![[logo] US EPA](../gif/logo_epaseal.gif){kind=logo}
December 6-8, 2005 Meeting Agenda
December 2
FIFRA SCIENTIFIC ADVISORY PANEL (SAP)
OPEN MEETING
DECEMBER 6-8, 2005
FIFRA SAP WEB SITE https://www.epa.gov/scipoly/sap/
OPP Docket Telephone: (703) 305-5805
Docket Number: OPP-2005-0249
PLANT-INCORPORATED PROTECTANTS BASED
ON VIRUS COAT PROTEIN GENES: SCIENCE
ISSUES ASSOCIATED WITH
THE PROPOSED RULE
TUESDAY, DECEMBER 6, 2005
Holiday Inn - National Airport
2650 Jefferson Davis Highway
Arlington , VA 22202
Telephone: (703) 684-7200
8:30 AM Introduction and Identification of Panel Members - Stephen Roberts, Ph.D. (FIFRA SAP Session Chair)
8:45 AM Administrative Procedures by Designated Federal Official - Paul Lewis, Ph.D.
8:50 AM Welcome - J. Thomas McClintock, Ph.D. (Director, Hazard Assessment Coordination and Policy Division, Office of Science Coordination and Policy, EPA)
8:55 AM Opening Remarks - Janet Andersen, PhD. (Director, Biopesticides and Pollution Prevention Division, Office of Pesticide Programs, EPA)
9:00 AM Regulatory Overview of PIPs - Sharlene Matten, Ph.D. (Office of Pesticide Programs, EPA)
9:15 AM Setting the Stage: PVCP-PIPs - Elizabeth Milewski, Ph.D. (Office of Science Coordination and Policy, EPA)
9:30 AM Summary of EPA's Position on Gene Flow and Its Environmental Impact - Anne Fairbrother, PhD. (National Health and Environmental Research Effects Laboratory, ORD, EPA)
10:00 AM BREAK
10:15 AM Summary of EPA's Position on Viral Interactions and PTGS - Melissa Kramer, Ph.D. (Office of Science Coordination and Policy, EPA)
10:45 AM Summary of EPA's Position on Issues Associated with Exposure to PVC-Proteins - Rebecca Edelstein, Ph.D. (Office of Pesticide Programs, EPA)
11:15 AM Summary of EPA's Position on Environmental Safety of Selectable Markers - Tessa Milofsky, M.S. (Office of Pesticide Programs, EPA)
12:00 PM LUNCH
1:00 PM Public Comments
2:00 PM Panel Discussion
Gene Flow Issues
With the assistance of the October 2004 SAP, EPA has identified the following plants as not having wild or weedy relatives in the United States, its possessions, or territories with which they can produce viable hybrids in nature : almond ( Prunus communis ), apricot ( Prunus armeniaca ), asparagus ( Asparagus officinale ), avocado ( Persea americana ), banana ( Musa acuminata ), barley ( Hordeum vulgare ), bean ( Phaseolus vulgaris ), black-eyed pea ( Vigna unguiculata ), cacao ( Theobroma cacao ), celery ( Apium graveolens ), chickpea ( Cicer arietinum ), citrus ( Citrus spp .), coffee ( Coffea arabicua ), corn ( Zea maize ), cucumber ( Cucumis sativus ), eggplant ( Solanum melongena ), guava ( Psidium guajava ), kiwi ( Actinidia spp. ), mango ( Mangifera indica ), nectarine ( Prunus persica ), okra ( Abelmoschus esculentus ), olive ( Olea europaea ), papaya ( Carica papaya ), parsley ( Petroselinum crispum ), pea ( Pisum sativum ), peach ( Prunus persica ), peanut ( Arachis hypogaea ), pineapple ( Ananas comosus ), pistachio ( Pistacia vera ), plum ( Prunus domestica ), potato ( Solanum tuberosum ), soybean ( Glycine max ), spinach ( Spinacia oleracea ), starfruit ( Averrhoa carambola ), taro ( Colocasia esculenta ), tomato ( Lycopersicon lycopersicum ), or watermelon ( Citrullus lanatus ) .
1(a). Does this list identify plant species that would present low risk of conferring any selective advantage on a wild or weedy relative in the United States , its possessions, or territories were they to contain a PVCP-PIP? Please explain the basis for your answer, providing documentation to support your decision.
