scholarly journals Defects in Cell Wall Differentiation of the Arabidopsis Mutant rol1-2 Is Dependent on Cyclin-Dependent Kinase CDK8

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 685
Author(s):  
Isabel Schumacher ◽  
Tohnyui Ndinyanka Fabrice ◽  
Marie-Therese Abdou ◽  
Benjamin M. Kuhn ◽  
Aline Voxeur ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Growth ◽  
Cell Walls ◽  
Developmental Defect ◽  
Cyclin Dependent Kinase ◽  
Plant Growth And Development ◽  
Rhamnogalacturonan I ◽  
Growth Defects ◽  
Arabidopsis Mutant ◽  
Cell Wall Architecture

Plant cells are encapsulated by cell walls whose properties largely determine cell growth. We have previously identified the rol1-2 mutant, which shows defects in seedling root and shoot development. rol1-2 is affected in the Rhamnose synthase 1 (RHM1) and shows alterations in the structures of Rhamnogalacturonan I (RG I) and RG II, two rhamnose-containing pectins. The data presented here shows that root tissue of the rol1-2 mutant fails to properly differentiate the cell wall in cell corners and accumulates excessive amounts of callose, both of which likely alter the physical properties of cells. A surr (suppressor of the rol1-2 root developmental defect) mutant was identified that alleviates the cell growth defects in rol1-2. The cell wall differentiation defect is re-established in the rol1-2 surr mutant and callose accumulation is reduced compared to rol1-2. The surr mutation is an allele of the cyclin-dependent kinase 8 (CDK8), which encodes a component of the mediator complex that influences processes central to plant growth and development. Together, the identification of the surr mutant suggests that changes in cell wall composition and turnover in the rol1-2 mutant have a significant impact on cell growth and reveals a function of CDK8 in cell wall architecture and composition.

Cell wall architecture as well as chemical composition determines fermentation of wheat cell walls by a faecal inoculum

2020 ◽  
Vol 107 ◽  
pp. 105858
Author(s):  
Shiyi Lu ◽  
Bernadine M. Flanagan ◽  
Barbara A. Williams ◽  
Deirdre Mikkelsen ◽  
Michael J. Gidley
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Cell Walls ◽  
Cell Wall Architecture

scholarly journals COMPOSITUM 1 contributes to the architectural simplification of barley inflorescence via meristem identity signals

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Naser Poursarebani ◽  
Corinna Trautewig ◽  
Michael Melzer ◽  
Thomas Nussbaumer ◽  
Udda Lundqvist ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Natural Selection ◽  
Cell Growth ◽  
Cell Walls ◽  
Molecular Breeding ◽  
Branch Formation ◽  
Genetic Mechanisms ◽  
Meristem Identity ◽  
Cell Wall Properties

Abstract Grasses have varying inflorescence shapes; however, little is known about the genetic mechanisms specifying such shapes among tribes. Here, we identify the grass-specific TCP transcription factor COMPOSITUM 1 (COM1) expressing in inflorescence meristematic boundaries of different grasses. COM1 specifies branch-inhibition in barley (Triticeae) versus branch-formation in non-Triticeae grasses. Analyses of cell size, cell walls and transcripts reveal barley COM1 regulates cell growth, thereby affecting cell wall properties and signaling specifically in meristematic boundaries to establish identity of adjacent meristems. COM1 acts upstream of the boundary gene Liguleless1 and confers meristem identity partially independent of the COM2 pathway. Furthermore, COM1 is subject to purifying natural selection, thereby contributing to specification of the spike inflorescence shape. This meristem identity pathway has conceptual implications for both inflorescence evolution and molecular breeding in Triticeae.

scholarly journals COMPOSITUM 1 (COM1) contributes to the architectural simplification of barley inflorescence via meristem identity signals

