title: β-1,3-Glucans are components of brown seaweed (Phaeophyceae) cell walls.
abstract: LAMP is a cell wall-directed monoclonal antibody (mAb) that recognizes a β-(1,3)-glucan epitope. It has primarily been used in the immunolocalization of callose in vascular plant cell wall research. It was generated against a brown seaweed storage polysaccharide, laminarin, although it has not often been applied in algal research. We conducted in vitro (glycome profiling of cell wall extracts) and in situ (immunolabeling of sections) studies on the brown seaweeds Fucus vesiculosus (Fucales) and Laminaria digitata (Laminariales). Although glycome profiling did not give a positive signal with the LAMP mAb, this antibody clearly detected the presence of the β-(1,3)-glucan in situ, showing that this epitope is a constituent of these brown algal cell walls. In F. vesiculosus, the β-(1,3)-glucan epitope was present throughout the cell walls in all thallus parts; in L. digitata, the epitope was restricted to the sieve plates of the conductive elements. The sieve plate walls also stained with aniline blue, a fluorochrome used as a probe for callose. Enzymatic digestion with an endo-β-(1,3)-glucanase removed the ability of the LAMP mAb to label the cell walls. Thus, β-(1,3)-glucans are structural polysaccharides of F. vesiculosus cell walls and are integral components of the sieve plates in these brown seaweeds, reminiscent of plant callose.
authors: Botany and Plant Science and Ryan Institute for Environmental, Marine and Energy Research, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland. sraimund@skidmore.edu.|Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA. sraimund@skidmore.edu.|Biology Department, and Skidmore Microscopy Imaging Center, Skidmore College, Saratoga Springs, NY, 12866, USA. sraimund@skidmore.edu.
authors: Sandra Cristina
authors: SC
authors: Raimundo
authors: Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA.
authors: Sivakumar
authors: S
authors: Pattathil
authors: Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA.
authors: Stefan
authors: S
authors: Eberhard
authors: Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA.
authors: Michael G
authors: MG
authors: Hahn
authors: Botany and Plant Science and Ryan Institute for Environmental, Marine and Energy Research, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
authors: Zoë A
authors: ZA
authors: Popper
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry*; D054794:Glycomics; D000459:Phaeophyceae / Q000378:metabolism* / Q000648:ultrastructure; D012624:Seaweed / Q000378:metabolism* / Q000648:ultrastructure; D013194:Staining and Labeling; D047071:beta-Glucans / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D047071:beta-Glucans; C033363:beta-1,3-glucan
keywords: Brown seaweed; Callose; Cell wall; Immunolabeling; LAMP mAb; β-1,3-Glucan