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Grow Your Own, Nevada! Summer 2012: GMO Seeds and Crops

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Grow Your Own, Nevada! Summer 2012: GMO Seeds and Crops

  1. 1. GMO SEEDS AND CROPS: Science and science fiction
  2. 2. 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).
  3. 3. EXAMPLE: FLAVR SAVR TOMATO  First commercially grown genetically engineered food to be granted a license for human consumption.
  4. 4. WHAT IS A GENE?  A short sequence of DNA that codes for a protein  Humans have 20,000 to 25,000 genes.
  5. 5. GENETIC ENGINEERING  Use viruses or bacteria to "infect" animal or plant cells with the new DNA.  Coat DNA onto tiny metal pellets, and firing them into cells with a special gun.
  7. 7. HOW DOES GM DIFFER FROM CONVENTIONAL BREEDING?  Both alter genetic makeup and properties of the product.  Conventional breeding can take place only between closely related life forms.  Genetic modification bypasses the checks and balances associated with the natural selection process.
  8. 8. GENETIC MODIFICATION ONLY ONE OF MANY BIOTECH TOOLS Biotechnology includes:  Genetic modification  Marker-assisted selection (MAS)  Tissue culture  Fermentation (wine, beer)  Agriculture Baby plants in tissue culture
  10. 10. The fact that the GM transformation process is artificial does not automatically make it dangerous.
  11. 11. MISINFORMATION ABOUNDS ON BOTH SIDES!  Scientists found that This picture is PhotoShopped! Arctic flounder produces an antifreeze gene.  Inserted into strawberry to increase frost- resistance (in the lab)  Marker-Assisted Selection and conventional breeding found to be more efficient. ~This strawberry does not exist~
  12. 12. 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 to erosion.  Advanced crops that are designed to survive heat waves and droughts.
  13. 13. GM CROPS ENGINEERED TO TOLERATE HERBICIDES  Roundup Ready® soybeans Roundup Ready® soybeans commercialized in 1996.  Alfalfa, corn, cotton, spring canola, sugar beets and winter canola came next.  Contain in-plant tolerance to Roundup® agricultural herbicides.
  14. 14. GM CROPS ENGINEERED TO EXPRESS BT TOXIN  Bt a bacterium that expresses a protein toxic to many insects.  Works against leaf- feeding insects  Used agriculturally as a spray, or incorporated into GM crops.
  15. 15. GM CROPS CAN BE NUTRITIONALLY ENHANCED  Rice is a staple in Golden Rice enhanced with Vitamin A many developing countries.  Rice modified to contain beta carotene.  Can prevent or treat maternal anemia and blindness.
  16. 16. POTENTIAL RISKS OF GMOS  Introducing allergens and toxins to food  Antibiotic resistance  Accidental contamination of non- genetically modified with genetically modified foods  Adversely changing the nutrient content of a crop  Creation of "superweeds” and other environmental risks
  17. 17. GM PROCESS IS IMPRECISE  Creates mutations within the genome.  Leads to multiple, unpredictable effects (genes interact with one another).  Potential non- target effects on other organisms or the environment
  18. 18. 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? these foods  FDA requires evidence that allergenic substances not incorporated into GMO.
  19. 19. ALLERGY ASSESSMENT HAS SHOWN SOME PROBLEMS:  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.
  20. 20. TWO CASES WITH SUSPECTED LINK TO GM PRODUCTS:  1989– L-tryptophan produced using GM bacteria – killed 37, disabled 1500 more.  2000 – StarLink Maize (corn)  Approved only as animal feed but cross- contamination led to…  Bt insecticidal protein, Cry9C, caused allergic reactions in humans.
  21. 21. 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.
  22. 22. WHAT STUDIES SHOW…  Resistance already widespread for antibiotics from which marker genes in commercial use are made (ampicillin).  Kanamycin not widely used in human populations.  Alternatives to antibiotic marker genes are being investigated.
  23. 23. 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 unmodified food).  If these tests show no significant difference between the modified and unmodified products, no further food safety testing is required.
  24. 24. UNIVERSITY OF MARYLAND MEDICAL CENTER- “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 individually.” Visit-- m112927.htm
