Lesson 5.ppt
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1、Plant Biotechnology and GMOsLesson 5GGenetically enetically MModified odified OOrganismrganismBlue roseBlue rose A blue roseblue rose is a flower of the genus Rosa (family Rosaceae) that presents blue-to-violet pigmentation instead of the more common red, white, or yellow. Blue roses are often portr
2、ayed in literature and art as a symbol of love and prosperity to those who seek it, but do not exist in nature as a result of genetic limitations.Blue rose-artificially colouredSince they do not exist in nature as roses lack the specific gene that has the ability to produce a “true blue” color, Blue
3、 roses are traditionally created by dyeing white roses.Nominal blue roses have been bred by conventional hybridization methods, but the results, such as Blue Moon are more accurately described as being lilac in color.Blue Moon Roses Blue moon roses are unusually colored roses that were initially int
4、roduced to the world in 1965. The roses are not an authentic blue, and resemble more of a pale lilac color instead. They are hybrid tea roses and are part of the Rosa genus. Blue moon roses are characterized by their long stems and are larger than many other varieties of roses, with raised centers.
5、They are highly fragrant with scents that are similar to sweet tea. These roses bloom from summer all the way into autumn.Delphinidin, the primary plant pigment that produces a blue hue but is not found naturally in roses.Rosa Cardinal de Richelieu rose, used for the first genetic engineering experi
6、mentsThe Blue Rose was developed by Suntory Flowers Prices were from 2,000 to 3,000 Yen or US$22 to 35 a stemIncreasing crop yieldsTo feed the increasing population we have to increase crop yields.FertilizersFertilizers - are compounds to promote growth; usually applied either via the soil, for upta
7、ke by plant roots, or by uptake through leaves. Can be organic or inorganicHave caused many problems!Algal bloomsAlgal blooms pollute lakes near areas of agriculture Increasing crop yields Algal blooms - a relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic sys
8、tem. Causes the death of fish and disruption to the whole ecosystem of the lake. International regulations has led to a reduction in the occurrences of these blooms.Chemical pest control Each year, 30% of crops are lost to insects and other crop pests. The insects leave larva, which damage the plant
9、s further. Fungi damage or kill a further 25% of crop plants each year. Any substance that kills organisms that we consider undesirable are known as a pesticide. An ideal pesticide would: Kill only the target species Have no effect on the non-target species Avoid the development of resistance Breakd
10、own to harmless compounds after a short timeChemical pest controlDDT was first developed in the 1930sVery expensive, toxic to both harmful and beneficial species alike.Over 400 insect species are now DDT resistant.As with fertilizers, there are run-off problems.Affects the food pyramid. Persist in t
11、he environmentChemical pest control DDT persists in the food chain. It concentrates in fish and fish-eating birds. Interfere with calcium metabolism, causing a thinning in the eggs laid by the birds break before incubation is finished decrease in population. Although DDT is now banned, it is still u
12、sed in some parts of the world.Plant Biotechnology The use of living cells to make products such as pharmaceuticals, foods, and beverages The use of organisms such as bacteria to protect the environment The use of DNA science for the production of products, diagnostics, and researchPlant Biotechnolo
13、gy “For centuries, humankind has made improvements to crop plants through selective breeding and hybridization the controlled pollination of plants. Plant biotechnology is an extension of this traditional plant breeding with one very one very important differenceimportant difference plant biotechnol
14、ogy allows for the transfer of a plant biotechnology allows for the transfer of a greater variety of genetic information in a more greater variety of genetic information in a more precise, controlled manner.”precise, controlled manner.”Genetically modified crops All plant characteristics, such as si
15、ze, texture, and sweetness, are determined on the genetic level. Also: The hardiness of crop plants. Their drought resistance. Rate of growth under different soil conditions. Dependence on fertilizers. Resistance to various pests and diseases. Used to do this by selective breedingWhy would we want t
16、o modify an organism? Better crop yield, especially under harsh conditions. Herbicide or disease resistance Nutrition or pharmaceuticals, vaccine delivery Ornamental purposeWhats your opinion on GM food?Genetically modified foodsl Genetically modified foods (or GM foods) are foods produced from orga
17、nisms that have had specific changes introduced into their DNA using the methods of genetic engineering. l These techniques have allowed for the introduction of new crop traits as well as a far greater control over a foods genetic structure than previously afforded by methods such as selective breed
18、ing and mutation breeding.l Commercial sale of genetically modified foods began in 1994, when Calgene first marketed its Flavr Savr delayed ripening tomato. l To date most genetic modification of foods have primarily focused on cash crops in high demand by farmers such as soybean, corn, canola, and
19、cotton seed oil. l These have been engineered for resistance to pathogens and herbicides and better nutrient profiles. l GM livestock have also been experimentally developed, although as of November 2013 none are currently on the market. But a GM salmon was awaiting regulatory approval at that time.
20、l There is broad scientific consensus that food on the market derived from GM crops poses no greater risk to human health than conventional food. l However, opponents have objected to GM foods on several grounds, including safety issues, environmental concerns, and economic concerns raised by the fa
21、ct that GM seeds (and potentially animals) that are food sources are subject to intellectual property rights owned by multinational corporations.Roundup Ready Gene The glyphosate resistance gene protects food plants against the broad-spectrum herbicide Glyphosate - N-(phosphonomethyl) glycine Roundu
22、p, which efficiently kills invasive weeds in the field. The major advantages of the Roundup Ready” system include better weed control, reduction of crop injury, higher yield, and lower environmental impact than traditional weed control systems. Notably, fields treated with Roundup require less tilli
23、ng; this preserves soil fertility by lessening soil run-off and oxidation.”Glyphosate- N-(phosphonomethyl) glycine An aminophosphonic analogue of the natural amino acid glycine. It is absorbed through foliage and translocated to actively growing points. (Meristems!) Mode of action is to inhibit an e
24、nzyme involved in the synthesis of the aromatic amino acids: tyrosine, tryptophan phenylalanine GlyphosateGlycineGlyphosate- N-(phosphonomethyl) glycine It does this by inhibiting the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which catalyzes the reaction of shikimate-3-phosphate (S
25、3P) and phosphoenol pyruvate to form 5-enolpyruvylshikimate-3-phosphate (ESP). ESP subsequently dephosphorylated to chorismate, an essential precursor in plants for these aromatic amino acids. GlyphosateGlycineRoundup Ready Gene Glyphosate functions by occupying the binding site of the phosphoenol p
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