JUVENILE HORMONE OR ONE OF ITS AGONISTS AS A CHEMICAL LIGAND TO CONTROL GENE EXPRESSION IN PLANTS BY RECEPTOR MEDIATED TRANSACTIVATION

A találmány tárgya eljárás, melyben a jűvenil hőrmőnt vagy egyikagőnistáját használják kémiai ligandűmként egy megcélzőtt pőlipeptidreceptőrral közvetített expressziójának szabályőzására egynövénysejtben, valamint transzgenikűs növénysejtekben, növényianyagban vagy növényekben, valamint ezeknek a megfelelő expresszióskazettát tartalmazó űtódaiban. ŕ The present invention is drawn to a method of controlling gene expression in plants. Specifically, the method comprises transforming a plant with a USP receptor expression cassette which encodes a USP receptor and at least one target expression cassette which encodes a target polypeptide. Contacting said transformed plant with juvenile hormone or one of its agonists activates expression of the target polypeptide in the presence of said USP receptor polypeptide. Optionally, additional "secondary" receptor expression cassettes may be used, wherein the secondary receptor expression cassette encodes a receptor polypeptide distinct from USP. The method is useful for controlling various traits of agronomic importance, such as plant fertility. Also disclosed is a method of identifying previously unknown ligands for USP. Substances to be tested are identified by placing them in contact with plant cells transformed with a USP receptor expression cassette and a target expression cassette. The target expression cassette encodes a reporter polypeptide whose expression can be determined quantitatively or qualitatively, whereby the test substance is identified as a ligand for USP.