1. BIOTECHNOLOGY
Risk Assessment &
Management

2. BIOTECHNOLOGY
 Science based technology and includes
recombinant DNA techniques, biochemistry,
molecular and cellular biology, microbiology,
and genetics

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