2020 ◽  
Author(s):  
N. Poursarebani ◽  
C. Trautewig ◽  
M. Melzer ◽  
T. Nussbaumer ◽  
U. Lundqvist ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Natural Selection ◽  
Cell Growth ◽  
Cell Walls ◽  
Molecular Breeding ◽  
Branch Formation ◽  
Genetic Mechanisms ◽  
Meristem Identity ◽  
Cell Wall Properties

AbstractGrasses have varying inflorescence shapes; however, little is known about the genetic mechanisms specifying such shapes among tribes. We identified the grass-specific TCP transcription factor COMPOSITUM 1 (COM1) expressed in inflorescence meristematic boundaries of different grasses. COM1 specifies branch-inhibition in Triticeae (barley) versus branch-formation in non-Triticeae grasses. Analyses of cell size, cell walls and transcripts revealed barley COM1 regulates cell growth, affecting cell wall properties and signaling specifically in meristematic boundaries to establish identity of adjacent meristems. COM1 acts upstream of the boundary gene Liguleless1 and confers meristem identity partially independent of the COM2 pathway. Furthermore, COM1 is subject to purifying natural selection, thereby contributing to specification of the spike inflorescence shape. This meristem identity pathway has conceptual implications for both inflorescence evolution and molecular breeding in Triticeae.

scholarly journals Golgi-localized TMN1/EMP12 functions in the deposition of rhamnogalacturonan II and I for cell growth in Arabidopsis

2021 ◽  
Author(s):  
Akihiko Hiroguchi ◽  
Shingo Sakamoto ◽  
Nobutaka Mitsuda ◽  
Kyoko Miwa
Keyword(s):  
Cell Growth ◽  
Cell Walls ◽  
Stem Elongation ◽  
Primary Root ◽  
Loss Of Function ◽  
Wild Type ◽  
Pectic Polysaccharides ◽  
Rhamnogalacturonan I ◽  
Rhamnogalacturonan Ii ◽  
Dependent Growth

Abstract Appropriate pectin deposition in cell walls is important for cell growth in plants. Rhamnogalacturonan II (RG-II) is a portion of pectic polysaccharides; its borate crosslinking is essential for maintenance of pectic networks. However, the overall process of RG-II synthesis is not fully understood. To identify a novel factor for RG-II deposition or dimerization in cell walls, we screened Arabidopsis mutants with altered boron (B)-dependent growth. The mutants exhibited alleviated disorders of primary root (PR) and stem elongation, and fertility under low B conditions, but reduced PR lengths under sufficient B conditions. Altered PR elongation was associated with cell elongation changes caused by loss of function in TMN1 (Transmembrane Nine 1) /EMP12, which encodes a Golgi-localized membrane protein of unknown function that is conserved among eukaryotes. Mutant leaf and root dry weights were lower than those of wild-type plants, regardless of B conditions. In cell walls, TMN1 mutations reduced contents of B, RG-II specific 2-keto-3-deoxy monosaccharides, and rhamnose largely derived from rhamnogalacturonan I (RG-I), suggesting reduced RG-II and RG-I. Together, our findings demonstrate that TMN1 is required for the deposition of RG-II and RG-I for cell growth and we also find that pectin levels modulate plant growth under low B conditions.

scholarly journals Cell wall polymers in the Phaeoceros placenta reflect developmental and functional differences across generations

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
JASON S. HENRY ◽  
ROBERTO LIGRONE ◽  
KEVIN C. VAUGHN ◽  
RENEE A. LOPEZ ◽  
KAREN S. RENZAGLIA
Keyword(s):  
Cell Wall ◽  
Calcium Binding ◽  
Cell Walls ◽  
Cell Types ◽  
Transfer Cells ◽  
Calcofluor White ◽  
Placental Cell ◽  
Rhamnogalacturonan I ◽  
Cell Wall Polymers ◽  
Two Generations

