Costas-Gil A, Díaz-Tielas C, Reigosa MJ and Sánchez-Moreiras AM
Dept of Plant Biology and Soil Science. Faculty of Biology. University of Vigo. Campus Lagoas-Marcosende s/n, 36310-Vigo (Spain);
Rosmarinic acid is a natural phenolic compound commonly found in land and aquatic plant species. Although the antibacterial, antiinflammatory, antimutagenic and antiviral activity of rosmarinic has been already demonstrated, its phytotoxic activity has been poorly investigated nor in land or aquatic ecosystems. Therefore, the effects of this secondary metabolite on growth and physiology of the diatom Phaeodactylum tricornutum Bohlin were analyzed in this study. Cell density and chlorophyll fluorescence were recorded along the treatment at different times. After five days, the distribution of polar and neutral lipids was observed by confocal microscopy with the fluorochrome Nile Red and photosynthetic pigments content was quantified by spectrophotometry. The results revealed a strong phytotoxic potential of rosmarinic acid with a decrease on cell density and chlorophyll content, and diminution of neutral lipids, which suggest the effect of rosmarinic acid on P. tricornutum plasma membrane permeability and survival.
Keywords: Secondary metabolite, phenolic compound, algicide, membrane permeability, phytotoxicity, microalgae.
RECEIVED: May 23, 2014
ACCEPTED: June 25, 2014