Colchicine and microfibril orientation

Robinson, David G.; Grimm, Immanuel; Sachs, H.

doi:10.1007/bf01275754

Cited by 28 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some form of guide-track under cellular control must direct the progress of the microfibril-synthesizing terminal complexes (3,17). In Oocystis, microfibril orientation appears to be controlled via cortical microtubules (14,29) and "granule bands" which can be made visible on P-fracture faces of freeze-fractured plasma membranes (2,23,32). No granule bands are present in Glaucocystis, and the cortical microtubules lie beneath the extended shields.…”

Section: Discussionmentioning

confidence: 99%

Cell wall structure and deposition in Glaucocystis

Willison¹,

Brown

1978

The Journal of Cell Biology

View full text Add to dashboard Cite

Events leading to cell wall formation in the ellipsoidal unicellular alga Glaucocystis are described. The wall is deposited in three phases: (a) a thin nonfibrillar layer, (b) cellulosic microfibrils arranged in helically crossed polylamellate fashion, and (c) matrix substances. At poles of cells, microfibrils do not terminate but pass around three equilaterally arranged points, resulting in microfibril continuity between the twelve helically wound wall layers. These findings were demonstrated in walls of both mother cells and freeze-fractured growing cells, and models of the wall structure are presented. Cellular extension results in spreading apart, and in rupture, of microfibrils.On freeze-fractured plasma membranes, there were 35 nm • 550 nm structures associated with the ends of microfibrils. These are interpreted as representing microfibril-synthesizing centers (terminal complexes) in transit upon the membrane. These terminal complexes are localized in a zone, or zones. The plasma membrane is subtended by flattened sacs, termed shields, which become crosslinked to the plasma membrane after completion of wall deposition. During wall deposition, microtubules lie beneath the shields, and polarized filaments lie between shields and plasma membrane.The significance of these findings in relation to understanding the process of cellulose deposition is discussed, and comparisons are made with the alga Oocystis.

show abstract

Section: Discussionmentioning

confidence: 99%

Cell wall structure and deposition in Glaucocystis

Willison¹,

Brown

1978

The Journal of Cell Biology

View full text Add to dashboard Cite

show abstract

“…Generally, in such instances, the microtubules are bridged to the plasmalemma as weH as to one another, and their orientation paralleis that of the fibriHar component of the wall (Cronshaw & Bouck 1965;Newcomb 1969 1982). Indeed, experiments have shown that the microtubules somehow orient the cellulose fibrils during deposition, and experiments causing dissolution of the former disturb the orientation (but not the deposition) of the latter (Picket-Heaps 1967;Hepler & Fosket 1971;Palevitz & Hepler 1976;Robinson et al 1976).…”

Section: At No Time During Torus Development Inmentioning

confidence: 99%

Notes on Torus Development in the Wood of Osmanthus Americanus (L.) Benth. ' Hook. Ex Gray (Oleaceae)

Dute¹,

Rushing²

1988

IAWA J

View full text Add to dashboard Cite

The development of the torus in the wood of Osmanthus americanus was investigated using transmission and scanning electron microscopy. Torus formation on either side of the pit membrane did not begin until after the development of the associated pit border was well underway. No plasmodesmata were encountered in the torus at any time during its ontogeny. Synthesis of torus material was correlated with a mass of randomly oriented microtubules and dictyosome vesicles. The two halves of the torus did not develop synchronously; deposits of torus material were evident first in the older of two adjacent cells. Selective hydrolysis of the matrix material of the margo also began fIrst on that side of the pit membrane associated with a mature tracheary element. Evidence is presented for a fibrillar as weIl as a matrix component in the torus.

show abstract

“…Cellulose microfibrils have an anomalous organization if the microtubules are destroyed (Robinson et al, 1976 ;Robinson and Herzog, 1977). In Nitella, colchicine destroys the microtubules and the orientation of new cellulose fibrils is fortuitous ; when colchicine is removed, the transverse arrangement of microfibrils resumes (Lyndon, 1990).…”

Section: Introductionmentioning

confidence: 99%

Colchicine-induced changes in the growth and secondary wall deposition of cotyledonless radish seedlings

Scialabba

Melati

Liberto

1995

Acta Botanica Gallica

View full text Add to dashboard Cite

(Manuscrit reru le 14 mars 1995; accepte le 5 octobre 1995)Summary.-Colchicine (at 0.2 %) reduces the percentage of germination of radish seeds and influence the growth, morphogenesis and differentiation of xylem elements of the cotyledonless seedling. Colchicine does not significantly influence either the fresh or the dry weight but it does reduce the length of the hypocotyl, root and the developing xylem elements. Hypocotyl diameter increases compared to the control. Root growth rate decreases and the differentiation of xylem elements advances toward the apex. The reduction in cell extension is accompanied by an increase in cell diameter and it is clear that colchicine has an effect on cellular expansion and cell shape. Treatment with colchicine changes the deposition pattern of the secondary wall and results in conspicuous irregularities in the form and distribution of wall thickening. The cotyledonless seedlings cultured in colchicine for 24 hours and successively transferred to water, show a modification of the xylem differentiation and of the wall deposition pattern only in the protoxylem elements differentiated during the treatment, while those differentiating after the 24 hours period are comparable to the controls, indicating that the effect of the drug ceases when it is removed.Resume.-La colchicine (a 0,2 %) reduit le pourcentage de germination des semis de radis et influence Ia croissance, Ia morphogenese et Ia differenciation des elements du xyleme de Ia plantule privee de ses cotyledons. La colchicine n'influence pas de maniere significative le poids frais, ni le poids sec, mais reduit Ia longueur de l'hypocotyle, de Ia racine et des elements du xyleme en cours de formation. Le diametre de l'hypocotyle est plus grand en comparaison des temoins. La vitesse de croisance de Ia racine diminue et le systeme du xyleme se differencie en direction basipete. La reduction de l'allongement cellulaire s'accompagne d'un accroissement du diametre cellulaire mettant en evidence !'influence de Ia colchicine sur !'expansion et Ia forme de Ia cellule. Le traitement a Ia colchicine modifie le mode d'elaboration de Ia paroi secondaire et provoque de nombreuses irregularites dans Ia forme et Ia repartition des epaississements secondaires de Ia paroi. Les plantules privees de cotyledons, cultivees en presence de colchicine pendant 24 h et transferees ensuite dans l'eau, montrent des modifications de !'elaboration de Ia paroi uniquement dans les elements du protoxyleme qui se sont differencies pendant le traitement. Ceux qui se differencient par Ia suite sont comparables aux temoins, ce qui indique que les effets de Ia colchicine cessent quand elle est supprimee.

show abstract

Colchicine and microfibril orientation

Cited by 28 publications

References 10 publications

Cell wall structure and deposition in Glaucocystis

Cell wall structure and deposition in Glaucocystis

Notes on Torus Development in the Wood of Osmanthus Americanus (L.) Benth. ' Hook. Ex Gray (Oleaceae)

Colchicine-induced changes in the growth and secondary wall deposition of cotyledonless radish seedlings

Contact Info

Product

Resources

About