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Mikkelsen MD, Harholt J, Ulvskov P, Johansen IE, Fangel JU, Doblin MS, Bacic A, Willats WGT. Evidence for land plant cell wall biosynthetic mechanisms in charophyte green algae. ANNALS OF BOTANY 2014; 114:1217-36. [PMID: 25204387 PMCID: PMC4195564 DOI: 10.1093/aob/mcu171] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 07/08/2014] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND AIMS The charophyte green algae (CGA) are thought to be the closest living relatives to the land plants, and ancestral CGA were unique in giving rise to the land plant lineage. The cell wall has been suggested to be a defining structure that enabled the green algal ancestor to colonize land. These cell walls provide support and protection, are a source of signalling molecules, and provide developmental cues for cell differentiation and elongation. The cell wall of land plants is a highly complex fibre composite, characterized by cellulose cross-linked by non-cellulosic polysaccharides, such as xyloglucan, embedded in a matrix of pectic polysaccharides. How the land plant cell wall evolved is currently unknown: early-divergent chlorophyte and prasinophyte algae genomes contain a low number of glycosyl transferases (GTs), while land plants contain hundreds. The number of GTs in CGA is currently unknown, as no genomes are available, so this study sought to give insight into the evolution of the biosynthetic machinery of CGA through an analysis of available transcriptomes. METHODS Available CGA transcriptomes were mined for cell wall biosynthesis GTs and compared with GTs characterized in land plants. In addition, gene cloning was employed in two cases to answer important evolutionary questions. KEY RESULTS Genetic evidence was obtained indicating that many of the most important core cell wall polysaccharides have their evolutionary origins in the CGA, including cellulose, mannan, xyloglucan, xylan and pectin, as well as arabino-galactan protein. Moreover, two putative cellulose synthase-like D family genes (CSLDs) from the CGA species Coleochaete orbicularis and a fragment of a putative CSLA/K-like sequence from a CGA Spirogyra species were cloned, providing the first evidence that all the cellulose synthase/-like genes present in early-divergent land plants were already present in CGA. CONCLUSIONS The results provide new insights into the evolution of cell walls and support the notion that the CGA were pre-adapted to life on land by virtue of the their cell wall biosynthetic capacity. These findings are highly significant for understanding plant cell wall evolution as they imply that some features of land plant cell walls evolved prior to the transition to land, rather than having evolved as a result of selection pressures inherent in this transition.
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Affiliation(s)
- Maria D Mikkelsen
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Jesper Harholt
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Peter Ulvskov
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Ida E Johansen
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Jonatan U Fangel
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark
| | - Monika S Doblin
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - William G T Willats
- Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark
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102
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Li L, Huang J, Qin L, Huang Y, Zeng W, Rao Y, Li J, Li X, Xu W. Two cotton fiber-associated glycosyltransferases, GhGT43A1 and GhGT43C1, function in hemicellulose glucuronoxylan biosynthesis during plant development. PHYSIOLOGIA PLANTARUM 2014; 152:367-79. [PMID: 24641584 DOI: 10.1111/ppl.12190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 02/11/2014] [Accepted: 02/13/2014] [Indexed: 05/02/2023]
Abstract
Xylan is the major hemicellulosic constituent in dicot secondary cell walls. Cell wall composition of cotton fiber changes dynamically throughout development. Not only the amounts but also the molecular sizes of the hemicellulosic polysaccharides show substantial changes during cotton fiber development. However, none of the genes encoding glycosyltransferases (GTs) responsible for synthesizing xylan have been isolated and characterized in cotton fiber. In this study, we applied a bioinformatics approach and identified two putative GTs from cotton, designated GhGT43A1 and GhGT43C1, which belong to the CAZy GT43 family and are closely related to Arabidopsis IRX9 and IRX14, respectively. We show that GhGT43A1 is highly and preferentially expressed in 15 and 20 days post-anthesis (dpa) cotton fiber, whereas GhGT43C1 is ubiquitously expressed in most organs, with especially high expression in 15 dpa fiber and hypocotyl. Complementation analysis demonstrates that GhG43A1 and GhGT43C1 are orthologs of Arabidopsis IRX9 and IRX14, respectively. Furthermore, we show that overexpression of GhGT43A1 or GhGT43C1 in Arabidopsis results in increased xylan content. We also show that overexpression of GhGT43A1 or GhGT43C1 leads to more cellulose deposition. These findings suggest that GhGT43A1 and GhGT43C1 likely participate in xylan synthesis during fiber development.
