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Geilfus CM, Tenhaken R, Carpentier SC. Transient alkalinization of the leaf apoplast stiffens the cell wall during onset of chloride salinity in corn leaves. J Biol Chem 2017; 292:18800-18813. [PMID: 28972176 DOI: 10.1074/jbc.m117.799866] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/11/2017] [Indexed: 12/13/2022] Open
Abstract
During chloride salinity, the pH of the leaf apoplast (pHapo) transiently alkalizes. There is an ongoing debate about the physiological relevance of these stress-induced pHapo changes. Using proteomic analyses of expanding leaves of corn (Zea mays L.), we show that this transition in pHapo conveys functionality by (i) adjusting protein abundances and (ii) affecting the rheological properties of the cell wall. pHapo was monitored in planta via microscopy-based ratio imaging, and the leaf-proteomic response to the transient leaf apoplastic alkalinization was analyzed via ultra-high performance liquid chromatography-MS. This analysis identified 1459 proteins, of which 44 exhibited increased abundance specifically through the chloride-induced transient rise in pHapo These elevated protein abundances did not directly arise from high tissue concentrations of Cl- or Na+ but were due to changes in the pHapo Most of these proteins functioned in growth-relevant processes and in the synthesis of cell wall-building components such as arabinose. Measurements with a linear-variable differential transducer revealed that the transient alkalinization rigidified (i.e. stiffened) the cell wall during the onset of chloride salinity. A decrease in t-coumaric and t-ferulic acids indicates that the wall stiffening arises from cross-linkage to cell wall polymers. We conclude that the pH of the apoplast represents a dynamic factor that is mechanistically coupled to cellular responses to chloride stress. By hardening the wall, the increased pH abrogates wall loosening required for cell expansion and growth. We conclude that the transient alkalinization of the leaf apoplast is related to salinity-induced growth reduction.
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Affiliation(s)
- Christoph-Martin Geilfus
- From SYBIOMA, Proteomics Core Facility, KU Leuven, O&N II Herestraat 49, bus 901, B-3000 Leuven, Belgium, .,the Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-University of Berlin, Albrecht-Thaer-Weg 1, 14195 Berlin, Germany
| | - Raimund Tenhaken
- the Department of Cell Biology, Division of Plant Physiology, University of Salzburg, Salzburg, Austria, and
| | - Sebastien Christian Carpentier
- From SYBIOMA, Proteomics Core Facility, KU Leuven, O&N II Herestraat 49, bus 901, B-3000 Leuven, Belgium.,the Department of Biosystems, Division of Crop Biotechnics, KU Leuven, Willem de Croylaan 42, Box 2455, B-3001 Leuven, Belgium
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Fujita M, Wasteneys GO. A survey of cellulose microfibril patterns in dividing, expanding, and differentiating cells of Arabidopsis thaliana. PROTOPLASMA 2014; 251:687-98. [PMID: 24169947 DOI: 10.1007/s00709-013-0571-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 10/14/2013] [Indexed: 05/02/2023]
Abstract
Cellulose microfibrils are critical for plant cell specialization and function. Recent advances in live cell imaging of fluorescently tagged cellulose synthases to track cellulose synthesis have greatly advanced our understanding of cellulose biosynthesis. Nevertheless, cellulose deposition patterns remain poorly described in many cell types, including those in the process of division or differentiation. In this study, we used field emission scanning electron microscopy analysis of cryo-planed tissues to determine the arrangement of cellulose microfibrils in various faces of cells undergoing cytokinesis or specialized development, including cell types in which cellulose cannot be imaged by conventional approaches. In dividing cells, we detected microfibrillar meshworks in the cell plates, consistent with the concentration at the cell plate of cellulose synthase complexes, as detected by fluorescently tagged CesA6. We also observed a loss of parallel cellulose microfibril orientation in walls of the mother cell during cytokinesis, which corresponded with the loss of fluorescently tagged cellulose synthase complexes from these surfaces. In recently formed guard cells, microfibrils were randomly organized and only formed a highly ordered circumferential pattern after pore formation. In pit fields, cellulose microfibrils were arranged in circular patterns around plasmodesmata. Microfibrils were random in most cotyledon cells except the epidermis and were parallel to the growth axis in trichomes. Deposition of cellulose microfibrils was spatially delineated in metaxylem and protoxylem cells of the inflorescence stem, supporting recent studies on microtubule exclusion mechanisms.
