An ethanol inducible gene switch for plants used to manipulate carbon metabolism.

Many transgenic plant studies use constitutive promoters to express transgenes. For certain genes, deleterious effects arise from constant expression in all tissues throughout development. We describe a chemically inducible plant gene expression system, with negligible background activity, that obviates this problem. We demonstrate its potential by showing inducible manipulation of carbon metabolism in transgenic plants. Upon rapid induction of yeast cytosolic invertase, a marked phenotype appears in developing leaves that is absent from leaves that developed before induction or after it has ceased.