Question

Describe how plant genes can be manipulated using the Ti plasmid carried by agrobacterium as a vector.

Answer 1

Agrobacterium tumefaciens is a bacteria that cause crown gall disease in plants. This bacterium enters in plant cell through the wound and releases Ti plasmid in bacteria cytoplasm. The T DNA present in the plasmid integrates into the plant genome and cause crown gall disease in plant.

Therefore this quality of Ti plasmid is used in genetic engineering to manipulate plant gene. A desired gene can be introduced in the place of T DNA of Ti plasmid and then this agrobacterium is used to infect a plant.

This will allow the bacterial Ti plasmid to integrate the desired DNA fragment in the host plant cells. So by this method plant genes can be manipulated.

Answer 2

The Ti plasmid is used as a vector for the transfer of genes in the plants. They are known to cause the crown gall disease in the plants. They have important economic value.

The transformation of the plant require the removal of tumor inducing gene for the formation of the disarmed pathogen. The gene of interest is kept in between the right and left border of the transfer DNA. This DNA is then introduced in the Agrobacterium. Then, it is cultivated with the target cells like callus so that the DNA can intgrate in the cells. The transformed cells are grown in a particular plants.