11 May 2003
Cave find questions GM safety
When in January 2000 the UK's leading supermarket chain Tesco indicated to growers that they were not willing to buy produce grown on sites used for GM trials, Professor Chris Pollock, Head of the UK Scientific Steering Committee on Farm Scale Evaluations, remonstrated with them in the media. As The Times reported, "Professor Chris Pollock, chairman of the scientific steering committee behind the farm-scale trials, accused Tesco of adding to, rather than allaying, public confusion. He said there was no evidence that DNA from GM crops persisted in the soil." [http://members.tripod.com/~ngin/farmcon.htm http://www.netlink.de/gen/Zeitung/2000/000107.html]
In reality, when Pollock made his remark there was already a significant amount of published research showing exactly the opposite (see list at end), with one team, for instance, reporting the persistence of transgenic DNA in soil and in bacteria under field conditions, even after 2 years. [see Gebhard, F. & Smalla, K. (1999)]
Now research in New Zealand has shown that plant (and animal) DNA far from not persisting can survive intact in soil for *millenia*. Professor Alan Cooper of Oxford University who made the discovery has already pointed out the worrying implications for genetic engineering.
Cave find questions GM safety
-Cave find upends DNA theory (01:49)
May 11, 2003
A remarkable discovery at a cave in Central Otago has raised new questions on the safety of genetic modification.
British-based Professor Alan Cooper unearthed plant and animal DNA thousands of years old surviving intact in the soil.
The find has turned DNA theory on its head.
The soil contains the genetic building blocks of two species of moa, a parakeet and numerous plants 2,000 years old, longer than it was previously thought possible for DNA to survive in the wild.
"We didn't expect to see dna surviving this long. The general idea being that DNA loose in soil would be very quickly eaten by bacteria and fungus or washed away or dissolved."
Professor Alan Cooper believes this DNA came from animal droppings, left undisturbed in the cave..
He is warning it may have implications for genetically modified dna. "It's very concerning that if we can stumble across something like this, that DNA survives much longer in the soil and therefore GM DNA would survive longer and presumably get to a broader distribution than we would've expected. How many other things don't we know at the moment?"
But Tony Conner, a plant geneticist with Crop and Research says in science there will always be unanswered questions. "The simple fact is that in the case of GM crops we know a lot more about them than their non-gm counterparts."
The moratorium on GM field trials ends in October. After that GM potatoes and onions resistent to pests will be first in the ground.
"The next step to advance the scientific knowledge is to go to larger scale trials with some controls imposed on them."
This ancient DNA also provides a snapshot of a New Zealand ecosystem before humans arrived.
Cooper is planning another expedition here to build a more complete picture.
Research showing persistence of GM plant DNA
Koskella, K. & Stotzky, G. (1997) 'Microbial Utilization of Free and Clay-Bound Insecticidal Toxins from Bt and Their Retention of Insecticidal Activity after Incubation with Microbes,' Applied and Environmental Microbiology, Sept. 1997, p. 3561-3568 H. http://www.psrast.org/btsoilecol.htm
Crecchio, C. & Stotzky, G. (1998) 'Insecticidal activity and biodegradation of the toxin from bacillus thuringiensis subsp. kurstaki bound to humic acids from soil', Soil Biology & Biochemistry, Volume 30, Vol. 30 (4) pp. 463-470, 1998. http://www.elsevier.nl/cgi-bin/cas/tree/store/sbb/cas_sub/browse/browse.cgi? year=1998&volume=30&issue=4&aid=1075
Tapp, H. & Stotzky, G. (1998) "Persistence of the Insecticidal Toxin from Bt subsp. Kurstaki in Soil," Soil Biology and Biochemistry, Vol. 30, No. 4, p. 471-476., 1998 http://www.elsevier.nl/cgi-bin/cas/tree/store/sbb/cas_sub/browse/browse.cgi? year=1998&volume=30&issue=4&aid=1076
Gebhard, F. & Smalla, K. 'Transformation of Acinetobacter sp. Strain BD413 by Transgenic Sugar Beet DNA' Applied and Environmental Microbiolology, April 1998, p. 1550-1554, Vol. 64, No. 4 http://aem.asm.org/cgi/content/full/64/4/1550
Gebhard, F. & Smalla, K. (1999) "Monitoring field releases of genetically modified sugar beets for persistence of transgenic plant DNA and horizontal gene transfer," FEMS Microbiology Ecology, 1999, Vol.28, No.3, pp.261-272 http://www.elsevier.nl/cgi-bin/cas/tree/store/femsec/cas_sub/browse/browse.c
PRAST, (1999) 'GE crops with Bacillus thuringiensis (Bt) genes suspected to harm soil ecology' http://www.psrast.org/btsoilecol.htm
Benbrook, C. (1999) 'Impacts on Soil Microbial Communities Needs Further Study', Ag BioTech InfoNet http://www.biotech-info.net/microbial_communities.html
Saxena, D. , Flores, S. and Stotsky, G. (1999) 'Insecticidal toxin in root exudates from Bt corn', Nature, Vol 402, 2 December 1999, p.480 http://www.nature.com/server-java/Propub/nature/402480A0.docframe and www.natural-law.ca/genetic/NewsNov-Dec99/GEN12-2BtLeak1FishHagel.html
Benbrook, C. (1999) 'Commentary on Insecticidal toxin in root exudates from Bt corn', Ag BioTech InfoNet http://www.biotech-info.net/exudates_cmb.html gi?year=1999&volume=28&issue=3&aid=999