METABOLITES EXTRACTED FROM CAULERPA SPP. INFLUENCE THE GROWTH OF POSIDONIA OCEANICA CUTTINGS: UNEXPECTED EFFECTS OF THEIR VEHICLE (DMSO)

Abstract

The Mediterranean hosts a large number of allochthonous macrophytes which can replace the native species, threatening the native biodiversity and altering the ecosystem. Among the species of greatest interest are tropical algae belonging to the genus Caulerpa and, more specifically, Caulerpa taxifolia and Caulerpa cylindracea, both highly invasive. Algae of the genus Caulerpa also have the ability to compete with seagrasses, and it has been hypothesized that, at the basis of this competition, there may be allelopathic interactions mediated by bioactive substances. Among the secondary metabolites produced by algae of the genus Caulerpa, the most studied are the alkaloid caulerpine and the sesquiterpene caulerpenina. The latter metabolite, in particular, was found to be abundant in C.taxifolia, but is also present in C.cylindracea and in the autochthonous species C.prolifera.

The aim of this research is to clarify the effects of these molecules on the growth, phenology and molecular responses of Posidonia oceanica cuttings acclimated under controlled conditions in mesocosm, creating the premises to clarify the metabolic pathways involved.