Grow Your Own, Nevada! Summer 2012: GMO Seeds and Crops
GMO SEEDS AND CROPS:
Science and science fiction
WHAT ARE GMOS ANYWAY?
GMO = Genetically modified organism
Anorganism whose genetic structure
has been altered by incorporating a
gene that will express a desirable trait
(process called genetic engineering).
EXAMPLE: FLAVR SAVR TOMATO
engineered food to
be granted a
license for human
WHAT IS A GENE?
A short sequence of DNA that codes for a
Humans have 20,000 to 25,000 genes.
Use viruses or
"infect" animal or
plant cells with
the new DNA.
Coat DNA onto
pellets, and firing
them into cells
with a special
HOW DOES GM DIFFER FROM
Both alter genetic makeup and
properties of the product.
Conventional breeding can take place
only between closely related life
Genetic modification bypasses the
checks and balances associated with
the natural selection process.
GENETIC MODIFICATION ONLY ONE OF MANY
Agriculture Baby plants in tissue culture
The fact that the GM
transformation process is artificial
does not automatically make it
MISINFORMATION ABOUNDS ON
Scientists found that
This picture is PhotoShopped!
Arctic flounder produces
an antifreeze gene.
Inserted into strawberry
to increase frost-
resistance (in the lab)
found to be more
~This strawberry does not exist~
THE PROMISE OF GMO TECHNOLOGY
Engineer allergenic foods to remove
allergens (wheat, soy).
Farmers grow more crops and feed
more people using less land.
Use fewer pesticides.
Reduce the amount of tilling that leads
Advanced crops that are designed to
survive heat waves and droughts.
GM CROPS ENGINEERED TO TOLERATE
Roundup Ready® soybeans
Alfalfa, corn, cotton,
spring canola, sugar
beets and winter
canola came next.
tolerance to Roundup®
GM CROPS ENGINEERED TO
EXPRESS BT TOXIN
Bt a bacterium that
expresses a protein toxic
to many insects.
Works against leaf-
Used agriculturally as a
spray, or incorporated
into GM crops.
GM CROPS CAN BE NUTRITIONALLY
Rice is a staple in Golden Rice enhanced with Vitamin A
Rice modified to
Can prevent or
POTENTIAL RISKS OF GMOS
Introducing allergens and toxins to
Accidental contamination of non-
genetically modified with genetically
Adversely changing the nutrient
content of a crop
Creation of "superweeds” and other
GM PROCESS IS IMPRECISE
within the genome.
Leads to multiple,
interact with one
target effects on
other organisms or
RISK OF INTRODUCING FOOD ALLERGENS
Milk, egg, wheat, fish,
tree nuts, peanuts, Question-
soybean, shellfish What if the GMO
Problem if GMO contains a protein
contained allergenic of unknown
protein from one of allergenicity?
FDA requires evidence
incorporated into GMO.
ALLERGY ASSESSMENT HAS SHOWN SOME
GM pest-resistant pea: study in rats
showed GM process can change
structure of the engineered protein.
GM soybean intended for animal feed
was engineered with a gene from
Brazil nut. Produced immune reactions
in people with Brazil nut allergies.
Pioneer Hi-Bred discontinued due to the
difficulty in ensuring that it would not
enter human food supply.
TWO CASES WITH SUSPECTED LINK TO GM
1989– L-tryptophan produced using
GM bacteria – killed 37, disabled 1500
2000 – StarLink Maize (corn)
Approved only as animal feed but cross-
contamination led to…
Bt insecticidal protein, Cry9C, caused
allergic reactions in humans.
GMOS HAVE ANTIBIOTIC RESISTANT
GENES IN THEM
believe that eating GM
food containing these
marker genes could
bacteria to develop
WHAT STUDIES SHOW…
Resistance already widespread for
antibiotics from which marker genes in
commercial use are made (ampicillin).
Kanamycin not widely used in human
Alternatives to antibiotic marker genes
are being investigated.
ARE GM CROPS RIGOROUSLY TESTED?
Substantial Equivalence test-
Product tested by the manufacturer
for unexpected changes in a limited
set of components (toxins, nutrients
or allergens that are present in the
If these tests show no significant
difference between the modified and
unmodified products, no further food
safety testing is required.
UNIVERSITY OF MARYLAND MEDICAL
“Genetically engineered foods are generally
regarded as safe. There has been no
adequate testing, however, to ensure
complete safety. There are no reports of
illness or injury due to genetically
engineered foods. Each new genetically
engineered food will have to be judged
TOO MUCH CONTROL IN CORPORATE
use of their seeds
approved by the
are blocked from
publication. Image: Matt Collins, Scientific American
Elson J. Shields, an entomologist at Cornell University, letter to an
official at the Environmental Protection Agency
HOW EXTENSIVE IS THE ISSUE?
Expertssay 60% to 70% of processed
foods on U.S. grocery shelves have
genetically modified ingredients.
Rapeseed oil (canola)
Makes large-scale clinical trials
TO LABEL OR NOT TO LABEL
required by law
to label foods
CALIFORNIA PROP 37 (2012):
LABELING GE FOODS
ARE ORGANICALLY GROWN FOODS
But…cross-contamination of fields is
possible and has been reported.
WHAT ARE THE ENVIRONMENTAL
Unintended transfer of transgenes
Contamination of non-GMO crops.
Unknown effects on other organisms
(e.g., soil microbes).
Increased herbicide use.
Potential for loss of crop biodiversity,
relying on only a few cultivars.
2011, scientists from the University of
Arkansas, North Dakota State University,
California State University and the US EPA
discovered large persistent populations of
genetically engineered canola lining
roadsides across North Dakota.
