When a soil bacterium infects a plant root and introduces its Ti plasmid, how does this affect both the infectious bacterium and the plant?

Question

What will be an ideal response?

Answer 1

A soil bacterium, Agrobacterium tumefaciens, contains a tumor-inducing (Ti) plasmid that is ~200 kb and contains the T DNA and the genes required to transfer that DNA to the plant cell.
Bacterial plasmids are circular, so DNA must be linearized in order to be able to incorporate into
the plant's linear chromosomes. When A. tumefaciens infects the plant, the bacterium must cut the
T DNA out of the circular plasmid. DNA is nicked at the right border sequence, yielding a region with single-stranded DNA. Single-stranded binding proteins attach to this single-stranded DNA. DNA synthesis will displace the single-stranded region and a second nick at the left border region will release the single-stranded T DNA fragment. Through the process of single strand DNA transfer (similar to bacterial conjugation), this fragment can be transferred to the plant cell. The DNA is targeted to the plant cell nucleus, where it can be incorporated into the host genome. Through homologous recombination, the DNA becomes integrated into the host genome, where
the gene products will be transcribed and translated as any other plant gene by the plant's own transcription and translation machinery.