Pectin synthesis

Boffey, S.A. and Northcote, D.H. (1975) Pectin synthesis during the wall regeneration of plasmolysed tobacco leaf cells. BiochemJ. 150 433-440. 

BolweU, G.P. and Northcote, D.H. (1981) Control of hemiccllulose and pectin synthesis during differentiation of vascular tissue in bean (Phaseolus vulgaris) caUus and in bean hypocotyl. Planta, 152 225-233. 

Experiments with oat seedlings concluded that MI and Glc pass through a common precursor of pectin and that the rate of pectin synthesis was limited by... 

Control of Pectin Synthesis and Deposition during Plant Cell Wall Growth... 

R. Sharmaand M. Ahuja, Thiolated pectin Synthesis, characterization and evaluation as a mucoadhesive polymer, Carbohydr. Polym., 85 (3), 658-663, 2011. 

At the beginning of grape development, the cell walls are primarily composed of cellulose. The veraison period is characterized by considerable pectin synthesis to such an extent that it becomes the majority polyoside in some varieties (Silacci... 

Paper ionophoresis, sugars, Maurice Stacey s work, 17 Pectic acid, 350, 352,414 Pectin, 348, 350-353 Pectinic acid, 353 Pentulose, synthesis, 281 D-cryt/iro-Pentulose 5-phosphate, 289 Peptidoglycans, 167-168 Per-O-acetylated di-D-fructose dianhydride derivatives... 

In our investigations, we also detected the sorption of isoPO from potato, Arabidopsis and wheat, by calcium pectate. Moreover, we observed the binding with calcium pectate of potato PO from the fraction of proteins ionically bound with cell walls. It is likely that the ability of some PO isoforms to bind with pectin ensures the spatial proximity of these enzymes to the sites of the initiation of lignin synthesis and that these "pectin-specific" isoforms take part in this process. 

In the absence of suitable cell wall mutants, DCB-adapted tomato cells provide an opportunity to characterise the pectin network of the plant cell wall. It should be noted that synthesis and secretion of hemicellulose is not inhibited but, in the absence of a cellulose framework for it to stick to, most of the xyloglucan secreted remains in soluble form in the cells culture medium (9, 10) while other non-cellulosic polysaccharides and other uronic-acid-rich polymers predominate in the wall. 

The substrate for HGA synthesis is UDP-D-galacturonic acid (UDP-GalA) (81). UDP-GalA has been isolated from plants (59) and several pathways for its synthesis in planta have been reported (31). In vitro studies on pectin biosynthesis have been hampered since radiolabeled UDP-galacturonic acid is not commercially available. Previous researchers have used several... 

The possibility that synthesis of the HGA in tobacco membranes might be limited by the lack of methyl donor was ruled out since the addition of exogenous S-adenosylmethionine, a methyl donor known to function in the methylesterification of pectin (41,70), did not... 

Doong, R.L., liljebjelke, K., FraUsh, G., Kumar, A., and Mohnen, D. (1995) CeU-free synthesis of pectin Identification and partial characterization of polygalacturonate 4-a-galacturonosyltransferase and its products fix)m membrane preparations of tobacco ceU-suspension cultures. Plant Physiol. 109 141-152. 

In most plant materials that have been examined, several PME isoforms have been extracted fixDm the cell walls. What is their reqjective fimction How is their synthesis regulated -Immunolocalisation experiments have shown that some Golgi vesicles can be labelled with the JIM 5 antibody, which is known to recognize low-ester pectins [19]. This raises the question of the action pattern of the pectin methyltransferases. Can they produce pectins with different... 

Fig. 5. Effect of PGl digestion on the ethylene synthesis-inducing activity of CDTA-soluble tomato pectin (a), Na2C03-soluble tomato pectin (b) and polygalacturonic acid (c). Controls were treated with solutions of heat-inactivated PGl. Treatment doses were 10 /tg of uronic acid equivalents. The line legends shown in panel a apply to all panels. Bars indicate SEs for the means of measurements of sets of 8 discs/teatment. fr wt, Fresh weight.

Erwinia chrysanthemi synthesizes and secretes a large number of pectinases. The major pectinases include a pectin methylesterase PemA and five isoenzymes of endo-pectate lyases PelA, PelB, PelC, PelD and PelE. In addition, secondary pectinases were identified a pectin methylesterase PemB, two endo-pectate lyases PelL and PelZ, an exo-pectate lyase PelX and an exopolygalacturonase, PehX. The regulation of pectinase synthesis is very complex and dependent on many environmental conditions. It is induced by pectin catabolic products and affected by growth phase, catabolite repression, osmolarity, iron or oxygen starvation... 

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