Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2025875 | Soil Biology and Biochemistry | 2007 | 6 Pages |
Abstract
The fate of extracellular DNA in the environment concerns both the fate of transgenes from genetically modified organisms and the evolution of active bacteria capable of incorporating this DNA into their genomes. This study addressed the possibility that DNA, like other organic molecules, could move vertically in the capillary fringe of groundwater aquifers. The targeted gene fragment used here was the 35S-nptII sequence, which was below detection levels in controls. Initial microcosm studies detected the DNA target molecule by PCR during the entire experiment. The vertical advection of water and DNA were monitored for a period of 3 days in soil columns. DNA was added as a water solution at the bottom of the unsaturated soil column, and then DNA-free water was added at the bottom after 12 and 24Â h. After the addition of the DNA solution, capillary water rose 4Â cm within the soil column and the target DNA was detected up to that height. After 60Â min, the entire soil column (10Â cm) was wetted and the target sequence was detected up to a height of 7.5Â cm. After the second wetting (12Â h later), the target sequence was detected up to the top of the soil column (10Â cm). However, after the third wetting (24Â h later), the marker sequence was only found at heights from 0.5 to 4Â cm. Results clearly show the vertical movement of DNA due the capillary rise and suggest the possibility of DNA degradation within the soil column.
Keywords
Related Topics
Life Sciences
Agricultural and Biological Sciences
Soil Science
Authors
Maria Teresa Ceccherini, Judith Ascher, Giacomo Pietramellara, Timothy M. Vogel, Paolo Nannipieri,