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Anders N, Wilson LFL, Sorieul M, Nikolovski N, Dupree P. β-1,4-Xylan backbone synthesis in higher plants: How complex can it be? FRONTIERS IN PLANT SCIENCE 2023; 13:1076298. [PMID: 36714768 PMCID: PMC9874913 DOI: 10.3389/fpls.2022.1076298] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/22/2022] [Indexed: 06/18/2023]
Abstract
Xylan is a hemicellulose present in the cell walls of all land plants. Glycosyltransferases of the GT43 (IRX9/IRX9L and IRX14/IRX14L) and GT47 (IRX10/IRX10L) families are involved in the biosynthesis of its β-1,4-linked xylose backbone, which can be further modified by acetylation and sugar side chains. However, it remains unclear how the different enzymes work together to synthesize the xylan backbone. A xylan synthesis complex (XSC) has been described in the monocots wheat and asparagus, and co-expression of asparagus AoIRX9, AoIRX10 and AoIRX14A is required to form a catalytically active complex for secondary cell wall xylan biosynthesis. Here, we argue that an equivalent XSC exists for the synthesis of the primary cell wall of the eudicot Arabidopsis thaliana, consisting of IRX9L, IRX10L and IRX14. This would suggest the existence of distinct XSCs for primary and secondary cell wall xylan synthesis, reminiscent of the distinct cellulose synthesis complexes (CSCs) of the primary and secondary cell wall. In contrast to the CSC, in which each CESA protein has catalytic activity, the XSC seems to contain proteins with non-catalytic function with each component bearing potentially unique but crucial roles. Moreover, the core XSC formed by a combination of IRX9/IRX9L, IRX10/IRX10L and IRX14/IRX14L might not be stable in its composition during transit from the endoplasmic reticulum to the Golgi apparatus. Instead, potential dynamic changes of the XSC might be a means of regulating xylan biosynthesis to facilitate coordinated deposition of tailored polysaccharides in the plant cell wall.
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Narciso JO, Zeng W, Ford K, Lampugnani ER, Humphries J, Austarheim I, van de Meene A, Bacic A, Doblin MS. Biochemical and Functional Characterization of GALT8, an Arabidopsis GT31 β-(1,3)-Galactosyltransferase That Influences Seedling Development. FRONTIERS IN PLANT SCIENCE 2021; 12:678564. [PMID: 34113372 PMCID: PMC8186459 DOI: 10.3389/fpls.2021.678564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/21/2021] [Indexed: 05/31/2023]
Abstract
Arabinogalactan-proteins (AGPs) are members of the hydroxyproline-rich glycoprotein (HRGP) superfamily, a group of highly diverse proteoglycans that are present in the cell wall, plasma membrane as well as secretions of almost all plants, with important roles in many developmental processes. The role of GALT8 (At1g22015), a Glycosyltransferase-31 (GT31) family member of the Carbohydrate-Active Enzyme database (CAZy), was examined by biochemical characterization and phenotypic analysis of a galt8 mutant line. To characterize its catalytic function, GALT8 was heterologously expressed in tobacco leaves and its enzymatic activity tested. GALT8 was shown to be a β-(1,3)-galactosyltransferase (GalT) that catalyzes the synthesis of a β-(1,3)-galactan, similar to the in vitro activity of KNS4/UPEX1 (At1g33430), a homologous GT31 member previously shown to have this activity. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmed the products were of 2-6 degree of polymerisation (DP). Previous reporter studies showed that GALT8 is expressed in the central and synergid cells, from whence the micropylar endosperm originates after the fertilization of the central cell of the ovule. Homozygous mutants have multiple seedling phenotypes including significantly shorter hypocotyls and smaller leaf area compared to wild type (WT) that are attributable to defects in female gametophyte and/or endosperm development. KNS4/UPEX1 was shown to partially complement the galt8 mutant phenotypes in genetic complementation assays suggesting a similar but not identical role compared to GALT8 in β-(1,3)-galactan biosynthesis. Taken together, these data add further evidence of the important roles GT31 β-(1,3)-GalTs play in elaborating type II AGs that decorate AGPs and pectins, thereby imparting functional consequences on plant growth and development.
