This document discusses the biosafety of genetically modified crops. It outlines the approach taken to assess safety, including potential risks like toxicity, allergenicity, antibiotic resistance, and gene flow. The regulatory framework for genetically modified crops in India is also mentioned. Specific concerns discussed include Brazil nut allergy in soybean, use of antibiotic resistance marker genes, consumption of foreign DNA, and effects on biodiversity and target species. Strategies to prevent unwanted gene flow are described.

1. Biosafety of Genetically Modified CropsBiosafety of Genetically Modified Crops
Ekatpure Sachin Chandrakant

2. 2
Biosafety of GM Crops
Policies and procedure adopted to ensure environmental
safety during the course of development and
commercialization of genetically modified organism
2

3. 3
Safety assessment approach for GM crops
3
35

4. 4
Elements of assessment
4
36

5. 5
Regulatory framework in India
5
37

6. 6
Risk of toxicity/ allergineicity
 Addition of new genetic material
may activate toxic pathways
 Appearance of novel metabolites
 Introduction of new protein
 Non immunogenic protein could
become immunogenic
6(Kaeppler, 2000)

7. Brazil nut allergy in soybean
 A well-known case of a GM soybean
allergy
 2S albumin gene from Brazil nut to
soybean (enhanced methionine)
(Julie et al,1996)
 Allergen transferred unintentionally
from Brazil nut to GM soybean
 Investigations with GM soybean
revealed immune reactions in people
with Brazil nut allergies 41

8. 8
Antibiotic resistance
 Marker gene could induce antibiotic resistance
 Would reduce effectiveness of antibiotics to fight diseases
 Conditions for HGT (horizontal gene transfer) :
 DNA must be free from the cells
 Bacterial recipient must be competent
 Integration depends on sequence homology
 Acid environment of human stomach
 HGT of nptII gene can occur 1 in 10 billion
 Specificity of promoter
8(Redenbaugh et al,1994)

9. Eating of foreign DNA
 DNA present in all living things and
eaten by humans with every meal
 Broken down during digestion process
 Small amount absorbed in blood stream
or excreted
 According to WHO amount of DNA
ingested- 0.1 to 1 g/day (novel DNA
represents 0.0001%)
(Chawla , 2009) 9

10. Use of promoters of virus origin
 Concerns expressed regarding human health
eg. 35S promoter of CaMV
 It might be harmful if it invades human cells and turns
on certain genes
 Probability is very low and no such report so far
10

11. Changes in nutrition level
 Accidental changes in nutritional component of GM crop
 Report spread in 1997 that Roundup Ready soybean
produces large quantities of phytoestrogen (causes breast
cancer) after glyphosate spray
 Investigation revealed no such increase
11
(SAG report, 1997)

12. 12
Gene Flow
 Accidental cross between GM
plant and traditional local varieties
or weedy relative
 Contaminate local variety with
transgene (eg.superweeds)
 Ryegrass highly resistant to
glyphosate already found in
Austrailia
12
(Gaur et al.,2010)

13. 13
Report on corn contaminated by GM genes
in Mexico
 David Quist and Ignacio Chapela in Nov 2001 reported
transgenic DNA construct 35s promoter sequence found
in Creole maize at Oaxacan state of Mexico
 CIMMYT amplified 28 accessions from Oaxacan
landraces with CaMV 35s promoter primer
 Samples did not show presence of 35s promoter
13(CIMMYT report,2001)

14. Strategies to prevent gene flow
 Isolation zone
 Trap crop
 Male sterility
 Chloroplast
transformation
 Clean gene technology
- Devoid of vegetation
- Use of non-transgenic variety
- Inactive pollens
- Gene construct introduced into
chloroplast
- Markerless GM
14(Chawla,2009)

15. 15
Resistance of target species
 Insect/ virus population rapidly adapt to environmental
pressure
 Development of new strains
 Gene pyramiding - Best solution
15

16. 16
Impact on biodiversity
 Reduction in genetic diversity by development and global
spread of improved varieties
 Sustainable agriculture depends on mixed cropping and
crop rotation
 Not unique to GM but is relevant to all improved varieties
 Bt protein is highly unstable rapidly degraded in stomach
juices of vertebrates and in soil
16

17. Monarch butterfly incidence
 Monarch butterfly catterpillers died when fed on Bt
maize pollen
 It was a lab experiment
 Butterfly fed only on Bt maize pollen
 For toxic effect of Bt protein it should meet specific dose
requirement
 In nature it is not possible to meet that dose level
17(Losey et al,1999)

18. Warangal Attempt
 Farmers of Warangal district of Andhra Pradesh reported cattle
and sheep dying on consuming Bt cotton plants
 No one has so far conclusively proved that Bt protein in the Bt
cotton plants was the real culprit
 Why do the cattle die eating Bt cotton only in the Telngana
region of Andhra Pradesh ?
 Clearly a mischievous and cheap attempt to denigrate and
discredit the Bt technology
(Rao, 2007)
58

19. Ethical issues
 Unacceptable intervention in “God’s creation
violating barriers in natural world”
 Objections to consuming animal genes in plants
and vice-versa
 Demand for GM and Non GM food labelling
19