Examples of gmo


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Examples of gmo

  1. 1. BIOTECHNOLOGY Risk Assessment & Management
  2. 2. BIOTECHNOLOGY  Science based technology and includes recombinant DNA techniques, biochemistry, molecular and cellular biology, microbiology, and genetics
  3. 3. Impact of biotechnology  Potential impact of transgenic crops on the environment – most hotly debated
  4. 4. Transgenic crops and traits GM Crops Traits ____________________________________________________ Canola Herbicide tolerance; modified seed fatty acid content Maize Herbicide tolerance; resistance to corn root worm; resistance to European corn borer Melon Delayed ripening Papaya Resistance to viral infection Potato Resistance to Colorado potato beetle; resistance to potato leafroll luteovirus Rice Herbicide tolerance; Beta-carotene Soya bean Herbicide tolerance; modified seed fatty acid content Squash Resistance to viral infection Tomato Delayed ripening; delayed softening
  5. 5. GM Crops under production  Corn 140 million hectares  Soybeans 72 million hectares  Cotton 34 million hectares  Canola 25 million hectares
  6. 6. Global Area of GM Crops  The United States (68%)  Canada (7%)  Argentina (23%)  China (1%)  Other (1%)
  7. 7. Delayed ripening in Tomato  Introduction of a gene that results in degradation of a precursor of the plant hormone, ethylene  Production of tomatoes for human consumption, either fresh or processed  Agritope Inc. USA
  8. 8. Genetic Trait  S-adenosylmethionine hydrolase (SAMase) encoding gene  E. coli bacteriophage T3
  9. 9. Modification  Transformed tomato plants that exhibit significantly reduced levels of SAM, the substrate in ethylene biosynthesis  Ethylene plays an important role in fruit ripening of climacteric fruits  Lack of a sufficient pool of SAM results in a tomato fruit with significantly reduced ethylene biosynthetic capabilities and a modified ripening phenotype
  10. 10. Resistance to Colorado potato beetle  Introduction of a toxin gene from a bacteria that results in insect resistance in potato  Production of potatoes for human consumption and livestock feed including potato process residue  Monsanto Company, USA
  11. 11. Trait  Colorado potato beetle resistant potatoes produced by inserting the cry3A gene from Bacillus thuringiensis (subsp. tenebrionis)  encodes an insecticidal crystalline Cry3A delta-endotoxin protein
  12. 12. Modification  Transformed potato plants expresses the insecticidal crystalline Cry3A delta-endotoxin protein  Cry3A protein binds selectively to specific sites localized on the brush border mid-gut epithelium of susceptible insect species  Causes loss of ions
  13. 13. Herbicide tolerance Corn  Glyphosate herbicide tolerance  Production of Z. mays for human consumption (wet mill or dry mill or seed oil), and meal and silage for livestock feed  Monsanto Company, USA
  14. 14. Trait  Glyphosate tolerant version of the enzyme 5- enolpyruvylshikimate-3-phosphate synthase (EPSPS) encoding gene  Isolated from Agrobacterium tumefaciens strain CP4 (CP4 EPSPS)
  15. 15. Modifcation  Biolistic transformation of embryogenic maize cells with genes encoding the CP4 EPSPS enzyme  The modified enzyme (CP4 EPSPS) has a reduced binding affinity for glyphosate and allows the plant to function normally in the presence of the herbicide
  16. 16. Papaya Resistant to viral infection  Resistance to papaya ringspot virus (PRSV)  Production of papaya for human consumption, either fresh or processed  Cornell University, USA & UWI, Jamaica
  17. 17. Trait  Papaya ringspot virus (PRSV) resistant papaya produced by inserting the coat protein (CP) encoding sequences from this plant potyvirus
  18. 18. Modification  Microparticle bombardment of plant cells or tissue  Transgenic papayas exhibit “pathogen- derived resistance” to infection and subsequent disease caused by PRSV through a process that is related to viral cross-protection
  19. 19. Virus resistant tomato  Insertion of a mutant gene from the virus to prevent replication  Production of tomatoes for human consumption, either fresh or processed  UW-Madison, Hebrew Univ., UWI
  20. 20. Agricultural Biotechnology  Benefits of transgenic plants – To improve agricultural, horticultural and ornamental value of a crop plant – Can act as a living bioreactor – Means of studying the action of genes
  21. 21. Benefits of the New Technology  Higher yields & lower pesticide usage – Provide indirect benefits for consumers and the environment through lower usage of pesticides and there are higher yields due to reduced pest losses – A transition to less toxic chemicals – Facilitation of zero-till agriculture
  22. 22. Benefits of the New Technology  More Nutritious Foods – increasing the levels of essential amino acids, vitamins, bio-available iron and to reduce toxicity – more nutritious harvested products that keep much longer in storage and transport.