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Affiliation(s)
- Joan Oñate Narciso
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Wei Zeng
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Sino-Australia Plant Cell Wall Research Centre, State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou, China
| | - Kris Ford
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Edwin R. Lampugnani
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - John Humphries
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Ingvild Austarheim
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Allison van de Meene
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Antony Bacic
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Sino-Australia Plant Cell Wall Research Centre, State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou, China
| | - Monika S. Doblin
- ARC Centre of Excellence on Plant Cell Walls, School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Sino-Australia Plant Cell Wall Research Centre, State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou, China
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Zhang W, Qin W, Li H, Wu AM. Biosynthesis and Transport of Nucleotide Sugars for Plant Hemicellulose. FRONTIERS IN PLANT SCIENCE 2021; 12:723128. [PMID: 34868108 PMCID: PMC8636097 DOI: 10.3389/fpls.2021.723128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 10/22/2021] [Indexed: 05/13/2023]
Abstract
Hemicellulose is entangled with cellulose through hydrogen bonds and meanwhile acts as a bridge for the deposition of lignin monomer in the secondary wall. Therefore, hemicellulose plays a vital role in the utilization of cell wall biomass. Many advances in hemicellulose research have recently been made, and a large number of genes and their functions have been identified and verified. However, due to the diversity and complexity of hemicellulose, the biosynthesis and regulatory mechanisms are yet unknown. In this review, we summarized the types of plant hemicellulose, hemicellulose-specific nucleotide sugar substrates, key transporters, and biosynthesis pathways. This review will contribute to a better understanding of substrate-level regulation of hemicellulose synthesis.
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Affiliation(s)
- Wenjuan Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
| | - Wenqi Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
| | - Huiling Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
| | - Ai-min Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architectures, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory of Lingnan Modern Agriculture, Guangzhou, China
- *Correspondence: Ai-min Wu,
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Li YL, Zhang YF, Li DD, Shi QS, Lou Y, Yang ZN, Zhu J. Acyl-CoA synthetases from Physcomitrella, rice and Arabidopsis: different substrate preferences but common regulation by MS188 in sporopollenin synthesis. PLANTA 2019; 250:535-548. [PMID: 31111205 DOI: 10.1007/s00425-019-03189-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/14/2019] [Indexed: 05/28/2023]
Abstract
ACOS5, OsACOS12 and PpACOS6 are all capable of fatty acyl-CoA synthetase activity but exhibit different substrate preferences. The transcriptional regulation of ACOS for sporopollenin synthesis appears to have been conserved in Physcomitrella, rice and Arabidopsis during evolution. Sporopollenin is the major constituent of spore and pollen exines. In Arabidopsis, acyl-CoA synthetase 5 (ACOS5) is an essential enzyme for sporopollenin synthesis, and its orthologues are PpACOS6 from the moss Physcomitrella and OsACOS12 from monocot rice. However, knowledge regarding the evolutionary conservation and divergence of the ACOS gene in sporopollenin synthesis remains limited. In this study, we analysed the function and regulation of PpACOS6 and OsACOS12. A complementation test showed that OsACOS12 driven by the ACOS5 promoter could partially restore the male fertility of the acos5 mutant in Arabidopsis, while PpACOS6 did not rescue the acos5 phenotype. ACOS5, PpACOS6 and OsACOS12 all complemented the acyl-CoA synthetase-deficient yeast strain (YB525) phenotype, although they exhibited different substrate preferences. To understand the conservation of sporopollenin synthesis regulation, we constructed two constructs with ACOS5 driven by the OsACOS12 or PpACOS6 promoter. Both constructs could restore the fertility of acos5 plants. The MYB transcription factor MS188 from Arabidopsis directly regulates ACOS5. We found that MS188 could also bind the promoters of OsACOS12 and PpACOS6 and activate the genes driven by the promoters, suggesting that the transcriptional regulation of these genes was similar to that of ACOS5. These results show that the ACOS gene promoter region from Physcomitrella, rice and Arabidopsis has been functionally conserved during evolution, while the chain lengths of fatty acid-derived monomers of sporopollenin vary in different plant species.
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Affiliation(s)
- Yue-Ling Li
- Zhejiang Provincial Key Laboratory of Plant Evolutionary and Conservation, Taizhou University, Taizhou, 318000, China
- Institute of Ecology, Taizhou University, Taizhou, 318000, China
| | - Yan-Fei Zhang
- Shanghai Key Laboratory of Plant Molecule Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Dan-Dan Li
- Shanghai Key Laboratory of Plant Molecule Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Qiang-Sheng Shi
- Shanghai Key Laboratory of Plant Molecule Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Yue Lou
- Shanghai Key Laboratory of Plant Molecule Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Zhong-Nan Yang
- Shanghai Key Laboratory of Plant Molecule Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Jun Zhu
- Shanghai Key Laboratory of Plant Molecule Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China.
