Cellulose synthesis in the Arabidopsis secondary cell wall

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


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.


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

2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.


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