Induction of terpene biosynthesis in dinoflagellate symbionts of Caribbean gorgonians.

This report describes a series of experiments designed to determine if terpene biosynthesis is inducible in two families of marine terpenes, pseudopterosins from the gorgonian coral Pseudopterogorgia elisabethae and fuscol from Eunicea fusca. Since we have recently shown that terpene biosynthesis is not under the control of the invertebrate host, but rather occurs within a dinoflagellate preparation, we examined the terpene content of the dinoflagellate symbiont following a decrease in UV/vis radiation as well as in response to the addition of methyl jasmonate, salicylic acid and gibberellic acid. We demonstrated that pseudopterosin and fuscol biosynthesis can be markedly increased through the addition of the plant bioactive substances.

Pseudopterosin biosynthesis in Symbiodinium sp., the dinoflagellate symbiont of Pseudopterogorgia elisabethae.

Investigations are reported that identify the biosynthetic source and origins of the pseudopterosins, pharmacologically important diterpene glycosides, in the gorgonian coral Pseudopterogorgia elisabethae. We report here the isolation of physiologically significant levels of endogenous pseudopterosins A, B, C, and D from purified symbionts identified as the dinoflagellate Symbiodinium sp. Biosynthetic studies in photosynthesizing symbiont isolates utilizing 14C-labeled inorganic carbon and the tritiated intermediate geranylgeranyl diphosphate yielded radiochemically pure pseudopterosins A through D and the first committed intermediate, elisabethatriene.