This document discusses biotechnology and genetically modified crops. It provides examples of GM crops developed for traits like herbicide tolerance, insect resistance, and virus resistance. It also discusses the global area under cultivation of major GM crops and countries growing them. Both benefits and risks of biotechnology are outlined. The document emphasizes the importance of assessing ecological risks and managing risks through strategies like conducting laboratory, small-scale and large-scale field trials before commercial release of GM crops.

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