scholarly journals Occurrence of the Primary Cell Wall Polysaccharide Rhamnogalacturonan II in Pteridophytes, Lycophytes, and Bryophytes. Implications for the Evolution of Vascular Plants

2003 ◽  
Vol 134 (1) ◽  
pp. 339-351 ◽  
Author(s):  
Toshiro Matsunaga ◽  
Tadashi Ishii ◽  
Sadamu Matsumoto ◽  
Masanobu Higuchi ◽  
Alan Darvill ◽  
...  
Keyword(s):  
Cell Wall ◽  
Vascular Plants ◽  
Primary Cell ◽  
Primary Cell Wall ◽  
Cell Wall Polysaccharide ◽  
Rhamnogalacturonan Ii

scholarly journals Pectin Rhamnogalacturonan II: On the “Small Stem with Four Branches” in the Primary Cell Walls of Plants

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Beda M. Yapo
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Vascular Plants ◽  
Minor Component ◽  
Primary Cell ◽  
Side Chains ◽  
Complex Cell ◽  
Rhamnogalacturonan Ii ◽  
Branching Point ◽  
A Chain

Rhamnogalacturonan II (RG-II) is a type of block copolymer of complex pectins that represents a quantitatively minor component of the primary cell walls of land (vascular) plants. The structural composition of RG-II is almost totally sequenced and appears to be remarkably conserved in all tracheophytes so far examined. The backbone of RG-II, released from complex (cell wall) pectins by endo-polygalacturonase (Endo-PG) treatment, has been found to contain up to 15 (1→4)-linked-α-D-GalpA units, some of which carry four well-defined side chains, often referred to as A-, B-, C-, and D-side chains. Nevertheless, the relative locations on the backbone of these four branches, especially the A chain, remain to be ascertained. A combination of different data suggests that neither the terminal nonreducing GalA nor the contiguous GalA unit is likely to be the branching point of the A chain, but probably the ninth GalA residue from the reducing end, assuming a minimum backbone length of 11 (1→4)-linked-α-d-GalpA. The latest reports on RG-II are here highlighted, with a provided update for the macrostructure and array of functionalities.

Changes in Hemicellulose-associated Pectin during Softening of Peach Fruit

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 640c-640
Author(s):  
Supreetha Hegde ◽  
Niels O. Maness
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
Sodium Carbonate ◽  
Middle Lamella ◽  
Apparent Molecular Weight ◽  
Primary Cell ◽  
Size Exclusion ◽  
Primary Cell Wall ◽  
Cell Wall Polysaccharide ◽  
Peach Fruit

Softening to a normal melting flesh texture in peaches involves a combined participation between polymers located in the middle lamella and primary cell wall. Pectins located in the primary cell wall polysaccharide matrix which cosolubilize when hemicellulose is extracted with KOH have received less attention than the chelator or sodium carbonate soluble pectin likely to be associated with the middle lamella. We conducted a series of extractions for cell walls prepared from softening peach fruit (47, 30, and 15 N firmness) using 0.5 m imidazole, sodium carbonate and a graded series of KOH. Hemicellulose-associated pectin was a substantial proportion of most KOH extracts (30 to 50 mole percent) and fractionated on size exclusion chromatography as a high apparent molecular weight peak which became more prominent as fruit softened and could be separated from two lower apparent molecular weight peaks by anion exchange chromatography. The nature of a hemicellulose-pectin interaction in peach was apparently by physical entrapment, versus covalent cross-linking. Softening related changes in hemicellulose-associated pectin will be addressed.

scholarly journals A Specialized Outer Layer of the Primary Cell Wall Joins Elongating Cotton Fibers into Tissue-Like Bundles

2009 ◽  
Vol 150 (2) ◽  
pp. 684-699 ◽  
Author(s):  
Bir Singh ◽  
Utku Avci ◽  
Sarah E. Eichler Inwood ◽  
Mark J. Grimson ◽  
Jeff Landgraf ◽  
...  
Keyword(s):  
Cell Wall ◽  
Outer Layer ◽  
Primary Cell ◽  
Primary Cell Wall ◽  
Cotton Fibers
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