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DD2002-41: Determination of the Safety of Dow AgroSciences Canada Inc. and Pioneer Hi-Bred International's Insect Resistant and Glufosinate - Ammonium Tolerant Corn (Zea mays L.) Line 1507

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Issued: 2002-10

This Decision Document has been prepared to explain the regulatory decision reached under the regulatory directive Dir94-08 "Assessment Criteria for Determining Environmental Safety of Plants with Novel Traits" and its companion document Dir94-11 "The Biology of Zea mays L. (Corn/Maize)" and Dir95-03 "Guidelines for the Assessment of Livestock Feed from Plants with Novel Traits."

The Canadian Food Inspection Agency (CFIA), specifically the Plant Biosafety Office and the Animal Feed Division, have evaluated information submitted jointly by Dow AgroSciences Canada Inc. and Pioneer Hi-Bred International. This information is in regard to the insect resistant and glufosinate ammonium tolerant corn line 1507. The CFIA has determined that this plant with novel traits does not present a significant risk to the environment, does not present concerns for the safety of livestock consuming feed derived from this plant with novel traits, when compared to currently commercialized corn varieties in Canada.

Unconfined release into the environment and livestock feed use of the corn line 1507 is therefore authorized as of October 10, 2002. Any other corn lines and intraspecific hybrids resulting from the same transformation event and all their descendants may also be released, and used for livestock feed, provided

  1. no inter-specific crosses are performed;
  2. the intended use is similar;
  3. it is known following thorough characterization that these plants do not display any additional novel traits and are substantially equivalent to currently commercialized corn, in terms of their potential environmental impact and livestock feed safety; and
  4. that insect resistance management requirements described in the present document are applied.

Table of Contents

I. Brief Identification of Plant with Novel Traits (PNT)

II. Background Information

III. Description of the Novel Trait

  1. Development Method
  2. Resistance to Lepidoperan Pests of Corn
  3. Glufosinate-Ammonium Herbicide Tolerance
  4. Stable Integration into the Plant's Genome

IV. Criteria for the Environmental Assessment

  1. Potential of Corn Line 1507 to Become a Weed of Agriculture
    or be Invasive of Natural Habitats
  2. Potential for Gene Flow from Line 1507 to Wild Relatives Whose
    Hybrid Offspring May Become More Weedy or More Invasive
  3. Altered Plant Pest Potential of Line 1507
  4. Potential Impact of Line 1507 on Non-Target Organisms
  5. Potential Impact of Corn Line 1507 on Biodiversity
  6. Potential for Development of Target Pest Resistance to Corn Line 1507
  7. Potential for the Development of Multiple Herbicide Tolerant
    Volunteers and Herbicide Tolerant Weeds

V. Criteria for the Livestock Feed Assessment

  1. Potential Impact on Livestock Nutrition
  2. Potential Impact on Livestock

VI. New Information Requirements

VII. Regulatory Decision

I. Brief Identification of Plant with Novel Traits (PNT)

Designation(s) of the PNT: Line 1507, OECD identifier DAS-01507-01

Applicant: Dow AgroSciences Canada Inc. and Pioneer Hi-Bred International

Species: Corn (Zea mays L.)

Novel Traits: Resistance to lepidopteran pests of corn, including European Corn Borer (Ostrinia nubilalis.), corn earworm (Helicoverpa zea), fall army worm (Spodopera frugiperda) and black cutworm (Agrotis ipsilon). Tolerance to glufosinate-ammonium herbicide.

Trait introduction method: Microprojectile bombardment of plant cells.

Intended use of the PNT: Production of corn for human consumption (wet mill products, dry mill products and seed oil) and oil, meal, grain, silage and other by-products for livestock feed. These materials are not intended to be grown outside the normal production area for corn in Canada.

II. Background Information

Dow AgroSciences and Pioneer Hi-Bred jointly developed a corn line resistant to certain lepidopteran pests and tolerant to the glufosinate-ammonium herbicide. The corn line, designated as line 1507, was developed to provide a method to control yield losses from insect feeding damage caused by certain lepidopteran pests, and to provide an alternative strategy for weed control.

Line 1507 was developed using recombinant DNA technology, resulting in the introduction of bacterial genes conferring lepidopteran resistance and tolerance to glufosinate-ammonium herbicide.

Dow AgroSciences and Pioneer Hi-Bred have jointly provided data on the identity of line 1507, a detailed description of the transformation method, data and information on the gene insertion site, gene copy number and levels of gene expression in the plant, the role of the inserted genes and regulatory sequences, and the full amino acid sequences of the novel proteins. Each novel protein was identified, the mode of action described, characterized and compared to the original donor bacterial proteins. An evaluation of their potential toxicity to livestock and non-target organisms and potential allergenicity to humans and to livestock was provided. Relevant scientific publications were also supplied.

