scholarly journals Rapid cell expansion and cellulose synthesis regulated by plasmodesmata and sugar: insights from the single-celled cotton fibre

2007 ◽  
Vol 34 (1) ◽  
pp. 1 ◽  
Author(s):  
Yong-Ling Ruan

Higher plants comprise mixtures of some 40 different cell types, and this often complicates the interpretation of data obtained at the tissue level. Studies for a given cell type may provide novel insights into the mechanisms underlying defined cellular and developmental processes. In this regard, the cotton fibre represents an excellent single-cell model to study the control of rapid cell elongation and cellulose synthesis. These single cells, initiated from the ovule epidermis at anthesis, typically elongate to ~3–5 cm in the tetraploid species before they switch to intensive secondary cell wall cellulose synthesis. By maturity, more than 94% of fibre weight is cellulose. To unravel the mechanisms of fibre elongation and cellulose synthesis, two hypotheses have been examined: (a) that sucrose degradation and utilisation mediated by sucrose synthase (Sus) may play roles in fibre development and (b) that symplastic isolation of the fibre cells may be required for their rapid elongation. Reverse genetic and biochemical analyses have revealed the critical role that Sus plays in fibre initiation and early elongation. Late in development, plasma-membrane and cell wall association of Sus protein seems to be involved in rapid cellulose synthesis. Cell biology and gene expression studies showed a temporary closure of fibre plasmodesmata (PD), probably due to the deposition of callose, at the rapid phase of elongation. The duration of the PD closure correlates positively with the final fibre length attained. These data support the view that PD closure may be required for fibres to achieve extended elongation. The branching of PD towards the secondary cell wall stage is postulated to function as a molecule sieve for tight control of macromolecule trafficking into fibres to sustain intensive cellulose synthesis.

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1599
Author(s):  
Xiaoyu Zhu ◽  
Frédérique Tellier ◽  
Ying Gu ◽  
Shundai Li

In higher plants, cellulose is synthesized by membrane-spanning large protein complexes named cellulose synthase complexes (CSCs). In this study, the Arabidopsis PASTICCINO2 (PAS2) was identified as an interacting partner of cellulose synthases. PAS2 was previously characterized as the plant 3-hydroxy-acyl-CoA dehydratase, an ER membrane-localized dehydratase that is essential for very-long-chain-fatty acid (VLCFA) elongation. The pas2-1 mutants show defective cell elongation and reduction in cellulose content in both etiolated hypocotyls and light-grown roots. Although disruption of VLCFA synthesis by a genetic alteration had a reduction in VLCFA in both etiolated hypocotyls and light-grown roots, it had a differential effect on cellulose content in the two systems, suggesting the threshold level of VLCFA for efficient cellulose synthesis may be different in the two biological systems. pas2-1 had a reduction in both CSC delivery rate and CSC velocity at the PM in etiolated hypocotyls. Interestingly, Golgi but not post-Golgi endomembrane structures exhibited a severe defect in motility. Experiments using pharmacological perturbation of VLCFA content in etiolated hypocotyls strongly indicate a novel function of PAS2 in the regulation of CSC and Golgi motility. Through a combination of genetic, biochemical and cell biology studies, our study demonstrated that PAS2 as a multifunction protein has an important role in the regulation of cellulose biosynthesis in Arabidopsis hypocotyl.


Cellulose ◽  
2004 ◽  
Vol 11 (3/4) ◽  
pp. 329-338 ◽  
Author(s):  
Neil G. Taylor ◽  
John C. Gardiner ◽  
Raymond Whiteman ◽  
Simon R. Turner

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1618
Author(s):  
Sheng Yao ◽  
Peizhen Chen ◽  
Ye Yu ◽  
Mengyang Zhang ◽  
Dengbao Wang ◽  
...  

