Transgenics and Genetic Engineering Concepts

Transgenics

• Transgenic organisms produce proteins that were not part of their species' proteome.
• The use of recombinant DNA technology allows the insertion of foreign genes.
• Transgenic organisms are produced through genetic engineering.
• Transgenic crops allow for the introduction of new traits, including pest resistance and herbicide tolerance.

Gene Identification, Gene Delivery Systems, and Gene Expression

• Gene identification refers to the process of identifying genes of interest within a genome.
• Gene delivery systems are methods used to introduce genetic material into organisms.
• Gene expression involves the process of a gene being transcribed into RNA and translated into protein.
• Genetic modification can be used to increase crop yield and overcome environmental resistance.
• Recombinant DNA technology can be used in agricultural biotechnology to enhance traits like pest resistance and nutrient content.
• An open reading frame (ORF) is a sequence of DNA that codes for a protein.

Methods of Gene Delivery

• Agrobacterium tumefaciens is a bacterium that can be used to deliver genes into plants.
• Biolistics (gene gun) is a method that uses high-speed projectiles to deliver DNA into target cells.
• Viral vectors like adenovirus can be used to deliver genes into specific cells.
• Electroporation is a technique that uses electric pulses to create temporary openings in cell membranes allowing DNA to enter.
• Microinjection is a method used to directly inject DNA into a cell's nucleus.

Plant Transgenesis Techniques

• Tissue culture allows for the growth of plant cells in a controlled environment, facilitating genetic modification.
• Genetic transformation is the process of introducing a new gene into a plant cell.
• Selection markers like antibiotic resistance genes help identify cells that have successfully incorporated the new gene.
• Transgenic plants are plants that have been genetically modified to possess desirable traits.

Marker Genes

• Marker genes are used to identify cells that have been successfully transformed.
• Marker genes can include antibiotic resistance or a reporter gene (e.g., GFP).

GM Crops and Environmental Impact

• GM crops are plants that have been genetically modified.
• The Ti (tumor-inducing) plasmid of Agrobacterium tumefaciens has been used to introduce glyphosate resistance into soybean crops.
• Genetic modification of the tobacco mosaic virus enables the production of the Hepatitis B vaccine in tobacco plants.
• Amflora potato has been genetically modified to produce a high proportion of amylopectin starch, making it useful for industrial applications.
• The environmental impact of glyphosate-tolerant soybeans is a topic of ongoing research and debate.

Use of Agrobacterium tumefaciens to Introduce Glyphosate Resistance in Soybeans

• Agrobacterium tumefaciens is a naturally occurring bacteria that causes crown gall disease in plants.
• The Ti plasmid is transferred from Agrobacterium tumefaciens into plant cells.
• The Ti plasmid contains genes for glyphosate resistance, which are incorporated into the plant's genome.
• These plants are then able to tolerate glyphosate herbicide, allowing for weed control.

Genetic Modification of Tobacco Mosaic Virus for Hepatitis B Vaccine Production

• Tobacco mosaic virus (TMV) is a plant virus commonly found in tobacco plants.
• The viral genome has been modified to express the Hepatitis B surface antigen.
• When these modified viruses are introduced into tobacco plants, the plants produce the Hepatitis B surface antigen.
• This antigen can then be harvested and used to produce a vaccine against Hepatitis B.

Amflora Potato for Paper and Adhesive Industries

• Amflora potato is a genetically modified potato with a high proportion of amylopectin starch.
• Amflora potato is used for paper and adhesive industries due to the high amylopectin content, which provides desirable properties.
• Amflora potato starch is also commonly used in other industrial applications, such as food processing and pharmaceuticals.

Environmental Impact of Glyphosate-Tolerant Soybeans

• Benefits: Reduced tillage, increased crop yield, less herbicide usage.
• Concerns: Potential for herbicide resistance in weeds, effects on biodiversity, potential for gene transfer to other plant species.

Potential Environmental Consequences of Using Glyphosate-Tolerant Soybeans

• Impact of tillage: Glyphosate use reduces the need for tillage, which minimizes soil erosion and fossil fuel consumption.
• Effects on biodiversity: Glyphosate's low toxicity to animals makes it less detrimental to wildlife populations.
• Cross contamination: Glyphosate resistance can be transferred to native weeds, leading to herbicide resistance in invasive populations.
• Unintended transfer of glyphosate resistance: This could lead to the spread of glyphosate resistance in non-target plants.