Lecture 9 &10 Insect resistant plants

Genetic engineering of plants and applications

Agriculture Transgenics On the 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 NormalTransgenic

Plasmid carrying the potato proteinase inhibitor II gene

α- amylase inhibitor gene amylase inhibitor - seed proteins of the common bean amylase inhibitor - seed proteins of the common bean the gene for the α -amylase inhibitor isolated the gene for the α -amylase inhibitor isolated under the transcriptional control of the strong seed- specific promoter for the bean phytohemagglutinin gene under the transcriptional control of the strong seed- specific promoter for the bean phytohemagglutinin gene transform pea plants (Pisum sativum) transform pea plants (Pisum sativum) Peas susceptible to cowpea weevils and azuki bean weevils Peas susceptible to cowpea weevils and azuki bean weevils transgenic pea plants that expressed the α -amylase inhibitor resistant to both of these insects transgenic pea plants that expressed the α -amylase inhibitor resistant to both of these insects

Bacterial cholesterol oxidase gene Cholesterol oxidase, present in different bacterial genera Cholesterol oxidase, present in different bacterial genera catalyzes the oxidation of 3-hydroxysteroids to ketosteroids and hydrogen peroxide 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) high level of insecticidal activity against larvae of the boll weevil (Anthonomus grandis grandis) acts by disrupting the insect’s midgut epithelial membrane acts by disrupting the insect’s midgut epithelial membrane cloned into a vector under the control of a plant virus (figwort mosaic virus) promoter 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 targeted to the tobacco protoplasts, the transformed cells actively expressed the cholesterol oxidase gene proving to be insect resistant transgenic plant