types of modifications alongwith advantages and disadvantages ethics included

1. RIDDHI KARNIK

2.  Was under trial and error for almost 9900 years.
 The first genetically modified plant was produced in 1982,
using an antibiotic-resistant tobacco plant.
 The first genetically modified crop approved for sale in the
U.S., in 1994, was the FlavrSavr tomato, which had a
longer shelf life, as it took longer to soften after ripening.
 As of mid-1996, a total of 35 approvals had been granted
to commercially grow 8 transgenic crops and one flower
crop of carnations, with 8 different traits in 6 countries
plus the EU. In 2000, with the production of golden rice,
scientists genetically modified food to increase its
nutrient value for the first time.
HISTORY

3. • To improve the agricultural, horticultural or ornamental
value of a crop plant
• To serve as a bioreactor for the production of economically
important proteins or metabolites
• To provide a powerful means for studying the action of
genes (and gene products) during development and other
biological processes
WHY GENETICALLY ENGINEER PLANTS?

4. Applications of Plant Genetic
Engineering
A.Crop Improvement
B.Genetically Engineered Traits: The Big Six
1.Herbicide Resistance
2.Insect Resistance
3.Virus Resistance
4.Altered Oil Content
5.Delayed Fruit Ripening
6.Pollen Control
C.Biotech Revolution: Cold and Drought
Tolerance and Weather-Gaurd Genes
D.Genetically Engineered Foods
1.Soybeans
2.Corn
3.Cotton
4.Other Crops

5. An Overview of the Crop Genetic Engineering cycle

6. Leaf Disc Method for A. t. Mediated Transformation
Leaf Disk Preparation Co-cultivation with Agrobacterium Selection for Transformation
Regeneration of Shoots
6

7. Genetic engineering techniques
applied to plants
METHOD SALIENT FEATURES
1.VECTOR MEDIATED GENE
TRANSFER
a. Agrobacterium mediated
gene transfer
b. Plant viral vectors
Very efficient but limited to a selected group of plants
Ineffective, hence not widely used
2.DIRECT OR VECTORLESS
DNA TRANSFER
a. Electroporation
b. Microprojectile
c. Liposome fusion
d. Silicon carbide fibres
Mostly confined to protoplasts that can be regenerated to
viable plants
Limited use only one cell can be microinjected at a time
Confined to protoplasts that can be regenerated into viable
whole plants
Requires regenerable cell suspensions
3 CHEMICAL METHODS
a. Polyethylene glycol
mediated
b.Diethylaminoethyl(DEAE)dext
ran- mediated
Confined to protoplasts. Regeneration of fertile plants is
frequently problematical
Very less results

8.  Herbicides are generally non-selective (killing both
weeds and crop plants) and must be applied before
the crop plants germinate
 Four potential ways to engineer herbicide resistant
plants
1. Inhibit uptake of the herbicide
2. Overproduce the herbicide-sensitive target protein
3. Reduce the ability of the herbicide-sensitive target
to bind to the herbicide
4. Give plants the ability to inactivate the herbicide
HERBICIDES AND HERBICIDE-RESISTANT
PLANTS

9. HERBICIDE-RESISTANT PLANTS:
REDUCING THE ABILITY OF THE HERBICIDE-SENSITIVE
TARGET TO BIND TO THE HERBICIDE
 Herbicide: Glyphosate (better known as Roundup)
 Resistance to Roundup (an inhibitor of the enzyme
EPSP involved in aromatic amino acid biosynthesis)
was obtained by finding a mutant version of EPSP
from E. coli that does not bind Roundup and
expressing it in plants (soybean, tobacco, petunia,
tomato, potato, and cotton)
 5-enolpyruvylshikimate-3-phosphate synthase
(EPSP) is a chloroplast enzyme in the shikimate
pathway and plays a key role in the synthesis of
aromatic amino acids such as tyrosine and
phenylalanine

10.  Genetic engineering here is more challenging;
however, some strategies are possible:
 Individually or in combination express pathogenesis-
related (PR) proteins, which include b1,3-glucanases,
chitinases, thaumatin-like proteins, and protease
inhibitors
 Overexpression of the NPR1 gene which encodes the
“master” regulatory protein for turning on the PR
protein genes
 Overproducing salicylic acid in plants by the addition
of two bacterial genes; SA activates the NPR1 gene
and thus results in production of PR proteins
FUNGUS- AND BACTERIUM-RESISTANT
PLANTS

11. Modification of plant nutritional
content: increasing the vitamin A
content of plants
• 124 million children
worldwide are deficient in
vitamin A, which leads to
death and blindness
• Mammals make vitamin A
from b-carotene, a common
carotenoid pigment normally
found in plant photosynthetic
membranes
• Here, the idea was to
engineer the b-carotene
pathway into rice
• The transgenic rice is yellow
or golden in color and is
called “golden rice”
*Expression of enzymes
of β-carotene pathway
in rice endosperm
*Amelioration of Vitamin
A deficiency

12. Edible Vaccines – Ongoing
Research Areas
Hepatitis B
Dental caries - Anti-tooth decay Ab
Autoimmune diabetes
Cholera
Rabies
HIV
Rhinovirus
Foot and Mouth
Enteritis virus
Malaria
Influenza
Cancer

13. EDIBLE VACCINES FROM PLANTS
Two strategies for production
1) Expression of foreign antigens in plant via stable
transformation
2) Delivery of vaccine epitopes via plant virus
(Mason and Arntzen, 1995)

14. Strategy for the production of candidate vaccine
antigens in plant tissues

15. e
RABIES VIRUS G PROTEIN IN TOMATO
• Gene linked to CaMV35S
promoter
• Introduced to tomato plants by
Agrobacterium- mediated
transformation
• Expression of recombinant
glycoprotein in leaves and fruits
• Protein localized in Golgi bodies,
vesicles and plasma lemma