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Haghighat M, Teng Q, Zhong R, Ye ZH. Evolutionary Conservation of Xylan Biosynthetic Genes in Selaginella moellendorffii and Physcomitrella patens. PLANT & CELL PHYSIOLOGY 2016; 57:1707-19. [PMID: 27345025 DOI: 10.1093/pcp/pcw096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 05/01/2016] [Indexed: 05/10/2023]
Abstract
Xylan is a major cross-linking hemicellulose in secondary walls of vascular tissues, and the recruitment of xylan as a secondary wall component was suggested to be a pivotal event for the evolution of vascular tissues. To decipher the evolution of xylan structure and xylan biosynthetic genes, we analyzed xylan substitution patterns and characterized genes mediating methylation of glucuronic acid (GlcA) side chains in xylan of the model seedless vascular plant, Selaginella moellendorffii, and investigated GT43 genes from S. moellendorffii and the model non-vascular plant, Physcomitrella patens, for their roles in xylan biosynthesis. Using nuclear magentic resonance spectroscopy, we have demonstrated that S. moellendorffii xylan consists of β-1,4-linked xylosyl residues subsituted solely with methylated GlcA residues and that xylans from both S. moellendorffii and P. patens are acetylated at O-2 and O-3. To investigate genes responsible for GlcA methylation of xylan, we identified two DUF579 genes in the S. moellendorffii genome and showed that one of them, SmGXM, encodes a glucuronoxylan methyltransferase capable of adding the methyl group onto the GlcA side chain of xylooligomers. Furthermore, we revealed that the two GT43 genes in S. moellendorffii, SmGT43A and SmGT43B, are functional orthologs of the Arabidopsis xylan backbone biosynthetic genes IRX9 and IRX14, respectively, indicating the evolutionary conservation of the involvement of two functionally non-redundant groups of GT43 genes in xylan backbone biosynthesis between seedless and seed vascular plants. Among the five GT43 genes in P. patens, PpGT43A was found to be a functional ortholog of Arabidopsis IRX9, suggesting that the recruitment of GT43 genes in xylan backbone biosynthesis occurred when non-vascular plants appeared on land.
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Affiliation(s)
- Marziyeh Haghighat
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Quincy Teng
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, USA
| | - Ruiqin Zhong
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Zheng-Hua Ye
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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Zeng W, Lampugnani ER, Picard KL, Song L, Wu AM, Farion IM, Zhao J, Ford K, Doblin MS, Bacic A. Asparagus IRX9, IRX10, and IRX14A Are Components of an Active Xylan Backbone Synthase Complex that Forms in the Golgi Apparatus. PLANT PHYSIOLOGY 2016; 171:93-109. [PMID: 26951434 PMCID: PMC4854693 DOI: 10.1104/pp.15.01919] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/01/2016] [Indexed: 05/17/2023]
Abstract
Heteroxylans are abundant components of plant cell walls and provide important raw materials for the food, pharmaceutical, and biofuel industries. A number of studies in Arabidopsis (Arabidopsis thaliana) have suggested that the IRREGULAR XYLEM9 (IRX9), IRX10, and IRX14 proteins, as well as their homologs, are involved in xylan synthesis via a Golgi-localized complex termed the xylan synthase complex (XSC). However, both the biochemical and cell biological research lags the genetic and molecular evidence. In this study, we characterized garden asparagus (Asparagus officinalis) stem xylan biosynthesis genes (AoIRX9, AoIRX9L, AoIRX10, AoIRX14A, and AoIRX14B) by heterologous expression in Nicotiana benthamiana We reconstituted and partially purified an active XSC and showed that three proteins, AoIRX9, AoIRX10, and AoIRX14A, are necessary for xylan xylosyltranferase activity in planta. To better understand the XSC structure and its composition, we carried out coimmunoprecipitation and bimolecular fluorescence complementation analysis to show the molecular interactions between these three IRX proteins. Using a site-directed mutagenesis approach, we showed that the DxD motifs of AoIRX10 and AoIRX14A are crucial for the catalytic activity. These data provide, to our knowledge, the first lines of biochemical and cell biological evidence that AoIRX9, AoIRX10, and AoIRX14A are core components of a Golgi-localized XSC, each with distinct roles for effective heteroxylan biosynthesis.
