Transcript Document

Maarten J. Chrispeels
Food from genetically engineered
crops. Should we worry?
Genetic change resulting from crop domestication
took 10,000 years.
Teosinte (top) and corn or maize (bottom)
The March of Genetic Technology
1860
1920
1950
1960
Mendel: making crosses, introducing genes
Discovery of hybrid vigor
Inducing mutations
Tissue culture and embryo rescue
1980 Plant transformation and GMOs
2000 Genomics
phenomenal population growth for the past 100 years.
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Plant Breeding and Crop Yield
4
2
1
1950
1960
1970
1980
Wheat in Mexico
0
Tons per hectare
3
The scientific basis of all crop improvement is
the identification of the genes that encode
certain phenotypic characteristics.
Those genes can now be transferred more easily
(via marker assisted breeding - no GM) or
directly (through genetic engineering - GM)
Molecular agriculture makes new gene
combinations possible
Peas (on the left) that make a genetically engineered
bean protein are insect-resistant and do not need to be
sprayed with pesticides.
Creation of a GM plant relies
on a natural gene transfer
mechanism
What are people’s concerns
• Is this food safe?
• Should food be labeled?
• Are there adverse
environmental effects?
• Patenting of seeds
• Discrimination against the
poor
• Who benefits?
All of these concerns
apply to food and
agriculture in general
These concerns are generally true
for all innovations. Governments
create policies based on the
following principles:
•
•
•
Promote the general welfare
Maintain people’s rights
(individuals, groups, corporations)
Ensure justice: burdens and
benefits must be fairly shared
Agriculture is the main cause of environmental
change and degradation
Fires burning in Northeast Brazil’s Maranhao region
Agriculture requires land clearing
Worldwide, 40 % of
our food production
depends on irrigation.
Depletion of aquifers
is occurring at twice
the re-charge rate.
Salinization is a
major consequence of
irrigation
Agriculture has narrowed the gene
pool and caused a loss of biodiversity
Wild Progenitors and Relatives
Land Races
Elite Lines
Environmental Hazards from Pesticides
• Substantial health
impacts on workers
• Pollution of natural
ecosystems/
waterways
• Loss of insect
biodiversity in
agroecosystems
• Creation of secondary
pests
• Creation of insect
races resistant to
pesticides
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Genetics is always better than chemicals:
GM Cotton with a Bacillus thuringiensis Cry gene is resistant
to Cotton Bollworm. Cry encodes an insecticidal protein
Reduced Pesticide Use with Insect-Protected Cotton
Insect Control Ledger for 2000: Bollgard® Cotton on Five Million Acres
Bollgard®
Cotton
Net
Distribution
Manufacturing

Saves 3.46 million
pounds of raw
material

Conserves 1.48
million gallons of
fuel oil

Eliminates 2.16
million pounds of
industrial waste


Transports and
stores 416,000
fewer gallons of
insecticide
Conserves
604,000 gallons
of fuel oil
Application


Applies 1.04 million
fewer pounds of
insecticide in 2.5 fewer
applications per acre
Disposes of 416,000
fewer insecticide
containers

Saves 41,250
10-hour farm
work days

Eliminates 2,150
10-hour days of aerial
application

Dr. Roger Leonard, LSU Agricultural Center
Dr. Ronald Smith, Auburn University
Financial Benefit
Conserves 2.41 million
gallons of fuel and 93.7
million gallons of water

Accrues
$168 million
in economic
benefits from
lower production
costs and
increased
cotton yield
Stewardship

Reduces pesticide
exposure risk

Preserves
beneficial insect
populations

Creates wildlife
benefits

Gives cotton
producers more
time for family
and community
activities

Gives cotton
producers peace
of mind
Consumer
Benefit

Produces fiber
equivalent to that
found in all
consumer
products derived
from cotton
Bollgard® is a registered trademark of Monsanto Company
© 2001 Monsanto Company
Some GM crops have the potential to
mitigate the environmental impact of
agriculture: less pesticide, less dust,
more biodegradable herbicides
“Roundup” tolerant soybeans can be
Planted with no-till procedures,
which eliminate plowing (dust),
Save water and use a biodegradable
herbicide
Hmm… I wonder if
there could be gene
flow?
Gene flow occurs when crops cross with wild relatives growing
in relative close proximity to the fields.
Gene flow requires sexual compatibility
Gene persistence requires an evolutionary advantage for the new trait
What about their nutritional value and safety?
What are the main food issues in the US?
The # 1 safety issue is bacteria (6000 deaths per yr.)
The # 1 health issues are fat, sugar and salt
Are GM foods safe and nutritious?
1. All GM foods have been extensively tested and
they are as safe as other foods in the market
place.
2. GM crops can be made into convenience and
“junk” food just like organic crops and other
crops!
3. Nutrition depends on the food, not the method of
crop breeding
Every year 250,000 children become blind
because of vitamin A deficiency
Some GM crops will improve the
nutritional quality of foods. Such
foods are now in the pipeline.
A GM soybean line, developed as a
collaboration between the USDA and
DuPont, is hypoallergenic in humans.
The approach is to down regulate the expression of the
gene encoding the major allergenic protein (antisense)
Hmmm.. Shouldn’t those things be labeled?
Labels are not neutral!
Produced by
Radiation
Breeding!
Truthful labels can be misleading or meaningless
There are no GM apples anywhere!
Is food labeled this way
nutritious?
How to Label?
Conventionally grown
Pesticides, twice a week
GMO
Pesticide free
Should foods from GM crops be labeled?
Perhaps!
The US takes the view that if
foods are “substantially equivalent”,
the method of producing them
need not be on the label.
Farmers use a variety of techniques, and keeping
production streams separate “from plow to plate”
costs money. Such separation is called “identity
preservation”. Who should pay for this?
Voluntary labeling works in the US for Kosher and Organic foods.
Europe requires that all food that has any ingredient that is
more than 1% GM be labeled as “GM containing”.
So, what’s the bottom line?
1. GM foods are as safe and there is promise for
more nutritious food.
2. For some crops, environmental impacts are
similar or less than conventional agriculture.
3. GM is an important tool for the plant breeder
4. GM technology can solve problems that can’t
be solved in other ways at present.
5. The benefits will be spread between biotech
companies, farmers and consumers.
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GM or no GM is a false issue. Sustainability is the real issue.
Through science and through ethics we have come to the
realization that we are bound by the laws of Nature. We must obey
those laws to make agriculture (and civilization) sustainable.
Our agricultural practices must reflect our new awareness that
many practices threaten sustainability. Food production must be
equitable and just, and sustainable, for all the peoples of the Earth.