For Final (final lecture sections) Flashcards
(35 cards)
In what 3 ways have biotechnology tools expanded the study of plant physiology?
- Targeted manipulation (mutation, over-expression) to help understand gene function.
- Tissue, cell, and sub-cellular localization of expression products.
- Measuring gene or protein function.
Name 4 ways plant biotechnology is more than genetic engineering.
- Utilization of plant products and processes
- Tissue culture
- Sequencing
- Phylogenetic analysis
Define traditional plant breeding.
Traditional plant breeding results in the combination of multiple genes in offspring, some of which may not be desirable.
Define “modern” plant breeding.
Using molecular tools. Deriving plants using molecular tools has been carried out since 1983.
What are Transgenic plants?
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).
How are Transgenic plants created?
Transgenic plants are created through transformation - the genetic manipulation of a cell resulting from delivery and incorporation of DNA from another source.
What is the act of transformation often referred to as?
an “event”
What is used in the Natural Transformation Process?
Agrobacterium tumefaciens, a soil bacterium
How does Agrobacterium tumefaciens work?
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.
What is the tumor-like growth that cells form from Agrobacterium tumefaciens called?
crown gall tumor
Who is Mary Dell Chilton?
Her and her colleagues recognized the ability of the Agrobacterium tumefaciens to be used in plant transformation in the late 1970’s.
List the process of transformation using Agrobacterium in 4 steps.
- Use recombinant DNA techniques to remove most of the genes that naturally induce tumor formation (transfer DNA or “T-DNA”)
- Maintain virulence genes that are responsible for inserting DNA into plant chromosomes.
- Insert DNA that encodes for desirable traits: genes of interest. (ex. resistance to insects)
- Result is a bacterium that will insert the DNA that you want but no crown gall formation.
What types of plants was Agrobacterium effective and what types was it not?
Effective in dicots, but not effective for monocots when first developed.
What is the alternative Transformation method used (for monocots)?
Biolistics or microprojectile bombardment, using a particle gun or “gene gun”.
How does biolistics work?
DNA of interest is coated on non-reactive metal particles (Gold or Tungsten) and physically forced inside of plant cells using gas pressure.
List 4 facts of “Gene Gun” Technology.
- Now used to transform several crop species (useful for monocots and dicots).
- Most challenging aspects of transgenic plant production is transformation and gene expression.
- Allowed advancements toward the development of blue carnations even though cut flowers do not produce blue hues.
- Much faster, but more expensive and not as precise.
List 4 ways you can verify that the Transformation was a success.
- Amplify the transgene DNA using PCR.
- 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!) - Physical indicators
- Reporter genes (observable indications)
What happens after a Transformation was a success?
- Take the successfully transformed cells and re-grow them into whole plants using tissue culture (the power of parenchyma!).
- Breeding: the new transgenic plants are bred with each other and existing crop plants that are vigorous (hard and high quality).
- Multiple rounds of breeding ensure that plants stably and consistently express the genes of interest.
List the 4 Tissue Culture stages.
- Callus formation
- Shoot induction
- Change in media to induce root growth
- Maturation and transplantation
What are the 2 main applications of Transgenic plants?
- Insect resistance
(Bacillus thruingiensis toxin production) - Herbicide tolerance
(Glyphosate and Gluefosinate)
List 7 other applications of Transgenic plants, besides insect resistance and herbicide tolerance.
- Pathogen resistance (viral, fungal, etc.)
- Improved nutritional content
- Increased biomass
- Drought, cold and salt tolerance
- Phytoremediation
- Production of novel compounds
- Regulate metabolic pathways and plant gene expression and physiology
Name 6 plants that have been transformed.
Apple, Banana, Bean, Cabbage, Carrot, Cotton, Cucumber, Lettuce, Corn, Potato, Rice, Sweetpotato, Wheat, Peanut, Tomato…
What gene is used for Insect Resistance and how does it work?
- Genes from the Cry gene family of the bacteria Bacillus thuringiensis (Bt), which encode for insecticidal toxin.
- Insects ingest protein and eventually starve.
What was the effect from using Bt for Insect Resistance?
Implementing Bt crops during 1996-2005, reduced insecticide use on cotton and corn by 35.6 million kg of active ingredient.