BOTANY Higher Secondary Second Year - Textbooks Online

techniques of plant breeding do not offer a way to enrich the crop.
Extracting carotene genes from daffodils, Potrykus and Beyer had
introduced these genes into the soil bacterium. Agrobacterium tumefaciens,
the transgenic agrobacteria were then incubated with rice embryos in plant
tissue culture medium. As the bacterium infects the rice cells, they also
transfer the genes for making beta carotene.
A number of examples are available where transgenic plants suitable
for food processing have been developed.
(i) Tomatoes with elevated sucrose and reduced starch could also be
produced using sucrose phosphate synthase gene.
(ii) Starch content in potatoes could be increased by 20 to 40 per cent by
using a bacterial ADP glucose pyrophosphorylase gene (ADP GPPase).
(iii) Vaccines, antibodies and interferons can be consumed directly along
with tomato, banana and cucumber.
Edible vaccine
Acute watery diarrhoea is caused by Escherichia coli and Vibrio
cholerae that colonize the small intestine and produce enterotoxin.
Attempts were made to produce transgenic potato tubers that they could
still retain vaccines in their tubers, even after the tubers had become 5 per
cent soft after boiling. 50 per cent of vaccine was still present in the
tubers.
Edible antibodies
Transgenic plants are being looked upon as a source of antibodies.
They can also provide passive immunization by direct application.
Edible interferons
Interferons are the substances made of proteins and are anti-viral in
nature. Scientists have successfully produced transgenic tobacco and maize
plants that secrete human interferons . Today, rice crops have been enriched
with vitamin A through gene manipulation. Similarly, pulse crop have been
tampered with to produce lysine-rich pulse seeds. Such genetically modified
food (GMF) are now becoming components of human staple food.
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