scholarly journals The rice BZ1 locus is required for glycosylation of arabinogalactan proteins and galactolipid and plays a role in both mechanical strength and leaf color

2020 ◽  
Author(s):  
Sitong Liu ◽  
Yijun Tang ◽  
Nan Ruan ◽  
Zhengjun Dang ◽  
Yuwei Huang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mechanical Strength ◽  
Agronomic Traits ◽  
Functional Characterization ◽  
Arabinogalactan Proteins ◽  
Lipid Profiling ◽  
Chloroplast Membrane ◽  
Rice Mutant ◽  
Altered Cell ◽  
Sugar Chains

Abstract Background: The cell wall and chloroplast are two fundamental structures determining plant mechanical strength and grain yield. Therefore, understanding mechanisms that improve plants’ ability to develop a robust cell wall and well-developed chloroplast is of utmost importance for agricultural activities. Results: In this study, we report the functional characterization of a novel rice mutant, brittle stem and zebra leaf (bz1), which displays altered cell wall composition and collapsed chloroplast membrane. Molecular and biochemical analysis revealed that BZ1 encodes a functional UDP-galactose/glucose epimerase (UGE) and is ubiquitously expressed with higher expression in stem and leaf tissues. Multiple techniques analyses, including immunoblots, immuno-gold, and cryogenic scanning electron microscopy, demonstrated a significantly impaired glycosylation of arabinogalactan proteins (AGPs) and disordered cellulose microfibril deposition in bz1. Lipid profiling assay showed that the amount of monogalactosyldiacylglycerols (MGDG), a major chloroplast membrane glycolipid, was significantly decreased in bz1. Taken together, these results strongly demonstrate that BZ1 participates in UDP-galactose supply for the sugar chains biosynthesis of AGPs and MGDG, which thereby, respectively, results in altered cell wall and abnormal chloroplast development. Due to inferior mechanical strength and reduced photosynthesis, bz1 plants displayed detrimental agronomic traits, whereas BZ1 overexpressing lines showed enhanced plant growth. Transcriptome analysis of stems and leaves further showed that numerous key genes involved in AGPs biosynthesis and photosynthesis metabolism were substantially suppressed in bz1.Conclusions: Our finding identifies BZ1 as a dual-targeting UGE protein for glycosylation of AGPs and MGDG and suggests a strategy for breeding robust elite crops.

scholarly journals The rice BZ1 locus is required for glycosylation of arabinogalactan proteins and galactolipid and plays a role in both mechanical strength and leaf color

2020 ◽  
Author(s):  
Sitong Liu ◽  
Yijun Tang ◽  
Nan Ruan ◽  
Zhengjun Dang ◽  
Yuwei Huang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mechanical Strength ◽  
Agronomic Traits ◽  
Functional Characterization ◽  
Arabinogalactan Proteins ◽  
Lipid Profiling ◽  
Chloroplast Membrane ◽  
Rice Mutant ◽  
Altered Cell ◽  
Cryogenic Scanning Electron Microscopy

Abstract Background: The cell wall and chloroplast are two fundamental structures determining plant mechanical strength and grain yield. Therefore, understanding mechanisms that improve plants’ ability to develop a robust cell wall and well-developed chloroplast is of upmost importance for agricultural activities. Results: In this study, we report the functional characterization of a novel rice mutant, brittle stem and zebra leaf ( bz1 ), which displays altered cell wall composition and collapsed chloroplast membrane. Molecular and biochemical analysis revealed that BZ1 encodes a functional UDP-galactose/glucose epimerase (UGE) and is ubiquitously expressed with higher expression in stem and leaf tissues. Multiple techniques analyses, including immunoblots, immuno-gold, and cryogenic scanning electron microscopy, demonstrated a significantly impaired glycosylation of arabinogalactan proteins (AGPs) and disordered cellulose microfibril deposition in bz1 . Lipid profiling assay showed that the amount of monogalactosyldiacylglycerols (MDGD), a major chloroplast membrane glycolipid, was significantly decreased in bz1 . Taken together, these results strongly demonstrate that BZ1 participates in UDP-galactose supply for the sidechain biosynthesis of AGPs and MDGD, which thereby, respectively, results in altered cell wall and abnormal chloroplast development. Due to inferior mechanical strength and reduced photosynthesis, bz1 plants displayed detrimental agronomic traits, whereas BZ1 overexpressing lines showed enhanced plant growth. Transcriptome analysis of stems and leaves further showed that numerous key genes involved in AGPs biosynthesis and photosynthesis metabolism were substantially suppressed in bz1 . Conclusions: Our finding identifies BZ1 as a dual-targeting UGE protein for glycosylation of AGPs and MDGD and suggests a strategy for breeding robust elite crops.

scholarly journals Functional Characterization of Hydroxyproline-O-Galactosyltransferases For Arabidopsis Arabinogalactan-Proteins synthesis