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Affiliation(s)
- Miki Fujita
- Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, B.C., V6T 1Z4, Canada
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Lei L, Li S, Du J, Bashline L, Gu Y. Cellulose synthase INTERACTIVE3 regulates cellulose biosynthesis in both a microtubule-dependent and microtubule-independent manner in Arabidopsis. THE PLANT CELL 2013; 25:4912-23. [PMID: 24368796 PMCID: PMC3903995 DOI: 10.1105/tpc.113.116715] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Anisotropic plant cell growth depends on the coordination between the orientation of cortical microtubules and the orientation of nascent cellulose microfibrils. Cellulose synthase interactive1 (CSI1) is a key scaffold protein that guides primary cellulose synthase complexes (CSCs) along cortical microtubules during cellulose biosynthesis. Here, we investigated the function of the CSI1-like protein, CSI3, in Arabidopsis thaliana. Similar to CSI1, CSI3 associates with primary CSCs in vitro, colocalizes with CSCs in vivo, and exhibits the same plasma membrane localization and bidirectional motility as CSI1. However, ProCSI1:GFP-CSI3 cannot complement the anisotropic cell growth defect in csi1 mutants, suggesting that CSI3 is not functionally equivalent to CSI1. Also, the colocalization ratio between CSI1 and CSI3 is low, which may suggest heterogeneity within the CSC population. csi1 csi3 double mutants showed an enhanced cell expansion defect as well as an additive reduction of CSC velocities, and CSI3 dynamics are dependent on CSI1 function. We propose that CSI3 is an important regulator of plant cellulose biosynthesis and plant anisotropic cell growth that modulates the velocity of CSCs in both a microtubule-dependent and microtubule-independent manner.
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SAXENA INDERM, BROWN RMALCOLM. Cellulose biosynthesis: current views and evolving concepts. ANNALS OF BOTANY 2005; 96:9-21. [PMID: 15894551 PMCID: PMC4246814 DOI: 10.1093/aob/mci155] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
AIMS To outline the current state of knowledge and discuss the evolution of various viewpoints put forth to explain the mechanism of cellulose biosynthesis. * SCOPE Understanding the mechanism of cellulose biosynthesis is one of the major challenges in plant biology. The simplicity in the chemical structure of cellulose belies the complexities that are associated with the synthesis and assembly of this polysaccharide. Assembly of cellulose microfibrils in most organisms is visualized as a multi-step process involving a number of proteins with the key protein being the cellulose synthase catalytic sub-unit. Although genes encoding this protein have been identified in almost all cellulose synthesizing organisms, it has been a challenge in general, and more specifically in vascular plants, to demonstrate cellulose synthase activity in vitro. The assembly of glucan chains into cellulose microfibrils of specific dimensions, viewed as a spontaneous process, necessitates the assembly of synthesizing sites unique to most groups of organisms. The steps of polymerization (requiring the specific arrangement and activity of the cellulose synthase catalytic sub-units) and crystallization (directed self-assembly of glucan chains) are certainly interlinked in the formation of cellulose microfibrils. Mutants affected in cellulose biosynthesis have been identified in vascular plants. Studies on these mutants and herbicide-treated plants suggest an interesting link between the steps of polymerization and crystallization during cellulose biosynthesis. * CONCLUSIONS With the identification of a large number of genes encoding cellulose synthases and cellulose synthase-like proteins in vascular plants and the supposed role of a number of other proteins in cellulose biosynthesis, a complete understanding of this process will necessitate a wider variety of research tools and approaches than was thought to be required a few years back.
