Mevalonosomes: specific vacuoles containing the mevalonate pathway in Plocamium brasiliense cortical cells (Rhodophyta).

Journal: Journal of phycology
Published Date: Feb 12, 2015

Abstract

This paper has identified, for the first time in a member of the Rhodophyta, a vacuolar organelle containing enzymes that are involved in the mevalonate pathway-an important step in red algal isoprenoid biosynthesis. These organelles were named mevalonosomes (Mev) and were found in the cortical cells (CC) of Plocamium brasiliense, a marine macroalgae that synthesizes several halogenated monoterpenes. P. brasiliense specimens were submitted to a cytochemical analysis of the activity of the 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS). Using transmission electron microscopy (TEM), we confirmed the presence of HMGS activity within the Mev. Because HMGS is necessary for the biosynthesis of halogenated monoterpenes, we isolated a hexanic fraction (HF) rich in halogenated monoterpenes from P. brasiliense that contained a pentachlorinated monoterpene as a major metabolite. Because terpenes are often related to chemical defense, the antifouling (AF) activity of pentachlorinated monoterpene was tested. We found that the settlement of the mussel Perna perna was reduced by HF treatment (2.25 times less than control; 40% and 90% of fouled surface, respectively; P = 0.001; F9,9 = 1.13). The HF (at 10 μg · mL(-1) ) also inhibited three species of fouling microalgae (Chlorarachnion reptans, Cylindrotheca cloisterium, and Exanthemachrysis gayraliae), while at a higher concentration (50 μg · mL(-1) ), it inhibited the bacteria Halomonas marina, Polaribacter irgensii, Pseudoalteromonas elyakovii, Shewanella putrefaciens, and Vibrio aestuarianus. The AF activity of P. brasiliense halogenated monoterpenes and the localization of HMGS activity inside Mev suggest that this cellular structure found in CC may play a role in thallus protection against biofouling.

Authors

  • Wladimir Costa Paradas
    Departamento de Biologia Marinha, Universidade Federal Fluminense, Outeiro São João Batista, s/no., Niterói, Rio de Janeiro, Brazil.
  • Thalita Mendes Crespo
    Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, Rio de Janeiro, Brazil.
  • Leonardo Tavares Salgado
    Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, Rio de Janeiro, Brazil.
  • Leonardo Rodrigues de Andrade
    Centro de Ciências da Saúde, Instituto de Ciências Biomédicas, Departamento de Histologia e Embriologia, Universidade Federal do Rio de Janeiro (UFRJ), Av. Carlos Chagas Filho, 373, bloco: B, sala F2-27, Rio de Janeiro, Brazil.
  • Angélica Ribeiro Soares
    Department of Organic Chemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Group of Natural Products from Aquatic Organisms, Center for Ecology and Socio-Environmental Development, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
  • Claire Hellio
    Université de Bretagne Occidentale, LEMAR UMR 6539, IUEM - Technopole Brest-Iroise, Rue Dumont d'Urville, Plouzané, France.
  • Ricardo Rogers Paranhos
    Departamento de Biologia Marinha, Universidade Federal Fluminense, Outeiro São João Batista, s/no., Niterói, Rio de Janeiro, Brazil.
  • Lilian Jorge Hill
    Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, Rio de Janeiro, Brazil.
  • Geysa Marinho de Souza
    Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, Rio de Janeiro, Brazil.
  • Alphonse Germaine Albert Charles Kelecom
    Departamento de Biologia Geral, Universidade Federal Fluminense, Outeiro São João Batista, s/no., Niterói, Rio de Janeiro, Brazil.
  • Bernardo Antônio Perez Da Gama
    Departamento de Biologia Marinha, Universidade Federal Fluminense, Outeiro São João Batista, s/no., Niterói, Rio de Janeiro, Brazil.
  • Renato Crespo Pereira
    Departamento de Biologia Marinha, Universidade Federal Fluminense, Outeiro São João Batista, s/no., Niterói, Rio de Janeiro, Brazil.
  • Gilberto Menezes Amado-Filho
    Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, Rio de Janeiro, Brazil.

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