The placenta of hornworts is unique among bryophytes in the restriction of transfer cells that are characterized by elaborate wall labyrinths to the gametophyte generation. During development, cells around the periphery of the sporophyte foot elongate, forming smooth-walled haustorial cells that interdigitate with gametophyte cells. Using immunogold labeling with 22 antibodies to diverse cell wall polymers, we examined compositional differences in the developmentally and morphologically distinct cell walls of gametophyte transfer cells and sporophyte haustorial cells in the placenta of Phaeoceros. As detected by Calcofluor White fluorescence, cellulose forms the cell wall scaffolding in cells on both sides of the placenta. Homogalacturonan (HG) and rhamnogalacturonan I (RG-I) pectins are abundant in both cell types, and haustorial cells are further enriched in methyl-esterified HGs. The abundance of pectins in placental cell walls is consistent with the postulated roles of these polymers in cell wall porosity and in maintaining an acidic apoplastic pH favorable to solute transport. Xyloglucan hemicellulose, but not mannans or glucuronoxylans, are present in cell walls at the interface between the two generations with a lower density in gametophytic wall ingrowths. Arabinogalactan proteins (AGPs) are diverse along the plasmalemma of placental cells and are absent in surrounding cells in both generations. AGPs in placental cell walls may play a role in calcium binding and release associated with signal transduction as has been speculated for these glycoproteins in other plants. Callose is restricted to thin areas in cell walls of gametophyte transfer cells. In contrast to studies of transfer cells in other systems, no reaction to the JIM12 antibody against extensin was observed in Phaeoceros.

scholarly journals A grass-specific cellulose–xylan interaction dominates in sorghum secondary cell walls

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Gao ◽  
Andrew S. Lipton ◽  
Yuuki Wittmer ◽  
Dylan T. Murray ◽  
Jenny C. Mortimer
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Secondary Cell Wall ◽  
Magic Angle Spinning ◽  
Crystalline Cellulose ◽  
Magic Angle ◽  
Amorphous Cellulose ◽  
Secondary Cell Walls ◽  
Promising Source ◽  
Cell Wall Architecture

AbstractSorghum (Sorghum bicolor L. Moench) is a promising source of lignocellulosic biomass for the production of renewable fuels and chemicals, as well as for forage. Understanding secondary cell wall architecture is key to understanding recalcitrance i.e. identifying features which prevent the efficient conversion of complex biomass to simple carbon units. Here, we use multi-dimensional magic angle spinning solid-state NMR to characterize the sorghum secondary cell wall. We show that xylan is mainly in a three-fold screw conformation due to dense arabinosyl substitutions, with close proximity to cellulose. We also show that sorghum secondary cell walls present a high ratio of amorphous to crystalline cellulose as compared to dicots. We propose a model of sorghum cell wall architecture which is dominated by interactions between three-fold screw xylan and amorphous cellulose. This work will aid the design of low-recalcitrance biomass crops, a requirement for a sustainable bioeconomy.

Thickened cell walls of Bacillus cereus grown in the presence of chloramphenicol: their fate during cell growth

1971 ◽  
Vol 17 (12) ◽  
pp. 1561-1565 ◽  
Author(s):  
K. L. Chung
Keyword(s):  
Cell Wall ◽  
Cell Growth ◽  
Bacillus Cereus ◽  
Cell Walls ◽  
Structural Changes ◽  
Synthetic Medium ◽  
Wall Material ◽  
Partial Removal ◽  
Daughter Cells ◽  
Thickened Wall

Bacillus cereus incubated for 4 h in a synthetic medium containing chloramphenicol was observed to form cell walls 2 to 3 times as thick as those from control cells growing in the same medium containing no antibiotic. Then the cells were washed and reincubated in fresh synthetic medium and the ultra-structural changes in the thickened walls during cell growth and elongation were examined by electron microscopy. After incubation for 20 min, multiple ruptured sites and internal fractures appeared randomly on the surface of the thickened cell wall. Large and small pieces of thickened wall fragments soon "peeled off" from the surface, leaving behind a deeper layer of wall material. Normal cell growth and elongation resumed after partial removal of the thickened cell wall. After several generations, thickened wall fragments were not observed on the surface of daughter cells.

