Question

Explain the role of Ti plasmids in biotechnology

Answer 1

• A Ti or tumor inducing plasmid is a circular plasmid that often, but not always, is a part of the genetic equipment that Agrobacterium tumefaciens and Agrobacterium rhizogenes use to transduce its genetic material to plants.
• The Ti plasmid is lost when Agrobacterium is grown above 28°C.
• Such cured bacteria do not induce crown galls, i.e. they become avirulent.
• pTi and pRi share little sequence homology but are functionally rather similar.
• The Ti plasmids are classified into different types based on the type of opine produced by their genes.
• The different opines specified by pTi are octopine, nopaline, succinimide, and leucinopine.
• The plasmid has 196 genes that code for 195 proteins. There is one structural RNA. The plasmid is 206,479 nucleotides long, the Guanine and Cytosine content is 56% and 81% of the material is coding genes.
  
• There are no pseudogenes.
  
• The modification of this plasmid is very important in the creation of transgenic plants