Genetic dissection of plant cell-wall biosynthesis

2002 ◽  
Vol 30 (2) ◽  
pp. 298-301 ◽  
Author(s):  
D. T. Bonetta ◽  
M. Facette ◽  
T. K. Raab ◽  
C. R. Somerville

The plant cell wall is a complex structure consisting of a variety of polymers including cellulose, xyloglucan, xylan and polygalacturonan. Biochemical and genetic analysis has made it possible to clone genes encoding cellulose synthases (CesA). A comparison of the predicted protein sequences in the Arabidopsis genome indicates that 30 divergent genes with similarity to CesAs exist. It is possible that these cellulose synthase-like (Csl) proteins do not contribute to cellulose synthesis, but rather to the synthesis of other wall polymers. A major challenge is, therefore, to assign biological function to these genes. In an effort to address this issue we have systematically identified T-DNA or transposon insertions in 17 Arabidopsis Csls. Phenotypic characterization of ‘knock-out’ mutants includes the determination of spectroscopic profile differences in mutant cell walls from wild-type plants by Fourier-transform IR microscopy. A more precise characterization includes cell wall fractionation followed by neutral sugar composition analysis by anionic exchange chromatography.

2020 ◽  
Author(s):  
Huimin Xu ◽  
Yuanyuan Zhao ◽  
Yuanzhen Suo ◽  
Yayu Guo ◽  
Yi Man ◽  
...  

Abstract Background: Cell wall imaging can considerably permit direct visualization of the molecular architecture of cell walls and provide the detailed chemical information on wall polymers, which is imperative to better exploit and use the biomass polymers; however, detailed imaging and quantifying of the native composition and architecture in the cell wall remains challenging.Results: Here, we describe a label-free imaging technology, coherent Raman scattering microscopy (CRS), including coherent anti-Stokes Raman scattering (CARS) microscopy and stimulated Raman scattering (SRS) microscopy, which images the major structures and chemical composition of plant cell walls. The major steps of the procedure are demonstrated, including sample preparation, setting the mapping parameters, analysis of spectral data, and image generation. Applying this rapid approach, which will help researchers understand the highly heterogeneous structures and organization of plant cell walls.Conclusions: This method can potentially be incorporated into label-free microanalyses of plant cell wall chemical composition based on the in situ vibrations of molecules.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4335
Author(s):  
Gerasimos Daras ◽  
Dimitris Templalexis ◽  
Fengoula Avgeri ◽  
Dikran Tsitsekian ◽  
Konstantina Karamanou ◽  
...  

The wall is the last frontier of a plant cell involved in modulating growth, development and defense against biotic stresses. Cellulose and additional polysaccharides of plant cell walls are the most abundant biopolymers on earth, having increased in economic value and thereby attracted significant interest in biotechnology. Cellulose biosynthesis constitutes a highly complicated process relying on the formation of cellulose synthase complexes. Cellulose synthase (CesA) and Cellulose synthase-like (Csl) genes encode enzymes that synthesize cellulose and most hemicellulosic polysaccharides. Arabidopsis and rice are invaluable genetic models and reliable representatives of land plants to comprehend cell wall synthesis. During the past two decades, enormous research progress has been made to understand the mechanisms of cellulose synthesis and construction of the plant cell wall. A plethora of cesa and csl mutants have been characterized, providing functional insights into individual protein isoforms. Recent structural studies have uncovered the mode of CesA assembly and the dynamics of cellulose production. Genetics and structural biology have generated new knowledge and have accelerated the pace of discovery in this field, ultimately opening perspectives towards cellulose synthesis manipulation. This review provides an overview of the major breakthroughs gathering previous and recent genetic and structural advancements, focusing on the function of CesA and Csl catalytic domain in plants.


Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Huimin Xu ◽  
Yuanyuan Zhao ◽  
Yuanzhen Suo ◽  
Yayu Guo ◽  
Yi Man ◽  
...  

Abstract Background New cell wall imaging tools permit direct visualization of the molecular architecture of cell walls and provide detailed chemical information on wall polymers, which will aid efforts to use these polymers in multiple applications; however, detailed imaging and quantification of the native composition and architecture in the cell wall remains challenging. Results Here, we describe a label-free imaging technology, coherent Raman scattering (CRS) microscopy, including coherent anti-Stokes Raman scattering (CARS) microscopy and stimulated Raman scattering (SRS) microscopy, which can be used to visualize the major structures and chemical composition of plant cell walls. We outline the major steps of the procedure, including sample preparation, setting the mapping parameters, analysis of spectral data, and image generation. Applying this rapid approach will help researchers understand the highly heterogeneous structures and organization of plant cell walls. Conclusions This method can potentially be incorporated into label-free microanalyses of plant cell wall chemical composition based on the in situ vibrations of molecules.


2003 ◽  
Vol 185 (5) ◽  
pp. 1518-1524 ◽  
Author(s):  
Koichiro Murashima ◽  
Akihiko Kosugi ◽  
Roy H. Doi

ABSTRACT Plant cell walls are comprised of cellulose and hemicellulose and other polymers that are intertwined, and this complex structure presents a barrier to degradation by pure cellulases or hemicellulases. In this study, we determined the synergistic effects on corn cell wall degradation by the action of cellulosomal xylanase XynA and cellulosomal cellulases from Clostridium cellulovorans. XynA minicellulosomes and cellulase minicellulosomes were found to degrade corn cell walls synergistically but not purified substrates such as xylan and crystalline cellulose. The mixture of XynA and cellulases at a molar ratio of 1:2 showed the highest synergistic effect of 1.6 on corn cell wall degradation. The amounts both of xylooligosaccharides and cellooligosaccharides liberated from corn cell walls were increased by the synergistic action of XynA and cellulases. Although synergistic effects on corn cell wall degradation were found in simultaneous reactions with XynA and cellulases, no synergistic effects were observed in sequential reactions. The possible mechanism of synergism between XynA and cellulases is discussed.


2020 ◽  
Vol 71 (16) ◽  
pp. 4797-4811 ◽  
Author(s):  
Bin Tu ◽  
Tao Zhang ◽  
Yuping Wang ◽  
Li Hu ◽  
Jin Li ◽  
...  

Abstract The rice (Oryza sativa) genome encodes 37 putative β-1,4-xylanase proteins, but none of them has been characterized at the genetic level. In this work, we report the isolation of slim stem (ss) mutants with pleiotropic defects, including dwarfism, leaf tip necrosis, and withered and rolled leaves under strong sunlight. Map-based cloning of the ss1 mutant identified the candidate gene as OsXyn1 (LOC_03g47010), which encodes a xylanase-like protein belonging to the glycoside hydrolase 10 (GH10) family. OsXyn1 was found to be widely expressed, especially in young tissues. Subcellular localization analysis showed that OsXyn1 encodes a membrane-associated protein. Physiological analysis of ss1 and the allelic ss2 mutant revealed that water uptake was partially compromised in these mutants. Consistently, the plant cell wall of the mutants exhibited middle lamella abnormalities or deficiencies. Immunogold assays revealed an unconfined distribution of xylan in the mutant cell walls, which may have contributed to a slower rate of plant cell wall biosynthesis and delayed plant growth. Additionally, water deficiency caused abscisic acid accumulation and triggered drought responses in the mutants. The findings that OsXyn1 is involved in plant cell wall deposition and the regulation of plant growth and development help to shed light on the functions of the rice GH10 family.


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