Modified (GM) Food
have been genetically modified to produce pest resistant crops
helping farmers and improving the general quality of crops
for the consumers.
example tomatoes have been produced containing genes which
result in them remaining fresh for much longer than usual
after picking. This makes it much easier and cheaper to transport
them from the grower to the shops and they have a much longer
modification of oilseed rape has opened up the door to an
alternative renewable oil source.
is used as a fuel, food and lubricant. It is used extensively
in the manufacture of detergents, leather goods, cosmetics,
paper, paints and textiles.
has been used as a source for oils for many years but growing
concerns about this fossil fuel running out in the future
have led scientists to explore alternative avenues.
is the bright yellow-headed flower crop we often see growing
in fields. However, the oil it produces is a long-chained
fatty acid of 22 or more Carbon atoms. This is too heavy or
long for many uses but okay for cosmetics.
a plant called Californian Bay makes oil with fatty acid chains
of 10-14 carbon atoms. These are great for making detergents
from. The plant contains a gene that codes for Thioesterase
the name for this short-chained oil.
can we make this oil in our easy to grow local rape seed oil
Thioesterase gene is identified and cut out of the Californian
is then inserted into a special Ti Plasmid (Tumour inducing)
from a bacterium. This plasmid is then inserted into a Vector
Agrobacterium tumefaciens. This bacteria and plasmid will
invade plant cells and cause them to divide rapidly making
a callus or ball of cells as a swelling on the plant.
Agrobacterium and the Ti plasmid insert the gene into the
rapeseed cells. They quickly invade the cells and swellings
grow on the plant. These transformed rapeseed cells are then
grown using tissue culture into whole new plants. Every cell
contains the new thioesterase gene and produces the oil.
entire process takes between 5 and 10 years.
Instead of using Agrobacterium we could of used ballistics
to shoot the gene into cells using a special gun.
why are many people worried about GM foods?
Herbicide resistance genes could be transferred into weeds.
Disease causing organisms could escape into the environment.
Toxins produced by GM crops could build up in insects and
then herbivores in the food chain.
Breakdown of GM crop tissue could release toxins, and change
Pollinating insects could be damaged.
Humans may have allergic reactions to the new foods.
GM food may transfer antibiotic resistant genes to bacteria
that will then infect humans/animals.