1. Success Story of
Transgenic crops

2. Important Traits for Crop Improvement
High crop yield
High nutritional quality
Abiotic stress tolerance
Pest resistance
Adaptation to inter-cropping
Nitrogen Fixation
Insensitivity to photo-period
Elimination of toxic compounds

3. TRANSGENIC PLANTS HYBRID DEVELOPMENT FOR HIGHER YIELD NUTRITIONAL
QUALITY
BIOTIC STRESS
TOLERANCE
TRANSGENIC PLANTS
ENHANCED
SHELF LIFE
ABIOTIC STRESS
TOLERANCE
INDUSTRIAL
PRODUCTS
PHARMACEUTICALS
& EDIBLE VACCINE

4. 1985 1988 1992 1994 1996 1998 1999 2000 1st transgenic plants produced
Particle bombardment developed
1992
GM crops considered substantially equivalent to hybrid varieties
1994
Flavr-Savr tomato is released
1996
Herbicide- and insect-resistant crops approved for cultivation
4.3 million acres of GM crops planted
1998
GM food is dangerous (UK TV)
Monarch butterfly paper causes uproar
1999
GM corn is excluded from its baby food
Greenpeace starts anti-GM campaign
75 million acres of GM crops planted
2000
Golden rice with ß-carotene developed
McDonald’s rejects GM potatoes

5. Tearless Onion

6. Colorful Cauliflowers

7. Purple tomatoes

8. Blue Roses

9. The big five successful traits
Insect Resistance
Delayed Fruit Ripening
Nutritional Enhancing
Herbicide Resistance
Virus Resistance

10. Herbicide Resistance Glyphosate Resistance Glufosinate Resistance
Glyphosate = “Roundup”, “Tumbleweed” = Systemic herbicide
Marketed under the name Roundup, glyphosate inhibits the enzyme EPSPS (S-enolpyruvlshikimate-3 phosphate – involved in chloroplast amino acid synthesis), makes aromatic amino acids.
The gene encoding EPSPS has been transferred from glyphosate-resistant E. coli into plants, allowing plants to be resistant.
Glufosinate Resistance
Glufosinate (the active ingredient being phosphinothricin) mimics the structure of the amino acid glutamine, which blocks the enzyme glutamate synthase.
Plants receive a gene from the bacterium Streptomyces (bar gene) that produce a protein that inactivates the herbicide.

11. Herbicide Resistance Bromoxynil Resistance
A gene encoding the enzyme bromoxynil nitrilase (BXN) is transferred from Klebsiella pneumoniae bacteria to plants.
Nitrilase inactivates the Bromoxynil before it kills the plant.
Sulfonylurea.
Kills plants by blocking an enzyme needed for synthesis of the amino acids valine, leucine, and isoleucine.
Resistance generated by mutating a gene in tobacco plants (acetolactate synthase), and transferring the mutated gene into crop plants.

12. Roundup Ready™ Soybeans
A problem in agriculture is the reduced growth of crops imposed by the presence of unwanted weeds. Herbicides such as RoundupTM and Liberty LinkTM are able to kill a wide range of weeds and have the advantage of breaking down easily. Development of herbicide resistant crops allows the elimination of surrounding weeds without harm to the crops.

13. ROUNDUP (Glyphosate) RESISTANCE ( HERBICIDE TOLERANCE IN CROPS)
Glucose
ROUNDUP
(Glyphosate )
3 phosphoglycerate
Tryptophan
Glycolysis
EPSP SYNTHASE
Phosphoenol
pyruvate
EPSP SYNTHASE
Tyrosine
Phenylalaline
ROUNDUP
(Glyphosate )
In transgenic plant, herbicide cannot bind the mutant of EPSPS (Roundup resistant cotton and soybean)

14. Anti-Insect Strategy - Insecticides
Insect resistance
Anti-Insect Strategy - Insecticides
a) Toxic crystal protein from Bacillus thuringensis
Toxic crystals found during sporulation
Alkaline protein degrades gut wall of lepidopteran larvae
Corn borer catepillars
Cotton bollworm catepillars
Tobacco hornworm catepillars
Gypsy moth larvae
Sprayed onto plants – but will wash off
The Bt toxin isolated from Bacillus thuringiensis has been used in plants. The gene has been placed in corn, cotton, and potato, and has been marketed.

15. Insect Resistance
Various insect resistant crops have been produced. Most of these make use of the Cry gene in the bacteria Bacillus thuringiensis (Bt); this gene directs the production of a protein that causes paralysis and death to many insects.
Corn hybrid with a Bt gene
Corn hybrid susceptible to European corn borer

16. δ -endotoxin gene (Cry gene) of Bacillus thuriengenesis
GENE FOR Bt TOXIN WAS TRANSFERRED
TO OBTAIN BT TRANSGENIC PLANTS
PLANT SYNTHESIZES INACTIVE PROTOXIN
PROTEINASE
DIGESTION IN
INSECT GUT
MAKES THE
ACTIVE TOXIN
INSECT FEEDS ON
TRANSGENIC PLANT
Toxin binds a receptor on the gut epithelial cells, forms a channel on the membrane. This causes electrolyte leakage and insect death

17. Virus resistance
Plants may be engineered with genes for resistance to viruses, bacteria, and fungi.
Virus-resistant plants have a viral protein coat gene that is overproduced, preventing the virus from reproducing in the host cell, because the plant shuts off the virus’ protein coat gene in response to the overproduction.
Coat protein genes are involved in resistance to diseases such as cucumber mosaic virus, tobacco rattle virus, and potato virus X.

