Integration of T-DNA into Plant Genome -

T-DNA enters plant cells in a single stranded form; it is immediately converted into a double stranded form.
The double stranded T-DNA integrates at random sites in the host plant genome most likely by a process of illegitimate recombination due to a homology in short segments of the host DNA.

Generally, T-DNA integration is accompanied by short deletions of 23-79 bp at the site of recombination (target site). The T-DNA is generally integrated in low copy numbers per cell, but up to 1 dozen copies/cell have been recorded.