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Dhonukshe P, Laxalt AM, Goedhart J, Gadella TWJ, Munnik T. Phospholipase d activation correlates with microtubule reorganization in living plant cells. THE PLANT CELL 2003; 15:2666-79. [PMID: 14508002 PMCID: PMC280570 DOI: 10.1105/tpc.014977] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Accepted: 08/22/2003] [Indexed: 05/18/2023]
Abstract
A phospholipase D (PLD) was shown recently to decorate microtubules in plant cells. Therefore, we used tobacco BY-2 cells expressing the microtubule reporter GFP-MAP4 to test whether PLD activation affects the organization of plant microtubules. Within 30 min of adding n-butanol, a potent activator of PLD, cortical microtubules were released from the plasma membrane and partially depolymerized, as visualized with four-dimensional confocal imaging. The isomers sec- and tert-butanol, which did not activate PLD, did not affect microtubule organization. The effect of treatment on PLD activation was monitored by the in vivo formation of phosphatidylbutanol, a specific reporter of PLD activity. Tobacco cells also were treated with mastoparan, xylanase, NaCl, and hypoosmotic stress as reported activators of PLD. We confirmed the reports and found that all treatments induced microtubule reorganization and PLD activation within the same time frame. PLD still was activated in microtubule-stabilized (taxol) and microtubule-depolymerized (oryzalin) situations, suggesting that PLD activation triggers microtubular reorganization and not vice versa. Exogenously applied water-soluble synthetic phosphatidic acid did not affect the microtubular cytoskeleton. Cell cycle studies revealed that n-butanol influenced not just interphase cortical microtubules but also those in the preprophase band and phragmoplast, but not those in the spindle structure. Cell growth and division were inhibited in the presence of n-butanol, whereas sec- and tert-butanol had no such effects. Using these novel insights, we propose a model for the mechanism by which PLD activation triggers microtubule reorganization in plant cells.
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Affiliation(s)
- Pankaj Dhonukshe
- Section of Molecular Cytology, Swammerdam Institute for Life Sciences, University of Amsterdam, NL-1090 GB Amsterdam, The Netherlands
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Baskin TI. On the alignment of cellulose microfibrils by cortical microtubules: a review and a model. PROTOPLASMA 2001; 215:150-71. [PMID: 11732054 DOI: 10.1007/bf01280311] [Citation(s) in RCA: 242] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The hypothesis that microtubules align microfibrils, termed the alignment hypothesis, states that there is a causal link between the orientation of cortical microtubules and the orientation of nascent microfibrils. I have assessed the generality of this hypothesis by reviewing what is known about the relation between microtubules and microfibrils in a wide group of examples: in algae of the family Characeae, Closterium acerosum, Oocystis solitaria, and certain genera of green coenocytes and in land plant tip-growing cells, xylem, diffusely growing cells, and protoplasts. The salient features about microfibril alignment to emerge are as follows. Cellulose microfibrils can be aligned by cortical microtubules, thus supporting the alignment hypothesis. Alignment of microfibrils can occur independently of microtubules, showing that an alternative to the alignment hypothesis must exist. Microfibril organization is often random, suggesting that self-assembly is insufficient. Microfibril organization differs on different faces of the same cell, suggesting that microfibrils are aligned locally, not with respect to the entire cell. Nascent microfibrils appear to associate tightly with the plasma membrane. To account for these observations, I present a model that posits alignment to be mediated through binding the nascent microfibril. The model, termed templated incorporation, postulates that the nascent microfibril is incorporated into the cell wall by binding to a scaffold that is oriented; further, the scaffold is built and oriented around either already incorporated microfibrils or plasma membrane proteins, or both. The role of cortical microtubules is to bind and orient components of the scaffold at the plasma membrane. In this way, spatial information to align the microfibrils may come from either the cell wall or the cell interior, and microfibril alignment with and without microtubules are subsets of a single mechanism.
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Affiliation(s)
- T I Baskin
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
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Kawagoe Y, Delmer DP. Pathways and genes involved in cellulose biosynthesis. GENETIC ENGINEERING 1997; 19:63-87. [PMID: 9193103 DOI: 10.1007/978-1-4615-5925-2_4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Y Kawagoe
- Section of Plant Biology, University of California, Davis 95616, USA
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Dazzo FB, Orgambide GG, Philip-Hollingsworth S, Hollingsworth RI, Ninke KO, Salzwedel JL. Modulation of development, growth dynamics, wall crystallinity, and infection sites in white clover root hairs by membrane chitolipooligosaccharides from Rhizobium leguminosarum biovar trifolii. J Bacteriol 1996; 178:3621-7. [PMID: 8655563 PMCID: PMC178135 DOI: 10.1128/jb.178.12.3621-3627.1996] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We used bright-field, time-lapse video, cross-polarized, phase-contrast, and fluorescence microscopies to examine the influence of isolated chitolipooligosaccharides (CLOSs) from wild-type Rhizobium leguminosarum bv. trifolii on development of white clover root hairs, and the role of these bioactive glycolipids in primary host infection. CLOS action caused a threefold increase in the differentiation of root epidermal cells into root hairs. At maturity, root hairs were significantly longer because of an extended period of active elongation without a change in the elongation rate itself. Time-series image analysis showed that the morphological basis of CLOS-induced root hair deformation is a redirection of tip growth displaced from the medial axis as previously predicted. Further studies showed several newly described infection-related root hair responses to CLOSs, including the localized disruption of the normal crystallinity in cell wall architecture and the induction of new infection sites. The application of CLOS also enabled a NodC- mutant of R. leguminosarum bv. trifolii to progress further in the infection process by inducing bright refractile spot modifications of the deformed root hair walls. However, CLOSs did not rescue the ability of the NodC- mutant to induce marked curlings or infection threads within root hairs. These results indicate that CLOS Nod factors elicit several host responses that modulate the growth dynamics and symbiont infectibility of white clover root hairs but that CLOSs alone are not sufficient to permit successful entry of the bacteria into root hairs during primary host infection in the Rhizobium-clover symbiosis.
