For Final (final lecture sections)

Question 1

In what 3 ways have biotechnology tools expanded the study of plant physiology?

Answer 1

1. Targeted manipulation (mutation, over-expression) to help understand gene function.
2. Tissue, cell, and sub-cellular localization of expression products.
3. Measuring gene or protein function.

Question 2

Name 4 ways plant biotechnology is more than genetic engineering.

Answer 2

1. Utilization of plant products and processes
2. Tissue culture
3. Sequencing
4. Phylogenetic analysis

Question 3

Define traditional plant breeding.

Answer 3

Traditional plant breeding results in the combination of multiple genes in offspring, some of which may not be desirable.

Question 4

Define “modern” plant breeding.

Answer 4

Using molecular tools. Deriving plants using molecular tools has been carried out since 1983.

Question 5

What are Transgenic plants?

Answer 5

Genetically engineered (aka "genetically modified") plants in which DNA from another species has been integrated into the host plant genome.  
(can be two different species of plants, or plant/animal combination).

Question 6

How are Transgenic plants created?

Answer 6

Transgenic plants are created through transformation - the genetic manipulation of a cell resulting from delivery and incorporation of DNA from another source.

Question 7

What is the act of transformation often referred to as?

Answer 7

an “event”

Question 8

What is used in the Natural Transformation Process?

Answer 8

Agrobacterium tumefaciens, a soil bacterium

Question 9

How does Agrobacterium tumefaciens work?

Answer 9

It inserts a fragment of its own DNA into the plant cells.

- induces those cells to produce the plant hormones auxin and cytokinin and divide.

Question 10

What is the tumor-like growth that cells form from Agrobacterium tumefaciens called?

Answer 10

crown gall tumor

Question 11

Who is Mary Dell Chilton?

Answer 11

Her and her colleagues recognized the ability of the Agrobacterium tumefaciens to be used in plant transformation in the late 1970’s.

Question 12

List the process of transformation using Agrobacterium in 4 steps.

Answer 12

1. Use recombinant DNA techniques to remove most of the genes that naturally induce tumor formation (transfer DNA or “T-DNA”)
2. Maintain virulence genes that are responsible for inserting DNA into plant chromosomes.
3. Insert DNA that encodes for desirable traits: genes of interest. (ex. resistance to insects)
4. Result is a bacterium that will insert the DNA that you want but no crown gall formation.

Question 13

What types of plants was Agrobacterium effective and what types was it not?

Answer 13

Effective in dicots, but not effective for monocots when first developed.

Question 14

What is the alternative Transformation method used (for monocots)?

Answer 14

Biolistics or microprojectile bombardment, using a particle gun or “gene gun”.

Question 15

How does biolistics work?

Answer 15

DNA of interest is coated on non-reactive metal particles (Gold or Tungsten) and physically forced inside of plant cells using gas pressure.

Question 16

List 4 facts of “Gene Gun” Technology.

Answer 16

1. Now used to transform several crop species (useful for monocots and dicots).
2. Most challenging aspects of transgenic plant production is transformation and gene expression.
3. Allowed advancements toward the development of blue carnations even though cut flowers do not produce blue hues.
4. Much faster, but more expensive and not as precise.

Question 17

List 4 ways you can verify that the Transformation was a success.

Answer 17

1. Amplify the transgene DNA using PCR.
2. Select for the trait being engineered.
   (ex: If you are engineering for resistance against an herbicide, then apply the herbicide and see if the plant lives!)
3. Physical indicators
4. Reporter genes (observable indications)

Question 18

What happens after a Transformation was a success?

Answer 18

1. Take the successfully transformed cells and re-grow them into whole plants using tissue culture (the power of parenchyma!).
2. Breeding: the new transgenic plants are bred with each other and existing crop plants that are vigorous (hard and high quality).
3. Multiple rounds of breeding ensure that plants stably and consistently express the genes of interest.

Question 19

List the 4 Tissue Culture stages.

Answer 19

1. Callus formation
2. Shoot induction
3. Change in media to induce root growth
4. Maturation and transplantation

Question 20

What are the 2 main applications of Transgenic plants?

Answer 20

1. Insect resistance
   (Bacillus thruingiensis toxin production)
2. Herbicide tolerance
   (Glyphosate and Gluefosinate)

Question 21

List 7 other applications of Transgenic plants, besides insect resistance and herbicide tolerance.

Answer 21

1. Pathogen resistance (viral, fungal, etc.)
2. Improved nutritional content
3. Increased biomass
4. Drought, cold and salt tolerance
5. Phytoremediation
6. Production of novel compounds
7. Regulate metabolic pathways and plant gene expression and physiology

Question 22

Name 6 plants that have been transformed.

Answer 22

Apple, Banana, Bean, Cabbage, Carrot, Cotton, Cucumber, Lettuce, Corn, Potato, Rice, Sweetpotato, Wheat, Peanut, Tomato…

Question 23

What gene is used for Insect Resistance and how does it work?

Answer 23

• Genes from the Cry gene family of the bacteria Bacillus thuringiensis (Bt), which encode for insecticidal toxin.
• Insects ingest protein and eventually starve.

Question 24

What was the effect from using Bt for Insect Resistance?

Answer 24

Implementing Bt crops during 1996-2005, reduced insecticide use on cotton and corn by 35.6 million kg of active ingredient.

Question 25

What benefits do Herbicide Tolerance have (list 3).

Answer 25

1. Weeds are a significant problem in crop fields
2. Tilling is expensive and time-consuming
3. Engineer crop plants with an enzyme that will make them resistant to herbicides and weeds will die while engineered plants survive

Question 26

What are farmer’s reason for adopting GE crops from most important to least?

Answer 26

1. Increase yields
2. Save management time and make other practices easier
3. Decrease pesticide input cost
4. Other

Question 27

When were herbicide tolerant and insect resistant crops introduced and have they decreased or increased since then?

Answer 27

1996

Increased

Question 28

What are stacked gene varieties and list some examples.

Answer 28

• Those in which more than one trait has been engineered.
• Bt is often engineered along with herbicide tolerance or resistance to other pests or pathogens. Now, drought tolerance as well.

Question 29

Name 2 examples of virus resistance in plants.

Answer 29

1. Papaya plants are impacted by a virus called Papaya Ring Spot Virus (PRSV). They have been engineered to be resistant.
2. Potatoes have also been engineered against Potato Virus X.

Question 30

How is golden rice an example of using GE for added nutritional value?

Answer 30

• Vitamin A deficiency is a severe problem in developing nations, leading to poor growth, bone under-formation and blindness.
• Beta-carotene is a vitamin A precursor, and is chemically converted in the small intestine.
• Rice engineered with 2 enzymes in beta-carotene production pathway from daffodil.

Question 31

Name 2 cellulosic biofuel sources and what makes them good sources.

Answer 31

1. Switchgrass: produces five times more energy than it requires to be grown, harvested and processed into ethanol.
2. Miscanthus: grows rapidly, has low nutrient requirement, and produces a large yield per acre. It’s also a C4 plant, so it can withstand high light and some heat stress.

Question 32

List 3 possible Biofuel sources that are being explored.

Answer 32

1. Arundo donax
2. Sweetpotato
3. Woodchips from species with lower lignin content

Question 33

What is the sum total of a plant’s genes called?

Answer 33

germplasm

Question 34

What is a small, circular piece of DNA naturally found in bacteria and capable of replicating independently of the bacterial chromosome called?

Answer 34

plasmid

Question 35

What is E. coli used for?

Answer 35

The bacterial workhorse of molecular genetics. The plasmid is added to the E. coli and the E. coli will replicate the recombinant plasmids.