TY - JOUR
T1 - Vertical movement in soil of insecticidal Cry1Ab protein from Bacillus thuringiensis
AU - Saxena, Deepak
AU - Flores, Saul
AU - Stotzky, G.
N1 - Funding Information:
These studies were supported, in part, by grant R826107-01 from the US Environmental Protection Agency and by grant N0721 from the NYU Research Challenge Fund. The opinions expressed herein are not necessarily those of the Agency or the Fund. We thank LanNa Lee for assistance.
PY - 2002
Y1 - 2002
N2 - The effects of montmorillonite (M) or kaolinite (K) on the vertical movement of the insecticidal Cry1Ab protein of Bacillus thuringiensis subsp. kurstaki (Bt) were studied in repacked soil columns. The protein was added to the columns either in a purified form, as root exudates from growing plants of Bt corn, or within the biomass of residues of Bt corn. The soil was amended to 0, 3, 6, 9, or 12% (vol vol-1) with the clays. Vertical movement of the protein generally decreased as the content of either clay was increased, and the amount of protein recovered in leachates increased as the concentration of purified protein added was increased. The largest amount of purified protein (ca. 75%) was leached from soil not amended with clay, whereas the lowest amount (ca. 16%) was recovered from columns containing soil amended to 12% with M or K. The Cry1Ab protein was also present in leachates from soil columns in which various hybrids of Bt corn were grown or to which biomass of Bt corn had been added, whereas it was absent in leachates from columns in which the respective isolines of non-Bt corn were grown or to which biomass of non-Bt corn had been added. The Cry1Ab protein exhibited stronger binding and higher persistence, as well as remaining nearer the soil surface, in soil that contained the higher clay concentrations (i.e. had a higher cation-exchange capacity and specific surface area), indicating that it could be transported to surface waters via runoff and erosion. In contrast, the protein was more readily leached through soil with lower clay concentrations, indicating that it could contaminate groundwater.
AB - The effects of montmorillonite (M) or kaolinite (K) on the vertical movement of the insecticidal Cry1Ab protein of Bacillus thuringiensis subsp. kurstaki (Bt) were studied in repacked soil columns. The protein was added to the columns either in a purified form, as root exudates from growing plants of Bt corn, or within the biomass of residues of Bt corn. The soil was amended to 0, 3, 6, 9, or 12% (vol vol-1) with the clays. Vertical movement of the protein generally decreased as the content of either clay was increased, and the amount of protein recovered in leachates increased as the concentration of purified protein added was increased. The largest amount of purified protein (ca. 75%) was leached from soil not amended with clay, whereas the lowest amount (ca. 16%) was recovered from columns containing soil amended to 12% with M or K. The Cry1Ab protein was also present in leachates from soil columns in which various hybrids of Bt corn were grown or to which biomass of Bt corn had been added, whereas it was absent in leachates from columns in which the respective isolines of non-Bt corn were grown or to which biomass of non-Bt corn had been added. The Cry1Ab protein exhibited stronger binding and higher persistence, as well as remaining nearer the soil surface, in soil that contained the higher clay concentrations (i.e. had a higher cation-exchange capacity and specific surface area), indicating that it could be transported to surface waters via runoff and erosion. In contrast, the protein was more readily leached through soil with lower clay concentrations, indicating that it could contaminate groundwater.
KW - Bacillus thuringiensis
KW - Bt corn
KW - Cry1Ab protein
KW - Groundwater
KW - Kaolinite
KW - Leaching
KW - Montmorillonite
KW - Root exudates
KW - Surfacewater
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U2 - 10.1016/S0038-0717(01)00193-6
DO - 10.1016/S0038-0717(01)00193-6
M3 - Article
AN - SCOPUS:0036163771
SN - 0038-0717
VL - 34
SP - 111
EP - 120
JO - Soil Biology and Biochemistry
JF - Soil Biology and Biochemistry
IS - 1
ER -