BIOTECHNOLOGY
What was the taco scare all about?
What is Bt toxin and how did it get into corn?
Bt stands for Bacillus thuringiensis.
A common bacterium in the
soil
It makes a protein in the form of a crystal -- in the spores
It’s toxic to the caterpiggles of certain insects, specifically
those of
Lepidopterans -- flutterbies and moths. Poisons their
digestive system
Harmless to mammals like us
One of the toxin proteins is called Cry1a
What is the function of the
toxin? Why does the bacterium make it???
Organic farmers and gardeners have used Bt for many years.
Dust plants with bacterial spores. Prevents damage to corn
and other veggies from chewing insects like corn ear worm.
But can't use this technique in mass production
agriculture.
bacterial spores easily wash
off plants, or are inactivated
How ‘bout a different strategy?
Why not put bacterial genes into plants? Use a promoter in
front of gene that will allow expression in plants.
Different Bt toxins.
Cry1a -- the kind used in most Bt corn
The taco fiasco involved a different gene for
a slightly different toxin, called Cry9c.
What went wrong?
IN WHAT OTHER WAYS HAVE HAVE PLANTS BEEN MODIFIED THRU BIOTECH?
Herbicide resistance
What is glyphosate?
How
does it work in plants?
Why are
plants made resistant to it via biotech?
How was
glyphosate resistance placed into crops?
Where did the resistance gene come from?
Vitamin A enriched rice
How is beta carotene related to vitamin A?
Why enrich rice with beta carotene? Why is this important?
How did the 'gene jockeys'
do it?
How
do daffodils fit in to the story? What about the bacterium Erwinia?
Why are promoters important in foreign gene transfer and proper
function in the plant?
What is meant by input and output traits?
How do you get a foreign gene into a plant's DNA?
What is a gene gun? Microprojectiles?
What role does plant regeneration
play in biotechnology?
Other ways to introduce genes into plants
What is Agrobacterium tumefasciens?
What does it do to plants naturally?
What is a plasmid?
How do scientists manipulate Agrobacterium to get
genes into plant cells
What does 'screening' mean in biotech speak, and why is it important in
biotech?
How do you make sure your pet gene got into
the plant?
What role do antibiotics play in
screening?