Abstract: Methods of controlling the copy number of one or more genes introduced into a transgenic plant cell, transgenic plants/plant part are disclosed. The method of increasing the gene copy number of a gene introduced into a transgenic plant cell, plant or plant part include contacting the plant cell, plant or plant part with a vector containing a construct which includes an expression cassettes containing multiple pairs of DNA repeats and one or more gene of interest to be introduced into a plant cell under conditions effective for uptake of the vector into the plant cell or a cell in the plant/plant part. Transgenic plant cell, or plants/plant part including one or more than one copies of an exogenous nucleic acid encoding a gene of interest, preferably integrated into the genome of the plant cell, are also disclosed.