title: Assessing the potential for interaction between the insecticidal activity of two genetically engineered cotton events combined by conventional breeding: An example with COT102 × MON 15985.
abstract: Bollgard(®) III was developed by combining cotton events COT102 and MON 15985 through conventional breeding to improve efficacy against lepidopteran feeding damage. COT102 produces the Vip3Aa19 protein and MON 15985 produces the Cry1Ac and Cry2Ab2 proteins. COT102 × MON 15985 has also been bred with Roundup Ready Flex(®) cotton (MON 88913) that confers glyphosate tolerance. This study evaluated the activity of COT102 and MON 15985 and the combined activity of COT102 and MON 15985 against the cotton bollworm (CBW, Helicoverpa zea). COT102, MON 15985, COT102 × MON 15985 and COT102 × MON 15985 × MON 88913 have comparable Vip3Aa19 and/or Cry1Ac, Cry2Ab2 protein expression levels as determined by enzyme-linked immunosorbent assay. CBW demonstrated concentration-dependent growth inhibition after 7-days of feeding on lyophilized leaf tissue derived from COT102, MON 15985, COT102 × MON 15985 and COT102 × MON 15985 × MON 88913 incorporated into an artificial diet. Observed EC50 values for COT102 × MON 15985 and COT102 × MON 15985 × MON 88913 were comparable (≤4% deviation) with the predicted EC50 value under the assumption of additivity using the combined activity of COT102 and MON 15985. No interaction in biological activity between COT102 and MON 15985 is consistent with results from competition and ligand blotting assays that demonstrated that Vip3Aa does not inhibit the binding of either Cry1Ac or Cry2Ab2 and vice versa. The results from this study demonstrate that the activity of COT102 × MON 15985 against CBW is consistent with predictions of additivity.
authors.affiliation: Global Regulatory Sciences, Monsanto Company, St. Louis, MO, 63167, United States. Electronic address: steven.l.levine@monsanto.com.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Levine
authors.affiliation: Global Regulatory Sciences, Monsanto Company, St. Louis, MO, 63167, United States.
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Mueller
authors.affiliation: Global Regulatory Sciences, Monsanto Company, St. Louis, MO, 63167, United States.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Uffman
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003433:Crosses, Genetic; D004731:Endotoxins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D003368:Gossypium / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D006790:Host-Parasite Interactions; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D009036:Moths / Q000254:growth & development* / Q000378:metabolism; D010572:Pest Control, Biological / Q000379:methods*; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism / Q000469:parasitology; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C447139:Vip3A protein, Bacillus thuringiensis; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Additivity; Bt protein; Concentration addition; Cotton; Cry1Ac; Cry2Ab2; Plant incorporated protectants; Vip3Aa19