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  • 1. BIOTECHNOLOGY Risk Assessment & Management
  • 2. BIOTECHNOLOGY
    • Science based technology and includes recombinant DNA techniques, biochemistry, molecular and cellular biology, microbiology, and genetics
  • 3.  
  • 4. Impact of biotechnology
    • Potential impact of transgenic crops on the environment – most hotly debated
  • 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
  • 6. GM Crops under production
    • Corn 140 million hectares
    • Soybeans 72 million hectares
    • Cotton 34 million hectares
    • Canola 25 million hectares
  • 7. Global Area of GM Crops
    • The United States (68%)
    • Canada (7%)
    • Argentina (23%)
    • China (1%)
    • Other (1%)
  • 8. 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
  • 9. Genetic Trait
    • S-adenosylmethionine hydrolase (SAMase) encoding gene
    • E. coli bacteriophage T3
  • 10. 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
  • 11. 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
  • 12. 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
  • 13. 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
  • 14. 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
  • 15. Trait
    • Glyphosate tolerant version of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) encoding gene
    • Isolated from Agrobacterium tumefaciens strain CP4 (CP4 EPSPS)
  • 16. 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
  • 17. 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
  • 18. Trait
    • Papaya ringspot virus (PRSV) resistant papaya produced by inserting the coat protein (CP) encoding sequences from this plant potyvirus
  • 19. 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
  • 20. 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
  • 21. 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
  • 22. 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
  • 23. 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.
  • 24. Benefits of the New Technology
    • Utilization of marginal lands
      • produce plants that are more tolerant to drought, salt and heat stresses, toxic heavy metals
  • 25. Problems with rDNA technology
    • Instability in transgene expression
    • Interruption or silencing of existing genes
    • Activation of silent genes
    • Expression of anti-nutrients
  • 26. 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
  • 27. 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
  • 28. Negative Impact
    • Food safety
    • Allergic reaction
    • Use of antibiotic marker genes
  • 29. 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
  • 30. 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”
  • 31. 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
  • 32. 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.
  • 33. 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
  • 34. 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
  • 35. 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
  • 36. 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
  • 37. Risk management
    • Important with regard to new or emerging technologies or programs that have associated risks
  • 38. 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
  • 39. Risk assessment
    • Process of characterizing and quantifying risk
    • Proper risk assessment also involves characterizing and quantifying uncertainties
  • 40. 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
  • 41.
    • 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
  • 42. 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
  • 43. 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
  • 44. 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
  • 45. 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
  • 46. 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