Persistence of Cry toxins and cry genes from genetically modified plants in two agricultural soils

• Published in: Agronomy for sustainable development Vol. 27; no. 3; pp. 231 - 236
• Main Authors: Marchetti, Elisa, Accinelli, Cesare, Talamè, Valentina, Epifani, Rosanna
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences 01.07.2007; Springer Verlag/EDP Sciences/INRA
• Subjects: Agricultural sciences; agricultural soils; Agronomy. Soil science and plant productions; Bacillus thuringiensis; bacterial toxins; bioavailability; Biochemistry; Biochemistry and biology; Biological and medical sciences; Biotechnology; Chemical, physicochemical, biochemical and biological properties; clay loam soils; crops; crystal proteins; Ecology, environment; Environment and pollution; environmental fate; Fundamental and applied biological sciences. Psychology; Genetic engineering applications; Genetically engineered organisms behavior (microorganisms, plants, animals); Genetics and breeding of economic plants; half life; Industrial applications and implications. Economical aspects; insecticidal proteins; Italy; Life Sciences; microbial insecticides; pesticide persistence; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant breeding: fundamental aspects and methodology; protein degradation; sandy soils; Soil science; soil texture; temporal variation; transgenes; transgenic plants; Italy; Emilia-Romagna; Europe; Biotechnology; Entomopathogen; Monocotyledones; Bacillus thuringiensis; Sandy soil; Bacillaceae; Temperate zone; Endotoxin; Texture; Cereal crop; Cry protein; Bacillales; Gramineae; Angiospermae; Bacteria; Multigene family; Soil science; Transgenic plant; Recombinant protein; Biopesticide; microbial insecticides; Zea mays; genetically modified crops; Ecotoxicology; Property of soil; Cry toxins; Agricultural soil; Biosafety; Physical properties; Clay loam soil; Persistence; Toxin; Structural gene; Environment; Genetic engineering; Spermatophyta; Molecular biology; Genetically modified organism; Soil plant relation; soil persistence; Microbial insecticide
• ISSN: 1774-0746; 1773-0155
• DOI: 10.1051/agro:2007010

The environmental impact of genetically modified crops has been the subject of intense research in the past decade. Since the introduction of insect-resistant crops in 1996, cultivation of this group of genetically modified crops has grown substantially. Most insect-resistant varieties, including corn and cotton, have been engineered to express crystal (Cry) toxins. Although several studies concerning the environmental fate of this group of insecticidal toxins have been conducted during the past decade, conflicting information exists dealing with the persistence of Cry toxins in soil. In the present investigation, the persistence of antilepidopteran Cry1Ab and Cry1Ac toxins in two different agricultural soils was studied. The potential of cry 1 Ab genes to persist in soil was also estimated. The results from this laboratory investigation indicated that the two toxins dissipated rapidly in both the sandy and in the clay loam soil. The two toxins showed similar degradation rates in soil. During the 35-day incubation period, more than 92 and 79% of the initial amount of Cry toxins dissipated in the sandy and clay loam soil, respectively. Extractable fractions of the two toxins were lower in the fine-textured soil with respect to the coarse soil. Reduced recovery efficiency from the clay loam soil and thus bioavailability were presumably involved in the lower decline of Cry toxins in this soil. Investigations conducted with an insect-resistant transgenic corn hybrid showed no detectable levels of cry 1 Ab genes in soil six months after plant harvest.