2021 ◽  
Author(s):  
Dasmeet Kaur ◽  
Michael A. Held ◽  
Mountain R. Smith ◽  
Allan M. Showalter
Keyword(s):  
Cell Wall ◽  
Seed Set ◽  
Pollen Viability ◽  
Expression Patterns ◽  
Functional Characterization ◽  
Primary Root ◽  
Arabinogalactan Proteins ◽  
Root Tip ◽  
Composition Analysis ◽  
Genetic Redundancy

Abstract Background: Arabinogalactan-proteins (AGPs) are structurally complex hydroxyproline-rich cell wall glycoproteins ubiquitous in the plant kingdom. AGPs biosynthesis involves a series of post-translational modifications including the addition of type II arabinogalactans to non-contiguous Hyp residues. To date, eight Hyp-galactosyltransferases (Hyp-GALTs; GALT2-GALT9) belonging to CAZy GT31, are known to catalyze the addition of the first galactose residues to AGP protein backbones and enable subsequent AGP glycosylation. The extent of genetic redundancy, however, remains to be elucidated for the Hyp-GALT gene family. Results: To examine their gene redundancy and functions, we generated various multiple gene knock-outs, including a triple mutant (galt5galt8galt9), two quadruple mutants (galt2galt5galt7galt8, galt2galt5galt7galt9), and one quintuple mutant (galt2galt5galt7galt8galt9), and comprehensively examined their biochemical and physiological phenotypes. The key findings include: AGP precipitations with β-Yariv reagent showed that GALT2, GALT5, GALT7, GALT8 and GALT9 act redundantly with respect to AGP glycosylation in cauline and rosette leaves, while the activity of GALT7, GALT8 and GALT9 dominate in the stem, silique and flowers. Monosaccharide composition analysis showed that galactose was decreased in the silique and root AGPs of the Hyp-GALT mutants. The AGP profile of 25789 quintuple mutant stems indicated changes in AGP profiles compared to WT. Additionally, TEM analysis of 25789 quintuple mutant stems indicated cell wall defects coincident with the observed developmental and growth impairment in these Hyp-GALT mutants. Correlated with expression patterns, GALT2, GALT5, GALT7, GALT8, and GALT9 display equal additive effects on insensitivity to β-Yariv-induced growth inhibition, silique length, plant height, and pollen viability. Interestingly, GALT7, GALT8, and GALT9 contributed more to primary root growth and root tip swelling under salt stress, whereas GALT2 and GALT5 played more important roles in seed morphology, germination defects and seed set. Pollen defects likely contributed to the reduced seed set in these mutants. Conclusion: Additive and pleiotropic effects of GALT2, GALT5, GALT7, GALT8 and GALT9 on vegetative and reproductive growth phenotypes were teased apart via generation of different combinations of Hyp-GALT knock-out mutants. Taken together, the generation of higher order Hyp-GALT mutants demonstrate the functional importance of AG polysaccharides decorating the AGPs with respect to various aspects of plant growth and development.

CO2 enrichment leads to altered cell wall composition in plants of Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae)

2021 ◽  
Author(s):  
Eliza Louback ◽  
Diego Silva Batista ◽  
Tiago Augusto Rodrigues Pereira ◽  
Talita Cristina Mamedes-Rodrigues ◽  
Tatiane Dulcineia Silva ◽  
...  
Keyword(s):  
Cell Wall ◽  
Co2 Enrichment ◽  
Cell Wall Composition ◽  
Pfaffia Glomerata ◽  
Altered Cell

Variation in Biomass Yield, Cell Wall Components, and Agronomic Traits in a Broad Range of Diploid Alfalfa Accessions

Crop Science ◽  
2011 ◽  
Vol 51 (5) ◽  
pp. 1956-1964 ◽  
Author(s):  
Muhammet Sakiroglu ◽  
Kenneth J. Moore ◽  
E. Charles Brummer
Keyword(s):  
Cell Wall ◽  
Biomass Yield ◽  
Agronomic Traits ◽  
Cell Wall Components ◽  
Wall Components

scholarly journals In silico and functional characterization of the promoter of a Eucalyptussecondary cell wall associated cellulose synthase gene (EgCesA1)

2011 ◽  
Vol 5 (S7) ◽  
Author(s):  
Nicky Creux ◽  
Minique De Castro ◽  
Martin Ranik ◽  
Antanas Spokevicius ◽  
Gerd Bossinger ◽  
...  
Keyword(s):  
Cell Wall ◽  
In Silico ◽  
Functional Characterization ◽  
Cellulose Synthase ◽  
Cellulose Synthase Gene

scholarly journals Golgi-localized exo-β1,3-galactosidases involved in AGP modification and root cell expansion in Arabidopsis