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Affiliation(s)
- Wei Zeng
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Edwin R Lampugnani
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Kelsey L Picard
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Lili Song
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Ai-Min Wu
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Isabela M Farion
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Jia Zhao
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Kris Ford
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Monika S Doblin
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
| | - Antony Bacic
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (W.Z., E.R.L., K.L.P., I.M.F., J.Z., K.F., M.S.D., A.B.);Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou 311300, China (L.S.); andState Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China (A.-M.W.)
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Berry EA, Tran ML, Dimos CS, Budziszek MJ, Scavuzzo-Duggan TR, Roberts AW. Immuno and Affinity Cytochemical Analysis of Cell Wall Composition in the Moss Physcomitrella patens. FRONTIERS IN PLANT SCIENCE 2016; 7:248. [PMID: 27014284 PMCID: PMC4781868 DOI: 10.3389/fpls.2016.00248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/15/2016] [Indexed: 05/11/2023]
Abstract
In contrast to homeohydric vascular plants, mosses employ a poikilohydric strategy for surviving in the dry aerial environment. A detailed understanding of the structure, composition, and development of moss cell walls can contribute to our understanding of not only the evolution of overall cell wall complexity, but also the differences that have evolved in response to selection for different survival strategies. The model moss species Physcomitrella patens has a predominantly haploid lifecycle consisting of protonemal filaments that regenerate from protoplasts and enlarge by tip growth, and leafy gametophores composed of cells that enlarge by diffuse growth and differentiate into several different types. Advantages for genetic studies include methods for efficient targeted gene modification and extensive genomic resources. Immuno and affinity cytochemical labeling were used to examine the distribution of polysaccharides and proteins in regenerated protoplasts, protonemal filaments, rhizoids, and sectioned gametophores of P. patens. The cell wall composition of regenerated protoplasts was also characterized by flow cytometry. Crystalline cellulose was abundant in the cell walls of regenerating protoplasts and protonemal cells that developed on media of high osmolarity, whereas homogalactuonan was detected in the walls of protonemal cells that developed on low osmolarity media and not in regenerating protoplasts. Mannan was the major hemicellulose detected in all tissues tested. Arabinogalactan proteins were detected in different cell types by different probes, consistent with structural heterogneity. The results reveal developmental and cell type specific differences in cell wall composition and provide a basis for analyzing cell wall phenotypes in knockout mutants.
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Affiliation(s)
| | | | | | | | | | - Alison W. Roberts
- Department of Biological Sciences, University of Rhode IslandKingston, RI, USA
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Song L, Zeng W, Wu A, Picard K, Lampugnani ER, Cheetamun R, Beahan C, Cassin A, Lonsdale A, Doblin MS, Bacic A. Asparagus Spears as a Model to Study Heteroxylan Biosynthesis during Secondary Wall Development. PLoS One 2015; 10:e0123878. [PMID: 25894575 PMCID: PMC4404143 DOI: 10.1371/journal.pone.0123878] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 02/23/2015] [Indexed: 11/18/2022] Open
Abstract
Garden asparagus (Asparagus officinalis L.) is a commercially important crop species utilized for its excellent source of vitamins, minerals and dietary fiber. However, after harvest the tissue hardens and its quality rapidly deteriorates because spear cell walls become rigidified due to lignification and substantial increases in heteroxylan content. This latter observation prompted us to investigate the in vitro xylan xylosyltransferase (XylT) activity in asparagus. The current model system for studying heteroxylan biosynthesis, Arabidopsis, whilst a powerful genetic system, displays relatively low xylan XylT activity in in vitro microsomal preparations compared with garden asparagus therefore hampering our ability to study the molecular mechanism(s) of heteroxylan assembly. Here, we analyzed physiological and biochemical changes of garden asparagus spears stored at 4 °C after harvest and detected a high level of xylan XylT activity that accounts for this increased heteroxylan. The xylan XylT catalytic activity is at least thirteen-fold higher than that reported for previously published species, including Arabidopsis and grasses. A biochemical assay was optimized and up to seven successive Xyl residues were incorporated to extend the xylotetraose (Xyl4) acceptor backbone. To further elucidate the xylan biosynthesis mechanism, we used RNA-seq to generate an Asparagus reference transcriptome and identified five putative xylan biosynthetic genes (AoIRX9, AoIRX9-L, AoIRX10, AoIRX14_A, AoIRX14_B) with AoIRX9 having an expression profile that is distinct from the other genes. We propose that Asparagus provides an ideal biochemical system to investigate the biochemical aspects of heteroxylan biosynthesis and also offers the additional benefit of being able to study the lignification process during plant stem maturation.