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Affiliation(s)
- Long Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China
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103
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Ren Y, Hansen SF, Ebert B, Lau J, Scheller HV. Site-directed mutagenesis of IRX9, IRX9L and IRX14 proteins involved in xylan biosynthesis: glycosyltransferase activity is not required for IRX9 function in Arabidopsis. PLoS One 2014; 9:e105014. [PMID: 25118690 PMCID: PMC4132061 DOI: 10.1371/journal.pone.0105014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 07/16/2014] [Indexed: 12/04/2022] Open
Abstract
Xylans constitute the main non-cellulosic polysaccharide in the secondary cell walls of plants. Several genes predicted to encode glycosyltransferases are required for the synthesis of the xylan backbone even though it is a homopolymer consisting entirely of β-1,4-linked xylose residues. The putative glycosyltransferases IRX9, IRX14, and IRX10 (or the paralogs IRX9L, IRX14L, and IRX10L) are required for xylan backbone synthesis in Arabidopsis. To investigate the function of IRX9, IRX9L, and IRX14, we identified amino acid residues known to be essential for catalytic function in homologous mammalian proteins and generated modified cDNA clones encoding proteins where these residues would be mutated. The mutated gene constructs were used to transform wild-type Arabidopsis plants and the irx9 and irx14 mutants, which are deficient in xylan synthesis. The ability of the mutated proteins to complement the mutants was investigated by measuring growth, determining cell wall composition, and microscopic analysis of stem cross-sections of the transgenic plants. The six different mutated versions of IRX9 and IRX9-L were all able to complement the irx9 mutant phenotype, indicating that residues known to be essential for glycosyltransferases function in homologous proteins are not essential for the biological function of IRX9/IRX9L. Two out of three mutated IRX14 complemented the irx14 mutant, including a mutant in the predicted catalytic amino acid. A IRX14 protein mutated in the substrate-binding DxD motif did not complement the irx14 mutant. Thus, substrate binding is important for IRX14 function but catalytic activity may not be essential for the function of the protein. The data indicate that IRX9/IRX9L have an essential structural function, most likely by interacting with the IRX10/IRX10L proteins, but do not have an essential catalytic function. Most likely IRX14 also has primarily a structural role, but it cannot be excluded that the protein has an important enzymatic activity.
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Affiliation(s)
- Yanfang Ren
- Joint Bioenergy Institute, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- College of Agriculture, Guizhou University, Guiyang, China
| | - Sara Fasmer Hansen
- Joint Bioenergy Institute, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Berit Ebert
- Joint Bioenergy Institute, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Jane Lau
- Joint Bioenergy Institute, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Henrik Vibe Scheller
- Joint Bioenergy Institute, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- * E-mail:
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104
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Wan Y, Gritsch C, Tryfona T, Ray MJ, Andongabo A, Hassani-Pak K, Jones HD, Dupree P, Karp A, Shewry PR, Mitchell RAC. Secondary cell wall composition and candidate gene expression in developing willow (Salix purpurea) stems. PLANTA 2014; 239:1041-53. [PMID: 24504696 PMCID: PMC3997797 DOI: 10.1007/s00425-014-2034-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/21/2014] [Indexed: 05/17/2023]
Abstract
The properties of the secondary cell wall (SCW) in willow largely determine the suitability of willow biomass feedstock for potential bioenergy and biofuel applications. SCW development has been little studied in willow and it is not known how willow compares with model species, particularly the closely related genus Populus. To address this and relate SCW synthesis to candidate genes in willow, a tractable bud culture-derived system was developed in Salix purpurea, and cell wall composition and RNA-Seq transcriptome were followed in stems during early development. A large increase in SCW deposition in the period 0-2 weeks after transfer to soil was characterised by a big increase in xylan content, but no change in the frequency of substitution of xylan with glucuronic acid, and increased abundance of putative transcripts for synthesis of SCW cellulose, xylan and lignin. Histochemical staining and immunolabeling revealed that increased deposition of lignin and xylan was associated with xylem, xylem fibre cells and phloem fibre cells. Transcripts orthologous to those encoding xylan synthase components IRX9 and IRX10 and xylan glucuronyl transferase GUX1 in Arabidopsis were co-expressed, and showed the same spatial pattern of expression revealed by in situ hybridisation at four developmental stages, with abundant expression in proto-xylem, xylem fibre and ray parenchyma cells and some expression in phloem fibre cells. The results show a close similarity with SCW development in Populus species, but also give novel information on the relationship between spatial and temporal variation in xylan-related transcripts and xylan composition.