The October 2004 SAP noted that some of the plants on this list (i.e., asparagus and celery) were able to escape cultivation and form occasional volunteer populations. EPA notes that in addition to these two species, many other species from this list have naturalized populations in the United States (i.e., plants occurring in natural areas outside of agricultural fields and not simply volunteer plants within other fields). For example, the USDA PLANTS database (accessible at http://plants.usda.gov/ ) indicates that almond, apricot, avocado, banana, barley, bean, black-eyed pea, cacao, chickpea, citrus, coffee, corn, cucumber, eggplant, guava, mango, okra, olive, papaya, parsley, pea, peach, peanut, pineapple, plum, potato, soybean, spinach, taro, tomato, and watermelon have "native or naturalized" populations in the United States.
Based on this information, it appears that the ability to naturalize is common for crops. However, it can be hypothesized that naturalized populations of these particular crop plants possess a suite of traits that facilitate cultivation in a managed habitat and likely confer a selective disadvantage on plants in the wild. Acquisition of a single trait, i.e., virus resistance, would therefore not be expected to provide sufficient competitive advantage to make naturalized populations of these plants significant weed problems outside of agricultural fields.
1(b) What data supports or refutes the rationale above that naturalized populations of plants on the list in question 1(a) would not be expected to become weedy or invasive outside of agricultural fields if they were to acquire virus resistance from a PVCP-PIP (assuming that the cultivated crop is negatively affected by virus infection and a PVCP-PIP targeted at that virus is developed)? If the rationale does not apply to all the crops on this list, is there an alternative rationale that would apply to particular plant species?
1(c) Please list any additional plants (including genus and species) that both (1) have no wild or weedy relatives in the United States, its possessions, or territories with which they can form viable hybrids in nature and (2) have low potential to naturalize and become weedy or invasive outside of agricultural fields with the acquisition of any PVCP-PIP. For each identified plant please explain why (2) is likely the case.
2(a) Please comment on whether the following criteria would allow the Agency to identify correctly those PVCP-PIPs that present low risk with respect to environmental concerns associated with gene flow of a PVCP-PIP. What data supports or refutes the Agency's rationale for developing these criteria?
i. the plant containing the PVCP-PIP is itself not a weedy or invasive species outside of agricultural fields in the United States , its possessions, or territories and
ii. the plant containing the PVCP-PIP does not have relatives outside of agricultural fields in the United States , its possessions, or territories that are weedy or invasive species or endangered/threatened species with which it can produce viable hybrids in nature.
2(b). Are there other factors besides a plant's weediness, invasiveness, and/or endangered/threatened status that should be taken into consideration when evaluating whether a PVCP-PIP poses low risk with respect to environmental concerns associated with gene flow of a PVCP-PIP?
2(c) Please describe any additional factors beyond those listed above that the Agency could use to evaluate whether a PVCP-PIP meets (i) or (ii).
3:00 PM BREAK
3:15 PM Panel Discussion (continued)
3. Please comment on the usefulness of the following criteria (i) and (ii) in correctly identifying PVCP-PIPs that present low risk with respect to environmental concerns associated with novel viral interactions . Please explain the basis for your answer, including whether the limitations imposed by the use of "viral pathotype," "naturally infect," "species," and " United States , its possessions, or territories " are necessary and/or sufficient. For example, could other parts of North America be included as part of criterion (i)?
(i) the viral pathotype used to create the PVCP-PIP has naturally infected plants in the United States , its possessions, or territories and
(ii) the viral pathotype used to create the PVCP-PIP naturally infects plants of the same species as that containing the PVCP-PIP.
4(a) Please comment on the usefulness of the following criteria (i) and (ii) in allowing the Agency in its review of the product to identify correctly whether the PVCP-PIP presents low risk with respect to environmental concerns associated with novel viral interactions 9 . Please explain the basis for your answer.
(i)the properties of the viral pathotype that are determined by the coat protein gene used to create the PVCP-PIP are substantially similar to the properties of a viral pathotype that naturally infects plants in the United States, its possessions, or territories, and the viral pathotype used to create the PVCP-PIP naturally infects plants of the same species as that containing the PVCP-PIP , or
(ii) viruses that naturally infect the plant containing the PVCP-PIP are unlikely to acquire the coat protein sequence through recombination and produce a viable virus with significantly different properties than either parent virus.
4(b) Please comment on the usefulness of the analyses described above for evaluating whether a PVCP-PIP meets (i) or (ii). Please describe any additional factors that the Agency could use in this evaluation (e.g., consideration of whether the plant virus species has an inherently low natural recombination frequency with respect to the coat protein gene).
