Titel:GM Potatoes Alter Soil Ecology
Bron:http://www.positivenews.org.uk/cgi-bin/zyview/D=articles/V=story/R=231

GM Potatoes Alter Soil Ecology

by Virginia Kennedy

A study undertaken at the Max Planck Insitute for Soil Microbiology in Marburg, Germany has revealed that the planting of genetically
modified potatoes results in changes to the bacterial communities in
soil. The findings cannot say whether or not the observed alterations are detrimental to future plantings on the site of the GM crop, however, the precautionary principle should be used to require that GM crops be removed from field planting until the impact of the ecological alteration is evaluated.

It is known that subtle changes in the microbial ecology can have devastating long term impacts by effecting soil fertility, the availability of nutrients or by creating environments that promote pathogens such as nematodes, fungi or harmful bacteria to flourish. The findings are an early indicator of the need for extensive research on the long term consequences of these changes in soil bacterial communities and their implications for biodiversity.

The study used DNA fingerprinting techniques to study the changes in soil microbes and compared species distribution in soil plots in a control group and following the cultivation of genetically modified potatoes. It proved a powerful technique for characterizing changes in soil microbiology pointing to a way to study the effects of cultivation of GM crops on soil ecology. The technique has not yet been used on the major GM crop releases such as Bt potato, Bt corn, or herbicide tolerant cotton, corn, canola and soybean.

FURTHER INFORMATION : For more information see original paper in FEMS Microbiol Ecol 2000 June 01;32(3):241-247 (ISSN: 0168-6496 ===

http://www.elsevier.nl/gej-ng/10/19/39/50/28/31/abstract.html FEMS Microbiology Ecology, Vol. 32 (3) (2000) pp. 241-247 © 2000 Published by Elsevier Science B.V. All rights reserved. PII: S0168-6496(00)00033-7

Use of the T-RFLP technique to assess spatial and temporal changes in the bacterial community structure within an agricultural soil planted with transgenic and non-transgenic potato plants Thomas Lukow1, Peter F. Dunfield and Werner Liesack * liesack@mailer.uni-marburg.de Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Straße, D-35043 Marburg, Germany Received 24 June 1999; received in revised form 23 March 2000; accepted 3 April 2000

Abstract
The aim of this study was to examine whether the terminal restriction fragment length polymorphism (T-RFLP) analysis represents an appropriate technique for monitoring highly diverse soil bacterial communities, i.e. to assess spatial and/or temporal effects on bacterial community structure. The T-RFLP method, a recently described fingerprinting technique, is based on terminal restriction fragment length polymorphisms between distinct small-subunit rRNA gene sequence types. This technique permits an automated quantification of the fluorescence signal intensities of the individual terminal restriction fragments (T-RFs) in a given community fingerprint pattern. The indigenous bacterial communities of three soil plots located within an agricultural field of 110 m2 were compared. The first site was planted with non-transgenic potato plants, while the other two were planted with transgenic GUS and Barnase/Barstar potato plants, respectively. Once prior to planting and three times after planting, seven parallel samples were taken from each of the three soil plots. The T-RFLP analysis resulted in very complex but highly reproducible community fingerprint patterns. The percentage abundance values of defined T-RFs were calculated for the seven parallel samples of the respective soil plot. A multivariate analysis of variance was used to test T-RFLP data sets for significant differences. The statistical treatments clearly revealed spatial and temporal effects, as well as spacextime interaction effects, on the structural composition of the bacterial communities. T-RFs which showed the highest correlations to the discriminant factors were not those T-RFs which showed the largest single variations between the seven-sample means of individual plots. In summary, the T-RFLP technique, although a polymerase chain reaction-based method, proved to be a suitable technique for monitoring highly diverse soil microbial communities for changes over space and/or time.

Keywords: Biomonitoring; Transgenic plant; Microbial community; Terminal restriction fragment length polymorphism analysis; Genetic fingerprint; Multivariate analysis of variance 1Present address: Fraunhofer-Institut für Umweltchemie und Ökotoxikologie, Auf dem Aberg 1, D-57392 Schmallenberg, Germany.

*Corresponding author. Tel.: +49 (6421) 178 720; Fax: +49 (6421) 178 809 ---