1. Genetically Modified Organisms
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2. GMOs: Genetically Modified Organism
Any organism that has had it’s genetic material changed or manipulated in some way, usually as a result of human intervention.
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This is the ancestor of what crop?

3. Strawberries with fish genes?
Anti-freeze proteins in strawberry and tomato plants

4. Trait targets of traditional plant breeding
Increase size (yield) of fruit or grain
Height of plants (taller OR shorter)
Flowering time to increase the number of crops in a year (rice)
Drought or cold tolerance
Appearance for ornamentals
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Traditional breeding is limited to available genetic material in closely related species

5. Traits for genetically engineered organisms
Increase nutrient content (example: Golden Rice)
Delay ripening of tomatoes for better shipping (example: Flavr-savr)
Resistance to naturally occurring pests (example: Bt cotton)
Resistance to otherwise harmful herbicides
(example: RoundUp Ready soybeans)
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If there is a gene out there, it can be used, regardless of the source.

6. GMO Labelling
Currently, only two products on the market are “labeled” for altered nutrient content:
High laurate canola
high oleic soybean

7. Agrobacterium tumefaciens: transfer of DNA into plants
Naturally occurring soil bacterium that causes crown gall disease
Bacteria contains the Ti (tumor-inducing) vector- a plasmid we can manipulate!
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8. Ti vector: modified for genetic engineering
Remove the tumor-inducing genes
Replace with gene of interest and promoter
Anything between the R and L border will be transferred.

9. Bt: example of genetic modification
Bacteria called Bacillus thuringiensis makes a protein with a crystal structure
The protein, when eaten by lepidoptera (caterpillars), sticks to the gut wall of the insect
Causes starvation and the dissolving of the internal organs
Purified protein has been used by organic farmers for years as a spray (is this a pesticide or herbicide?)
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10. GMOs in the Market
At least 70% of processed foods contain genetically modified ingredients:
Corn- in packaged foods (corn syrup, corn starch, etc.)
Cotton- Cotton isn’t just clothing:
cottonseed oil is present in many food items
Soy -in packaged foods and animal feed
Canola- the healthy oil

12. Genetically modified foods: Others
Papayas
Potatoes
Tomatoes
Sugarbeets
Cantaloupe
Banana
Radicchio
Flax
Rice
Squash
Wheat
and more...
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While these have been modified and approved, you are most likely not eating these

13. Modifications currently approved
Herbicide tolerance (soy, cotton, corn, radicchio, sugarbeet, flax, rice, bentgrass, wheat, alfalfa)
Pesticide production (cotton, corn, potato, tomato)
Disease resistance (papaya, squash, potato, plum)
Delay in ripening (tomato, cantaloupe)
Improved (healthier) oil content (canola, soybean)
Reduced nicotine content (tobacco)
Increased amino acid content (corn)

14. On the SF bart…
What do you think?

15. Genes for which we are testing: RuBisCo, Bt, 35S
RuBisCo- 599 bp- found only in plants. An enzyme that converts carbon dioxide into sugars and carbohydrates for the plant. This is our internal control. Most abundant protein found in nature.
Bt- 421 bp cry gene (toxin gene) will indicate that the plant is genetically modified
35S promotor of the cauiliflower mosaic virus (CaMV 35s 221 bp -promoter element common in most transgenic plants. Its the “start” of a gene. Also indicates the plant is genetically modified)
8/ NHM

16. Testing for GMOs in the field or pantry
ELISA uses a color-change system to signal the presence of a protein. Limits: protein must not be denatured, as is often the case in processed foods.
PCR uses gene-specific primers to detect the presence of the transgene itself. Limits: expensive, not able to do in the field.
* Enzyme-Linked ImmunoSorbent Assay

17. Golden Rice Staple food world-wide is deficient in Vit. A
Ingo Potrykus, et al. developed rice that produces beta carotene, precursor to Vit. A
Still not available for human consumption

18. Hawaiian papayas Papaya ring spot virus found in Hawaiian crops
Cornell and Univ. Hawaii researchers developed papaya that produces viral coat protein

19. SCREENABLE/ SELECTABLE MARKER
DNA cassette
PROMOTER
GENE OF INTEREST
SCREENABLE/ SELECTABLE MARKER

20. Genetically modified foods: Corn
Bt to protect from European corn borer
RoundUp Ready (or other herbicide tolerance), to allow spraying of herbicides
Stacked varieties
Image: msucares.edu
Corn and corn derivatives are found in almost all packaged foods (corn syrup, corn starch, etc.)
In 2009, 85% of U.S. corn planted was genetically engineered

21. Genetically modified foods: Soy
Herbicide tolerance is the only modification of soy
Soy and derivatives are found in most packaged foods
Important as animal feed
In 2009, 91% of soy planted in the U.S. was engineered
Image: cropwatch.unl.edu

22. Genetically modified foods: Cotton
Both Bt and herbicide tolerant varieties
Cotton isn’t just clothing:
cottonseed oil is present in many food items
Image: ipm.ncsu.edu
In 2009, 88% of U.S. cotton planted was engineered

23. 3. There are 2 sequences of DNA that are most associated with GMO’s.
35 S promotor of the cauiliflower mosaic virus (CaMV 35s)
Terminator of the nopaline synthase (NOS) gene of Agrobacterium tumefaciens.
We will look for either or both of these sequences in the food that we test.
PCR will allow us to isolate those segments of DNA and copy them.
An electrophoresis will give us a visual of the segments.

24. Genetically modified foods: Canola
Herbicide tolerant varieties
Canola is touted as one of the “healthiest” oils
In 2005, 80% of Canadian canola was engineered
Image: canola-council.org
8/ NHM

25. DNA sequence based on a known gene
Plasmid (circular DNA from bacteria)
Host DNA
Electroporate into
Agrobacterium tumefaciens
+ ligase and
open plasmid
gene of
interest
(goi)
gene of
interest
selectable
marker
plasmid
leaf disks
Transfer to shoot and root
growth media
Screen for transformants
using selectable marker
Incubate leaf disks
with Agrobacterium
Each cell of the plant contains
the new gene of interest
Agrobacterium injects the
gene of interest into the plant cell
nucleus
The gene of interest is
inserted into the
chromosomes of the plant
with helper proteins
Pot transformed plants
and propagate

26. PCR is a method to amplify DNA
Transfer genes by transformation- what do you need? A plasmid
The bacteria Agrobacterium has a Ti plasmid (tumor inducing plasmid) that allows you to insert new genes (foreign DNA) regardless of size). Normally Ti causes tumors
Scientist have engineered a cassette (sequence of genes) and are able to insert new genes much more easily.
Bt gene confers resistance to insects

27. B. GMO PCR product
Check plant pcr: is there a 455 bp band from GMO + (lane 5)?
Check GMO PCR: is there a 203 bp band from GMO + (lane 6)

28. Types of genetic modification in plants
Selective breeding
selecting traits
marker assisted breeding
radiation/ mutagen induced
Hybridization (triticale)
Grafting (rootstock and scion)
Genetic engineering
Image: farrer.csu.edu.au