ROLE OF MsMYB AND EUGENOL SYNTHASES IN SECONDARY METABOLISM OF AROMATIC PLANTS

Abstract

The main objective of this project involves characterization of transcription factors and enzymes involved in secondary metabolic pathway(s) of aromatic plants mainly spearmint and sweet basil. A glandular trichome specific R2R3-MYB gene MsMYB was identified, which regulates monoterpene production in spearmint. Ectopic expression of MsMYB, in sweet basil and tobacco, perturbed sesquiterpene and diterpene production also. MsMYB was found to bind and suppress geranyl diphosphate synthase large subunit (MsGPPS.LSU) expression. These results suggest that MsMYB is a novel negative regulator of terpene biosynthesis. Sweet basil plants produce eugenol as a major secondary metabolite. Four eugenol synthases (EGS) were isolated by RNA seq and functionally characterized by in-vitro and in-vivo studies. It was found that eugenol was produced in the roots of soil grown plants but could not be detected in roots of sterile plants. Eugenol was produced in sterile roots under elicitation suggesting eugenol production occurs as a stress response.