Biotechnology - traditional Modification by microorganisms of materials for human use Modification by microorganisms of materials for human use Use of biological organisms in agriculture and industrial processes Use of biological organisms in agriculture and industrial processes –Fermentation of fruit juice into wine, grains into beer –Conversion of milk into cheese, yogurt –Production of bread –Sewage and solid waste treatment –Production of antibiotics

Biotechnology - today Molecular techniques now used Molecular techniques now used Use of recombinant DNA technology to alter the heredity of organisms. Use of recombinant DNA technology to alter the heredity of organisms. DNA recombination: insertion of foreign DNA into existing DNA (not sexual). DNA recombination: insertion of foreign DNA into existing DNA (not sexual). Transformed organism: foreign DNA has become permanent part of genome. Transformed organism: foreign DNA has become permanent part of genome.

DNA recombination Selection and insertion of genes from a different organism, in vitro Selection and insertion of genes from a different organism, in vitro Transformation or organism is more rapid and efficient that traditional breeding techniques. Transformation or organism is more rapid and efficient that traditional breeding techniques.

DNA recombination If foreign gene inserted into genome: Genetically Engineered Plant If foreign gene inserted into genome: Genetically Engineered Plant If inserted gene is from another species: Transgenic Plant If inserted gene is from another species: Transgenic Plant

Transformation Process 1. Locate and identify gene for desired trait –Most limiting step –Must sequence sections of DNA –Determine what segments are of interest 2. Isolate gene from rest of DNA –Cut strand and piece back together again

Transformation Process 3. Insert gene into plant cell and use tissue culture to propagate –Agrobacterium transforms plant tissue to produce new DNA (dicots) –Gene gun: gold particles coated with gene blasted into plant tissue. Penetrates cell wall. (monocots)

Transformation Process 4. Screen plant material for presence of new gene –Inserted gene usually has additional antibiotic resistance attached –Screen on culture medium that contains antibiotic –Tissues with desired gene will be resistant and not die

Applications of biotechnology Plants as living factories: molecular farming Plants as living factories: molecular farming –Plants are genetically modified to produce certain chemicals –Usually for pharmaceutical use: “pharming” –Superior to mammalian production b/c free of animal pathogens, not hosts of agents that may cause human disease

Applications of biotechnology Vaccine delivery Vaccine delivery –Plant produces disease gene –Plant is consumed to impart vaccine orally –(must be raw b/c cooking destroys immunological properties) –Cheaper than yeast or other microbial production (require expensive facilities) –Still being developed

Applications of biotechnology Herbicide resistance Herbicide resistance –Plants are transformed to not be susceptible to herbicide –Kill weeds with herbicides, avoid injury to crop –Roundup™-Ready Soybeans –More than half of total soybean acreage in US and Canada –(Roundup halts a.a. synthesis in a pathway that exists only in plants; little residual in soil)

Applications of biotechnology Herbicide resistance, cont. Herbicide resistance, cont. –Increased use of herbicide can result in herbicide- resistant weeds –Decrease amount of herbicides used, move away from more harmful herbicides

Applications of biotechnology Insect resistance Insect resistance –Bt corn and cotton: StarLink –Plant produces toxin made by Bacillus thuringiensis –Kills Lepidopteran larvae that feed on the resistant crop –Crops used for animal feed only –Bt sprays used by organic farmers, home gardeners

Applications of biotechnology Insect resistance, cont. Insect resistance, cont. –Does not affect humans due to differences in digestive tract lack receptors in gut lining lack receptors in gut lining Humans acidic; insects alkaline Humans acidic; insects alkaline –Insect biodiversity higher than when treated with traditional chemicals –Minimal pollen transfer during monarch feeding periods

Applications of biotechnology Yield properties Yield properties –Ripening (tomato) FlavrSavr: ripening without softening FlavrSavr: ripening without softening Yield, flavor, disease were problems Yield, flavor, disease were problems –Oil production (canola) –Nutritional value Increase protein in sweet potatoes Increase protein in sweet potatoes Increase beta-carotene in rice Increase beta-carotene in rice Virus resistance Virus resistance –Tomato, potato Environmental tolerances Environmental tolerances