Plant Biotechnology

• Agriculture is 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. Example: Resistant to herbicides, Pest resistant, and Vaccines
• Methods Used in Plant Transgenesis

  • Selective Breeding
  • Protoplast Fusion
  • Transformation by Agrobacterium Method
  • Leaf Fragment Technique
  • Transformation by Gene Gun Method
  • Chloroplast Engineering
  • Plant Breeding and Testing
  • Antisense Technology
  • RNA Interference (RNAi)
• 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 recombination can be found more easily.
• Plants have been regenerative capabilities, even from one cell. Species boundaries and sexual compatibility are no longer an issue.
• Selective Breeding


  Farmers cross plants with desirable traits to increase the likelihood of producing offspring with that trait.
• Protoplast Fusion


  Degrade cell wall with cellulase.
• Protoplast Fusion


  The protoplasts from different species of plants can be fused together to create a hybrid.
• Protoplast Fusion


  The fused protoplasts grow in nutrient agar for a few weeks.
• Protoplast Fusion


  The colonies are then transferred to media to induce root and shoot growth.
• A cell lacking a cell wall is called a protoplast.
• Transgene – gene for a desirable trait introduced into a novel organism.
• Transgene construct contains a promoter, terminator, and selectable marker gene.
• 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.
• Leaf Fragment Technique


  Small discs of leaf incubated with genetically modified Agrobacterium

  Ti plasmid.
• Leaf Fragment Technique


  Treat with hormones to stimulate shoot and root development.
• Transformation by Gene Gun Method


  Blast tiny metal beads coated with DNA into an embryonic plant cell.
• Chloroplast Engineering


  More genes can be inserted at one time.
• Chloroplast Engineering


  Genes are more likely to be expressed.
• Chloroplast Engineering


  DNA is separate from the nucleus.
• Antisense Technology


  A method to inhibit or downregulate the production of a target protein by using antisense DNA or RNA molecules.
• RNA Interference (RNAi)


  Inhibits gene expression by interfering with transcription or translation of RNA molecules.
• Disease Resistance


  Vaccines for plants contain dead or weakened strains of plant viruses to turn on the plant’s immune system.
• Disease Resistance


  Transgenic plants express viral proteins to confer immunity.
• Insect Control

  Bacillus thuringiensis (Bt) produces a protein that is toxic to plant pests
• Insect Control

  Transgenic plants contain the gene for the Bt toxin and have a built-in defense against these plant pests.
• Practical Applications in the Field

  • Disease Resistance
  • Insect Control
  • Weed Management
  • Safe Storage
  • Stronger fibers
  • Enhanced Nutrition
  • Future Transgenic Products
  • The Future: From Pharmaceuticals to Fuel
  • Metabolic Engineering
• Weed Management


  Herbicide resistance
• Safe Storage

  avidin - blocks the availability of biotin for insects
• Stronger fibers


  Increase strength of cotton fiber by 60%
• Enhanced Nutrition


  Golden rice that is genetically modified to produce large amounts of beta carotene

  QPM: Maize with increased nutritive value
• Future Transgenic Products


  RNAi to generate caffeine free coffee beans.

  Biotech Crop Database
• The Future: From Pharmaceuticals to Fuel

  Plant - based petroleum for fuels

  Biofuel – fuel derived from biomass
• Types of Biofuels

  • Bioethanol
  • Biodiesel
• Bioethanol – alcohol made by fermenting plant based sugar compounds.
• Biodiesel - vegetable oil or animal fat derived diesel fuel.
• Metabolic Engineering


  Manipulation of plant biochemistry to produce nonprotein products or to alter cellular properties.
• Health and Environmental Concerns

  • Human Health (Allergens, Antibiotic resistance)
  • Environmental Impact (Effect on non-target species, Super weeds)
  • Regulations
• Biotechnology is the use of biology to develop new products, methods and organisms intended to improve human health and society. Biotechnology, often referred to as biotech, has existed since the beginning of civilization with the domestication of plants, animals and the discovery of fermentation.