16. Norwalk virus (cold virus) capsid protein in potato
and tobacco
• Causative agent for acute epidemic
gastroenteritis
• NVCP was fused to CaMV35S promoter
• Transformation by Agrobacterium
• Expression level: varies with plant
(

17. DEVELOPMENT OF STRESS- AND
SENESCENCE-TOLERANT PLANTS: GENETIC
ENGINEERING OF SALT-RESISTANT PLANTS
 Overexpression of
the gene encoding
a Na+/H+ antiport
protein which
transports Na+ into
the plant cell
vacuole
 This has been done
in Arabidopsis and
tomato plants
allowing them to
survive on 200 mM
salt (NaCl)

18. Frost Resistance
• Ice-minus bacteria
• Ice nucleation on plant surfaces caused by
bacteria that aid in protein-water coalescence 
forming ice crystals @ 0oC (320F)
• Ice-minus Pseudomonas syringae
• Modified by removing genes responsible for
crystal formation
• Sprayed onto plants
• Displaces wild type strains
• Protected to 23oF
• Dew freezes beyond this point
• Extends growth season
• First deliberate release experiment – Steven
Lindow – 1987- sprayed potatoes

19. Development of stress- and senescence-tolerant
plants: genetic engineering of flavorful tomatoes
Fruit ripening is a natural aging or senescence process that involves two
independent pathways, flavor development and fruit softening.
Typically, tomatoes are picked when they are not very ripe (i.e., hard and
green) to allow for safe shipping of the fruit.
Polygalacturonase is a plant enzyme that degrades pectins in plant cell
walls and contribute to fruit softening.
In order to allow tomatoes to ripen on the vine and still be hard enough
for safe shipping of the fruit, polygalacturonase gene expression
was inhibited by introduction of an antisense polygalacturonase
gene and created the first commercial genetically engineered
plant called the FLAVR SAVR tomato.
Flavor development pathway
Fruit softening pathway
Green Red
Hard Soft
polygalacturonaseantisense polygalacturonase

20.  Crop Organization Gene
 Brinjal IARI, New Delhi cr y1Ab, cr y1Ac
 MAHYCO, Mumbai
 Cauliflower MAHYCO, Mumbai cr y1Ac
Sungrow Seeds Ltd., New Delhi
 Cabbage Sungrow Seeds Ltd., New Delhi cr y1Ac
 Chickpea ICRISAT, Hyderabad cr y1Ac, cr y1Ab
 Groundnut ICRISAT, Hyderabad IPCVcp, IPCV replicase,
 Maize Monsanto, Mumbia CP4 EPSPS
 Mustard IARI, New Delhi CodA, Osmotin,
NRCWS, Jabalpur bar, barnase, barstar
TERI, New Delhi Ssu-maize, Psy, Ssu-tpCr tI
UDSC, New Delhi bar, barnase, barstar
 Okra MAHYCO, Mumbai cr y1Ac
 Pigeonpea ICRISAT, Hyderabad cr y1Ab + SBTI
MAHYCO, Mumbai cr y1Ac
 Potato CPRI, Simla cr y1Ab
NCPGR, New Delhi Ama-1
 Rice Directorate of Rice Research, Bacterial blight res, Xa -21,
Hyderabad
Osmania University, Hyderabad cr y1Ab, gna gene,
IARI, New Delhi gna
MAHYCO, Mumbai Bt, chitinase, cr y1Ac and Aa
MKU, Madurai cr y1Ac
MSSRF, Chennai chitinase, B -1,3-glucanase
TNAU, Coimbatore chitinase
 Sorghum MAHYCO, Mumbai cr y1Ac
Transgenic crop under development and field trials in India

21. • improved nutritional quality
• increased crop yield
• insect resistance
• disease resistance
• herbicide resistance
• salt tolerance
• biopharmaceuticals
• saving valuable topsoil
• ability to grow plants in harsh environments
ADVANTAGES OF GM CROPS

22. • Damage to human health
•allergies
•horizontal transfer and antibiotic resistance
•eating foreign DNA
•changed nutrient levels
• Damage to the natural environment
•crop-to-weed gene flow
•leakage of GM proteins into soil
•reductions in pesticide spraying: are they real?
• Disruption of current practices of farming and food
production in developed countries
•crop-to-crop gene flow
• Disruption of traditional practices and economies in
less developed countries.
• Lack of research on consequences of transgenic
crops.
DISADVANTAGES OF GM CROPS

23.  Foods produced using biotechnology has not been
established as safe and are not adequately
regulated.
 Crops produced using biotechnology will negatively
impact the environment.
 The long term
effects of foods developed using biotechnology are
unknown.
MYTHS RELATED TO GENETIC MODIFICATION

24.  Genetically-modified foods have the potential
to solve many of the world's hunger and
malnutrition problems, and to help protect and
preserve the environment by increasing yield
and reducing reliance upon chemical pesticides
and herbicides. Yet there are many challenges
ahead for governments, especially in the areas
of safety testing, regulation, international
policy and food labeling. Many people feel that
genetic engineering is the inevitable wave of
the future and that we cannot afford to ignore
a technology that has such enormous potential
benefits. However, we must proceed with
caution to avoid causing unintended harm to
human health and the environment as a result
of our enthusiasm for this powerful technology.
CONCLUSION

25.  Principles of genetic manipulations.
PRIMROSE 5th EDITION
 INTERNET
 MOLECULAR BIOTECHNOLOGY by GLICK
 http://en.wikipedia.org/wiki/Genetically_modified_crops
REFERENCES