Faculty Opinions recommendation of The rice dynamin-related protein DRP2B mediates membrane trafficking, and thereby plays a critical role in secondary cell wall cellulose biosynthesis.

Single fiber strengths and crystalline structures of greenhouse-grown Maxxa Acala cotton fibers at varying stages of development and at maturity are reported and compared with those of SJ-2 cotton fibers. Single fiber breaking forces of the Maxxa variety increase most significantly during the fourth week of fiber development; these increases correlate to the 60 to 90 mg seed fiber weight range. The forces required to break single fibers are similar for the SJ-2 and Maxxa varieties through the end of the fourth week of development. Beyond 30 dpa, both single fiber breaking forces and tenacities of the Maxxa cotton fibers are higher than those of the SJ-2 cotton fibers. Four waxd peaks located near 2θ angles of 14.7, 16.6, 22.7, and 34.4° are characteristic of the 101, 101, 002, and 040 reflections of cellulose I, respectively. The 002 peak intensity increases greatly during cellulose biosynthesis, indicating improved alignment of the glucosidic rings and improved order of atoms located within the glucosidic rings as the secondary cell wall thickens. The overall crystallinity and apparent crystallite sizes normal to the 101, 101, and 002 planes increase with fiber development for both varieties. Within each variety, the single fiber breaking forces are positively related to both the overall crystallinity and crystallite sizes. Between these two varieties, increasing breaking forces and tenacities appear to be related more to crystallite size than to crystallinity.

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

Functional Plant Biology ◽

10.1071/fp06234 ◽

2007 ◽

Vol 34 (1) ◽

pp. 1 ◽

Cited By ~ 66

Author(s):

Yong-Ling Ruan

Keyword(s):

Cell Wall ◽

Cell Biology ◽

Secondary Cell Wall ◽

Higher Plants ◽

Single Cells ◽

Critical Role ◽

Fibre Length ◽

Cotton Fibre ◽

Cellulose Synthesis ◽

Temporary Closure

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.

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PtrKOR1 is required for secondary cell wall cellulose biosynthesis in Populus

Tree Physiology ◽

10.1093/treephys/tpu020 ◽

2014 ◽

Vol 34 (11) ◽

pp. 1289-1300 ◽

Cited By ~ 20

Author(s):

L. Yu ◽

H. Chen ◽

J. Sun ◽

L. Li

Keyword(s):

Cell Wall ◽

Secondary Cell Wall ◽

Cellulose Biosynthesis

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Golgi-localized GALT7 and GALT8 participate in cellulose biosynthesis

10.1101/2021.04.21.440809 ◽

2021 ◽

Author(s):

Pieter Nibbering ◽

Romain Castilleux ◽

Gunnar Wingsle ◽

Totte Niittylä

Keyword(s):

Cell Wall ◽

Golgi Apparatus ◽

Secondary Cell Wall ◽

Plant Cell Wall ◽

Arabinogalactan Protein ◽

Primary Cell Wall ◽

Cellulose Content ◽

Cellulose Biosynthesis ◽

Cell Wall Assembly ◽

Protein Levels

AbstractArabinogalactan protein (AGP) glycan biosynthesis in the Golgi apparatus contributes to plant cell wall assembly, but the mechanisms underlying this process are largely unknown. Here, we show that two putative galactosyltransferases -named GALT7 and GALT8 -from the glycosyltransferase family 31 (GT31) of Arabidopsis thaliana participate in cellulose biosynthesis. galt7galt8 mutants show primary cell wall defects manifesting as impaired growth and cell expansion in seedlings and etiolated hypocotyls, along with secondary cell wall defects, apparent as collapsed xylem vessels and reduced xylem wall thickness in the inflorescence stem. These phenotypes were associated with a ∼30% reduction in cellulose content, a ∼50% reduction in secondary cell wall CELLULOSE SYNTHASE (CESA) protein levels and reduced cellulose biosynthesis rate. CESA transcript levels were not significantly altered in galt7galt8 mutants, suggesting that the reduction in CESA levels was caused by a post-transcriptional mechanism. We provide evidence that both GALT7 and GALT8 localise to the Golgi apparatus, while quantitative proteomics experiments revealed reduced levels of the entire FLA subgroup B in the galt7galt8 mutants. This leads us to hypothesize that a defect in FLA subgroup B glycan biosynthesis reduces cellulose biosynthesis rate in galt7galt8 mutants.

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