Chapter 6 Plant Biotechnology Agriculture The Next Revolution

Chapter 6 Plant Biotechnology

Agriculture: The Next Revolution v Biggest industry in the world ($1. 3 trillion of products per year) v Plant transgenesis allows innovations that are impossible to achieve with conventional hybridization methods • Resistant to herbicides • Pest resistant • Vaccines

Methods Used in Plant Transgenesis v 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

Methods Used in Plant Transgenesis v Selective Breeding • Farmers cross plants with desirable traits to increase the likelihood of producing offspring with that trait. selective breeding animation

Methods Used in Plant Transgenesis v 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 v. Selective Breeding vs. Biotechnology Traditional selective breeding vs. biotechnology

Methods Used in Plant Transgenesis v Transgene – gene for a desirable trait introduced into a novel organism • Transgene construct contains a promoter, terminator, and selectable marker gene

Methods Used in Plant Transgenesis v Transformation by Agrobacterium Method • Ti plasmid integrates into the DNA of the host cell, making it an ideal vehicle for transferring recombinant DNA to plant cells Animation: Gene Transfer in Plants Using Ti Plasmid

Methods Used in Plant Transgenesis v Leaf Fragment Technique • Small discs of leaf incubated with genetically modified Agrobacterium Ti plasmid • Treat with hormones to stimulate shoot and root development Animation: Engineer a Crop

Methods Used in Plant Transgenesis v Transformation by Gene Gun Method • Blast tiny metal beads coated with DNA into an embryonic plant cell Gene Gun animation

Methods Used in Plant Transgenesis v Chloroplast Engineering • More genes can be inserted at one time • Genes are more likely to be expressed • DNA is separate from the nucleus

Methods Used in Plant Transgenesis v. Plant Breeding and Testing Overview of crop genetic engineering

Methods Used in Plant Transgenesis v 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 m. RNA that binds to the normal m. RNA inactivating the normal m. RNA for this enzyme Antisense technology

Methods Used in Plant Transgenesis v RNA Interference (RNAi) • Inhibits gene expression by interfering with transcription or translation of RNA molecules Active protein expression Protein expression silenced by RNAi video and animations

Practical Applications in the Field v Disease Resistance • 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

Practical Applications in the Field v Insect Control • 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 Animation: How Bt Affects Insects

Practical Applications in the Field v Weed Management • Herbicide resistance Weed-infested soybean plot Transgenic soybean plot after Roundup treatment

Practical Applications in the Field v Safe Storage • avidin-blocks the availability of biotin for insects v Stronger fibers • Increase strength of cotton fiber by 60%

Practical Applications in the Field v Enhanced Nutrition • Golden rice that is genetically modified to produce large amounts of beta carotene • QPM: Maize with increased nutritive value QPM program in Haiti

Practical Applications in the Field v Future Transgenic Products • RNAi to generate caffeine free coffee beans. • Biotech Crop Database Animation: Future GMOs

Practical Applications in the Field v. The Future: From Pharmaceuticals to Fuel • Plant-based petroleum for fuels • Biofuel – fuel derived from biomass

Types of Biofuels v Bioethanol – alcohol made by fermenting plant based sugar compounds Video tour of an Ethanol Plant

Types of Biofuels v Biodiesel-vegetable oil or animal fat derived diesel fuel Comparison of biodiesel output for different feed stocks

Biofuel Production v Generation 1 Biofuels: Food Sources

Biofuel Production Corn Used for Ethanol production 1985 -2008

Biofuel Production v Biotechnology Solutions for Generation 1 • The soybean

Biofuel Production v Generation 2 Biofuels: Non-Food Sources

Biofuel Production v Biotechnology Solutions for Generation 2 • GM Jatropha doubles oil yield

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

Health and Environmental Concerns v. Human Health • Allergens • Antibiotic resistance

Health and Environmental Concerns v. Environmental Impact • Effect on non-target species • Super weeds

Health and Environmental Concerns v Regulations • US Department of Agriculture (USDA) • Safe to grow • Food and Drug Administration (FDA) • Safe to consume • Environmental Protection Agency (EPA) • Poses little or no environmental risk

Plant Biotechnology