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