Ti and Ri Plasmids as Vectors for Higher Plants

Ti and Ri Plasmids as Vectors for Higher Plants - Among Higher plants, Ti plasmid of Agrobacterium tumefaciens or Ri plasmid of rhizogenes is the best known vector. T- DNA, from Ti or Ri plasmid Agrobacterium, is considered to be a very potential vector for cloning experiments with higher plants.

This will involve the following steps

(i)foreign DNA has to be first cloned into T-DNA of Ti or Ri plasmid

(ii) modified hybrid T-DNA can be transferred to the genome of plan cells by Agrobacterium infection. Recombinant Ti plasmids can also b obtained by cloning of a large fragment of Ti plasmid in pBR322. The recombinant Ti plasmids can then be used for transformation of higher plants.

This system can be widely used, since Agrobacterium infects nearly all dicotyledonous plants. Such cloning in plants has proved to be of immense use to modify agricultural plants to increase the productivity.