Induction of latent biosynthetic activities of secondary metabolites in higher plants as the novel medicinal resources of natural products

The aim of the present study is the elucidation of the signal transduction mechanism of the induction of secondary metabolic activity induced by the stimulation of a plant hormone, jasmonic acid. Several cDNA cloned encoding Rac GTPase, a family of monomeric GTP-binding proteins specifically observed in higher plants, were isolated, and a homologue of which translate product should function in jasmonate-signaling was identified. Several medicinal plants were transformed by the Rac GTPase gene, and it was found that these transgenic plants showed high productivities of the useful natural products. These results suggested that the engineering of jasmonates-signaling processes in plant cells by transformation with appropriate genes would be a novel method for the transcriptional activation of several biosynthetic enzymes involved in secondary metabolism of various useful plants.