Wood formation originates in the biosynthesis of lignin and further leads to secondary cell wall (SCW) biosynthesis in woody plants. Masson pine (Pinus massoniana Lamb) is an economically important industrial timber tree, and its wood yield affects the stable development of the paper industry. However, the regulatory mechanisms of SCW formation in Masson pine are still unclear. In this study, we characterized PmMYB4, which is a Pinus massoniana MYB gene involved in SCW biosynthesis. The open reading frame (ORF) of PmMYB4 was 1473 bp, which encoded a 490 aa protein and contained two distinctive R2 and R3 MYB domains. It was shown to be a transcription factor, with the highest expression in semi-lignified stems. We overexpressed PmMYB4 in tobacco. The results indicated that PmMYB4 overexpression increased lignin deposition, SCW thickness, and the expression of genes involved in SCW formation. Further analysis indicated that PmMYB4 bound to AC-box motifs and might directly activate the promoters of genes (PmPAL and PmCCoAOMT) involved in SCW biosynthesis. In addition, PmMYB4-OE(over expression) transgenic lines had higher lignin and cellulose contents and gene expression than control plants, indicating that PmMYB4 regulates SCW mainly by targeting lignin biosynthetic genes. In summary, this study illustrated the MYB-induced SCW mechanism in Masson pine and will facilitate enhanced lignin and cellulose synthesis in genetically engineered trees.


2020 ◽  
Author(s):  
Song Chen ◽  
Xin Lin ◽  
Xiyang Zhao ◽  
Su Chen

Abstract BackgroundCellulose is an essential structural component of plant cell wall and is an important resource to produce paper, textiles, bioplastics and other biomaterials. The synthesis of cellulose is among the most important but poorly understood biochemical processes, which is precisely regulated by internal and external cues.ResultsHere, we identified 46 gene models in 7 gene families which encoding cellulose synthase and related enzymes of Betula pendula, and the transcript abundance of these genes in xylem, root, leaf and flower tissues also be determined. Based on these RNA-seq data, we have identified 8 genes that most likely participate in secondary cell wall synthesis, which include 3 cellulose synthase genes and 5 cellulose synthase-like genes. In parallel, a gene co-expression network was also constructed based on transcriptome sequencing.ConclusionsIn this study, we have identified a total of 46 cell wall synthesis genes in B. pendula, which include 8 secondary cell wall synthesis genes. These analyses will help decipher the genetic information of the cell wall synthesis genes, elucidate the molecular mechanism of cellulose synthesis and understand the cell wall structure in B. pendula.


2004 ◽  
Vol 52 (2) ◽  
pp. 243 ◽  
Author(s):  
Celeste L. Kremer ◽  
Andrew N. Drinnan

The cytoskeleton and ultrastructural events associated with cell differentiation and secondary cell wall and pore formation in hyaline cells of Sphagnum are investigated. Microtubules reorient from random arrays in undifferentiated hyaline cells to transverse arrays in elongating cells. Once cells are fully elongated, broad bands of microtubules aggregate into a spiral that predicts the site of secondary cell wall deposition. The secondary wall has a similar fibrillar composition to the primary wall. After the secondary wall is deposited, the thin primary wall covering the pore breaks down, usually by cell-wall degradation at the centre of the pore and around its margin. Finally, the hyaline cell undergoes cytoplasmic degeneration. The orientation of microtubules associated with hyaline-cell formation and secondary cell wall patterning resembles ultrastructural development in tracheary elements of higher plants. The similarities in cytoskeletal arrays during cell differentiation and secondary-wall formation suggest a fundamental pathway of development shared by bryophytes and higher plants.


2011 ◽  
Vol 6 (11) ◽  
pp. 1638-1643 ◽  
Author(s):  
Venugopal Mendu ◽  
Jozsef Stork ◽  
Darby Harris ◽  
Seth DeBolt

2018 ◽  
Vol 121 (6) ◽  
pp. 1107-1125 ◽  
Author(s):  
Miranda J Meents ◽  
Yoichiro Watanabe ◽  
A Lacey Samuels

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