An ultrastructural approach to the adaptive role of the cell wall in the intertidal algaFucus virsoides

Effects of copper pollution on the ultrastructure of Lessonia spp.

“…Heavy metals are retained in such a way by many algae (Kloareg, 1981;Kloareg et aI., 1986;Lestang & Quillet, 1974;Percival, 1979). Mariani et al (1985) have suggested that the cell wall has a role in adaptive resistance to changes in the ionic environment during the tidal cycle by means of cation-binding to the negatively charged polysaccharides. A second form of Cu retention was found in L. trabeculata; the metal was accumulated as compact aggregates situated between the sheaths of the inner wall layer.…”

Ecophysiology of the hypotonic response in the salt‐tolerant charophyte alga Lamprothamnium papulosum

“…Some measurements were made from photographs taken on Kodak (Sydney, Australia) EPY64T professional film rated at 64 ISO. Histochemical stains Toluidine Blue at pH 1 and Alcian Blue at pH 1 were used to detect sulphated polysaccharides (McCully 1970; Mariani, Tolomio & Braghetta 1985). Toluidine Blue (0·5%) was made up in 50 mol m –3 KCl/HCl buffer, pH 1, for detection of sulphated polysaccharides, and in sodium tetraborate buffer at pH 6·8 for detection of neutral polysaccharides (O’Brien & McCully 1981).…”

Ultrastructure of acidic polysaccharides from the cell walls of brown algae

“…In this sample, EDXA spectra showed that Zn was associated with Ca and S (besides C and O), indicating that alginic acid and sulfated fucan are the molecules responsible for the binding of heavy metal. Mariani et al (1985) have studied the elemental composition of polysaccharides isolated from Fucus virsoides by X-ray microanalysis in SEM, and suggested that Ca 2þ and Mg 2þ were strongly complexed with alginic acid in algal cell walls, stabilizing the wall architecture. In contrast, the seawater cations were mainly bound to the sulfated polysaccharides, which regulate the passive ion disposed to the algal cells.…”