Transcript
WHAT ARE GMOS ANYWAY? GMO = Genetically Modified Organism
A GMO is an organism whose genome has been altered by the techniques of genetic engineering so that its DNA contains one or more genes not normally found there.
The process is referred to as Genetic Engineering (GE).
WHAT IS A GENE? A short sequence of DNA that codes for a
protein Humans have 20,000 to 25,000 genes.
http://ghr.nlm.nih.gov/handbook/basics/chromosome
ALL LIVING ORGANISMS SHARE MANY COMMON GENES
One-fourth of human genes are also found in rice.
We share 99 percent of our genome with the chimpanzee.
Humans even have the genetic information necessary to develop wings.
Source: www.geneticliteracyproject.org
HOW IS GE DONE? Use of viruses or
bacteria to "infect" the plant cells with the new DNA.
Coat DNA onto tiny metal pellets, and firing them into cells with a special gun.
Gene Gun
FARMERS HAVE BEEN GENETICALLY MODIFYING CROPS FOR THOUSANDS OF YEARS!
Well…not exactlyAgricultural revolution about
12,000 years agoHumans evolved from a hunter-
gatherer lifestyle to a farming lifestyle.
Systematic “modification” of crops began in the 1940’s
FARMERS HAVE BEEN SYSTEMATICALLY ALTERING CROPS GENETICALLY SINCE THE GREEN REVOLUTION (1940’S TO 1960’S)
Increase in agricultural production due to: Improvement in irrigation infrastructureModernization of farm managementDevelopment of synthetic fertilizersDevelopment and use of pesticidesDevelopment of high-yielding varieties of
cereal grainsDistribution of hybridized seeds
HOW DOES GE DIFFER FROM CONVENTIONAL BREEDING? Both alter genetic makeup and
properties of the product. Classical breeding operates on
traits, only indirectly selecting genes. Biotechnology targets genes,
attempting to influence traits. The potential of biotechnology is to
rapidly accelerate the rate of progress and efficiency of breeding.
FLAVR SAVR TOMATO First commercially
grown genetically engineered food to be granted a license for human consumption.
Available from 1994-1997 by Calgene
CAN I BUY GMO SEEDS AT MY LOCAL GARDEN CENTER?NO…!GMO seeds are purchased by
farmers from the biotech company that produced them.
The farmer must sign a use agreement that he/she will not replant the seeds and will follow EPA-mandated stewardship programs.
GMO SEEDS ARE NOT STERILE Monsanto owns a patent on the
“Terminator” gene or terminator technology, which results in sterile seeds.
…however, Monsanto has committed to never using this technology, and
it has yet to commercialize a crop using the technology.
MOST FRESH PRODUCE IS NOT GMO
Commercially available GMO food crops (U.S.): Soybean Corn Cotton Canola Sugar beet Papaya (Hawaiian) Squash (zucchini and yellow summer)
FIRST GENERATION GE CROPS Crops engineered to tolerate
herbicides (mostly glyphosate). Crops engineered to produce their own
insecticide (Bt crops). These traits are incorporated into over
90 percent of the soybean, corn and cotton grown in the U.S.
HERBICIDE-TOLERANT CROPS HELP IMPROVE SOIL AND WATER QUALITY
Have increased adoption of no-till.
No-till systems may prevent: soil erosion compaction runoff of water,
sediments, chemicals Have the potential to
benefit soil and water quality.
GLYPHOSATE-TOLERANT CROPSThe Good News:Glyphosate has replaced more
toxic and persistent herbicides.
The Challenge:Evolution of glyphosate-resistance
in some weed species. Herbicide resistance was happening
prior to the introduction of GE crops.
RELIANCE ON ONE HERBICIDE REDUCES THE EFFECTIVENESS OF HERBICIDE TOLERANCE
Glyphosate-resistance has been documented in 28 weed species worldwide (14 species in the U.S.)
Source: University of Minnesota
Source: Ian Heap, International Survey of Herbicide Resistant Weeds www.weedscience.org/graphs/soagraph.aspx (2013)
GLYPHOSATE-RESISTANCE AMONG WEED POPULATIONS IN RECENT YEARS MAY HAVE INDUCED FARMERS TO RAISE APPLICATION RATES.
WHAT CAUSED GLYPHOSATE RESISTANCE?
Overreliance on glyphosate for weed management.
Reduction in the diversity of weed management practices adopted by crop producers.
In both GE and non-GE systems, a greater emphasis on integrated weed management is needed.
