Bt Brinjal The scope and adequacy of the GEAC environmental risk assessment
Bt Brinjal: The scope and adequacy of the GEAC ... - Down To Earth
Bt Brinjal: The scope and adequacy of the GEAC ... - Down To Earth
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20 <strong>Bt</strong> <strong>Brinjal</strong>: <strong>The</strong> <strong>GEAC</strong> <strong>environmental</strong> <strong>risk</strong> <strong>assessment</strong>Product Quality <strong>of</strong> EE-1 <strong>Bt</strong> <strong>Brinjal</strong>Conclusion 2. <strong>The</strong> EE-1 transgene may be a second-rate <strong>Bt</strong> brinjal product. EE-1 was probably produced in<strong>the</strong> late 1980s or early 1990s, its control <strong>of</strong> BFSB is low, <strong>and</strong> o<strong>the</strong>r Cry toxins might perform better.During <strong>the</strong> late 1980s, Monsanto developed Event 531, <strong>the</strong> cry1Ac transgene in <strong>Bt</strong> cotton Bollgard I. This transgene wasformed from a plasmid with nptII <strong>and</strong> aad, which are marker genes for kanamycin <strong>and</strong> streptomycin resistance respectively (see,e.g., Zambryski 1992). During <strong>the</strong> early 1990s, Monsanto developed Event 15985, <strong>the</strong> cry2Ab transgene in <strong>Bt</strong> cotton BollgardII (McCabe <strong>and</strong> Martinell 1993). This transgene was formed by co-transformation with two plasmids. One contained nptII<strong>and</strong> <strong>the</strong> o<strong>the</strong>r uidA, which was eliminated from <strong>the</strong> final product by segregation. During <strong>the</strong> early 1990s, Monsanto developedMon810, <strong>the</strong> cry1Ab transgene in <strong>Bt</strong> maize, Yieldgard (AGBIOS 2003). This transgene was formed by co-transformation withtwo plasmids. Segregation eliminated some <strong>of</strong> <strong>the</strong> undesired elements from <strong>the</strong> final product, which contained only nptII.More recent methods used by Monsanto produce transgenes with no antibiotic markers. Because EE-1 contains both nptII <strong>and</strong>aad, this suggests that it was produced by Monsanto sometime during <strong>the</strong> late 1980s or early 1990s, before Event 15985 <strong>and</strong>Mon810.As will be reviewed below, efficacy <strong>of</strong> EE-1 is low. It provides only 73% control <strong>of</strong> BFSB in <strong>the</strong> MST field trials (Dossiervol. 6) <strong>and</strong> sometimes requires an insecticide application to control BFSB. BFSB is in <strong>the</strong> family Crambidae in <strong>the</strong> orderLepidoptera. Several o<strong>the</strong>r stem boring Crambids have been targeted for control by o<strong>the</strong>r <strong>Bt</strong> crops. <strong>The</strong>se include Ostrinianubilalis (European corn borer), Diatraea gr<strong>and</strong>iosella (southwestern corn borer), Diatraea saccharalis (sugar cane borer), <strong>and</strong>Chilo partellus (spotted stemborer). <strong>Bt</strong> maize typically shows 100% control for all <strong>the</strong>se Crambid species.<strong>The</strong>re may be a better transgene than Ccry1A for control <strong>of</strong> BFSB. Mon810 is based on <strong>the</strong> Cry1Ab toxin, which affects <strong>the</strong>high level <strong>of</strong> control <strong>of</strong> Crambids. A comparison <strong>of</strong> susceptibility in O. nubilalis to Cry1Ab <strong>and</strong> Cry1Ac suggests that it is moresusceptible to Cry1Ab than Cry1Ac (Denolf et al. 1993, Marçon et al. 1999). Thus, it is possible that a more modern transgenebased on Cry1Ab would control BFSB better <strong>and</strong> reduce concerns associated with <strong>the</strong> marker genes.Given <strong>the</strong>se considerations, it seems clear that <strong>the</strong> applicant (ei<strong>the</strong>r Monsanto or Mahyco) has invested little in <strong>the</strong>development <strong>of</strong> a useful <strong>Bt</strong> brinjal product for India. Indeed, an inflammatory characterisation <strong>of</strong> <strong>the</strong> process so far would bea case <strong>of</strong> “transgene dumping.” It would seem in India’s best interest to require a modern transgene that exhibits much betterefficacy against BFSB. Such a request, if fulfilled, would eliminate several <strong>risk</strong> issues associated with inadequate transgenecharacterisation <strong>of</strong> EE-1 <strong>and</strong> would diminish o<strong>the</strong>r <strong>environmental</strong> <strong>risk</strong> issues, especially related to resistance evolution in BFSB.