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Affiliation(s)
- F B Dazzo
- Department of Microbiology, Michigan State University, East Lansing 48824, USA
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Selker JM, Steucek GL, Green PB. Biophysical mechanisms for morphogenetic progressions at the shoot apex. Dev Biol 1992; 153:29-43. [PMID: 1516750 DOI: 10.1016/0012-1606(92)90089-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Leaf primordia, first visible as small bumps, are produced in a cyclical pattern at the edges of the shoot apex, a smooth region at the top of the stem. Their formation is a biomechanical process. This review first considers hypothetical construction mechanisms and then summarizes research that provides information about how and where the primordia are made. Studies of growth at the primordium site indicate the importance of growth parallel to the surface in generating the forces for primordium emergence. The symmetry of the pattern of reinforcement by cellulose microfibrils correlates with the subsequent pattern of primordium production. Finite element models of the apex reveal that lateral bulging of the apex results in a gradient of shear stress, with high shear at the future primordium site. In contrast, tension parallel to the surface is lowest at the primordium site. Response of apical surface tissue to punctures indicates that an existing primordium can exert a pulling force tangential to its base and a compressive force perpendicular to its base. These observations lead to identification of a continuous biophysical cycle for apex morphogenesis, in which most of the steps are direct physical consequences of the previous step. Biophysical processes, subject to input from genetic, hormonal, and environmental sources, are thus involved in the construction and patterning of leaf primordia.
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Affiliation(s)
- J M Selker
- Institute of Molecular Biology, University of Oregon, Eugene 97403
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10
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Orientation of Cortical Microtubules in Interphase Plant Cells. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/s0074-7696(08)60511-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Herth W. Plasma-membrane rosettes involved in localized wall thickening during xylem vessel formation of Lepidium sativum L. PLANTA 1985; 164:12-21. [PMID: 24249494 DOI: 10.1007/bf00391020] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/1984] [Accepted: 09/20/1984] [Indexed: 06/02/2023]
Abstract
Developing xylem vessel elements in roots of cress, Lepidium sativum L., were freeze-fractured after rapid freezing in nitrogen slush (without cryoprotection). With the double-replica technique, both the plasmatic fracture face (PF) and the extraplasmatic fracture face (EF) of the plasma membrane were exposed. The EF revealed abundant, but rather indistinct "terminal globules"; whereas the PF showed numerous "rosettes". Terminal globules and rosettes were localized, restricted to regions of secondary wall thickening only, and showed comparale frequencies per μm(2), supporting the assumption that they are part of the same synthase complex. The abundance of rosettes in regions of high cellulose production supports their postulated involvement in cellulose microfibril formation. With up to 191 rosettes per μm(2), the rosettes appear to be too densely arranged to be directly aligned on individual microtubules. This favors the channelling hypothesis of synthase movement in the plasma membrane.
