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[SANET-MG] roundup ready alfalfa



December 15, 2004
Prof. Joe Cummins
“Roundup-ready alfalfa: ready to spread through the ecosystems”
Many readers may be quite weary of the tedious and confusing array of
natural and synthetic genes going into genetically modified (GM) crops.
Nevertheless, repetition of the makeup of the crops is important because
the corporate public relations machines have created an illusion that
only a gene or two is introduced into each crop. Truly, the devil is in
the detail of each crop because it contains an array of synthetic and
natural genes needed to make a synthetic transgene work. It is important
to spread the word that the GM crop  is more a machine with synthetic
parts  than a crop with “a” transgene .
At the present time the main commercial transgenic crops include maize,
soybean, cotton, canola and potato. Currently the feed crop , alfalfa,
is poised to join that  gallery of genetic experiments. Monsanto
corporation has petitioned for deregulation and commercial release of
glyphosate resistant roundup ready  alfalfa. It is likely that the
petition will be approved, leading to extensive planting by next season(1).
       Alfalfa is the oldest forage crop originating  at the beginning  of
agriculture. It is an important forage crop with 23 million acres under
cultivation in the United States. Alfalfa is valuable for animal feed
because of its high protein content and digestibility . Alfalfa sprouts
are also a popular human  food. Commercial alfalfa , Medicago sativa,
is an allotetraploid ( a hybrid between two species) with 32
chromosomes. Alfalfa readily hybridizes with wild species and feral  weeds.
       Monsanto petitioned for deregulation (commercial production) of two
transgene insertion events  designated J101 and J163 (the events have
incorporated  similar synthetic genes at separate but unspecified loci).
The main gene was a synthetic approximation  of a
5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene isolated from
Agrobacterium CP4. The synthetic approximation of the EPSPS gene was
adjusted for the codon preference of the plant cell (2) .The insertion
was accompanied by an array of  regulatory genes that will be described
later.
       The petition for deregulation was accompanied by  a petition  to EPA to
introduce a new glyphosate tolerance  for alfalfa seed of  0.5ppm
because the Roundup ultramax formulation with 50.2% glyphosate  (Roundup
original  has 41% glyphosate)  was being employed. In 2000 EPA   set a
glyphosate tolerance on forage of 175 ppm, and on alfalfa hay of 400ppm
(3). Certainly, a high level of herbicide is allowed in the diet of
cattle of horses which are unlikely to be genetically modified for
herbicide tolerance.
       The genetic architecture of the  transgenes inserted in events J101 and
J163 is similar and that arrangement is similar to the other roundup
ready crops. The synthetic EPSPS gene was driven by the 35S figwort
mosaic virus promoter , transcription was further enhanced  by a petunia
heat shock protein leader sequence,  a sequence for  a chloroplast
transit peptide is provided  a gene from Arabidopsis EPSPS gene, the
transit peptide  directs the synthetic EPSPS gene to the chloroplast
where aromatic amino acids are made. Transcription is terminated using
a termination signal derived from the pea ribulose byphosphate
carboxylase gene,  the termination signal also provided polyadenlation
information. The synthetic EPSPS gene produced  proteins somewhat
similar to the  protein produced by the bacterial ESPHS gene. Several
amino acids seem to be missing near the start (N terminus) of the
protein and the analysis of  the first twenty amino acids included many
amino acids designated X (for undetermined), less than half of the amino
acods in the protein from synthetic both  genetic events were
determined. The proteins  for both events were similar in size and
response to EPSPS antibodies   characteristic of  the bacterial EPSPS
gene but not enough information was provided  to insure that the event
proteins to the  EPSPS protein from the bacterium (2).
It is worth mentioning that the bacterial protein has been used a
surrogate in safety testing of the ESPS enzyme produced in the modified
crops. However, there does not seem to have been any effort to test the
EPSPS protein synthesized in alfalfa for its impact on the environment
and humans.
The evaluation of  RR alfalfa  was mainly directed toward its  agronomic
productivity traits. There was, however, some efforts to deal with the
.introgression of alfalfa into related species and into feral alfalfa.
The environment assessment conducted by USDA/APHIS  acknowledged the
fact that pollen would spread form the RR alfalfa fields to neighboring
non-transgenic cultivars bur t they argued the spread would have minimal
impact. It was argued that sprout production would be protected because
the transgenic seeds would have to be labeled. The impact on organic
alfalfa producers seemed a bit cold blooded “Organic certification
involves oversight by an accredited certifying agent of the materials
and practices used to produce or handle an organic agricultural product.
This oversight includes an annual review of the certified operation’s
organic system plan and on-site inspections of the certified operation
and its records. Although the National Organic Standards prohibit the
use of excluded methods, they do not require testing of inputs or
products for the presence of excluded methods. The presence of a
detectable residue of a product of excluded methods alone does not
necessarily constitute a violation of the National Organic Standards.
The unintentional presence of the products of excluded methods will not
affect the status of an organic product or operation when the operation
has not used excluded methods and has taken reasonable steps to avoid
contact with the products of excluded methods as detailed in their
approved organic system plan(4). Organic certification of a production
or handling operation is a process claim, not a product claim.” USDA,
which controls organic certification seems to argue that transgene
polluted crops will be certified as being organic.  They seem to be
targeting a time when transgenic crops  will be certified by them as
“organic”.
       Alfalfa is mainly pollinated by honey bees and leaf cutter bees. A
study of  pollen flow from a alfalfa plot indicated that a minimal
isolation distance over 5000 feet is required to prevent gene flow (5).
Interestingly, no effort was made to study the impact of RR pollen on
bee behavior and health. Gene flow was recorded for migration of genes
from cultivated alfalfa to wild relatives in Europe (6), for that reason
importation of transgenic alfalfa, even for field tests, seems unwise.
The population genetics of transgene containment has been studied. Even
with limited transgene escape the probability of escape within as few as
ten generations would be appreciable. Alfalfa escape is inescapable and
immediate!

