Chapter 12, Problem 1BYB

Summary Introduction

To identify:

The procedures that are used to introduce a bacterial gene into a plant.

Introduction:

Genetic engineering causes the formation of improved quality of crops and plants that have been modified by the insertion of the desired gene. Genetic engineering plays an important role to improve the quality of crops and plants, to prevent the food spoilage, to make plant resistant to insects, and to yield more crops.

Genetic engineering allows us to use the genetically modified plants and crops such as corn, potato, soybean, and cotton that have been engineered with desired genes. For the insertion of the foreign gene (bacterial) into a plant, there are various methods. They are:

• Agrobacterium-based plant transformation.

• Gene gun method

Explanation of Solution

Insertion of a foreign DNA or gene has been done to develop a transgenic plant or genetically modified plants or crops. To improve the efficiency of gene transfer, various special vectors must be used. The desired gene is inserted into the specific vector and then transferred into a host cell.

Agrobacterium based plant transformation:

Agrobacterium tumefaciens (a plant-pathogen) are bacteria that form tumors into plants that are known as crown- gall disease. It comprises a plasmid that is Ti plasmid that can be used for the transfection of plant cell. Ti-plasmid consist a T-DNA region where a foreign gene can be inserted.

T-DNA is a tumor inducing gene. Foreign or desired gene are inserted into the Ti-plasmid and transferred into a plant cell. It then gets integrated by its T-DNA. This pathogen infects the plants by integrating its genome in the host genome. When this pathogen with desired gene is inserted in the host, it integrates the desired gene and the gene expression takes place in the host plant.

Gene gun method:

It is a physical method to insert a desired gene with the use of gene gun. The gold particles are coated with the desired gene or foreign DNA. The gene gun is pressurized with Helium gas and fired to penetrate the cell walls of plants. The foreign DNA is integrated into the plant cell and becomes a part of it.

Conclusion

To improve a crop or a plant, it must be infected with a desired gene or foreign gene. Genetic engineering uses various tools to improve the quality of crops and plants to prevent the food spoilage and to make plant resistant to insects. These genetically modified plants with the use of recombinant techniques are termed as transgenic plants.