Week 9 Full

TA: Zara Tabi ([email protected]) BICD 120: Dr. Crawford AIM: ztabi06 OH: By email Appt. Week 9 Plants, Population, and the Environment! -The human population is growing at an extremely fast rate! • There are many ways we can go from here - Leveling off of the population - Continue to grow larger - Population Crash • BUT: How will we feed them all? - Why can’t we simply increase land used for agriculture?  Current agricultural practices already consuming 70% of earth’s H2O and 40% land • Cannot afford to use more—want to increase yields without increasing land use The Green Revolution (1940’s) and Industrial Agriculture - In response to famines in Asia - Key Person: Norman Borlaug  Won Nobel peace prize because of his achievements - Breeders developed super cultivars through traditional-style breeding • Characteristics of super cultivars: 1) Disease Resistance 2) Dwarf plants (GA mutants)  More sturdy, easy to harvest by machine 3) Polyploidy  Larger, More vigor, higher yield 4) Hybrid Vigor  Crossing two different varieties of the same plant will produce more sturdy plants with better yield (in F1 Generation) - Inputs of Industrial agriculture • Irrigation • Use of fertilizers • Mechanization - Although yields have increased tremendously such methods of agriculture has its flaws: 1) Loss of Biodiversity  only plant monocultures of supervarieties - What 6 crops provide 80% of our calorie intake? 2) High energy input  Increased 4x since 1945 - Agriculture a major CO2 contributor and major oil consumer (150 gal/acre) - Modern agricultural production system not as efficient as other methods • (cal out/cal in) ratio very low  using more energy than we are getting out of it -ex. Corn Farming (0.1-2)

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• Most productive system: manual labor farming and irrigation 3) High use of inorganic fertilizers (N, P, K) - Requires high amounts of energy to mine and produce - Pollutes underground water systems  Leeches out of soil - Creates large algal blooms in the oceans which leads to dead zones • Regions of low O2 4) Increased Use of Pesticides  toxic for people as well as the environment

-From these flaws we realize that industrial agriculture is NOT sustainable • What solutions do we have? Genetic Engineering Standpoint - Aims for increased yield and decreased pesticide and fertilizer use through genetic engineering of plants - Herbicide resistance  produce plants that will not die when exposed to herbicides  kill weeds only! • Avoid soil erosion - Insect Resistance  Produce plants that have built in insect toxin  less pesticide use • Bt-toxin (aka Cry9, starlink)  transform plants to produce this toxin - When moths and their caterpillars eat the plant, they will shortly die after - What do we need to include with the coding region and selectable marker to introduce a foreign gene into a plant? • Promoter region (ex. 35S promoter— Strong, universal plant promoter) • Terminal region WHY?  If we want to express the gene in a specific part of the plant (leaves, flowers, etc) Sustainable and Organic Practices Aims to use practices that respect the local ecosystem, which includes: - Growing food more locally - Natural composting instead of fertilizer - Improving soil health - Increase biodiversity - “Smart” Farming • Joel Salatin’s farm in Michael Pollan’s Omnivore’s Dillema