Lecture 13 Chapter 8

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Lecture 13 Chapter 8

• Genes and traits of interest II
• Neal Stewart

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Discussion questions

• 1. Other than the products discussed in this
  chapter, what other sorts of genes or strategies
  might be useful in engineering transgenic plants
  resistant to insects or pathogens?
• 2. Golden Rice producing provitamin A has the
  potential to help many impoverished people who
  might benefit from eating it. Although
  application of this technology is supported by
  many people and organizations, there are also
  some who oppose the technology. Considering their
  possible motivations and potential biases,
  discuss some of the reasons that groups have come
  out in favor or in opposition to Golden Rice.
• 3. What are the potential benefits of producing
  pharmaceutical proteins in plants? What are some
  of the disadvantages or potential dangers?
• 4. Animal genes can be inserted into plants and
  expressed. Would you be opposed to eating foods
  from plants expressing proteins encoded by animal
  genes? By human genes? Discuss the reasons for
  your answers.

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Insect resistance
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Controlling Colorado potato beetle is not easy
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Bt corn
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Bt cotton
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Bacillus thuringiensis
Stewart, 2004. Genetically Modified Planet 2004
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Bt Cry structure
III
I
II
Stewart, 2004. Genetically Modified Planet 2004
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Figure 8.3
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Bt toxin
Insect midgut cells that have bound Bt toxin.
Same gut cells a few hours later note the damage
and leakage.
Stewart, 2004. Genetically Modified Planet 2004
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Bt
Insect midgut cells that have bound Bt toxin.
Mutated receptors cannot bind Bt toxin.
Receptors are not present cells cannot bind Bt
Stewart, 2004. Genetically Modified Planet 2004
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Different Bt Crys

• Cry 1skills caterpillars (lepidoptera)
• Cry 2skills caterpillars (lepidoptera)
• Cry 3skills beetles (coleoptera)

Canola plant expresses a Bt cry1Ac gene
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Transgenic disease resistance

• Viruses (yes)
• Bacteria (no)
• Fungi (no)
• Nematodes (no)

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Figure 8.4
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RNA virus structure
Stewart, 2004. Genetically Modified Planet 2004
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Discussion question

• Other than the products discussed in this
  chapter, what other sorts of genes or strategies
  might be useful in engineering transgenic plants
  resistant to insects or pathogens?

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Figure 8.5
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Second generation

• Output traits

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Improved nutrition, better foods

• Golden rice
• Modified oils from oilseeds
• Vitamin E enhancements

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Golden rice producing provitamin A
www.goldenrice.org
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Biotechnologist of the dayIngo Potrykus
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Figure 8.6
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Golden Rice producing provitamin A has the
potential to help many impoverished people who
might benefit from eating it. Although
application of this technology is supported by
many people and organizations, there are also
some who oppose the technology. Considering
their possible motivations and potential biases,
discuss some of the reasons that groups have come
out in favor or in opposition to Golden Rice.
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Third generation

• Non-traditional products

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Examples

• Pharmaceuticals
• Oral vaccines
• Phytoremediation
• Phytosensors
• Biofuels

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Plant-made pharmaceuticalsakaMolecular pharming
Duckweed
Grow in lab Or field
Protein Purification
Genetic Engineering
Oral vaccine eat the fruit
Corn
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What are the potential benefits of producing
pharmaceutical proteins in plants? What are some
of the disadvantages or potential dangers?
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Phytorediation exampleHow to remediate mercury
in soil
www.uga.genetics.edu/rmblab
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Phytosensor exampleplants to detect landmines
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Phytosensor exampleplants to detect landmines

No TNT
TNT
induction
Using inducible promoter/GFP fusions
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So, transgenic plants could be used in a lot of
applications

• Are there any we should avoid?