title: CELL WALL VARIABILITY IN THE GREEN SEAWEED CODIUM VERMILARA (BRYOPSIDALES CHLOROPHYTA) FROM THE ARGENTINE COAST(1).
abstract: Cell wall chemistry in the coencocytic green seaweed Codium vermilara (Olivi) Delle Chiaje (Bryopsidales, Chlorophyta) is well understood. These cell walls are composed of major amounts of neutral β-(1→4)-D-mannans (Mn), sulfated polysaccharides (SPs), which include pyranosic arabinan sulfates (ArpS), pyruvylated galactan sulfates (pGaS), and mannan sulfates (MnS); also minor amounts of O-glycoproteins are present. In this study, cell wall samples of C. vermilara were investigated with regard to their monosaccharide composition and infrared spectra (using Fourier transform infrared spectroscopy coupled to principal component [FTIR-PC] analysis). Samples from three different populations of C. vermilara from the Argentine coast showed: (i) an important variation in the relative arabinan content, which increases from north to south, and (ii) a measurable degree of cell wall variability in the sulfate distribution between the different sulfated polysaccharides, independent of the amount of each polysaccharide present and of total sulfate content. When cell wall composition was analyzed over three consecutive years in a single geographic location, the quantity of Mn and overall sulfate content on SPs remained constant, whereas the pGaS:ArpS molar ratio changed over the time. Besides, similar cell wall composition was found between actively growing and resting zones of the thallus, suggesting that cell wall composition is independent of growth stage and development. Overall, these results suggest that C. vermilara has developed a mechanism to adjust the total level of cell wall sulfation by modulating the ArpS:pGaS:MnS molar ratio and also by adjusting the sulfation level in each type of polymer, whereas nonsulfated Mn, as the main structural polysaccharide, did not change over the time or growing stage.
authors.affiliation: Cátedra de Química de Biomoléculas, Departamento de Biología Aplicada y Alimentos (CIHIDECAR-CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE Buenos Aires, ArgentinaDepartamento de Fisiología, Biología Molecular y Celular (IFIByNE-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria - Pabellón 2, 1428 Buenos Aires, Argentina.
authors.forename: Paula V
authors.initials: PV
authors.lastname: Fernández
authors.affiliation: Cátedra de Química de Biomoléculas, Departamento de Biología Aplicada y Alimentos (CIHIDECAR-CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE Buenos Aires, ArgentinaDepartamento de Fisiología, Biología Molecular y Celular (IFIByNE-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria - Pabellón 2, 1428 Buenos Aires, Argentina.
authors.forename: Marina
authors.initials: M
authors.lastname: Ciancia
authors.affiliation: Cátedra de Química de Biomoléculas, Departamento de Biología Aplicada y Alimentos (CIHIDECAR-CONICET), Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE Buenos Aires, ArgentinaDepartamento de Fisiología, Biología Molecular y Celular (IFIByNE-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria - Pabellón 2, 1428 Buenos Aires, Argentina.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Estevez
keywords: Codium vermilara; cell wall; green seaweed; sulfated polysaccharides; temporal and geographic variation; β-mannans