The present invention relates to a method for the production of a heterologous protein or peptide in a plant or a plant cell. The method involves providing a plant or a plant cell comprising construct comprising a harvest-inducible regulatory element that is operably linked with a heterologous coding sequence of interest, growing the plant or plant cell, and applying ABA or an analog thereof to the plant or plant cell, thereby inducing expression of the heterologous protein or peptide. If a plant is used, then following the application of ABA or an analogue thereof, the plant may be harvested.