1. Chapter 6 Plant Biotechnology

2. Plant Structure

3. CO 2 + H 2 O →C 6 H 12 O 6 + O 2 Plant Structure

4. Agriculture: The Next Revolution  Biggest industry in the world ($1.3 trillion of products per year)  Plant transgenesis allows innovations that are impossible to achieve with conventional hybridization methods Resistant to herbicides Pest resistant Vaccines

5. Methods Used in Plant Transgenesis  Unique advantages of plants: The long history of plant breeding provides plant geneticists with a wealth of strains that can be exploited at the molecular level Plants produce large numbers of progeny; so rare mutations and recombinations can be found more easily Plants have been regenerative capabilities, even from one cell Species boundaries and sexual compatibility are no longer an issue

6.  Protoplast Fusion to create plant hybrids Degrade cell wall with cellulase A cell lacking a cell wall is called a protoplast The protoplasts from different species of plants can be fused together to create a hybrid The fused protoplasts grow in nutrient agar for a few weeks The colonies are then transferred to media to induce root and shoot growth Methods Used in Plant Transgenesis

7.  Ti plasmid – found in Agrobacter, a type of soil bacteria that infects plants Integrates into the DNA of the host cell, making it an ideal vehicle for transferring recombinant DNA to plant cells

8.  Leaf fragment Technique Small discs of leaf incubated with genetically modified Agrobacter Ti plasmid Treat with hormones to stimulate shoot and root development Limitation: cannot infect monocotyledonous plants only dicotyledonous such as tomatoes, potatoes, apples and soybeans Methods Used in Plant Transgenesis Transgenic Plant Animation

9.  Gene Guns Use on Agrobacter-resistant crops Blast tiny metal beads coated with DNA into an embryonic plant cell Aim at the nucleus or a chloroplast Shoot in gene of interest and a gene marker (reporter) Methods Used in Plant Transgenesis

10.  Chloroplast Engineering More genes can be inserted at one time Genes are more likely to be expressed DNA is separate from the nucleus

11.  Antisense Technology Flavr Savr TM tomato introduced in 1994 Ripe tomatoes normally produce the enzyme, polyglacturonase (PG) which digests pectin Scientists isolated the PG gene, produced a complementary gene which produces a complementary mRNA that binds to the normal mRNA inactivating the normal mRNA for this enzyme Methods Used in Plant Transgenesis

12.  RNA Interference (RNAi) Inhibits gene expression by interfering with transcription or translation of RNA molecules Methods Used in Plant Transgenesis RNAi video and animations

13. Practical Applications in the Field  Vaccines for Plants Contain dead or weakened strains of plant viruses to turn on the plant’s immune system Transgenic plants express viral proteins to confer immunity

14. Practical Applications in the Field  Genetic Pesticides Bacillus thuringiensis (Bt) produces a protein that is toxic to plant pests Transgenic plants contain the gene for the Bt toxin and have a built-in defense against these plant pests

15. Practical Applications in the Field  Herbicide Resistance –resistant to glyphosate

16. Practical Applications in the Field  Safe Storage avidin-blocks the availability of biotin for insects  Stronger fibers  Enhanced Nutrition Golden rice that is genetically modified to produce large amounts of beta carotene

17.  The Future: From Pharmaceuticals to Fuel Plant-based petroleum for fuels, alternatives to rubber, nicotine-free tobacco, etc Practical Applications in the Field

18.  Metabolic Engineering Manipulation of plant biochemistry to produce nonprotein products or to alter cellular properties Practical Applications in the Field

19. Health and Environmental Concerns  Human Health Allergens  Environment Super weeds