PENDING INTRODUCTION OF CROPS WITH TOLERANCE TO 2,4-D AND DICAMBA
Different site of action than glyphosate.
Historically few weed-resistance issues with these chemicals.
Will need to monitor for: Increase in weed-resistance Potential for “drift” onto nontarget
plants Farmer simultaneous adoption of other
integrated weed management strategies
IPM MAY HELP SUSTAIN EFFECTIVENESS OF HERBICIDE-TOLERANT CROPS
USDA NRCS supports: Diversification of weed management
strategies Crop rotation Increased intensity of tillage for weed
controlUnion of Concerned Scientists supports: Increased crop rotation and cover crops Decreased emphasis on monoculture
cropping systems
GE CROPS ENGINEERED TO EXPRESS THE BT TOXIN
Bacillus thuringiensis (Bt) is a naturally occurring soil bacterium that produces a protein toxic to certain insects.
Genes from Bt are inserted into crop plants so they make the protein.
Bt sprays are permitted in organic production; crops engineered to produce Bt toxin are not.
INSECT RESISTANCE TO BT CROPS Incidence of insect resistance to Bt crops has been remarkably low but is increasing:Pink bollworm (cotton, India)Corn rootworm (corn, U.S.)
Refuges delay resistance by providing susceptible insects to mate with the resistant ones from the GE crop.
www.evolution.berkeley.edu
NON-TARGET EFFECTS OF BT Initial study in 1999 indicated harm. Monarch caterpillars feed exclusively on
milkweed leaves. Early concern that pollen from Bt corn could
blow onto milkweed leaves. Later extensive work showed (published in
PNAS): Current Bt corn varieties do not express large
amounts of Bt proteins in their pollen. Levels of pollen shed on milkweed leaves is
much lower than amounts shown to cause harm.
EFFECTS OF GE ON CROP YIELDS Current GE crop varieties not
engineered for increased yield over conventional varieties.
Economic benefit comes from enhanced protection from yield loss due to pests.
The greatest yields are seen with crops engineered to have multiple (stacked) GE traits.
WHO BENEFITS FROM FIRST GENERATION GE CROPS?
Mostly farmers and seed companies
Focus has been on two traits:Bt crops decrease amount of
insecticides sprayedGlyphosate-resistant crops reduce
use of the most toxic chemicals to fight weeds
HERBICIDE- AND PEST-TOLERANCE ARE NOT THE ONLY TRAITS THAT CAN BE GENETICALLY ENGINEERED INTO CROPS….
WHAT CROP TRAITS WOULD BENEFIT A HOTTER, FLATTER, MORE CROWDED PLANET?
Crops engineered for increased yield and quality
Crops engineered to use nitrogen fertilizer more efficiently
Crops engineered for drought, salinity and/or heat tolerance
GE CROPS CAN BE NUTRITIONALLY ENHANCED
Rice is a staple in many developing countries.
Rice modified to contain beta carotene.
Can prevent or treat maternal anemia and blindness.
Golden Rice enhanced with Vitamin A
http://www.goldenrice.org/
GE HAWAIIAN PAPAYA: A BIOTECHNOLOGY SUCCESS STORY?
Papaya Ringspot-Virus (PRSV) threatened to decimate the industry in Hawaii.
Hawaiian papaya engineered with resistance to PRSV.
Viral genes encoding capsid proteins transferred to papaya genome.
Elicits an immune response in papaya.
PRSV-infected papaya on the left; virus-resistant papaya on the right
WHY IS THE TECHNOLOGY CURRENTLY IN THE HANDS OF LARGE AGROCHEMICAL COMPANIES?
Cost of discovery, development and authorization of a new plant biotechnology trait introduced between 2008 and 2012 was $136 million.
About 26 percent of those costs were incurred as part of the regulatory testing and registration process.
Average time from initiation of a discovery project to commercial launch is about 13 years.
PUBLIC CONCERNS ABOUT GMOS Antibiotic-resistance genes Food safety – are GE foods safe to eat? Mistrust of the regulatory process “Super weeds” – gene transfer of
herbicide resistance gene to weedy relatives
Gene containment – transfer of traits and protection of conventional or organic crops
GMOS HAVE ANTIBIOTIC RESISTANT GENES IN THEM
Some scientists believe that eating GM food containing these marker genes could encourage gut bacteria to develop antibiotic resistance.
HOW ARE GMOS REGULATED?
USDA APHIS• Determines
risk of transgenic crop becoming a pest
U.S. EPA• Ensures
safety of pest-resistant transgenic crops
U.S. FDA• Regulates
food and animal feed derived from transgenic crops
ARE GM CROPS RIGOROUSLY TESTED?