  23. 23. Benefits of the New Technology  Utilization of marginal lands – produce plants that are more tolerant to drought, salt and heat stresses, toxic heavy metals
  24. 24. Problems with rDNA technology  Instability in transgene expression  Interruption or silencing of existing genes  Activation of silent genes  Expression of anti-nutrients
  25. 25. Unanticipated effects in transgenic crops  Canola – over expression of phytoene synthase resulted in X500 increase in levels of and -carotene  Maize – the stems of Bt maize contain more lignin  Potato – expressing kanamycin showed changes in phynotypic and yield performance
  26. 26. Agricultural Biotechnology  Arguments against transgenic plants – Possible negative effects of transgenes on non- target organism – Potential for transgene escape – Impact of gene flow on biodiversity
  27. 27. Negative Impact  Food safety  Allergic reaction  Use of antibiotic marker genes
  28. 28. Food safety  Unsafe for human consumption ? – Allergic reaction to new proteins – 60% of processes foods in supermarkets in the USA contain a GM ingredient – Soy, corn, canola and some fresh vegetables
  29. 29. Allergic reaction  Cry9C a protein in Starlink corn  Insecticidal protein shares properties with proteins that are known food allergen  Not licensed for human consumption  “Taco Bell Home originals”
  30. 30. Antibiotic marker genes  Antibiotics – kanamycin, hygromycin, tetracycline, ampicillin  Used to identify plants carrying the transgene  Presence of the gene in the gut could enter gut organism, increase resistance  WHO report that antibiotic genes are safe
  31. 31. Impact on non-target species  Pollen from GM corn contains the insecticidal Bt toxin thought to be a danger to the monarch butterfly  Milkweed with pollen from Bt corn plants could kill monarch caterpillars that fed on them  Six recent studies finds that pollen from varieties of Bt corn most commonly grown in the USA do not contain enough toxin to harm monarchs.
  32. 32. Gene Flow  Gene flow - natural process and can occur between same or different species  Gene flow between trangenics and traditional maize in Mexico  12 of the world’s 13 most important food crop hybridize with at least one wild relative
  33. 33. Gene flow on Biodiversity  Transgene flow might have impact on the within-species genetic diversity of domesticated populations  Introduction of invasive alien species could have far greater impact on biodiversity  Pest or pathogen resistance and tolerance to various abiotic stresses – may be highly advantageous in the wild
  34. 34. Risk Assessment  Assessing ecological risk prior GMO release  May take years for the true environmental effects of transgene escape to be known  Predictions can be made about particular crops or traits that are likely to pose the greatest environmental risk  Transgenes that are advantageous in the wild or are weedy forms of a plant are most likely to pose a significant risk
  35. 35. Ecological risk assessment  Lack of key information on the ecology of native plant species  Need to generate information to enable risk assessment to be carried out using local information
  36. 36. Risk management  Important with regard to new or emerging technologies or programs that have associated risks
  37. 37. Biosafety Assessment  Biosafety assessment includes hazard and risk  Hazard can be defined as a potentially adverse outcome of an event or activity  Risk - The probability and severity of an adverse event
  38. 38. Risk assessment  Process of characterizing and quantifying risk  Proper risk assessment also involves characterizing and quantifying uncertainties
  39. 39. Objective of risk management  Anticipate detrimental effects that might follow the release of a GMO during experimentation or commercialization  Design monitoring systems for the early detection of adverse outcomes  Plan intervention strategies to avert and, if necessary, remediate adverse environmental or health effects
  40. 40.  Define regulatory authority to prevent the development and/or importation of potentially dangerous GMOs  Encouraging continued development of increasingly effective biosafety procedures  Providing public information about biosafety
  41. 41. Laboratory investigations  Basic molecular genetic analyses and analyses of physiological performance, done to characterize the GMO and indicate whether it expresses the intended phenotypic properties, and whether the properties are altered  Experiments (growth chamber & greenhouse) to study potential ecological impacts and genetic stability of the GMO
  42. 42. Small field trials  Done after laboratory investigations suggest that GMO maybe efficacious, genetically stable, and ecologically benign  Suitable protocols are required – design, sample size, controls and statistical analysis  Assay for genetic exchange and genetic stability
  43. 43. Larger field trials  If small field trials indicate both efficacy and safety, larger field trials can be done  The same requirement of good experimental design apply as with smaller field trials
  44. 44. Commercial release  Initially, commercialization or widespread application should take place in the areas where larger field trials have been completed and found to indicate a high probability of GMO safety and efficacy  Periodic monitoring after a GMO is released into a new environment is essential  DNA markers for the GMO is essential
  45. 45. Impact on society  Many countries are actively reviewing the safety and ethics of biotechnology research and its applications  Some countries have established research guidelines and biosafety framework