2020 ◽  
Author(s):  
Pieter Nibbering ◽  
Bent L. Petersen ◽  
Mohammed Saddik Motawia ◽  
Bodil Jørgensen ◽  
Peter Ulvskov ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Expansion ◽  
Glycosyl Hydrolase ◽  
Functional Characterization ◽  
Gum Arabic ◽  
Root Cell ◽  
Growth Media ◽  
Galactosidase Activity ◽  
Loss Of Function ◽  
Yariv Phenylglycoside

AbstractPlant arabinogalactan proteins (AGPs) are a diverse group of cell surface- and wall-associated glycoproteins. Functionally important AGP glycans are synthesized in the Golgi apparatus, but the relationships between their glycosylation, processing, and functionality are poorly understood. Here we report the identification and functional characterization of two Golgi-localized exo-β-1,3-galactosidases from the glycosyl hydrolase 43 (GH43) family in Arabidopsis thaliana. GH43 loss of function mutants exhibit root cell expansion defects in sugar-containing growth media. This root phenotype is associated with an increase in the extent of AGP cell wall association, as demonstrated by Yariv phenylglycoside dye quantification and comprehensive microarray polymer profiling of sequentially extracted cell walls. Recombinant GH43 characterization showed that the exo-β-1,3-galactosidase activity of GH43s is hindered by β-1,6 branches on β-1,3-galactans. In line with this steric hindrance, the recombinant GH43s did not release galactose from cell wall extracted glycoproteins or AGP rich gum arabic. These results show that Arabidopsis GH43s are involved in AGP glycan biosynthesis in the Golgi, and suggest their exo-β-1,3-galactosidase activity influences AGP and cell wall matrix interactions, thereby adjusting cell wall extensibility.

scholarly journals Arabinogalactan Proteins in Plant Roots – An Update on Possible Functions

2021 ◽  
Vol 12 ◽  
Author(s):  
Dagmar Hromadová ◽  
Aleš Soukup ◽  
Edita Tylová
Keyword(s):  
Cell Wall ◽  
Regulatory Networks ◽  
Developmental Plasticity ◽  
Molecular Mechanisms ◽  
Arabinogalactan Proteins ◽  
Cellular Level ◽  
Environmental Response ◽  
Essential Components ◽  
Surface Signaling ◽  
Cell Surface Signaling

Responsiveness to environmental conditions and developmental plasticity of root systems are crucial determinants of plant fitness. These processes are interconnected at a cellular level with cell wall properties and cell surface signaling, which involve arabinogalactan proteins (AGPs) as essential components. AGPs are cell-wall localized glycoproteins, often GPI-anchored, which participate in root functions at many levels. They are involved in cell expansion and differentiation, regulation of root growth, interactions with other organisms, and environmental response. Due to the complexity of cell wall functional and regulatory networks, and despite the large amount of experimental data, the exact molecular mechanisms of AGP-action are still largely unknown. This dynamically evolving field of root biology is summarized in the present review.

scholarly journals Downregulation of p‐COUMAROYL ESTER3‐HYDROXYLASEin rice leads to altered cell wall structures and improves biomass saccharification

2018 ◽  
Vol 95 (5) ◽  
pp. 796-811 ◽  
Author(s):  
Yuri Takeda ◽  
Yuki Tobimatsu ◽  
Steven D. Karlen ◽  
Taichi Koshiba ◽  
Shiro Suzuki ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biomass Saccharification ◽  
Wall Structures ◽  
Altered Cell

scholarly journals Properties of Arabinogalactan Proteins (AGPs) in Apple (Malus × Domestica) Fruit at Different Stages of Ripening

Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 225
Author(s):  
Agata Leszczuk ◽  
Justyna Cybulska ◽  
Tomasz Skrzypek ◽  
Artur Zdunek
Keyword(s):  
Cell Wall ◽  
Malus Domestica ◽  
Arabinogalactan Proteins ◽  
Ex Situ ◽  
Morphological Properties ◽  
Mature Stage ◽  
Fruit Storage ◽  
Cell Wall Assembly ◽  
Wall Assembly

Arabinogalactan proteins (AGPs) are constituents of the cell wall–plasma membrane continuum in fruit tissue. The aim of the study was to characterise AGPs contained in fruit by determination of their chemical structure and morphological properties. The results were obtained from in and ex situ investigations and a comparative analysis of AGPs present in Malus × domestica fruit at different stages of ripening from green fruit through the mature stage to over-ripening during fruit storage. The HPLC and colorimetric methods were used for analyses of the composition of monosaccharides and proteins in AGPs extracted from fruit. We have found that AGPs from fruit mainly consists of carbohydrate chains composed predominantly of arabinose, galactose, glucose, galacturonic acid, and xylose. The protein moiety accounts for 3.15–4.58%, which depends on the various phases of ripening. Taken together, our results show that the structural and morphological properties of AGPs and calcium concentration in AGPs are related to the progress of ripening, which is correlated with proper fruit cell wall assembly. In line with the existing knowledge, our data confirmed the typical carbohydrate composition of AGPs and may be the basis for studies regarding their presumed properties of binding calcium ions.

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