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Affiliation(s)
- W Herth
- Zellenlehre, Universität Heidelberg, Im Neuenheimer Feld 230, D-6900, Heidelberg, Federal Republic of Germany
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13
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Emons AM. Plasma-membrane rosettes in root hairs of Equisetum hyemale. PLANTA 1985; 163:350-359. [PMID: 24249406 DOI: 10.1007/bf00395143] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/1984] [Accepted: 08/25/1984] [Indexed: 06/02/2023]
Abstract
Particle arrangement in the plasma membrane during cell wall formation was investigated by means of the double-replica technique in root hairs of Equisetum hyemale. Particle density in the protoplasmic fracture face of the plasma membrane was higher than in the extraplasmic fracture face. Apart from randomly distributed particles, particle rosettes were visible in the PF face of the plasma membrane. The rosettes consisted of six particles arranged in a circle and had an outer diameter of approx. 26 nm. No gradient in the number of rosettes was found, which agrees with micrifibril deposition taking place over the whole hair. The particle rosettes were found individually, which might indicate that they spin out thin microfibrils as found in higher-plant cell walls. Indeed microfibril width in these walls, measured in shadowed preparations, is 8.5±1.5 nm. It is suggested that the rosettes are involved in microfibril synthesis. Non-turgid cells lacked microfibril imprints in the plasma membrane and no particle rosettes were present on their PF face. Fixation with glutaraldehyde caused, probably as a result of plasmolysis, the microfibril imprints to disappear together with the particle rosettes. The PF face of the plasma membrane of non-turgid hairs sometimes showed domains in which the intramembrane particles were aggregated in a hexagonal pattern. Microfibril orientation during deposition will be discussed.
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Affiliation(s)
- A M Emons
- Department of Botany, University of Nijmegen, Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands
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Neville AC, Levy S. Helicoidal orientation of cellulose microfibrils in Nitella opaca internode cells: ultrastructure and computed theoretical effects of strain reorientation during wall growth. PLANTA 1984; 162:370-384. [PMID: 24253172 DOI: 10.1007/bf00396750] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/1983] [Accepted: 03/24/1984] [Indexed: 06/02/2023]
Abstract
The ultrastructure of the mature internode cell wall of Nitella opaca is described. It is interpreted in terms of a helicoidal array of cellulose microfibrils set in a matrix. A helicoid is a multiple 'plywood' made up of layers of parallel microfibrils. There is a progressive change in direction from ply to ply, giving rise to characteristic arced patterns in oblique sections. A critical tilting test, using an electron microscope fitted with a goniometric stage, showed the expected reversal of direction of the arced pattern. Nitella cell wall is thus more regularly structured than previous studies have shown. From a survey of the cell-wall literature, we show that such arced patterns are common. This indicates that the helicoidal structure may be more widespread than is generally realised, although numerous other cell walls show no signs of it. Nevertheless, there are examples in most major plant taxa, and in several types of cells, including wood tracheids. Most of the examples, however, need confirmation by tilting evidence. There are possible implications for wall morphogenesis. Helicoidal cell walls might arise by selfassembly via a liquid crystalline phase, since it is known that the cholesteric state is itself helicoidal. A computer graphics programme has been developed to plot the expected effects of growth strain on the patterns in oblique sections of helicoids with various original angles between consecutive layers. Herringbone patterns typical of crossed polylamellate texture can be generated in this way, indicating a possible mode of their formation.
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Affiliation(s)
- A C Neville
- Department of Zoology, University of Bristol, Woodland Road, BS8 1UG, Bristol, UK
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Abstract
The cell walls of sieve elements in the primary phloem of the Carboniferous fern Tubicaulis contain structural features that morphologically resemble cellulose microfibrils in extant plants. This may be the oldest example of distinct fibrillar structures in the fossil record. The possible identity and significance of these features are discussed and their structure is compared with that of cell walls in other fossil and extant plants.
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Itoh T, Brown RM. The assembly of cellulose microfibrils in Valonia macrophysa Kütz. PLANTA 1984; 160:372-381. [PMID: 24258586 DOI: 10.1007/bf00393419] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/1983] [Accepted: 11/01/1983] [Indexed: 06/02/2023]
Abstract
The assembly of cellulose microfibrils was investigated in artificially induced protoplasts of the alga, Valonia macrophysa (Siphonocladales). Primary-wall microfibrills, formed within 72 h of protoplast induction, are randomly oriented. Secondary-wall lamellae, which are produced within 96 h after protoplast induction, have more than three orientations of highly ordered microfibrils. The innermost, recently deposited micofibrils are not parallel with the cortical microtubules, thus indicating a more indirect role of microtubules in the orientation of microfibrils. Fine filamentous structures with a periodicity of 5.0-5.5 nm and the dimensions of actin were observed adjacent to the plasma membrane. Linear cellulose-terminal synthesizing complexes (TCs) consisting of three rows, each with 30-40 particles, were observed not only on the E fracture (EF) but also on P fracture (PF) faces of the plasma membrane. The TC appears to span both faces of the bimolecular leaflet. The average length of the TC is 350 nm, and the number of TCs per unit area during primary-wall synthesis is 1 per μm(2). Neither paired TCs nor granule bands characteristic of Oocystis were observed. Changes in TC structure and distribution during the conversion from primary- to secondary-wall formation have been described. Cellulose microfibril assembly in Valonia is discussed in relation to the process among other eukaryotic systems.