18. Delayed Fruit Ripening
Allow for crops, such as tomatoes, to have a higher shelf life.
Tomatoes generally ripen and become soft during shipment to a store.
Tomatoes are usually picked and sprayed with the plant hormone ethylene to induce ripening, although this does not improve taste
Tomatoes have been engineered to produce less ethylene so they can develop more taste before ripening, and shipment to markets

19. Delayed Fruit Ripening
What happened to the Flavr Savr tomato?
Produced by blocking the polygalacturonase (PG) gene, which is involved in spoilage. PG is an enzyme that breaks down pectin, which is found in plant cell walls.
Plants were transformed with the anti-sense PG gene, which is mRNA that base pair with mRNA that the plant produces, essentially blocking the gene from translation.
First genetically modified organism to be approved by the FDA, in 1994.
Tomatoes were delicate, did not grow well in Florida, and cost much more than regular tomatoes.
Calgene was sold to Monsanto after Monsanto filed a patent-infringement lawsuit against Calgene, and the Flavr Savr tomato left the market.

20. First biotech plant product – Flav’r Sav’r tomato
“Rot-Resistant Tomato”
Anti-sense gene  complementary to polygalacturonase (PG)
PG = pectinase  accelerates plant decay/rotting

21. Nutritionally Enhanced Plants
More than one third of the world’s population relies on rice as a food staple, so rice is an attractive target for enhancement.
Golden Rice was genetically engineered to produce high levels of beta-carotene, which is a precursor to vitamin A. Vitamin A is needed for proper eyesight.
Other enhanced crops include iron-enriched rice and tomatoes with three times the normal amount of beta-carotene

22. Golden Rice
Normal rice
Transgenic technology produced a type of rice that accumulates beta-carotene in rice grains. Once inside the body, beta-carotene is converted to vitamin A.
“Normal” rice
“Golden” rice

23. Gernayl Gernayl diphosphate (GGPP)
Phytoene synthase
Phytoene
Phytoene desaturase
Lycopene
Lycopene cyclase
Beta carotene
Complete biochemical pathway in the rice for production of beta-carotene, a precursor for vitamin A

24. The prototype of golden rice was developed in 2000 and is a light yellow color (b). It contains 1.6 mg/g of carotenoid.
In 2005, new transgenic lines were developed that dramatically increased the amount of carotenoid synthesized, making the rice a deep golden color (c).
This latest form contains 37 mg/g of carotenoid, of which 84% is b-carotene – trial

25. Molecular Farming
A new field where plants and animals are genetically engineered to produce important pharmaceuticals, vaccines, and other valuable compounds.
Plants may possibly be used as bioreactors to mass-produce chemicals that can accumulate within the cells until they are harvested.
Soybeans have been used to produce monoclonal antibodies with therapeutic value for the treatment of colon cancer. Drugs can also be produced in rice, corn, and tobacco plants
Plants have been engineered to produce human antibodies against HIV. Pharmaceuticals has begun clinical trials with herpes antibodies produced in plants.

26. Why Plants?
Plants offer unique benefits for the production of pharmaceutical proteins:
Ease of Scale-up
Low Cost
Reduced Capital Expenditures
No Animal Contaminants (virus)

27. Molecular Farming (Vaccines)
Making plants that produce vaccines
Potatoes have been studied using a portion of the E. coli enterotoxin in mice and humans.
Other candidates for edible vaccines include banana and tomato, and alfalfa, corn, and wheat are possible candidates for use in livestock.
Edible vaccines may lead to the eradication of diseases such as hepatitis B and polio.

28. Pharmaceutical Production in Plants
Genetically modified plants have been used as “bioreactors” to produce therapeutic proteins for more than a decade. A recent contribution by transgenic plants is the generation of edible vaccines.
Edible vaccines are vaccines produced in plants that can be administered directly through the ingestion of plant materials containing the vaccine. Eating the plant would then confer immunity against diseases.
Edible vaccines produced by transgenic plants are attractive for many reasons. The cost associated with the production of the vaccine is low, especially since the vaccine can be ingested directly, and vaccine production can be rapidly up scaled should the need arises. Edible vaccine is likely to reach more individuals in developing countries.
The first human clinical trial took place in Vaccine against the toxin from the bacteria E.coli was produced in potato. Ingestion of this transgenic potato resulted in satisfactory vaccinations and no adverse effects.

29. Edible Vaccines
One focus of current vaccine effort is on hepatitis B, a virus responsible for causing chromic liver disease. Transgenic tobacco and potatoes were engineered to express hepatitis B virus vaccine. During the past two years, vaccines against a E.coli toxin, the respiratory syncytial virus, measles virus, and the Norwalk virus have been successfully expressed in plants and delivered orally. These studies have supported the potential of edible vaccines as preventive agents of many diseases.
There is hope to produce edible vaccines in bananas, which are grown extensively throughout the developing world.

30. Molecular Farming (Biopolymers and Plants)
Plant seeds may be a potential source for plastics that could be produced and easily extracted.
A type of PHA (polyhydroxylalkanoate) polymer called “poly-beta-hydroxybutyrate”, or PHB, is produced in Arabidopsis, or mustard plant.
PHB can be made in canola seeds by the transfer of three genes from the bacterium Alicaligenes eutrophus, which codes for enzymes in the PHB synthesis pathway.
A polymer called PHBV produced through Alicaligenes fermentation, which is sold under the name Biopol.