Submitted to: Transgenic Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2007
Publication Date: N/A
Citation: Interpretive Summary: The utilization of genetically engineered crops to improve agricultural production, decrease pesticide use, and improve food quality depends on the documented safety of this technology. In order to evaluate the safety of virus resistant GE plum trees, the environmental impact of field release of transgenic plums (European plum, species Prunus domestica) was assessed in a nine-year field trial in Valencia, Spain. The effects of the GE plums on virus populations and the numbers and species of insects (pests, potential biocontrol insects, and others) that visited GE and conventional plums were estimated. No differences in terms of diversity of virus populations and numbers of insect species that visited trees were detected between GE and non-GE plums. The overall data indicate that the growth of virus resistant GE plums under Mediterranean conditions does not represent an environmental risk beyond that of the cultivation of conventional plum trees.
Technical Abstract: The environmental impact of field release of transgenic European plums (Prunus domestica L.) carrying the coat protein gene of Plum pox virus (PPV) was assessed in Valencia, Spain. The molecular variability of PPV populations present in transgenic vs. non-transgenic plums was compared, and total numbers and species of aphids (PPV transmission vectors) and other insects that visited transgenic and conventional plums were estimated. Additionally, the possibility of recombination between the transcripts derived from the transgene, and the infecting viral RNA was tested. Five different P. domestica transgenic lines (the PPV-resistant C5 'HoneySweet' line and the PPV-susceptible C4, C6, PT-6 and PT-23 lines) and non-transgenic P. domestica and P. salicina trees were tested. No differences in terms of diversity of PPV populations and numbers of aphids and other insect species that visited trees were detected between transgenic and non-transgenic plums. No recombination between the transgene transcripts and the incoming viral RNA was detected over an eight-year period of exposure to natural PPV infection in the field. The overall data indicate that the growth of PPV-CP transgenic European plums under Mediterranean conditions does not represent an environmental risk in terms of the parameters studied beyond that of the cultivation of conventional plum trees.