Extracellular Matrix Assembly in Diatoms (Bacillariophyceae): I. A Model of Adhesives Based on Chemical Characterization and Localization of Polysaccharides from the Marine Diatom Achnanthes longipes and Other Diatoms

• Published in: Plant physiology (Bethesda) 1997-04, Vol.113 (4), p.1059-1069
• Main Authors: Brandon A. Wustman, Gretz, Michael R., Hoagland, Kyle D.
• Format: Article
• Language: English
• Subjects: Adhesives; Biochemistry and Enzymology; Biological and medical sciences; Cell motility; Cell motion; Cell physiology; Cell walls; Diatoms; Fundamental and applied biological sciences. Psychology; Lectins; Methylation; Monosaccharides; Plant physiology and development; Polymers; Polysaccharides; Uronic acids
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.113.4.1059

Extracellular adhesives from the diatoms Achnanthes longipes, Amphora coffeaeformis, Cymbella cistula, and Cymbella mexicana were characterized by monosaccharide and methylation analysis, lectin-fluorescein isothiocyanate localization, and cytochemical staining. Polysaccharide was the major component of adhesives formed during cell motility, synthesis of a basal pad, and/or production of a highly organized shaft. Hot water-insoluble/hot 0.5 M NaHCO3-soluble anionic polysaccharides from A. longipes and A. coffeaeformis adhesives were primarily composed of galactosyl (64-70%) and fucosyl (32-42%) residues. In A. longipes polymers, 2,3-, t-, 3-, and 4-linked/substituted galactosyl, t-, 3-, 4-, and 2-linked fucosyl, and t- and 2-linked glucuronic acid residues predominated. Adhesive polysaccharides from C. cistula were EDTA-soluble, sulfated, consisted of 83% galactosyl (4-, 4,6-, and 3,4-linked/substituted) and 13% xylosyl (t-, $4_{\text{f}}/5_{\text{p}}$-, and $3_{\text{p}}$-linked/substituted) residues, and contained no uronosyl residues. Ulex europaeus agglutinin uniformly localized α(1,2)-L-fucose units in C. cistula and Achnanthes adhesives formed during motility and in the pads of A. longipes. D-Galactose residues were localized throughout the shafts of C. cistula and capsules of A. coffeaeformis. D-Mannose and/or D-glucose, D-galactose, and α(t)-L-fucose residues were uniformly localized in the outer layers of A. longipes shafts by Cancavalia ensiformis, Abrus precatorius, and Lotus tetragonolobus agglutinin, respectively. A model for diatom cell adhesive structure was developed from chemical characterization, localization, and microscopic observation of extracellular adhesive components formed during the diatom cell-attachment process.