TRANSGENIC PLANTS
Transgene:
• It is a foreign gene or genetic material that has been transferred
by genetic engineering techniques from one organism to
another.
Transgenesis:
• The process of introduction of exogenous DNA into the genome.
Transgenic Plant:
• The plant whose genome is altered by adding one or more
transgenes
TRANSGENIC PLANTS
History
• 1982, 1st transgenic plant produced which is tobacco plant.
• 1984, 1st successful plant genetic engineering experiments using
caulimovirus vector
• 1994, 1st genetically modified crop approved for sale in U.S. was
FlavrSavr tomato.
• 1995, 1st pesticide producing crop, Bt. potato was approved by
U.S. Environment protection department.
TRANSGENIC PLANTS
• 1996, 1st genetically modified flower Moondust, bluish colored
carnation, was introduced.
• 2000, Golden rice with ß-carotene developed with increased
nutrient value.
• Valuable tool in studies
• Improved coloration
• Pharmaceuticals and vaccines products
• Improvement of crop yield and quality
• Phytoremediation
Popular tree
TRANSGENIC PLANTS
PRODUCTION OF TRANSGENIC
PLANTS
Methods
Recombinant DNA
Selection and isolation of desired gene
Insertion of gene into vector
Transformation
Agrobacterium gene transfer
Gene gun method (also called Particle gun method)
Electroporation method
AGROBACTERIUM MEDIATED
GENE TRANSFER
• Agrobacterium is treated as nature’s most effective plant genetic
engineer
• The bacterium releases T-DNA segment of Ti plasmid into the
plant cell cytoplasm which induce crown gall disease
• Several dicots are affected by this disease e.g. Grapes, Roses etc.
ELECTROPORATION
• The process in which an
electricity is applied to cell
membrane to form pores on its
surface for transfer of foreign
gene.
• If DNA is present in the buffer
solution at sufficient
concentration, it will be taken up
through these pores.
• Protoplast is used in this process.
ELECTROPORATION
• Protoplast and gene of interest are placed in a solution and
electric pluses are given
• Foreign DNA then integrated into plant genome
GENE GUN
• Also known as Biolistic, particle
gun, bio blaster or micro
projectile bombardment.
• Process occurs with a highly
accelerated velocity into the plant
cell nuclei
• Introduction of DNA into the cell
using micro projectile
• DNA coated particles shot into
target cell
GOLDEN RICE
• Transgenic technology produced a
type of rice that accumulates ß-
carotene in rice grains.
• When it is consumed, b-carotene
is converted into vitamin-A
• It contain 37mg/g of carotenoid
of which 84% is ß-carotene.
FLAVR SAVR TOMATO
• This is produced by antisense
technology.
• The polygalactouronase gene,
which is responsible for fruit
decay is silenced.
BT COTTON
• Bt cotton is a genetically modified
crop that is resistant to pest
bollworm.
BT CORN
• Corn modified with a bacterial
insecticide gene so that it
produces insect toxins within its
cells, protecting it from pest
species.
TRANSGENIC PLANTS
• Advantages
1. Increase yields
2. Rich in nutrients
3. Resistance to biotic and abiotic
stresses
• Disadvantages
1. May cause allergic reactions
2. Loss of biodiversity
3. GM crops could cross breed
with wild crops and
contaminate them with
unexpected results.