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Affiliation(s)
- Lili Song
- Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Lin’an, Hangzhou, 311300, P. R. China
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Wei Zeng
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Aimin Wu
- College of Forestry, South China Agricultural University, Guangzhou, 510642, China
| | - Kelsey Picard
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Edwin R. Lampugnani
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Roshan Cheetamun
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Cherie Beahan
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Andrew Cassin
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Andrew Lonsdale
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Monika S. Doblin
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, the University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, the University of Melbourne, Parkville, VIC 3010, Australia
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9
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Jensen JK, Johnson NR, Wilkerson CG. Arabidopsis thaliana IRX10 and two related proteins from psyllium and Physcomitrella patens are xylan xylosyltransferases. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:207-15. [PMID: 25139408 DOI: 10.1111/tpj.12641] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/16/2014] [Accepted: 08/11/2014] [Indexed: 05/17/2023]
Abstract
The enzymatic mechanism that governs the synthesis of the xylan backbone polymer, a linear chain of xylose residues connected by β-1,4 glycosidic linkages, has remained elusive. Xylan is a major constituent of many kinds of plant cell walls, and genetic studies have identified multiple genes that affect xylan formation. In this study, we investigate several homologs of one of these previously identified xylan-related genes, IRX10 from Arabidopsis thaliana, by heterologous expression and in vitro xylan xylosyltransferase assay. We find that an IRX10 homolog from the moss Physcomitrella patens displays robust activity, and we show that the xylosidic linkage formed is a β-1,4 linkage, establishing this protein as a xylan β-1,4-xylosyltransferase. We also find lower but reproducible xylan xylosyltransferase activity with A. thaliana IRX10 and with a homolog from the dicot plant Plantago ovata, showing that xylan xylosyltransferase activity is conserved over large evolutionary distance for these proteins.
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Affiliation(s)
- Jacob Krüger Jensen
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA; DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA
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10
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Grienenberger E, Douglas CJ. Arabidopsis VASCULAR-RELATED UNKNOWN PROTEIN1 regulates xylem development and growth by a conserved mechanism that modulates hormone signaling. PLANT PHYSIOLOGY 2014; 164:1991-2010. [PMID: 24567189 PMCID: PMC3982757 DOI: 10.1104/pp.114.236406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 02/22/2014] [Indexed: 05/17/2023]
Abstract
Despite a strict conservation of the vascular tissues in vascular plants (tracheophytes), our understanding of the genetic basis underlying the differentiation of secondary cell wall-containing cells in the xylem of tracheophytes is still far from complete. Using coexpression analysis and phylogenetic conservation across sequenced tracheophyte genomes, we identified a number of Arabidopsis (Arabidopsis thaliana) genes of unknown function whose expression is correlated with secondary cell wall deposition. Among these, the Arabidopsis VASCULAR-RELATED UNKNOWN PROTEIN1 (VUP1) gene encodes a predicted protein of 24 kD with no annotated functional domains but containing domains that are highly conserved in tracheophytes. Here, we show that the VUP1 expression pattern, determined by promoter-β-glucuronidase reporter gene expression, is associated with vascular tissues, while vup1 loss-of-function mutants exhibit collapsed morphology of xylem vessel cells. Constitutive overexpression of VUP1 caused dramatic and pleiotropic developmental defects, including severe dwarfism, dark green leaves, reduced apical dominance, and altered photomorphogenesis, resembling brassinosteroid-deficient mutants. Constitutive overexpression of VUP homologs from multiple tracheophyte species induced similar defects. Whole-genome transcriptome analysis revealed that overexpression of VUP1 represses the expression of many brassinosteroid- and auxin-responsive genes. Additionally, deletion constructs and site-directed mutagenesis were used to identify critical domains and amino acids required for VUP1 function. Altogether, our data suggest a conserved role for VUP1 in regulating secondary wall formation during vascular development by tissue- or cell-specific modulation of hormone signaling pathways.
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11
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Xu B, Ohtani M, Yamaguchi M, Toyooka K, Wakazaki M, Sato M, Kubo M, Nakano Y, Sano R, Hiwatashi Y, Murata T, Kurata T, Yoneda A, Kato K, Hasebe M, Demura T. Contribution of NAC transcription factors to plant adaptation to land. Science 2014; 343:1505-8. [PMID: 24652936 DOI: 10.1126/science.1248417] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The development of cells specialized for water conduction or support is a striking innovation of plants that has enabled them to colonize land. The NAC transcription factors regulate the differentiation of these cells in vascular plants. However, the path by which plants with these cells have evolved from their nonvascular ancestors is unclear. We investigated genes of the moss Physcomitrella patens that encode NAC proteins. Loss-of-function mutants formed abnormal water-conducting and supporting cells, as well as malformed sporophyte cells, and overexpression induced ectopic differentiation of water-conducting-like cells. Our results show conservation of transcriptional regulation and cellular function between moss and Arabidopsis thaliana water-conducting cells. The conserved genetic basis suggests roles for NAC proteins in the adaptation of plants to land.