Corn line 1507 has been field tested in Canada under confined research field trial conditions from 1999 to 2002. Data generated from field trials in the United States, Chile and Europe was also used to support the application.

Agronomic characteristics of corn hybrids derived from corn line 1507 such as seed dormancy, vegetative vigour, early stand establishment, time to maturity, flowering period, susceptibilities to various corn pests and pathogens, and seed production, were compared to those of unmodified corn counterparts. These comparisons contributed to the safety assessment.

The Plant Biosafety Office, CFIA, has reviewed the above information, in light of the assessment criteria for determining environmental safety of plants with novel traits, as described in the regulatory directive Dir94-08:

The Animal Feed Division, CFIA, has also reviewed the above information with respect to the assessment criteria for determining the safety and efficacy of livestock feed, as described in Dir95-03. The following have been considered:

III. Description of the Novel Traits

1. Development Method

2.Resistance to Lepidoperan Pests of Corn

3. Glufosinate-Ammonium Herbicide Tolerance

4. Stable Integration into the Plant's Genome

IV. Criteria for the Environmental Assessment

1. Potential of Corn Line 1507 to Become a Weed of Agriculture or be Invasive of Natural Habitats

The above considerations, together with the fact that the novel traits have no demonstrable effects on weediness or invasiveness, led the CFIA to conclude that corn line 1507 has no altered weed or invasiveness potential compared to currently commercialized corn.

2. Potential for Gene Flow from Line 1507 to Wild Relatives Whose Hybrid Offspring May Become More Weedy or More Invasive

CFIA therefore concludes that gene flow from line 1507 to wild corn relatives is not possible in Canada.

3. Altered Plant Pest Potential of Line 1507

Based on these points, the CFIA has determined that line 1507 does not display any altered plant pest potential.

4. Potential Impact of Line 1507 on Non-Target Organisms

Based on the above, the CFIA has determined that the unconfined release of line 1507, when compared with currently commercialized corn, will not result in altered impacts on non-target organisms.

5. Potential Impact of Corn Line 1507 on Biodiversity

The CFIA has therefore concluded that the potential impact on biodiversity of corn line 1507 does not present a significantly altered impact in comparison to corn varieties currently being grown in Canada.

6. Potential for Development of Target Pest Restance to Corn Line 1507

CFIA believes that sound management practices and IRM strategies can significantly reduce and delay the development of Cry1F resistant ECB populations, however the ECB populations must be monitored for the development of resistance in a regular and consistent manner. CFIA understands that Dow AgroSciences and Pioneer Hi-Bred have developed and will implement an insect resistance management plan that includes the following key components:

(i) The use of structured refugia to provide a population of insects that have not been exposed to the Cry1F protein and are available to reproduce with potentially resistant insects that may emerge from the Bt crop.

(ii) The early detection of insect populations resistant to the corn-expressed insecticidal protein is extremely important. Close monitoring for the presence of such populations, in insect-resistant corn fields and surrounding areas, is therefore warranted. Monitoring includes the development of appropriate detection tools such as visual field observations and laboratory bioassays, education of growers, reporting schedules, and enforcement procedures in case of resistance development.

(iii) Education tools will be developed and provided to all growers, district managers and field managers. These will include information on product performance, resistance management, monitoring procedures and timetables, detection protocols for resistant individuals, instructions to contact Dow AgroSciences and Pioneer Hi-Bred, and strategies to be followed if unexpected levels of lepidopteran pest damage occur.

(iv) Dow AgroSciences and Pioneer Hi-Bred will have procedures in place for responding to these reported instances of unexpected target pest damage. These procedures will include, where warranted, the collection of plant tissue and pest insects and use of appropriate bioassays to evaluate suspected Cry1F resistant individuals, and a protocol for immediate action to control resistant individuals.

(v) Detection of confirmed resistant lepidopteran pest populations and subsequent action plan will immediately be reported to CFIA.

(vi) Integrated Pest Management practices will be promoted, such as prediction of infestation problems from previous years and crop rotation.

Note: The Plant Biosafety Office periodically audits compliance with the IRM requirements.

7. Potential for the Development of Multiple Herbicide Tolerant Volunteers and Herbicide Tolerant Weeds

If there is general adoption of several different crop species with novel herbicide tolerances, then the potential exists for the development of crop volunteers with a combination of tolerances to different herbicides. Therefore, this technology should be managed as part of an integrated approach which may include currently available weed control products with alternate modes of action, or alternative methods of weed control. Of additional note is the use several crop species in rotation which all rely on tolerance to the same herbicide. Another potential concern is that the continued use of a specific herbicide may provide significant selective pressure for the potential development of herbicide tolerant weeds. Therefore, agricultural extension personnel in both the private and public sectors should promote careful management practices for growers who use these herbicide-tolerant crops to minimize the development of multiple herbicide tolerant crop volunteers as well as tolerant weed populations. The CFIA is currently working with the Pest Management Regulatory Agency of Health Canada to develop strategies which address the issues of multiple herbicide tolerant volunteers and herbicide tolerant weeds in a broad industry led stewardship program.

