I Genetic Engineering G Benefits and Risks 1

I. Genetic Engineering G. Benefits and Risks 1. Benefits • a. b. Accelerated improvement of crop strains Elevated yields, either plant or per acre • Usually involves inserting growth factor • Plants grow larger, faster or both • Con – Accelerated growth may alter chemical composition Allergies, digestive problems, etc. Accelerated maturation process • Increased yield per acre, more crops per year • Con – Plants produce different compounds at different life stages • Young plants tend to produce more irritants and toxins (self defense) • Potential to cause digestive or allergic problems

I. Genetic Engineering G. Benefits and Risks 1. Benefits c. d. Increased resistance to disease, pests, toxins • Reduced losses Greater yield • Reduced application of chemicals • Con – Potential transfer of resistance genes to weedy plant species through pollination • Less problematic in areas where crop plants don’t have wild relatives • Con – Development of resistance in pests Increased longevity of harvested produce • Resistance to spoilage • Ex – Potato engineered with bacterial gene for antifungal properties • Helps potatoes to stay in storage without rotting • Con – Chemicals that resist decomposition likely to be more difficult to digest

I. Genetic Engineering G. Benefits and Risks 1. Benefits e. f. Increased resistance to cultural extremes • Ex – Insertion of Arctic flounder antifreeze protein genes into strawberry • Confers greater frost resistance and better fruit storage properties • Con – Potential transfer of antifreeze genes to weedy plant species Increased nutritional value • Ex – High starch potato that absorbs less oil when cooking (low fat potato chips) • Ex – Canola oil (Laurical®) with healthier composition • Con – Unknown effects of eating modified foods • Ex – Insertion of Brazil nut gene into soybeans to increase protein content • Many people allergic to Brazil nuts

I. Genetic Engineering G. Benefits and Risks 1. Benefits g. Reduced dependence on chemical fertilizers • More efficient growth lower use of fertilizer • American farmers spend >$12 billion a year on chemical fertilizers • 50% or more of fertilizer applied to crops is not absorbed and enters runoff water pollution • Con – Transfer of genes for greater growth efficiency to weeds could be disastrous • Con – Substitution of dependence on big western agribusiness

I. Genetic Engineering G. Benefits and Risks 2. Risks a. Unexpected effects • May or may not be beneficial • Ex – Klebsiella planticola (soil bacterium) engineered to transform plant residue into ethyl alcohol (fuel) • GM strain in soils produced Et. OH, leading to poisoning of grasses and decrease in populations of beneficial mycorrhizal fungi • Ex – Pseudomonas putida (bacterium) engineered to degrade 2, 4 -D (herbicide) • Breakdown products highly toxic to fungi, including mycorrhizae • Ex – Bacillus thuringiensis (Bt) toxin may bind to soil particles, slowing degradation and maintaining toxicity for longer than expected