4 :30 PM ADJOURNMENT
FIFRA SCIENTIFIC ADVISORY PANEL (SAP)
OPEN MEETING
DECEMBER 6-8, 2005
FIFRA SAP WEB SITE https://www.epa.gov/scipoly/sap/
OPP Docket Telephone: (703) 305-5805
Docket Number: OPP-2005-0249
PLANT-INCORPORATED PROTECTANTS BASED
ON VIRUS COAT PROTEIN GENES: SCIENCE
ISSUES ASSOCIATED WITH
THE PROPOSED RULE
DECEMBER 7, 2005
Holiday Inn - National Airport
2650 Jefferson Davis Highway
Arlington , VA 22202
Telephone: (703) 684-7200
8:30 AM Introduction and Identification of Panel Members - Stephen Roberts, Ph.D. (FIFRA SAP Session Chair)
8:35 AM Administrative Procedures by Designated Federal Official - Paul Lewis, Ph.D.
8:40 AM Follow-up from Previous Day's Discussion - Melissa Kramer, Ph.D. (Office of Pesticide Programs, EPA)
9:00 AM Panel Discussion (continued)
PVC-Protein Production Issues
Therefore, PVCP-PIPs that present low risk with respect to nontarget and human non-dietary exposures to PVC-proteins could be described by the following language: the genetic material (i) encodes a protein that is minimally modified from a coat protein from a virus that naturally infects plants or (ii) produces no protein. In determining whether a PVC-protein is "minimally modified" from a natural viral coat protein, EPA would consider first whether the protein is substantially similar to a natural viral coat protein by evaluating information on the genetic construct, amino acid sequence, and molecular weight of the PVC-protein. EPA might also evaluate information developed by the submitter from public sequence databases on where the PVC-protein sequence falls relative to the range of natural variation. Those PVC-proteins that are determined to be substantially similar would be further evaluated to determine whether the modified PVC-protein is as safe as an unmodified protein by considering information on the expression level of the PVC-protein relative to levels generally found in plants and information from amino acid sequence comparisons with known toxins and allergens. The type and extent of information that would need to be provided with an exemption request in order for EPA to determine whether a PVC-protein is "minimally modified" and therefore qualifies for the exemption would be determined on a case-by-case basis.
5. Please comment on the usefulness of the above factors in allowing the Agency to identify correctly those PVCP-PIPs that present low risk with respect to nontarget and human non-dietary exposure to PVC-proteins.
10:30 AM BREAK
10:45 AM Panel Discussion (continued)
Post-Transcriptional Gene Silencing (PTGS) Issues
6(a) Please identify any characteristics of a PVCP-PIP construct that would indicate it is unlikely to produce PVC-protein. Please discuss the likelihood that protein production could nevertheless occur from constructs with these characteristics (i) in some tissues, (ii) at some life stages, (iii) under some environmental conditions, (iv) in the case of suppression of gene silencing, or (v) under any other circumstances. For example, how likely is PVC-protein production from a construct containing an inverted repeat of the coat protein gene (e.g., Mitter et al. 2003) or from a construct lacking a start codon (AUG sequence) and/or a ribosome binding site on the expressed RNA?
6(b) Assuming a PVCP-PIP construct does not possess any characteristics that would indicate a low likelihood of protein expression but PVC-protein is not detected in plants containing the PVCP-PIP, presumably because virus resistance is conferred through RNA, please comment on the likelihood and expected quantity of both RNA and protein that would be present (i) only transiently, (ii) only in certain tissues, (iii) only at certain life stages, (iv) only under certain environmental conditions, or (v) in the case of suppression of gene silencing? How likely is suppression of gene silencing to occur in the environment over time?
6(c) Please identify conditions under which protein detection methods should be conducted to determine whether PVC-protein is produced from the PVCP-PIP. For example, how many replicates and what particular tissues, life stages, and/or environmental conditions should be tested?
6 (d) Compared with protein-mediated virus resistance, how does RNA-mediated virus resistance (e.g., during PTGS) affect the likelihood and possible environmental impact of (i) gene flow of a PVCP-PIP transgene and (ii) recombination of an infecting virus with a PVCP-PIP transgene or RNA transcript.
12:00 PM LUNCH
1 :00 PM Panel Discussion (continued)
Food Safety Issues
7(a) What is the potential for novel human exposure to a PVC-protein when it is expressed in food from a plant species that the virus used to create the PVCP-PIP does not naturally infect (assuming that the virus naturally infects another food plant species)? What is the potential for allergenicity to be associated with such PVC-proteins? How would use of a small segment of such a protein (e.g., to achieve gene expression) affect relative concern for allergenicity?
7(b). Please comment on the likelihood that PVC-proteins containing terminal deletions are within the range of natural variation of plant virus coat proteins. What is the likelihood such truncated proteins would have increased toxicity or allergenicity relative to the corresponding full-length plant virus coat protein? What relevance does the size of the deletion have to this issue? What relevance does deletion at the C-terminus versus N-terminus have to this issue?
