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Microscopic and NMR analysis of the external coat from seeds of Magonia pubescens
Author(s) -
De Oliveira Cíntia M. Ribas,
Iacomini Marcello,
Alquini Yedo,
Gorin Philip A. J.
Publication year - 2001
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.0028-646x.2001.00279.x
Subject(s) - magic angle spinning , lignin , nuclear magnetic resonance spectroscopy , chemistry , magic angle , scanning electron microscope , polysaccharide , cell wall , solid state nuclear magnetic resonance , carbon 13 nmr , chemical structure , crystallography , materials science , stereochemistry , organic chemistry , biochemistry , nuclear magnetic resonance , composite material , physics
Summary• The chemical composition and structure of the layers of the external coat and the three‐dimensional organization of the gel during the swelling process are reported here for seeds of Magonia pubescens . • Histochemical–light and scanning electron microscopy (SEM) were used in conjunction with CP‐MAS (cross polarization – magic angle spinning: solid state) 13 C NMR spectroscopy to analyse the seed coat layers. • M. pubescens seeds extrude a gel from the second of five regions of the external seed coat when immersed in water. This gel, visualized by SEM, had an extruded cylindrical, laminated structure. Staining revealed two anionic components in the cells of the second layer; the cytoplasm showed the presence of carbohydrates containing vicinal hydroxyl groups and at least some of these carbohydrates were acidic polysaccharides. Part of the β‐linked glucan present in this layer was cellulosic material. Phenolic compounds were not detected in the second layer, but existed in other layers. Lignin and/or tannins were shown in the cell walls of the three innermost layers by CP‐MAS 13 C NMR spectroscopy. • The solid‐state NMR technique had the advantage of being more sensitive and quantitative compared with light microscropy and might prove to be a useful tool in investigating cell components.