Control of gene expression in plants by receptor mediated transactivation in the presence of a chemical ligand

A transgenic plant comprising:

• a) a first receptor expression cassette which encodes a first receptor polypeptide comprising a first DNA binding domain;
• b) a second receptor expression cassette encoding a second receptor polypeptide comprising a second DNA binding domain, wherein said first and second receptor polypeptides are members of the Class II steroid and thyroid hormone superfamily of nuclear receptors and wherein said first and second receptor polypeptides function together as a heterodimer;
• and
• c) a target expression cassette comprising a 5' regulatory region operably linked to a nucleotide sequence encoding a target polypeptide, wherein said 5' regulatory region comprises one or more response elements complementary to said first or second DNA binding domain.

A receptor expression cassette comprising:

• a) a 5' regulatory region capable of promoting expression in a plant cell;
• b) an operably linked coding sequence encoding an Ecdysone receptor comprising a heterologous transactivation domain from the C1 regulatory gene of maize;
• and
• c) a 3' terminating sequence.

A receptor expression cassette comprising:

• a) a 5' regulatory region capable of promoting expression in a plant cell;
• b) an operably linked coding sequence encoding an Ecdysone receptor comprising a heterologous DNA binding domain from the GAL4 protein of yeast;
• and
• c) a 3' terminating sequence.

A receptor expression cassette comprising:

• a) a 5' regulatory region capable of promoting expression in a plant cell;
• b) an operably linked coding sequence encoding a USP receptor polypeptide comprising a heterologous transactivation domain from the VP16 protein of herpes simplex;
• and
• c) a 3' terminating sequence.