The invention provides a method for selectively controlling the
transcription of a gene of interest, comprising producing one or more
plants that express either a first, a second, or both the first and
second genetic constructs. The first genetic construct comprises a first
regulatory region operatively linked to a gene of interest and at least
one repressor sequence capable of controlling the activity of the first
regulatory region. The second genetic construct comprises a second
regulatory region in operative association with a nucleic acid molecule,
or a derivative thereof, encoding a repressor protein, the repressor
protein exhibiting both repressor operator sequence binding activity and
repressor activity.