The Ultrastructure of Phycopeltis (Chroolepidaceae: Chlorophyta). I. Sporopollenin in the Cell Walls

Abstract

Electron microscope observations on Phycopeltis epiphyton, a subaerial green alga found growing on the leaves of vascular plants and bryophytes, revealed the presence of a densely staining material within the inner and outer zones of the cell walls. This material resists acetolysis, is degraded by chromic acid, is unaffected by ethanolamine and exhibits secondary fluorescence when stained with the fluorochrome Primuline. These characteristics, together with infrared absorption spectra indicate that, on the basis of currently accepted criteria, the densely staining material is a sporopollenin and that it is a major component of the cell wall. Tests for cellulose, chitin, and lignin were negative, and little if any silica is present. It is suggested that negative results in tests for cellulose may be due to a masking effect by the sporopollenin. Comparison of the fine structure of the cell walls of P. epiphyton, pollen grains, and algal cells (known to contain sporopollenin) supports the suggestion that sporopollenin deposition on “unit membranes” is universal. Morphological similarity among sporopollenin lamellae in P. epiphyton, pollen grains, spores of land plants, and the trilaminar sporopollenin sheath in Chlorella, Scenedesmus, and Pediastrum indicates that the structures may be analogous. As in pollen grains, sporopollenin may provide protection against desiccation and parasitism. It may also be involved in the adhesion of Phycopeltis to host plants and in the adhesion between adjacent filaments of the thallus.

Studies on the cell wall of dinoflagellate resting cysts : morphological development, ultrastructure, and chemical composition

“…Several studies have been published which describe IR spectra of resistant outer walls isolated from algal species outside of the Dinophyceae. Many of these Good and Chapman, 1978;Konig and Peveling, 1980;Devries et al, 1983;Delwiche et al, 1989) employed acetolysis as the isolation mechanism and therefore results are not directly comparable to those reported here. Investigations by Berkaloff et al, (1983), , and Burczyk (1987), however, isolated resistant cell wall biopolymers from various green algae using techniques similar to those of the present study.…”

A Review of Macromolecular Organic Compounds That Comprise Living Organisms and Their Role in Kerogen, Coal, and Petroleum Formation

“…In other species, the trilaminar structure is no longer visible following the drastic chemical treatments required for algaenan isolation, and the precise location of the TLS within the outer wall cannot be established (Atkinson et a1., 1972). In the aerial alga PhycopeWs sp., the thick outer wall results from the stacking of numerous TLS (Good and Chapman, 1978). While the presence of algaenans is often associated with the occurrence of a trilaminar outer wall, there is not a strict relationship between these two features.…”

Acetolysis Applied to Microscopical Honey Analysis

“…1972, Fzegi & Iversen 1975, Staehelin & Pickett-Heaps 1975, Strohl e t al. 1977, Brooks & Shaw 1978, Good & Chapman 1978.…”