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Similar to A presentation on insect_resistance_plants.ppt
A presentation on insect_resistance_plants.ppt
- 1. Dr. MJ Mukhopadhyay Dr.MJ Mukhopadhyay Insect Insect resistant plants resistant plants
- 2. Genetic engineering ofplants and applications
- 4. Insect tolerant cropsby using Bt • Bt protein crystal toxic for insect larvae – Bacillus thuringiensis protein – Biological crop protection product – Environmentally friendly – Toxic for specific group of insects, for example only for beetles or only for caterpillars • Transgenic plant produces Bt-protein BT
- 6. Stewart, 2004. GeneticallyModified Planet 2004 Bacillus thuringiensis
- 7. Bt Cry structure I III II α-helicalcylinder forms domain 1- involved in membrane insertion and pore formation Domain II- a triple β sheet structure involved in receptor recognition. Domain III- β sandwich-protection from degradation and receptor binding.
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- 9. Insect midgut cellsthat have bound Bt toxin. Same gut cells a few hours later– note the damage and leakage. Bt toxin Stewart, 2004. Genetically Modified Planet 2004
- 10. Insect midgut cellsthat have bound Bt toxin. Bt Mutated receptors cannot bind Bt toxin. Receptors are not present– cells cannot bind Bt Stewart, 2004. Genetically Modified Planet 2004
- 11. t Bt Crys •Cry1s—kills caterpillars (lepidoptera) •Cry 2s—kills caterpillars (lepidoptera) •Cry 3s—kills beetles (coleoptera) Canola plant expresses a Bt cry1Ac gene
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- 13. Agriculture Transgenics Onthe Market Source: USDA Insect resistant cotton – Bt toxin kills the cotton boll worm • transgene = Bt protein Insect resistant corn – Bt toxin kills the European corn borer • transgene = Bt protein Normal Transgenic
- 19. Plasmid carrying thepotato proteinase inhibitor II gene
- 20. α- amylase inhibitorgene • amylase inhibitor - seed proteins of the common bean • the gene for the α -amylase inhibitor isolated • under the transcriptional control of the strong seed-specific promoter for the bean phytohemagglutinin gene • transform pea plants (Pisum sativum) • Peas susceptible to cowpea weevils and azuki bean weevils • transgenic pea plants that expressed the α -amylase inhibitor resistant to both of these insects
- 21. Bacterial cholesterol oxidasegene • Cholesterol oxidase, present in different bacterial genera • catalyzes the oxidation of 3-hydroxysteroids to ketosteroids and hydrogen peroxide • high level of insecticidal activity against larvae of the boll weevil (Anthonomus grandis grandis) • acts by disrupting the insect’s midgut epithelial membrane • cloned into a vector under the control of a plant virus (figwort mosaic virus) promoter • targeted to the tobacco protoplasts, the transformed cells actively expressed the cholesterol oxidase gene proving to be insect resistant transgenic plant
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- 23. • Study onwebsite of isaaa: www.isaaa.org/kc/Issues/benefits_China.html • Cotton of Monsanto or CAAS (China Academy of Agricultural Sciences) • Grown by 3 million small farmers in 2000 (ca. 10%) • On average 20-23% lower costs with Bt-katoen • 15.000 ton less insecticide (- 47kg/ha) • Less farmer intoxications with Bt- cotton: (4.7% compared to non-Bt: 22%) Bt-cotton in China BT
- 24. Why useit? The farmer Lower costs for the farmer Higher yields Less work: no of few spraying needed For the environment No or low use of insecticides Much more target specific than insecticides BT
- 25. Concerns Btcrops may affect some useful insects but less than with traditional insecticides Large scale cultivation of Bt-crops can enhance the emergence of resistant insects BT
- 26. Worldwide total GMcrops 1 million ha in 1996 28 million ha in 1998 58 million ha in 2002 81 million ha in 2004 90 million ha in 2005 www.isaaa.org Europe: only some crops are allowed (mainly corn)
- 27. Transgenic crops inthe field: 90 mil. ha in 2005 18% 12% 8% 2% 1% 54% 4% USA Argentinie Brazilie Canada China Paraguay India Zuid-Afrika 17% 10% 1% 72% HT Bt HT + Bt andere Most important production areas
- 28. Transgenic crops inthe field: 90 mil. ha in 2005 The traits in the transgenic plants in the field: mainly HT and BT
Editor's Notes
- #13 Bt stands for Bacillus thuringiensis, a bacteria that produces a toxin that kills the insects. The gene that encodes the toxin protein was inserted into plants.