       In the rush to commercialize transgenic crops questions about the human
and environmental safety have been ignored, and as more crops are
commercialized the concerns are not addressed, instead there appears to
be reinforcement and amplification of based on the important concerns
earlier ignored. It is as if the regulators believed  that the absence
of “evidence” of  hazard proved that the products were free from hazard.
That is the old head in sand model, I believe. The absence of labeling
has not fazed the academic and bureaucratic authorities from claiming
there has been “no” injury to people consuming  GM products even though
there has been no way of clearly identify and measuring exposure to GM
products!
References
1. Department of Agriculture   Monsanto Co. and Forage Genetics
International; Availability of Petition and Environmental Assessment for
Determination of Non-regulated Status for Alfalfa Genetically Engineered
for Tolerance to the Herbicide Glyphosate Federal Register 2004, 69,68300-1
2.Rogan,G. and Fitzpatrick,S  Petition for Nonregulated  Status:
 Roundup Ready Alfalfa (Medicago sativa) Events J101 and J163
USDA/APHIS  2004
http://www.aphis.usda.gov/brs/aphisdocs/04_11001p.pdf
3.Environmental Protection Agency  Glyphosate Pesticide Tolerance
Federal Register 2000, 65,57957-66
4. USDA/APHIS Environmental Assessment   Petition 04-110-01p for
Determination of Nonregulated Status for Alfalfa Genetically Engineered
for Tolerance to the Herbicide Glyphosate 2004
http://www.aphis.usda.gov/brs/aphisdocs/04_11001p_pea.pdf
5.SeedQuest Risk assessment for biotech alfalfa 2001
http://www.seedquest.com/News/releases/usa/Usda/n3853.htm
6.Muller, M, Prosperi,J, Santoni,S. and Ronfort,J. How mitochondrial DNA
diversity can help to understand the dynamics of wild-cultivated
complexes. The case of Medicago sativa in Spain  2001 Molecular Ecology
10,2753-63
7. Haygood,R, Ives,A. and Andow,D. Population genetics of transgene
containment Ecology Letters 2004,7,213-20









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