Chemical and in situ characterization of macromolecular components of the cell walls from the green seaweed Codium fragile

JOSÉ MANUEL ESTEVEZ; PAULA VIRGINIA FERNÁNDEZ; LUCIANA KASULIN; PAUL DUPREE; MARINA CIANCIA

GLYCOBIOLOGY

Oxford University Press

Año: 2009 vol. 19 p. 212 - 228

0959-6658

A comprehensive analysis of the carbohydrate-containing macromolecules from the coencocytic green seaweed Codium fragile and their arrangement in the cell wall was carried out. Cell walls in this seaweed are highly complex structures composed of 31% (w/w) of linear (1¨4)-ƒÀ-Dmannans, 9% (w/w) of pyruvylated arabinogalactan sulfates (pAGS), and low amounts of hydroxyproline richglycoprotein epitopes (HRGP). In situ chemical imaging by synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy and by immunolabeling using antibodies against specific cell wall carbohydrate epitopes revealed that ƒÀ-D-mannans and pAGS are placed in the middle part of the cell wall, whereas HRGP epitopes (arabinogalactan proteins (AGPs) and extensins) are located on the wall boundaries, especially in the utricle apical zone. pAGS are sulfated at C-2 and/or C-4 of the 3-linked ƒÀ-Larabinopyranose units and at C-4 and/or C-6 of the 3-linkedand their arrangement in the cell wall was carried out. Cell walls in this seaweed are highly complex structures composed of 31% (w/w) of linear (1¨4)-ƒÀ-Dmannans, 9% (w/w) of pyruvylated arabinogalactan sulfates (pAGS), and low amounts of hydroxyproline richglycoprotein epitopes (HRGP). In situ chemical imaging by synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy and by immunolabeling using antibodies against specific cell wall carbohydrate epitopes revealed that ƒÀ-D-mannans and pAGS are placed in the middle part of the cell wall, whereas HRGP epitopes (arabinogalactan proteins (AGPs) and extensins) are located on the wall boundaries, especially in the utricle apical zone. pAGS are sulfated at C-2 and/or C-4 of the 3-linked ƒÀ-Larabinopyranose units and at C-4 and/or C-6 of the 3-linked¨4)-ƒÀ-Dmannans, 9% (w/w) of pyruvylated arabinogalactan sulfates (pAGS), and low amounts of hydroxyproline richglycoprotein epitopes (HRGP). In situ chemical imaging by synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy and by immunolabeling using antibodies against specific cell wall carbohydrate epitopes revealed that ƒÀ-D-mannans and pAGS are placed in the middle part of the cell wall, whereas HRGP epitopes (arabinogalactan proteins (AGPs) and extensins) are located on the wall boundaries, especially in the utricle apical zone. pAGS are sulfated at C-2 and/or C-4 of the 3-linked ƒÀ-Larabinopyranose units and at C-4 and/or C-6 of the 3-linkedƒÀ-D-mannans and pAGS are placed in the middle part of the cell wall, whereas HRGP epitopes (arabinogalactan proteins (AGPs) and extensins) are located on the wall boundaries, especially in the utricle apical zone. pAGS are sulfated at C-2 and/or C-4 of the 3-linked ƒÀ-Larabinopyranose units and at C-4 and/or C-6 of the 3-linkedƒÀ-Larabinopyranose units and at C-4 and/or C-6 of the 3-linked ƒÀ-D-galactopyranose residues. In addition, high levels of ketals of pyruvic acid were found mainly at 3,4- of some terminal-D-galactopyranose residues. In addition, high levels of ketals of pyruvic acid were found mainly at 3,4- of some terminal ƒÀ-D-Galp units forming a five-membered ring. Ramification was found at some C-6 of the 3-linked ƒÀ-D-Galp-D-Galp units forming a five-membered ring. Ramification was found at some C-6 of the 3-linked ƒÀ-D-GalpƒÀ-D-Galp units. In agreement with the immunolabeled AGP epitopes, a nonsulfated branched furanosidic arabinan with 5-linked ƒ¿-L-Araf, 3,5-linked ƒ¿-L-Araf, and terminal ƒ¿-L-Araf units and a nonsulfated galactan structure composed of 3-(3,6)- linked ƒÀ-D-Galp residues, both typical of type-II AG glycans were found, suggesting that AGP structures are present at low levels in the cell walls of this seaweed. Based on this study, it is starting to emerge that Codium has developed unique cell wall architecture, when compared, not only with that of vascular plants, but also with other related green seaweeds and algae.-L-Araf, 3,5-linked ƒ¿-L-Araf, and terminal ƒ¿-L-Araf units and a nonsulfated galactan structure composed of 3-(3,6)- linked ƒÀ-D-Galp residues, both typical of type-II AG glycans were found, suggesting that AGP structures are present at low levels in the cell walls of this seaweed. Based on this study, it is starting to emerge that Codium has developed unique cell wall architecture, when compared, not only with that of vascular plants, but also with other related green seaweeds and algae.ƒÀ-D-Galp residues, both typical of type-II AG glycans were found, suggesting that AGP structures are present at low levels in the cell walls of this seaweed. Based on this study, it is starting to emerge that Codium has developed unique cell wall architecture, when compared, not only with that of vascular plants, but also with other related green seaweeds and algae.Codium has developed unique cell wall architecture, when compared, not only with that of vascular plants, but also with other related green seaweeds and algae.