Substantial Equivalence (U.S.) Product tested by the manufacturer for
unexpected changes in a limited set of components (toxins, nutrients or allergens that are present in the unmodified food).
If these tests show no significant difference between the modified and unmodified products, no further food safety testing is required.
IS THIS RIGOROUS ENOUGH? Substantial equivalence not a strict
definition. Compositional analysis tests only a
limited number of components. Regulations focus on the product, not
the technology. If a GE food is deemed substantially
equivalent, it is exempt from further testing.
Both GE and conventional breeding can lead to unexpected results.
PRECAUTIONARY PRINCIPLE (EU) Invoked in the event of a potential
risk – even if it cannot be fully demonstrated or quantified, or its effects determined.
Appropriate measures to anticipate and prevent harm should be taken.
It is impossible to precisely predict every possible outcome from GE technology.
AMERICAN MEDICAL ASSOCIATION“Our AMA supports mandatory pre-market systematic safety assessments of bioengineered foods and encourages: (a) development and validation of additional techniques for the detection and/or assessment of unintended effects; (b) continued use of methods to detect substantive changes in nutrient or toxicant levels in bioengineered foods as part of a substantial equivalence evaluation; (c) development and use of alternative transformation technologies to avoid utilization of antibiotic resistance markers that code for clinically relevant antibiotics, where feasible; and (d) that priority should be given to basic research in food allergenicity to support the development of improved methods for identifying potential allergens. The FDA is urged to remain alert to new data on the health consequences of bioengineered foods and update its regulatory policies accordingly.”
THE TECHNOLOGY IS ADVANCING… Focus on use of plant (rather than
animal or bacterial) genes that control agronomically important traits (stress resistance, improved yield)
Chloroplast engineering to reduce risk of pollen drift and toxicity to non-target species.
Remove antibiotic-resistance marker genes.
Pursue alternative technologies.
MARKER ASSISTED SELECTION Molecular breeding Precision breeding Speeds up
conventional breeding process from decades to as little as 5 years
Breeding heirloom tomatoes to be resistant to most common tomato diseases.
CAN GE AND NON-GE COEXIST?
Expand research funding for public crop breeding programs, so that a broad range of non-GE as well as GE crop varieties will remain available.
Expand public research funding and incentives to further develop and adopt agroecologically based farming systems.
Take steps—such as changes in patent law—to facilitate independent scientific research on GE risks and benefits.
Take a more rigorous, independently verified approach to GE product approvals, so that products do not come to market until their risks and benefits are understood through non-biased review.
Support food labeling laws that require foods containing GE crops to be clearly identified as such, so that consumers can make informed decisions about supporting GE applications in agriculture. - Union of concerned scientists
THE LAND INSTITUTE (SALINAS, KS)
Working to develop perennial crops using conventional breeding for a polycultural agricultural system
Perennials develop deeper root systems
Outcompete annual weeds for light Form complex ecosystems Prevent soil erosion Improves soil fertility Decreased use of chemical
fertilizers and pesticides Sequester carbon/reduction in
greenhouse gas emissions
Breeding program is focused on perennializing wheat, and domesticating perennial intermediate wheatgrass (which we have named Kernza™), several species of sunflower, and sorghum. http://www.landinstitute.org/our-work/solutions/
GENETICALLY ENGINEERED CROPS IN THE UNITED STATES
http://www.ers.usda.gov/publications/err-economic-research-report/err162.aspx#.U22IXFf15I0
INFORMATION:Science-based info on agriculture and GE: http://www.geneticliteracyproject.org/ http://www.ucsusa.org/our-work/food-agricult
ure/our-failing-food-system/genetic-engineering-agriculture#.VSMN05NUU8N
Safety of Genetically Engineered Foods:Approaches to Assessing Unintended Health Effects http://
www.nap.edu/catalog.php?record_id=10977#toc
News updates on GMO issues (global perspective): http://www.gmo-compass.org/eng/home/
MORE INFORMATION:Info on alternative cropping systems: http://
www.pfaf.org/user/cmspage.aspx?pageid=40 http://www.landinstitute.org/Info on EPAs shift towards use of IPM and biocontrols in agriculture: http://blog.epa.gov/epaconnect/2015/02/farm
ers-shift-towards-virtually-non-toxic-alternatives-for-pest-control/
Biotech safety and security issues: http://fas.org/biosecurity/education/dualuse-a
griculture/2.-agricultural-biotechnology/index.html
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