1. Biotechnology in
Agriculture
Chapter 11

2. Learning Outcomes
Define and contrast the terms agriculture and agricultural biotechnology
Give specific examples of agricultural and horticultural biotechnology applications, including genetically modified organism (GMO) crops, hydroponics, and plant-made pharmaceuticals
Explain how genomic and plasmid DNA can be isolated from cells, including the additional steps required for plant cell DNA isolation
Discuss how proteins of interest may be purified from plant samples and how DNA or protein samples may be assayed for their concentration and purity
Describe the role that Agrobacterium tumefaciens plays in producing genetically modified plant crops
Summarize the methods used to produce transgenic plants, and explain the selection processes for identifying transformed plant cells
Describe the role of biotechnologies in food production, food processing, and food security

3. 11.1 New Applications of Biotech in Agriculture and Horticulture
Selective breeding of animals (livestock) and plant crops has been practiced for centuries.
New techniques are now being applied.
With DNA fingerprinting, breeders can test parent animals and plants for several beneficial genes and recognize several undesirable genes.

4. Benefits of Selective Breeding and Propagation
Animals:
Improved nutritional value
Fewer feed additives
Increased growth rate
Plants:
Resistant to selected viruses
Higher nutritional content
Less fertilizer or herbicide
Less environmental impact from run-off pollution

5. Hydroponics
Soil-less, water-based medium in which to grow plants

6. Vocabulary
Agriculture – the practice of growing and harvesting animal or plant crops for food, fuel, fibers, or other useful products
Inbreeding – the breeding of closely related organisms
Bacillus thuringiensis (B. thuringienses or BT) – the bacterium from which the Bt gene was originally isolated; the Bt gene codes for the production of a compound that is toxic to insects
Horticulture – the practice of growing plants for ornamental purposes
Hydroponics – the practice of growing plants in a soilless, water-based medium
Macronutrients – the minerals required by plants in high concentrations
Micronutrients – the minerals required by plants in low concentrations

7. 11.1 Review Questions
What is it called when very closely related animals are bred? Why is it discouraged?
List several employment opportunities for people interested in the science or business of horticulture.
Name two advantages of growing plants hydroponically.

8. 11.2 Advances in Agriculture through DNA Technology
As in medicine and industry, agricultural scientists began developing the processes necessary to genetically engineer agricultural products on the molecular level.
Plant crop scientists, in particular, have produced several new and unique crops using DNA technology.
Isolating Genomic DNA
Inserting Foreign DNA Into Plant Cells

9. Vocabulary Genomic DNA – the chromosomal DNA of a cell
Agrobacterium tumefaciens – a bacterium that transfers the “Ti plasmid” to certain plant species, resulting in a plant disease called crown gall; used in plant genetic engineering
Ti plasmid – a plasmid found in Agrobacterium tumefaciens that is used to carry genes into plants, with the goal that the recipient plants will gain new phenotypes

10. 11.2 Review Questions Which is larger, gDNA or pDNA, and by how much?
Plant DNA is difficult to get out of plant cells. List a few “tricks” used by biotechnicians to isolate plant DNA.
Why is the bacterium, A. tumefaciens, of interest to biotechnologists?
Why is Ti plasmid of interest to biotechnologists?

11. 11.3 Plant Proteins as Agricultural Products
Many plants contain proteins of agricultural or medicinal value.

12. Plant Characteristics
Phenotypes are the observable expressions of genes. Spherical is a phenotype. Dented is another phenotype. Phenotypes result from the presence or lack of specific proteins.

13. Vocabulary
Plant-based pharamaceutical (PBP) – a human pharmaceutical produced in plants; also called plant-made pharmaceutical (PMP)

14. Extracting Protein Molecules from Cells
Plants are sometimes dense.
Grating a sample increases extraction yields.
Grinding a sample in liquid nitrogen can increase yields.
Removing or Weakening Cell Walls
Enzymes can be used.
Cell walls can be crushed.
Cells can be burst open by “freeze fracture.”
Visualizing Protein Samples
If a gel shows evidence of a protein of interest, more studies are conducted.

15. 11.3 Review Questions
Distinguish between phenotype and genotype using examples.
What does GMO stand for? Explain how Monsanto Roundup Ready® soybeans are an example of a GMO.
What is the most challenging part about trying to isolate plant DNA or plant proteins from cells?
How are PMPs related to genetically engineered organisms?

16. 11.4 Plant Genetic Engineering
Using A. tumefaciens to Genetically Engineer Plants
Transforming Agrobacterium. Before A. tumefaciens can be used to transform a plant, its Ti plasmid must be transformed with the gene(s) of interest.

17. Ti Plasmid. The Ti plasmid has two selection genes on it, NPT II and beta-D-glucuronidase (GUS), so that when it gets into plant cells, the plasmid transfer can be recognized. Cells receiving this plasmid will be able to survive on kanamycin-containing agar (from NPT II expression). They will also be able to convert a white carbohydrate in the medium to a blue color (due to GUS expression), which makes the entire colony blue, allowing the researcher to ascertain successful DNA transfer.

18. Arabidopsis thaliana, a Model Organism for Plant Genetic Engineering
Arabidopsis thaliana has been the target of plant genetic engineering studies.

19. Vocabulary
Transgenic plants – the plants that contain genes from another species; also called genetically engineered or genetically modified plants
NPT II (neomycin phosphotransferase) gene – a gene that codes for the production of the enzyme, neomycin phosphotransferase, which gives a cell resistance to the antibiotic kanamycin
GUS gene – a gene that codes for an enzyme called beta-glucuronidase, an enzyme that breaks down the carbohydrate, X-Gluc, into a blue product

20. 11.4 Review Questions
What is the name of the naturally occurring bacterium and the plasmid that can infect plants and transfer DNA molecules?
Name at least two selection genes that are used to confirm that Ti plasmid transformation has occurred.
How does GUS act as a selection gene?
Why are so many plant genetic-engineering experiments conducted with Aradibopsis, even though it has little, if any, economic value?

21. 11.5 Biotechnology in Food Production and Processing
Advances in agricultural biotechnology have impacted food production and processing.
The results are improved food supplies, increased nutritional content of some foods, and increased food safety and security.

22. Biotech and Food Production
Biotech and Food Security
Risk Assessment and Biotech Food Products

23. Vocabulary
Feedstock– the raw materials needed for some process, such as corn for livestock feed or biofuel production
Foodborne pathogens – disease-causing microorganisms found in food or food products

24. 11.5 Review Questions
Give an example of how genetic modification has led to disease resistance in a plant crop.
List some food-borne pathogens that may be detected by biotechnologies.
What type of biotechnologies can be used for allergen testing of food products?
Summarize the roles of the USDA, FDA, and EPA in biotechnology food products and processing.

25. Questions and Comments?