HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Icoz, I. Articles by Stotzky, G. Search for Related Content PubMed Articles by Icoz, I. Articles by Stotzky, G. Agricola Articles by Icoz, I. Articles by Stotzky, G. Related Collections Sustainable Agriculture Soil Microbiology Plant and Soil Interactions Insect Resistance Soil Biochemistry

TECHNICAL REPORTS

Ecological Risk Assessment

Microbial Populations and Enzyme Activities in Soil In Situ under Transgenic Corn Expressing Cry Proteins from Bacillus thuringiensis

^a Lab. of Microbial Ecology, Dep. of Biology, New York Univ., New York, NY 10003
^b Basic Science, College of Dentistry, New York Univ., New York, NY 10010
^c Dep. of Entomology, Univ. of Minnesota, St. Paul, MN 55108

^* Corresponding author (gs5{at}nyu.edu).

Received for publication July 4, 2007. Transgenic Bt crops produce insecticidal Cry proteins that are released to soil in plant residues, root exudates, and pollen and that may affect soil microorganisms. As a continuation of studies in the laboratory and a plant-growth room, a field study was conducted at the Rosemount Experiment Station of the University of Minnesota. Three Bt corn varieties that express the Cry1Ab protein, which is toxic to the European corn borer (Ostrinia nubilalis Hübner), and one Bt corn variety that expresses the Cry3Bb1 protein, which is toxic to the corn rootworm complex (Diabrotica spp.), and their near-isogenic non-Bt varieties were evaluated for their effects on microbial diversity by classical dilution plating and molecular (polymerase chain reaction-denaturing gradient gel electrophoresis) techniques and for the activities of some enzymes (arylsulfatases, acid and alkaline phosphatases, dehydrogenases, and proteases) involved in the degradation of plant biomass. After 4 consecutive years of corn cultivation (2003–2006), there were, in general, no consistent statistically significant differences in the numbers of different groups of microorganisms, the activities of the enzymes, and the pH between soils planted with Bt and non-Bt corn. Numbers and types of microorganisms and enzyme activities differed with season and with the varieties of corn, but these differences were not related to the presence of the Cry proteins in soil. The Cry1Ab protein of Bt corn (events Bt11 and MON810) was detected in most soils during the 4 yr, whereas the Cry3Bb1 protein was not detected in soils of Bt corn (event MON863) expressing the cry3Bb1 gene.

Abbreviations: ARISA, automated ribosomal intergenic spacer analysis • Bt, Bacillus thuringiensis • CLPP, community level physiological profiles • MANOVA, multivariate analysis of variance • MPN, most probable numbers • PCR-DGGE, polymerase chain reaction–denaturing gradient gel electrophoresis • PNP, p-nitrophenol • SPRM-ANOVA, split-plot repeated measure ANOVA