Incorporation of D-[U-14C]Glucose in the Cell Wall of Linum Plantlets during the First Steps of Growth

Morvan, C.; Hafez, Abdulwahab M.; Jauneau, Alain; Thoiron, Bernard; Demarty, Mauríce

doi:10.1093/oxfordjournals.pcp.a078123

Cited by 30 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Cell wall material was sequentially extracted first with 2 M TFA to extract RG-pectins and hemicellulose and then concentrated sulfuric acid (H 2 SO 4 ) to extract homogalacturonans (calcium pectates) and hemicellulosic sugars linked to cellulose. Cell wall material was incubated in 2 M TFA at a concentration of 1 mL TFA per mg dried cell wall material for 2 h at 110°C (Morvan et al, 1991;Douchiche et al, 2007). Cell wall residue was removed from the TFA extract by filtration and was then extracted with concentrated (18 M) sulfuric acid for 1 h at room temperature and then was diluted with water to 1 M sulfuric acid and incubated for 2 h at 110°C.…”

Section: Cell Wall Biochemistrymentioning

confidence: 99%

Development of Cellulosic Secondary Walls in Flax Fibers Requires β-Galactosidase

et al. 2011

View full text Add to dashboard Cite

(N.Y.M., A.V.S., T.A.G.) Bast (phloem) fibers, tension wood fibers, and other cells with gelatinous-type secondary walls are rich in crystalline cellulose. In developing bast fibers of flax (Linum usitatissimum), a galactan-enriched matrix (Gn-layer) is gradually modified into a mature cellulosic gelatinous-layer (G-layer), which ultimately comprises most of the secondary cell wall. Previous studies have correlated this maturation process with expression of a putative b-galactosidase. Here, we demonstrate that b-galactosidase activity is in fact necessary for the dynamic remodeling of polysaccharides that occurs during normal secondary wall development in flax fibers. We found that developing stems of transgenic (LuBGAL-RNAi) flax with reduced b-galactosidase activity had lower concentrations of free Gal and had significant reductions in the thickness of mature cellulosic G-layers compared with controls. Conversely, Gn-layers, labeled intensively by the galactan-specific LM5 antibody, were greatly expanded in LuBGAL-RNAi transgenic plants. Gross morphology and stem anatomy, including the thickness of bast fiber walls, were otherwise unaffected by silencing of b-galactosidase transcripts. These results demonstrate a specific requirement for b-galactosidase in hydrolysis of galactans during formation of cellulosic G-layers. Transgenic lines with reduced b-galactosidase activity also had biochemical and spectroscopic properties consistent with a reduction in cellulose crystallinity. We further demonstrated that the tensile strength of normal flax stems is dependent on b-galactosidase-mediated development of the phloem fiber G-layer. Thus, the mechanical strength that typifies flax stems is dependent on a thick, cellulosic G-layer, which itself depends on b-galactosidase activity within the precursor Gn-layer. These observations demonstrate a novel role for matrix polysaccharides in cellulose deposition; the relevance of these observations to the development of cell walls in other species is also discussed.

show abstract

Section: Cell Wall Biochemistrymentioning

confidence: 99%

Development of Cellulosic Secondary Walls in Flax Fibers Requires β-Galactosidase

et al. 2011

View full text Add to dashboard Cite

show abstract

“…It was finally observed that the acid pectic components were located mainly in the middle lamellae and cell junctions of soybean hypocotyls (Goldberg et al, 1986) and of flax hypocotyls (Morvan et al, 1991), or sometimes also in the primary cell walls of potato tubers (Sasaki and Nagahashi, 1989). The nature of the interactions between calcium and pectic substances in plant cell walls is still under debate.…”

Section: Ura Cnrs 203 Facult6 Des Sciences Et Des Techniques Bp 118mentioning

confidence: 99%

Differential extractability of calcium and pectic substances in different wall regions of epicotyl cells in young flax plants.

Jauneau

Morvan²,

Lefebvre³

et al. 1992

J Histochem Cytochem.

View full text Add to dashboard Cite

We applied the simultaneous use of a subtractive method and two imaging techniques (secondary ion mass spectrometry and electron microsco y after PATAg staining) to correof young flax plants. The calcium images were compared with the structural electron miaoscopy images. This suggests that the linkage of the pectic substances within the wall is mainly by calcium bridges in the intercellular junctions of most types of cells under study (epidermis, subepidermis, fiber layer, and endodermis) and in the outer part (close to the cutide) of the wall of the epidermal cells. In the primary walls of the various types of cells under study and in the inner part (dose to the cytoplasm) of the wall of the late the distribution of Ca 4 + to pectic substances in cell walls epidermal cells, the linkage of the pectic substances would be mainly by covalent bonds. In the middle lamellae of the various cells, and in the intercellular junctions within the cortical parenchyma, both types oflinkages apparently coexist. The mechanism of "ionic condensation" may provide an interpretation for the chemical status of the Ca2* ions which are associated with the pectic components solubilized in boiling water, and which do not seem to contribute to the linkage of these components within the wall. (J hiitochem

show abstract

“…L'état t, est obtenu par transfert des plantes (t 0 ) sur milieu de cu~ure liquide et en lumière continue (2000 lux) (Morvan et al, 1991). L'état~ correspond à des hypocotyles étiolés lorsque les plantes t 0 sont laissées à l'obscurité.…”