V. Criteria for the Livestock Feed Assessment

1. Potential Impact on Livestock Nutrition

Nutritional Composition of Corn Line 1507

Composition of grain and whole plant from Line 1507 was compared with an unmodified control corn line with the same genetic background. Data were obtained from trials conducted in four locations in Chile, with sufficient replication to allow for statistical analysis. Whole plant analysis included proximates, acid digestible fibre (ADF) and neutral digestible fibre (NDF). Grain analysis included proximates, major fatty acids, amino acids, tocopherols, B vitamins and minerals. Slight but statistically significant differences in ADF in whole plant were reported. No other differences in whole plant were observed. In grain, there was significantly lower fat, lower manganese and higher potassium in line 1507 compared to the control. These differences were not of significant nutritional consequence, and were likely due to normal variability. There were no other differences between Line 1507 and control grain. All nutrients measured were within the normal range for corn. Additional supporting data from agronomic trials of Line 1507 grown in Ontario was submitted. A study conducted in Italy and France on the nutrient composition in grain and forage of line 1507 and Mycogen Inc. brand hybrid 2722 (a corn variety with similar genetic background as line 1507), showed no difference in proximate analysis for both grain and forage between the two corn lines. The CFIA therefore concludes that line 1507 has equivalent nutritional composition to commercial current corn.

2. Potential Impact on Livestock

Based on the expected exposure levels and the results of the above tests, the CFIA concludes that there is not expected to be any significant risk to livestock from dietary exposure to the Cry1F and PAT proteins in livestock feed.

VI. New Information Requirements

If at any time, Dow AgroSciences and Pioneer Hi-Bred become aware of any information regarding risk to the environment, including the development of lepidopteran pest resistance, or risk to human or animal health that could result from release of these materials in Canada, or elsewhere, Dow AgroSciences and Pioneer Hi-Bred will immediately provide such information to the CFIA. On the basis of such new information, the CFIA will re-evaluate the potential impact of the proposed feed use and environmental release and will re-evaluate its decision with respect to the livestock feed use and environmental release authorizations of this corn line.

VII. Regulatory Decision

Based on the review of data and information submitted by Dow AgroSciences and Pioneer Hi-Bred, and through comparisons of corn line 1507 with unmodified corn counterparts, the Plant Biosafety Office, CFIA, has concluded that the novel genes and their corresponding traits do not confer to these plants any characteristic that would result in intended or unintended significant environmental effects following unconfined release. Dow AgroSciences and Pioneer Hi-Bred have developed and will implement a resistance management plan.

Based on the review of submitted data and information by Dow AgroSciences and Pioneer Hi-Bred, including comparisons of corn line 1507 with unmodified corn counterparts, the Animal Feed Division, CFIA, has concluded that the modified gene and its corresponding novel trait will not confer to these plants any characteristic that would raise any concerns regarding the safety or nutritional composition of corn line 1507 for livestock animals. Grain corn, its byproducts and corn oil are currently listed in Schedule IV of the Feeds Regulations and are, therefore approved for use in livestock feeds in Canada. Corn line 1507 has been assessed and found to be substantially equivalent to traditional corn varieties, with respect to safety and nutritional quality. Corn line 1507 and its products are considered to meet present ingredient definitions and are approved for use as livestock feed ingredients in Canada.

Unconfined release into the environment and livestock feed use of the corn line 1507 is therefore authorized as of October 10, 2002. Any other corn lines and intraspecific hybrids resulting from the same transformation event, and all of their descendants, are also approved, provided no inter-specific crosses are performed, provided the intended use is similar, provided it is known following thorough characterization that these plants do not display any additional novel traits and are substantially equivalent to currently grown corn, in terms of their potential environmental impact and livestock feed safety and provided that pest resistance management requirements described in the present document are applied.

The corn line 1507 is subject to the same phytosanitary import requirements as its unmodified counterparts

Please refer to Health Canada's Decisions on Novel Foods for a description of the food safety assessment of corn line 1507.

This bulletin is published by the Plant Health and Biosecurity Directorate, Canadian Food Inspection Agency. For further information, please contact the Plant Biosafety Office or the Animal Feed Division at:

Plant Biosafety Office
Plant Health and Biosecurity Directorate
59 Camelot Drive
Ottawa ON K1A 0Y9
613-225-2342
Animal Feed Division
Animal Health Directorate
59 Camelot Drive
Ottawa ON K1A 0Y9
613-225-2342
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