technology has been rapidly adopted by growers with plantings of corn rootworm-protected corn hybrids increasing from approximately 0.2 M ha in 2003 to approximately 4 M ha in 2006. In 1998, Monsanto commercialized first generation Roundup Ready corn, which allowed for the control of weeds by over-the-top application of Roundup agricultural herbicides. This was followed in 2001 by the commercialization of second-generation Roundup Ready Corn 2 (NK603) containing the cp4 epsps gene, which allows for a wider application window and higher rates of Roundup agricultural herbicides for enhanced weed control with minimal crop injury. In the U.S., plantings of corn with Roundup Ready technology have increased from approximately 0.4 M ha in 1998 to approximately 13 M ha in 2006. The introduction of MON 88017 will provide growers with the combined benefits of corn rootworm technology and the Roundup Ready 2 corn system. MON 88017 was developed using a single transformation vector containing both the cry3Bb1 and cp4 epsps genes. This approach, known as vector stacking, increases the efficiency of breeding multiple traits into new corn hybrids, thereby providing growers an earlier ™ ® YieldGard VT Rootworm/RR2 is a trademark of Monsanto Technology LLC. YieldGard, Roundup Ready and Roundup are registered trademarks of Monsanto Technology LLC. access to improved germplasm containing both these traits rather than through conventional inbred stacking. The amino acid sequence of the Cry3Bb1 produced in MON 88017 is >99.8% identical (a difference of one amino acid) to that of the Cry3Bb1 produced in MON 863. The amino acid sequence of the CP4 EPSPS produced in MON 88017 is the same or >99% identical to the CP4 EPSPS produced in the commercial Roundup Ready crops: NK603 corn, soybean cotton, sugarbeet and canola. Therefore, the safety assessment of the Cry3Bb1 and CP4 EPSPS proteins produced in MON 88017 is based on the extensive safety information previously developed for these proteins. The data and information presented in this summary demonstrate the food, feed and environmental safety of MON 88017 based on several lines of evidence. Detailed molecular characterization confirms the insertion of single functional copies of the cry3Bb1 and cp4epsps expression cassettes at a single locus within the genome, the absence of backbone sequences, and stability of the insert across multiple generations. Detailed biochemical characterization of the Cry3Bb1 and CP4 EPSPS proteins produced in MON 88017 demonstrate that they are equivalent to their counterparts produced by recombinant strains of Escherichia coli for use in various safety assessment studies. A thorough assessment of the allergenic and toxic potential of the Cry3Bb1 and CP4 EPSPS proteins produced in MON 88017 show no meaningful risks to human or animal health from exposure to these proteins. The safety of Cry3Bb1 is demonstrated by its lack of allergenic potential, the lack of acute toxicity when ingested, the >99% amino acid sequence identity with the Cry3Bb1 protein produced in MON 863, and similarity to other Cry proteins that have a history of safe use. The safety of the CP4 EPSPS protein is demonstrated by its lack of allergenic potential, the lack of acute toxicity when ingested, the >99% amino acid sequence identity with the CP4 EPSPS proteins present in Roundup Ready crops that have a history of safe use. The risk to humans and animals from exposure to the Cry3Bb1 and CP4 EPSPS proteins in the diet is low based on high margins of exposure calculated from acute toxicology tests and dietary intake estimates. A compositional assessment based on the analysis of 62 important corn food and feed nutrients and antinutrients demonstrates that MON 88017 is substantially equivalent to conventional corn. A nutritional assessment in a broiler feeding study shows that diets containing MON 88017 are as wholesome as diets containing control or conventional corn. An environmental assessment, including the evaluation of phenotypic, agronomic, and ecological interaction characteristics, show that MON 88017 is no more likely to become a weed than conventional corn. An assessment of the potential effects of Cry3Bb1 on nontarget organisms (NTOs), based on the history of safe use of Cry3 proteins in Bt microbial products and the functional equivalence to the Cry3Bb1 produced in MON 863, shows it poses no increased risk to NTOs in the environment including endangered species. Likewise, an assessment of the potential effects of CP4 EPSPS on nonpest organisms, based on the lack of biological activity and confirmatory observations, shows that it is unlikely to have an impact on nontarget and endangered species. An environmental fate assessment of the Cry3Bb1 and CP4 EPSPS proteins shows that they are rapidly degraded in the environment and are unlikely to have an impact on soildwelling NTOs. These conclusions regarding the food, feed and environmental safety of MON 88017 are supported by a number of independent reviews conducted by governmental agencies that have granted regulatory approvals for this product.