The present invention relates to transformed plants with an altered terpene content, preferably over-accumulating a mono- or sesqui-terpene. By transformation of plants with genes encoding terpene synthases (TS), and prenyl transferases (PRT), plants accumulating at least 1000 ng/per g of fresh leaf of a specific terpene were obtained. The present invention provides an advantageous system for production of terpenes in that any desired mono- or sesqui-terpene at the choice of the skilled person can be produced in plants. Preferably, the transformed plants contain at least one recombinant plastid targeted TS and PRT