Comprised up to 45% of roadside plants
GE Rapeseed was able to hybridize to create
novel combinations of transgenic traits.
ORGANICALLY GROWN CROPS
Rape seed is very
Spills can cause
neighboring fields or
in crops rotated in
(such as wheat).
Australian organic farmer had his organic certification
status pulled because his organic wheat field was
contaminated by a nearby genetically-modified (GM)
PESTICIDEUSE INCREASING, NOT
GM crops reduced
overall pesticide use
in the first three
years of commercial
1998) by 1.2%,
2.3%, and 2.3% per
use by 20% in 2007
and by 27% in 2008.
“GM crops have increased pesticide use
by 383 million pounds in the U.S. in the
first 13 years since their introduction.”
- Charles Benbrook, The Organic
Center (based on USDA pesticide use
LET‟S BREAK THIS DOWN…
Over the first 13 years of GM
technology in the U.S.,
Modest reduction in insecticide use
Dramatic increase in herbicide use
21 glyphosate- Recognize these?
resistant weeds - Common ragweed
worldwide - Kochia
- Annual bluegrass
identified in 22
STACKED HERBICIDE RESISTANCE
crops with combined
Neglect of IPM
SUPERWEEDS LESS SUSCEPTIBLE TO DISEASE?
Because of changes in soil microbes, "We
may be selecting not only for glyphosate
resistance, but inadvertently selecting for
weeds that have disease resistance as well.“
- Schafer, Hallett & Johnson
2012, Weed Science
BT SPRAYS NOT THE SAME AS GM BT
is a microbe that
exposed for only
a brief period.
POTENTIAL RISKS TO GM WITH BT
Invasiveness – Few introduced
organisms become invasive, yet it‟s a
concern for the users.
Resistance to Bt – example,
Cross-contamination of genes -
Although unproven, genes from GM
crops can potentially introduce the
new genes to native species.
University of California San Diego
GM CUT FLOWERS –WHIMSICAL?
the first blue rose
produced in rose.
gene from pansy.
U.S. PUBLIC PERCEPTION OF GMO
Pew survey showed
consumers do not
new uses of the
Rather, they seek
an active role from
ensure that new
products are safe.
IS THERE AN ALTERNATIVE TO GM
Breeding heirloom tomatoes to
be resistant to most common
CAN GM FEED THE WORLD?
Dramatic increases in yield have not
Most GM crops used for biofuels,
animal feed, processed foods.
Poor farmers cannot afford the
GM seed patented; farmers not
permitted to save seed.
WHAT‟S NEEDED TO ENSURE
Long-term, multi-generational safety
trials in animals (no longer possible in
Mandatory labeling laws
Remove barriers to research that put
control in the hands of corporations.
Safety of Genetically Engineered Foods:
Approaches to Assessing Unintended Health
News updates on GMO issues (global
Genetic engineering can be done with plants, animals, or microorganisms. Historically, farmers bred plants and animals for thousands of years to produce the desired traits. For example, they produced dogs ranging from poodles to Great Danes, and roses from sweet-smelling miniatures to today's long-lasting, but scent-free reds.Read more: http://www.umm.edu/ency/article/002432.htm#ixzz24Odmdu6Q
Produced by the California company Calgene. Approved by FDA in 1992, came onto the market in 1994. Ceased production in 1997. Bred to prevent rotting on the vine so could be picked when ripe. Had a positive effect on shelf life but not on softening, so shipping was a problem and taste was bland. Company later acquired by Monsanto.
Because living organisms have natural barriers to protect themselves against the introduction of DNA from a different species, genetic engineers have to find ways to force the DNA from one organism into another.
Natural breeding can take only take place closely related forms of life
So it’s up to humans to test for unintended consequences.
Biotechnology = biological functions harnessed for various purposes. But keep in mind that GM is only one tool in the biotech toolbox.
It is the consequences of the procedure that are of concern.
Bt GM crops are protected specifically against European corn borer, southwestern corn borer, tobacco budworm, cotton bollworm, pink bollworm and the Colorado potato beetle.
Current understanding of the way in which DNA works is extremely limited, and any change to the DNA of an organism at any point can have side effects that are impossible to predict or control. The new gene could, for example, alter chemical reactions within the cell or disturb cell functions. This could lead to instability, the creation of new toxins or allergens, and changes in nutritional value.
One immediate health concern with eating genetically modified foods is allergens. Opponents point to an incident involving Starlink modified corn. In 2000, StarLink (approved by the EPA for animal feed in 1998 but not for human consumption because of concerns it contained a protein that could cause dangerous allergic reactions) turned up in many Kraft products, including their Taco Bell corn shells. Some corn crops were accidentally contaminated with the StarLink seed. Several people reported severe allergic reactions, and major recalls resulted. In the end, the EPA said federal tests didn't conclude that genetically modified corn causes allergies, nor did they eliminate the possibility that it could not cause such a reaction.
The techniques used to transfer genes have a very low success rate, so the genetic engineers attach "marker genes" that are resistant to antibiotics to help them to find out which cells have taken up the new DNA. These marker genes are resistant to antibiotics that are commonly used in human and veterinary medicine. Some scientists believe that eating GE food containing these marker genes could encourage gut bacteria to develop antibiotic resistance.
And you can’t be sure that organically produced animals haven’t been fed GMO grains.
In July 2005 British scientists showed that transfer of a herbicide-resistance gene from GM oilseed rape to a wild cousin, charlock, and wild turnips was possible.
The diamondback larvae feed on all plants in the mustard family, including canola, mustard, broccoli, and cabbage.Refuge planting and crop rotation
We could now quickly screen tomato seedlings for DR alleles, and thus only evaluate segregating populations in the field that we already knew were DR --- resistant to most of the common tomato diseases.