This enzyme is a class I terpene synthase [1]. 9¦Â-Pimara-7,15-diene is a precursor of momilactones A and B, rice diterpenoid phytoalexins that are produced in response to attack (by a pathogen, elicitor or UV irradiation) and are involved in the defense mechanism of the plant. Momilactone B can also act as an allochemical, being constitutively produced in the root of the plant and secreted to the rhizosphere where it suppresses the growth of neighbouring plants and soil microorganisms [1].