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Affiliation(s)
- T Itoh
- Wood Research Institute, Kyoto University, 611, Uji, Kyoto, Japan
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Toward a Dynamic Helical Model for the Influence of Microtubules on Wall Patterns in Plants. INTERNATIONAL REVIEW OF CYTOLOGY 1984. [DOI: 10.1016/s0074-7696(08)60176-x] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Seagull RW. The role of the cytoskeleton during oriented microfibril deposition. I. Elucidation of the possible interaction between microtubules and cellulose synthetic complexes. JOURNAL OF ULTRASTRUCTURE RESEARCH 1983; 83:168-75. [PMID: 6683324 DOI: 10.1016/s0022-5320(83)90074-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A detailed analysis of changes in the cytoskeletal organization during cell elongation and oriented microfibril deposition has been done in the four plant species, clover (Trifolium repens), radish (Raphanus sativus), corn (Zea mays), and sorghum (Sorghum vulgare). Microtubules of variable lengths were found in all the cells examined. Some grouping of microtubules was observed with inter microtubule distances ranging from 14 to 40 nm. Single microfilaments were often observed between parallel microtubules. During cell elongation, microtubule frequency (No./microns) was maintained, thus indicating that microtubules must be formed continuously. The parallel orientation of wall microfibrils is disrupted as they deviate around plasmodesmata and pit-fields; however the cortical microtubules, thought to be influencing microfibril orientation, exhibit no consistent deviation around pit-fields. These observations are used to argue that cortical microtubules cannot influence microfibril orientation through a direct association with cellulose synthetic complexes via microtubule cross bridges.
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Mueller SC, Brown RM. The control of cellulose microfibril deposition in the cell wall of higher plants : II. Freeze-fracture microfibril patterns in maize seedling tissues following experimental alteration with colchicine and ethylene. PLANTA 1982; 154:501-515. [PMID: 24276345 DOI: 10.1007/bf00402994] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/1981] [Accepted: 02/19/1982] [Indexed: 05/28/2023]
Abstract
Cells of maize (Zea mays L.) seedling that are not fixed or cryoprotected contain the impressions of cellulose microfibrils on freeze-fractured plasma membranes. Impressions of the most recently deposited microfibrils have terminal complexes associated with them (see preceding paper). The orientations of microtubules in cytoplasmic fractures are parallel to the newest microfibrils observed on adjacent plasma membrane fractures. Small groups of microfibrils, distinguished from the next older layer by their new orientation, are sometimes observed directly adjacent and parallel to individual microtubules. Whereas microtubules are parallel to microfibril orientations which vary from transverse to occasionally longitudinal, microfilaments are parallel to the longitudinal cell axis. After colchicine treatment, cytoplasmic microtubules are absent, as are the bands of microfibrils that are observed on the membrane of control cells. Parallel orientations of microfibrils and normal pitfield outlines are often still observed after colchicine treatment. However, on some membranes, multidirectionally-oriented microfibril tips occur, associated with perturbations of microfibril orientation and rounded pit-field outlines. In ethylene-treated cells, some membranes have microfibril tips oriented in only one direction in new layers of longitudinal microfibrils. On other membranes, longitudinal bands of microfibril tips are oriented in opposing directions. We propose that after colchicine treatment, the patterns of microfibrils reflect an orientation mechanism which has been uncoupled from the influence of microtubules but which is still under some other form of cellular control. We propose that membrane flow could orient the lateral movement of synthesizing complexes in the membrane and that microtubules modulate this movement, apparently organizing the microfibrils into parallel bands in newly-forming wall layers.
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Affiliation(s)
- S C Mueller
- Department of Botany, University of North Carolina, 27514, Chapel Hill, NC, USA
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