Section: Matériel Et Méthodesunclassified

“…Isolement des parois et extractions des polymères pariétaux.-Après isolement des parois en milieu organique selon un protocole précédemment défini (Morvan et al, 1991), la masse des parois sèches est mesurée et un taux de paroi est défini comme le rapport entre cette masse (ms ) et celle (mf) des plantes fraiches {t = ms,tmf). L'extraction des principaux composés pariétaux a été décrite par ailleurs (Morvan et al 199tÏ : un premier traitement des parois avec une solution de edla-NB:, solubilise des oligomères (ol) et une fraction polymérique (P cooal qui sont séparés ultérieurement par chromatographie d'exclusion par taille sur Sephacryl S-200 (Pharmacia).…”

Section: Matériel Et Méthodesunclassified

See 1 more Smart Citation

Les composés pectiques, marqueurs de la croissance du lin

Morvan

Hafez

Jauneau

et al. 1991

Bulletin de la Société Botanique de France. Actualités Botaniqu

View full text Add to dashboard Cite

Résumé.-L'hypocotyle de lin (Linum usitatissimum) peut présenter en quelques jours, selon son environnement, des métabolismes pectiques très d~férents, en particulier du point de vue de la densité de charges. Après 3 jours de germination à l'obscur~é. la paroi est particulièrement riche en acides pectiques, qui lui sont liés covalentement. L'utilisation du rouge de ruthénium en microscopie électronique à transmission localise ces acides polygalacturoniques, en majorité, dans la paroi primaire. Lorsque les plantes sont laissées à l'obscurité, le métabolisme pariétal s'oriente vers une synthèse importante de polysaccharides hydrosolubles neutres, de type hémicellulosique. Les pectines sont également majoritairement neutres, quelle que so~ leur localisation dans la paroi. L'utilisation de l'hydroxylamine ferrique en microscopie électronique à transmission met en évidence que la neutralisation des pectines affecte l'ensemble des tissus. Au contraire. lorsque les plantes sont transférées à la lumière, les acides pectiques sont plutôt localisés dans les espaces intercellulaires et liés à la paroi par des liaisons ioniques, alors que les pectines neutres sont davantage liées covalentement à la paroi primaire. Le marquage des parois avec le rouge de ruthénium confirme l'acidification des lamelles moyennes et jonctions cellulaires d'une part et la neutralisation de la paroi primaire, d'autre part. la variation en quelques jours de la composition pariétale de l'hypocotyle de lin met en évidence une régulation dans les zones en maturation, via les enzymes pariétales, et dans les zones en élongation, via de nouvelles synthèses.Par ailleurs, l'emploi du rouge du ruthenium et de l'hydroxylamine ferrique a permis de localiser des acides polygalacturoniques acétylés liés à des rhamnogalacturonanes 1 dans les jonctions cellulaires de cellules du phloème-les cellules mères des fibres -apparemment non différenciées. l'ensemble des résu~ats indique que les polymères pectiques peuvent être considérés comme des marqueurs précoces de la maturation cellulaire et de la différenciation des cellules dans les tissus principaux.Summary.-Flax hypocotyls (Linum usitatissimum) showed different pectic metabolisms: alter 3 days of germination, the cali walls were rich in acidic pectins, linked covalently. Using red ruthenium in transmission electronic microscopy allowed to localize these pectic acids in the primary cell walls. When the hypocotyls were etiolated, hydrosoluble polysaccharides were mainly neutra!, including the pectins. Ferric hydroxylamine stalning showed thal the cell walls of the main tissues (cortex and liber) were enriched in methylated polygalacturonic blacks. On the contrary, when the plants were transfered in light, the acidic pectins were mainly found ionically linked in the intercellular junction, whereas the neutra! pectins were mainly covalently linked to the primary cell walls. Then the cell wall composition appeared regulated in the mature zones, mainly via the cali wall enzymes, and in the elongation zones, via new s...

show abstract

Incorporation of D-[U-14C]Glucose in the Cell Wall of Linum Plantlets during the First Steps of Growth

Cited by 30 publications

References 0 publications

Development of Cellulosic Secondary Walls in Flax Fibers Requires β-Galactosidase

Development of Cellulosic Secondary Walls in Flax Fibers Requires β-Galactosidase

Differential extractability of calcium and pectic substances in different wall regions of epicotyl cells in young flax plants.

Les composés pectiques, marqueurs de la croissance du lin

Contact Info

Product

Resources

About