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Affiliation(s)
- Bo Xu
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
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12
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Hao Z, Mohnen D. A review of xylan and lignin biosynthesis: Foundation for studying Arabidopsisirregular xylemmutants with pleiotropic phenotypes. Crit Rev Biochem Mol Biol 2014; 49:212-41. [DOI: 10.3109/10409238.2014.889651] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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13
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Pauly M, Gille S, Liu L, Mansoori N, de Souza A, Schultink A, Xiong G. Hemicellulose biosynthesis. PLANTA 2013; 238:627-42. [PMID: 23801299 DOI: 10.1007/s00425-013-1921-1] [Citation(s) in RCA: 207] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/14/2013] [Indexed: 05/17/2023]
Abstract
One major component of plant cell walls is a diverse group of polysaccharides, the hemicelluloses. Hemicelluloses constitute roughly one-third of the wall biomass and encompass the heteromannans, xyloglucan, heteroxylans, and mixed-linkage glucan. The fine structure of these polysaccharides, particularly their substitution, varies depending on the plant species and tissue type. The hemicelluloses are used in numerous industrial applications such as food additives as well as in medicinal applications. Their abundance in lignocellulosic feedstocks should not be overlooked, if the utilization of this renewable resource for fuels and other commodity chemicals becomes a reality. Fortunately, our understanding of the biosynthesis of the various hemicelluloses in the plant has increased enormously in recent years mainly through genetic approaches. Taking advantage of this knowledge has led to plant mutants with altered hemicellulosic structures demonstrating the importance of the hemicelluloses in plant growth and development. However, while we are on a solid trajectory in identifying all necessary genes/proteins involved in hemicellulose biosynthesis, future research is required to combine these single components and assemble them to gain a holistic mechanistic understanding of the biosynthesis of this important class of plant cell wall polysaccharides.
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Affiliation(s)
- Markus Pauly
- Energy Biosciences Institute, University of California, Berkeley, CA, 94720, USA,
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14
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Leroux O, Eeckhout S, Viane RLL, Popper ZA. Ceratopteris richardii (C-fern): a model for investigating adaptive modification of vascular plant cell walls. FRONTIERS IN PLANT SCIENCE 2013; 4:367. [PMID: 24065974 PMCID: PMC3779834 DOI: 10.3389/fpls.2013.00367] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 08/29/2013] [Indexed: 05/22/2023]
Abstract
Plant cell walls are essential for most aspects of plant growth, development, and survival, including cell division, expansive cell growth, cell-cell communication, biomechanical properties, and stress responses. Therefore, characterizing cell wall diversity contributes to our overall understanding of plant evolution and development. Recent biochemical analyses, concomitantly with whole genome sequencing of plants located at pivotal points in plant phylogeny, have helped distinguish between homologous characters and those which might be more derived. Most plant lineages now have at least one fully sequenced representative and although genome sequences for fern species are in progress they are not yet available for this group. Ferns offer key advantages for the study of developmental processes leading to vascularisation and complex organs as well as the specific differences between diploid sporophyte tissues and haploid gametophyte tissues and the interplay between them. Ceratopteris richardii has been well investigated building a body of knowledge which combined with the genomic and biochemical information available for other plants will progress our understanding of wall diversity and its impact on evolution and development.
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Affiliation(s)
- Olivier Leroux
- Botany and Plant Science and The Ryan Institute for Environmental, Marine and Energy Research, School of Natural Sciences, National University of IrelandGalway, Ireland
- Department of Biology, Research Group Pteridology, Ghent UniversityGhent, Belgium
| | - Sharon Eeckhout
- Department of Biology, Research Group Pteridology, Ghent UniversityGhent, Belgium
| | - Ronald L. L. Viane
- Department of Biology, Research Group Pteridology, Ghent UniversityGhent, Belgium
| | - Zoë A. Popper
- Botany and Plant Science and The Ryan Institute for Environmental, Marine and Energy Research, School of Natural Sciences, National University of IrelandGalway, Ireland
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