Genetically Modified Organisms (GMOs)
Transgenic Plants
All cells are totipotent
Can de-differentiate to recreate a new plant
Possible to alter just one cell and recreate an altered plant
When a piece of plant tissue is cultured in a sterile medium
containing nutrients and appropriate growth regulators -
some cells are stimulated to proliferate indefinitely in a
disorganised manner producing a mass of relatively
undifferentiated cells = callus
If growth regulators are carefully manipulated , a formation of a shoot can be
induced
Tobacco, petunia, carrot, potato, Arabidopsis – single cell from a callus can be grown
into a small clump of cells from which a whole plant can be regenerated
Helped to isolate receptors for growth regulators and in analysing mechanisms of
morphogenesis and plant gene expression
Agriculture: modify ratio of lipid starch and protein content in seeds, pest and virus
resistance, create plants to tolerate extreme habitats
Variety of rice to genetically engineered to produce β-carotene (precursor of
vitamin A)
Agrobacterium Biology (Agrobacterium tumefaciens)
Uses horizontal gene transfer (T-plasmid) to cause tumours in plants
Transfers “T-DNA” to cause dysregulated growth – auxins + opines for selective
growth advantage
Plasmid can be altered to include specific genes – antibiotic resistance, increased
growth
Biolistics (Gene Gun)
, Directly fire DNA into cells – helium-propelled
tungsten/gold particles
Transgenic Rapeseed GM corn
Herbicide-resistant Rapeseed BT corn - Bacillus thuringiensis proteins
Resistant to glyphosate (roundup) Delta-endotoxins, pore-forming
5-enolpyruvylshikimate-3-phosphate Less insecticide needed
synthase (EPSPS) Meant to be inactive on mammals
Bacterial resistance enzymes added to Possibly off target effects-
genome butterflies, bees. (targets corn
More pesticides can be used borers)
Gene transfer to weeds = resistant
weeds?
GM Rice GM Tomatoes
Vitamin A deficiency kills 700,000 Increased shelf life:
children under 5 a year Longer lasting tomatoes, bananas,
Golden Rice 2: Oryza sativa rice strawberries
Inhibition of N-glycan processing
engineered to produce 23x β-
enzymes (Meli et al., 2010)
carotene (vitamin A)
Can be ripened for longer in the sun
2 years of ‘successful’ field testing
Production of Biofuels
Enogen: maize seed that converts starch to sugar shortcuts biofuel production
(reduces costs)
Transgenic Animals
Transgenic Plants
All cells are totipotent
Can de-differentiate to recreate a new plant
Possible to alter just one cell and recreate an altered plant
When a piece of plant tissue is cultured in a sterile medium
containing nutrients and appropriate growth regulators -
some cells are stimulated to proliferate indefinitely in a
disorganised manner producing a mass of relatively
undifferentiated cells = callus
If growth regulators are carefully manipulated , a formation of a shoot can be
induced
Tobacco, petunia, carrot, potato, Arabidopsis – single cell from a callus can be grown
into a small clump of cells from which a whole plant can be regenerated
Helped to isolate receptors for growth regulators and in analysing mechanisms of
morphogenesis and plant gene expression
Agriculture: modify ratio of lipid starch and protein content in seeds, pest and virus
resistance, create plants to tolerate extreme habitats
Variety of rice to genetically engineered to produce β-carotene (precursor of
vitamin A)
Agrobacterium Biology (Agrobacterium tumefaciens)
Uses horizontal gene transfer (T-plasmid) to cause tumours in plants
Transfers “T-DNA” to cause dysregulated growth – auxins + opines for selective
growth advantage
Plasmid can be altered to include specific genes – antibiotic resistance, increased
growth
Biolistics (Gene Gun)
, Directly fire DNA into cells – helium-propelled
tungsten/gold particles
Transgenic Rapeseed GM corn
Herbicide-resistant Rapeseed BT corn - Bacillus thuringiensis proteins
Resistant to glyphosate (roundup) Delta-endotoxins, pore-forming
5-enolpyruvylshikimate-3-phosphate Less insecticide needed
synthase (EPSPS) Meant to be inactive on mammals
Bacterial resistance enzymes added to Possibly off target effects-
genome butterflies, bees. (targets corn
More pesticides can be used borers)
Gene transfer to weeds = resistant
weeds?
GM Rice GM Tomatoes
Vitamin A deficiency kills 700,000 Increased shelf life:
children under 5 a year Longer lasting tomatoes, bananas,
Golden Rice 2: Oryza sativa rice strawberries
Inhibition of N-glycan processing
engineered to produce 23x β-
enzymes (Meli et al., 2010)
carotene (vitamin A)
Can be ripened for longer in the sun
2 years of ‘successful’ field testing
Production of Biofuels
Enogen: maize seed that converts starch to sugar shortcuts biofuel production
(reduces costs)
Transgenic Animals