  25. 25. TOO MUCH CONTROL IN CORPORATE HANDS?  End-user agreements forbid use of their seeds for independent research.  Only studies approved by the company are published.  Unflattering results 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
  26. 26. HOW EXTENSIVE IS THE ISSUE?  Expertssay 60% to 70% of processed foods on U.S. grocery shelves have genetically modified ingredients.  Soybeans  Maize  Cotton  Rapeseed oil (canola)  Makes large-scale clinical trials difficult.
  27. 27. TO LABEL OR NOT TO LABEL  Currently,food companies aren't required by law to label foods containing genetically modified ingredients.
  28. 28. CALIFORNIA PROP 37 (2012): LABELING GE FOODS prop-37-genetically-modified-foods-labeling.html
  29. 29. ARE ORGANICALLY GROWN FOODS GMO FREE?  Yes!  But…cross-contamination of fields is possible and has been reported. Some scientists are concerned that open-air experiments cannot be contained.
  30. 30. WHAT ARE THE ENVIRONMENTAL RISKS?  Unintended transfer of transgenes through cross-pollination  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.
  31. 31. CONTAMINATION ISSUES  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 sampled.  GE Rapeseed was able to hybridize to create novel combinations of transgenic traits.
  32. 32. CONTAMINATION ENDANGERS ORGANICALLY GROWN CROPS  Rape seed is very fine.  Spills can cause contamination of neighboring fields or in crops rotated in rapeseed fields (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) canola field.
  33. 33. PESTICIDEUSE INCREASING, NOT DECREASING  GM crops reduced overall pesticide use in the first three years of commercial introduction (1996- 1998) by 1.2%, 2.3%, and 2.3% per year.  Increased pesticide use by 20% in 2007 and by 27% in 2008.
  34. 34. “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 data)
  35. 35. 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
  36. 36. GLYPHOSATE-RESISTANT SUPERWEEDS  21 glyphosate- Recognize these? resistant weeds - Common ragweed worldwide - Kochia  Glyphosate- - Annual bluegrass resistant weeds - Johnsongrass identified in 22 U.S. states.
  37. 37. STACKED HERBICIDE RESISTANCE  Now developing crops with combined resistance to glyphosate and synthetic auxin herbicides (2,4-D).  Yikes!  Super-duper weeds  Further increasing herbicide use  Neglect of IPM Palmer‟s pigweed
  38. 38. 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 Purdue University, 2012, Weed Science
  39. 39. BT SPRAYS NOT THE SAME AS GM BT CROPS  Bacillus thuringiensis (Bt) is a microbe that produces chemicals toxic to insects.  Target pests exposed for only a brief period.
  40. 40. POTENTIAL RISKS TO GM WITH BT CROPS:  Invasiveness – Few introduced organisms become invasive, yet it‟s a concern for the users.  Resistance to Bt – example, diamondback moth  Cross-contamination of genes - Although unproven, genes from GM crops can potentially introduce the new genes to native species. University of California San Diego
  41. 41. GM CUT FLOWERS –WHIMSICAL?  November 2011, Suntory introduced the first blue rose „APPLAUSE‟  Delphinidin pigment not naturally produced in rose.  Inserted delphinidin gene from pansy.
  42. 42. U.S. PUBLIC PERCEPTION OF GMO  Pew survey showed that American consumers do not support banning new uses of the technology  Rather, they seek an active role from regulators to ensure that new products are safe.
  43. 43. IS THERE AN ALTERNATIVE TO GM TECHNOLOGY?  Marker Assisted Selection (MAS) or precision breeding  Speeds up conventional breeding process Breeding heirloom tomatoes to be resistant to most common tomato diseases.
  44. 44. CAN GM FEED THE WORLD?  Dramatic increases in yield have not been realized.  Most GM crops used for biofuels, animal feed, processed foods.  Poor farmers cannot afford the technology.  GM seed patented; farmers not permitted to save seed.
  45. 45. WHAT‟S NEEDED TO ENSURE GMO SAFETY?  Long-term, multi-generational safety trials in animals (no longer possible in humans)  Mandatory labeling laws  Remove barriers to research that put control in the hands of corporations.
  46. 46. MORE INFORMATION: Anti-GMO perspective:  s/58 Safety of Genetically Engineered Foods: Approaches to Assessing Unintended Health Effects  10977#toc News updates on GMO issues (global perspective): 

Editor's Notes

  • 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:
  • 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.