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Lecture 13 Chapter 8 Genes and traits of interest II Neal Stewart 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. Insect resistance Controlling Colorado potato beetle is not easy Bt corn Bt cotton Bacillus thuringiensis Stewart, 2004. Genetically Modified Planet 2004 Bt Cry structure III I II Stewart, 2004. Genetically Modified Planet 2004 Figure 8.3 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 Bt Insect midgut cells that have bound Bt toxin. Mutated receptors cannot bind Bt toxin. Stewart, 2004. Genetically Modified Planet 2004 Receptors are not present– cells cannot bind Bt Different Bt Crys • Cry 1s—kills caterpillars (lepidoptera) • Cry 2s—kills caterpillars (lepidoptera) • Cry 3s—kills beetles (coleoptera) Canola plant expresses a Bt cry1Ac gene Transgenic disease resistance • • • • Viruses (yes) Bacteria (no) Fungi (no) Nematodes (no) Figure 8.4 RNA virus structure Stewart, 2004. Genetically Modified Planet 2004 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? Figure 8.5 Second generation Output traits Improved nutrition, better foods • Golden rice • Modified oils from oilseeds • Vitamin E enhancements Golden rice: producing provitamin A Biotechnologist of the day: Ingo Potrykus Figure 8.6 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. Third generation Non-traditional products Examples • • • • • Pharmaceuticals Oral vaccines Phytoremediation Phytosensors Biofuels Plant-made pharmaceuticals aka Molecular pharming Duckweed Genetic Engineering Grow in lab Or field Protein Purification Oral vaccine– eat the fruit, or purify the vaccine pill or injection Corn Fraunhofer USA: one plantbased platform to produce pharmaceutical proteins: vaccines http://www.youtube.com/watch?v= oCGFW1WOFTY What are the potential benefits of producing pharmaceutical proteins in plants? What are some of the disadvantages or potential dangers? Phytorediation example How to remediate mercury in soil www.uga.genetics.edu/rmblab Phytosensor example: plants to detect landmines Phytosensor example: plants to detect landmines No TNT induction Using inducible promoter/GFP fusions +TNT So, transgenic plants could be used in a lot of applications… Are there any we should avoid?