7(c). Please comment on the likelihood that a PVC-protein modified by an additional methionine at the N- or C-terminus would have increased toxicity or allergenicity relative to the corresponding unmodified plant virus coat protein. What relevance does the terminus at which the amino acid is added have to this issue? Of what relevance is the particular amino acid added? Of what relevance is the number of additional amino acids?
7(d). Please identify type(s) of protein modification(s) (e.g., internal deletions, amino acid substitutions, addition of certain amino acid residues) that could be introduced without resulting in a PVC-protein that would have increased toxicity or allergenicity relative to the corresponding unmodified plant virus coat protein, e.g., because the changes are expected to be within the range of natural variation for all virus families.
Under EPA's current approach, in determining whether a PVC-protein is "minimally modified" from a natural viral coat protein, the Agency would consider first whether the protein is substantially similar to a natural viral coat protein by evaluating information on the genetic construct, amino acid sequence, and molecular weight of the PVC-protein. EPA might also evaluate information developed by the submitter from public sequence databases on where the PVC-protein sequence falls relative to the range of natural variation. Those PVC-proteins that are determined to be substantially similar would be further evaluated to determine whether the modified PVC-protein is as safe as an unmodified protein by considering information on the expression level of the PVC-protein relative to levels generally found in plants humans consume and information from an amino acid sequence comparison with known toxins and allergens. The type and extent of information that would need to be provided in order for EPA to determine whether a PVC-protein is "minimally modified" would be determined on a case-by-case basis.
8. Please comment on the usefulness of the factors described above for evaluating food safety of the encoded PVC-protein . How important is it to characterize the expressed protein, e.g., to determine whether any post-translational modifications have occurred?
3:00 PM BREAK
3 :15 PM Panel Discussion (continued)
9(a). What is the likelihood that a chimeric PVC-protein would have increased toxicity or allergenicity relative to the corresponding non-chimeric plant virus coat proteins? Can you describe any objective criteria to identify those chimeric PVC-proteins with novel toxic or allergenic properties?
9(b) Please address the relevance of the following factors to the potential toxicity or allergenicity of a chimeric PVC-protein:
(i) the size of the various segments comprising the chimeric PVC-protein,
(ii) the viral source(s) of the various segments, and/or
(iii) the location on the protein where fusions occur.
9(c) Are the factors specified in question 8 applicable to evaluating the safety of chimeric PVC-proteins? Are there any additional factors specific to chimeric proteins that should be considered?
Other Issues
10. Please comment on the Agency's environmental risk assessment of each of the six selectable markers (found in attachment III). Does the SAP concur that CP4 EPSPS, GOX/GOXv247, PAT each pose a low probability of risk to the environment when used in one of the plants listed in question 1(a)? Does the SAP concur that beta-D-glucuronidase, NPTII, and PMI each pose a low probability of risk to the environment when used in any plant?
5 :00 PM ADJOURNMENT
FIFRA SCIENTIFIC ADVISORY PANEL (SAP)
OPEN MEETING
DECEMBER 6-8, 2005
FIFRA SAP WEB SITE https://www.epa.gov/scipoly/sap/
OPP Docket Telephone: (703) 305-5805
Docket Number: OPP-2005-0249
PLANT-INCORPORATED PROTECTANTS BASED
ON VIRUS COAT PROTEIN GENES: SCIENCE
ISSUES ASSOCIATED WITH
THE PROPOSED RULE
DECEMBER 8, 2005
Holiday Inn - National Airport
2650 Jefferson Davis Highway
Arlington , VA 22202
Telephone: (703) 684-7200
8:30 AM Introduction and Identification of Panel Members - Stephen Roberts, Ph.D. (FIFRA SAP Session Chair)
8:35 AM Administrative Procedures by Designated Federal Official - Paul Lewis, Ph.D.
8:40 AM Follow-up from Previous Day's Discussion - Melissa Kramer, Ph.D. (Office of Pesticide Programs, EPA)
9:00 AM Panel Discussion (continued)
• 11. Please comment on whether the criteria discussed above that EPA is considering for PVCP-PIPs (i.e., relating to gene flow, viral interactions, and protein production) would be applicable for other PIPs conferring virus resistance, e.g., those based on virus replicase genes (Ehrenfeld et al. 2004) or defective interfering RNA (Kollar et al. 1993) . Please indicate the scientific rationale for including any additional PIPs under such an exemption and whether any additional (or fewer) qualifications would be needed.
1:0 0 PM ADJOURNMENT
Please be advised that agenda times are approximate. For further information, please contact the Designated Federal Official for this meeting, Paul Lewis via telephone: (202) 564-8450; fax: (202) 564-8382; or email: lewis.paul@epa.gov