Transgenic Plants Dr. Sanjay Singh C.M.P. College Allahabad Seminar presented at Department of Botany, University of Allahabad, Allahabad on 15-12-2010

Introduction Transgenic plants are plants that have been genetically modified by inserting genes directly in to a single plant cell. Transgenic plants contain a gene or genes which have been artificially inserted instead of the plant acquiring them through pollination. Formerly, sexual cross barriers were a problem for moving genes between species. Now these barriers are not a problem for mixing gene pools. Animal, fungus, and bacteria genes can now become plant genes.

What are Transgenic Plants ? Transgenic plants are also known as Genetically Modified Organisms GMO, Recombinant DNA plants, Bioengineered plants or Biotech plants. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a complete different species: Transgenic Bt corn, for example, which produces its own insecticide, contains a gene from a bacterium Bt Bacillus thuringiensis

Why are Transgenics important? We can develop plants that express a “novel” trait not normally found in the species. Insect resistant cotton – Bt toxin kills the cotton boll worm transgene = Bt protein Insect resistant brinjal – Bt toxin kills the insect transgene = Bt protein

Transgenic plants Herbicide resistant crops Now: soybean, corn, canola Coming: sugarbeet, lettuce, strawberry alfalfa, potato, wheat transgene = modified EPSP synthase or phosphinothricin-N-acetyltransferase Virus resistance - papya resistant to papaya ringspot virus transgene = virus coat protein

How we can make a transgenic plant? GENE ISOLATION GENE TRANSFER SYSTEMS: include use of vectors (Ti Plasmids of Agrobacterium tumefaciens), gene gun, micro injection, electroporation, etc. GENE EXPRESSION: transferred gene must expressed in its new host. However, transgenic trait must not interfere with normal plant development. REGENERATION : it is ability of transform cells to regenerate fertile plants.

The Lab Steps Transgenic plants

Negative effects of Transgenic Plants These create some potential ecological risks to humans and others consumers. Transgenic plants can produce unanticipated toxins and allergins. Gene transfer can occur between transgenic plants and bacteria that creating some ecological consequences which are catastrophic. Transgenic plants serves as a source of new disease and as a medium for evolution of new pathogens because of their altered physiology and biochemistry.

The controversy Should we develop transgenic plants ? Should we release transgenic plants ? Are transgenic plants safe ? Are transgenic plants a threat to non transgenic production systems ? Are transgenic plants a threat to natural ecosystems ?

Transgenic Plants : benefits vs. risks Hypothetical benefits Hypothetical risks Decrease herbicide and pesticide use Increase yield Claim marginal lands Address health/ nutrition issues Food safety Unintended environmental consequences Increase influence of multinationals in agriculture

Creating a balance Improved Nutrition Resistance to disease Reduced use of chemicals Environmental risks Health risks Economic risks Consumers, the government and scientists should be responsible for weighing the benefits against the costs.