scholarly journals If Homogalacturonan Were a Side Chain of Rhamnogalacturonan I. Implications for Cell Wall Architecture

2003 ◽  
Vol 132 (4) ◽  
pp. 1781-1789 ◽  
Author(s):  
Jean-Paul Vincken ◽  
Henk A. Schols ◽  
Ronald J.F.J. Oomen ◽  
Maureen C. McCann ◽  
Peter Ulvskov ◽  
...  
Keyword(s):  
Cell Wall ◽  
Side Chain ◽  
Rhamnogalacturonan I ◽  
Cell Wall Architecture

Chemical and ultrastructural changes of ash wood thermally modified (TMW) using the thermo-vacuum process: II. Immunocytochemical study of the distribution of noncellulosic polysaccharides

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 615-625 ◽  
Author(s):  
Jong Sik Kim ◽  
Jie Gao ◽  
Nasko Terziev ◽  
Ottaviano Allegretti ◽  
Geoffrey Daniel
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Middle Lamella ◽  
Degradation Process ◽  
Thermal Modification ◽  
Ultrastructural Changes ◽  
Immunogold Localization ◽  
Immunocytochemical Study ◽  
Rhamnogalacturonan I ◽  
Compound Middle Lamella

AbstractFollowing structural and cytochemical studies (Part I) on thermally modified ash wood (TMW) by the thermo-vacuum (Termovuoto) process, changes in the distribution of noncellulosic polysaccharides have been investigated in TMW treated for 3 h at 220°C (TMW3 h, 220°C) by means of immunogold localization methods. Pectins (homogalacturonan, rhamnogalacturonan-I) and xyloglucan were significantly degraded in compound middle lamella (CML), including the middle lamella cell corner regions (CMLcc), of all xylem cells after thermal modification. Xylan and mannan degradation were also visible in fiber cell walls. In particular, degradation of mannan was very significant and showed variation between cell wall regions even within the same cell wall. The degradation of pectins was more significant than that of hemicelluloses. In summary, results suggest that each noncellulosic polysaccharide may have a different degradation process in ash TMWs.

scholarly journals Changes in pectins of the Xylopodium of Ocimum nudicaule from dormancy to sprouting

2006 ◽  
Vol 18 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Márcia Regina Braga ◽  
Nicholas C. Carpita ◽  
Sonia M. C. Dietrich ◽  
Rita de Cássia L. Figueiredo-Ribeiro
Keyword(s):  
Cell Wall ◽  
Molecular Mass ◽  
Cell Walls ◽  
Cell Wall Polysaccharides ◽  
Pectic Polysaccharides ◽  
Pectic Polysaccharide ◽  
Rhamnogalacturonan I ◽  
Composition And Structure ◽  
Cell Wall Extension ◽  
Phenological Phases

The thickened underground organ of Ocimum nudicaule is a tuber-like structure (xylopodium) that is dormant in winter and sprouts at the beginning of the spring. Changes in content of cell wall polysaccharides were shown to occur from dormancy to sprouting. Pectic polysaccharides of O. nudicaule were analyzed in relation to composition, molecular mass, and linkage structure in these two phenological phases. The pectin content was 33 % lower during sprouting when compared to dormancy. Changes were also observed in the molecular mass of the pectin fraction from dormancy to sprouting. Galacturonic acid was the predominant sugar, suggesting the presence of a homogalacturonan as the main pectic polysaccharide. A decrease in the acidic polysaccharides, homogalacturonans and rhamnogalacturonan I, equally accounted for the decrease in the pectin composition upon sprouting. These acidic carbohydrates were predominantly detected in the cell walls of the phellogen region of the xylopodium, suggesting catabolism of the cell walls of this tissue during bud flushing. These results suggest that variations in the content and in the molecular mass of pectins, in addition to changes in their composition and structure could be related to storage function as well as cell wall extension growth, both required for the sprouting of new buds in the xylopodium of O. nudicaule.

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