An extra-chromosomal DNA which delivers gene of interest into variety of plants and act as cloning vector is called Ti plasmid. They are present in Agrobacterium tumifaciens. Ti plasmid vectors are used for genetic transformation in many dicot plants. The tumour inducing (Ti) plasmid of Agrobacterium tumifaciens has been modified into a cloning vector which is no more pathogenic to the plants but is still able to use the mechanisms to deliver genes of interest into a variety of plants.
