Vectors For Plants

Plants cells do not contain any plasmid. BUt two plasmids called pTi and pRi, and present in the bacteria Agrobacterium tumefaciens and A. rhizogens respectively provide a naturally occuring transformation system. These plasmids transfer a part their DNA called T-DNA into the genomes of most dicot and some monocot plants These plasmids, especially the Ti plasmid, have been used to develop a variety of vectors. In addition, genomes of many plant viruses are being developed in vectors. The purpose of plant vectors is almost always a stable transformation ordinarily in the form of integration in plant genomes. But in the case of virus vectors, the objective is to produce large quantities of the protein encoded by DNA insert.