Agriculture Biotechnology Flashcards
What do scientists see as the beginning of biotechnology?
Domestication
Define Food preservation
Using processes that prevent or slow spoilage
Where were the Aztecs located?
Modern day Mexico, and Tenochtitlan was the capital city and is located in what is now present day Mexico City
Briefly explain the history of corn
- Scientists believe corn developed about 7000 years ago
- Bred from a wild grass called teosinte
- Without human interference, corn could NOT have survived
Which groups is known for their reliance on corn?
Mayans
- Thought it was a gift from the gods, their sacred duty to cultivate it
- 70-80% of their diet consisted of corn
How did corn spread throughout Europe?
Christopher Columbus shipped corn back to Spain and it spread throughout Europe and it was less expensive
How was corn introduced to Africa?
Portuguese most likely introduced
corn as a staple food for slaves
Define GMO
- GENETICALLY MODIFIED ORGANISMS
- Created by inserting DNA from one organism into another (I.e. fish genes into apples)
- modifying an organism’s DNA to attain a desirable trait. (I.e. a tomato with reversed DNA to slow down ripening).
Provide 3 examples of GMO crops
- Flavr Savr tomato: introduced
as the first GM food. It is supposed to be “tastier, firmer and fresher” than the average tomato. - Golden rice – enriched rice containing beta-carotene (Vitamin A).
- Bt corn – corn containing a chemical normally found in bacteria (Bacillus thuringiensis). This is toxic to insects, not humans. Insects try to eat the plant and die.
Methods used in plant transgenesis: Leaf fragment technique
- Small discs are cut from leaf
- Cultured in a medium containing genetically
modified Agrobacter (Agrobacterium
tumefaciens) - Leaf discs are treated with plant hormones to
stimulate shoot and root development
Explain Agrobacterium tumefaciens in leaf fragment technique
– A soil bacterium that infects plants
– Bacterium contains a plasmid, the TI plasmid, that can be genetically modified
– DNA from the TI plasmid integrates with DNA of the
host cell
Methods used in plant transgenesis: Gene Guns
- Used to blast tiny metal beads coated with DNA into an embryonic plant cell
- Aimed at the nucleus or the chloroplast
- Use marker genes to distinguish genetically transformed cells
- Technique is useful in plants that are resistant to Agrobacter
Methods used in plant transgenesis: Chloroplast engineering
- DNA in chloroplast can accept several new genes at once
- High percentage of genes will remain active
- DNA in chloroplast is completely separate from DNA released in pollen – no chance that transformed genes will be carried on wind to distant crops
Methods used in plant transgenesis: Antisense technology
- Process of inserting a complementary copy of a gene into a cell
- Gene encodes an mRNA molecule called an antisense molecule
- Antisense molecule binds to normal mRNA (sense molecule) and inactivates it
- Example: Flavr Savr tomato
Provide a practical example of vaccines for plants
- Vaccine is encoded in a plant’s DNA
- For example, a gene from Tobacco
Mosaic Virus (TMV) inserted into tobacco plants - Plant becomes resistant to virus
Explain Bacillus thuringiensis (Bt)
- bacterium
that produces a protein that kills harmful insects and their larvae - Stomach toxins, must be ingested to kill
- protein binds to receptors in intestines insect stops eating
- Resistant to UV and heat
What are the 4 dangers of Bt Corn
- Potential allergic response of people to CRY protein
- May kill other insects (selective for
lepidopterans):
- Monarch butterfly larvae - Gene flow –> production of “superweeds”
- Produce resistance in target pest
How is storage important especially with these transgenic crops?
- Millions of dollars are lost every year to insect infestations of crops during storage
- Transgenic corn that expresses avidin is highly resistant to pests during storage
- Avidin blocks the availability of biotin, a vitamin required by insects to grow
Plant Biotechnology in Pharmacology
- Plants can be ideal protein factories
- Used to grow medicines
- Inexpensive edible vaccines that do not require
refrigeration - “Molecular farming” of phytochemicals that
produce chemicals useful to human health
Explain Plant Biotechnology: Fuels
- Biofuels are fuels produced from biological
products, such as plants
– The need for alternatives to fossil fuels in increasing
– However, it take 7 gallons of gasoline to produce 10 gallons of kernel corn ethanol
What are the 4 Benefits of GMOs
- Increased crop productivity
- Cold tolerance + Drought and Salinity tolerance
- Improved nutrition
- Phytoremediation
Explain Benefit #1 of GMO: Increased crop productivity
- This includes herbicide tolerance,
- pest and disease resistance
- E.g. “Roundup ready” crops, and BT corn.
- Could mean using less spray
Explain Benefit #2 of GMO: Cold Tolerance + Drought & Salinity tolerance
- plants developed to tolerate cold temperatures
- Withstand unexpected frost which typically could destroy seedlings
- Currently inhospitable regions can now be cultivated
Explain Benefit #3 of GMO: Improved nutrition
- crops like rice are a staple in developing countries
- GM “golden rice” is high in beta-carotene (vitamin A)
- Reduces eye-related problems like blindness due to malnutrition