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Affiliation(s)
- Yongfang Wan
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ UK
| | | | - Theodora Tryfona
- Biochemistry Department, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW UK
| | - Mike J. Ray
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | | | | | - Huw D. Jones
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ UK
| | - Paul Dupree
- Biochemistry Department, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW UK
| | - Angela Karp
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ UK
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105
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Zhang B, Zhao T, Yu W, Kuang B, Yao Y, Liu T, Chen X, Zhang W, Wu AM. Functional conservation of the glycosyltransferase gene GT47A in the monocot rice. JOURNAL OF PLANT RESEARCH 2014; 127:423-32. [PMID: 24723033 DOI: 10.1007/s10265-014-0631-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 01/28/2014] [Indexed: 05/10/2023]
Abstract
Glucuronoarabinoxylan is the major hemicellulose in grass cell walls, yet the mechanism of xylan synthesis in monocot plants is still unclear. Unraveling the genes involved in the biosynthesis of xylan in rice will be very important for the utilization of rice straw as a source of bioenergy in the future. In this report, we investigated the functional role of a rice gene homologous to Arabidopsis IRREGULAR XYLEM10 (IRX10), belonging to the glycosyl transferase (GT) gene family 47 (GT47), in the biosynthesis of xylan. The protein sequence of OsGT47A from rice exhibits a 93.49% similarity to IRX10, which is involved in the biosynthesis of glucuronoxylan in Arabidopsis. Phylogenetic analysis of the GT47 glycosyl transferase family in the rice genome revealed that OsGT47A is a closely related homolog of IRX10 and IRX10L. Expression pattern analysis showed that the OsGT47A gene is highly expressed in the rice stem. Overexpression of OsGT47A in the irx10 irx10L double mutant rescued the plant growth phenotype and restored secondary wall thickness. Analysis of monosaccharides indicated that the rescued plants had levels of xylose identical to those of the wild type plants, and the fluorescence signals were restored in the complementation plants by xylan immunolocalization. The OsGT47A complementation under the native promoter of Arabidopsis IRX10L (ProIRX10L) partially rescued the double mutant, indicating that OsGT47A is functionally equivalent to IRX10L. Together, these results suggest that the IRX10 homolog OsGT47A exhibits functional conservation and is most likely involved in xylan synthesis in rice.
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Affiliation(s)
- Baolong Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, China
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106
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Yuan Y, Teng Q, Lee C, Zhong R, Ye ZH. Modification of the degree of 4-O-methylation of secondary wall glucuronoxylan. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 219-220:42-50. [PMID: 24576763 DOI: 10.1016/j.plantsci.2014.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 05/02/2023]
Abstract
Plant secondary walls are the major constituent of plant biomass targeted for second-generation biofuel production. Therefore, a thorough understanding of how secondary walls are constructed is critical for a better utilization of plant biomass for biofuel production. One of the major components in secondary walls is xylan, which is composed of a linear chain of β-1,4-linked xylosyl residues. In Arabidopsis, about 10% of xylosyl residues in xylan are substituted with glucuronic acid (GlcA), of which 60% are methylated at O-4. By contrast, all of the GlcA substituents in Populus xylan are methylated at O-4. It is not known how the degree of GlcA methylation in xylan is controlled. In this report, we demonstrated that simultaneous T-DNA knockout mutations of the three glucuronoxylan methyltransferase (GXM) genes, GXM1, GXM2, and GXM3/GXMT1, which are specifically expressed in secondary wall-forming cells, led to a complete loss of GlcA methylation in xylan in Arabidopsis stems. Overexpression of GXM2 and GXM3 in wild-type Arabidopsis resulted in an up to 5-fold increase in glucuronoxylan methyltransferase activity and as a result, up to 90% of the GlcA side chains in xylan were methylated as opposed to 60% seen in the wild type. The increased degree of GlcA methylation in xylan had no discernable effects on cell wall sugar composition and lignin monomer composition. These results reveal that the activities of GXM1, GXM2 and GXM3 are responsible for all of the GlcA methylation in xylan in Arabidopsis stems and that the degree of GlcA methylation in xylan can be modified by altered expression of GXMs.
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Affiliation(s)
- Youxi Yuan
- 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
| | - Chanhui Lee
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA; Department of Plant and Environmental New Resources, Kyung Hee University, Yongin, South Korea
| | - 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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107
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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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108
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Mishima K, Fujiwara T, Iki T, Kuroda K, Yamashita K, Tamura M, Fujisawa Y, Watanabe A. Transcriptome sequencing and profiling of expressed genes in cambial zone and differentiating xylem of Japanese cedar (Cryptomeria japonica). BMC Genomics 2014; 15:219. [PMID: 24649833 PMCID: PMC3999911 DOI: 10.1186/1471-2164-15-219] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 03/07/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Forest trees have ecological and economic importance, and Japanese cedar has highly valued wood attributes. Thus, studies of molecular aspects of wood formation offer practical information that may be used for screening and forward genetics approaches to improving wood quality. RESULTS After identifying expressed sequence tags in Japanese cedar tissue undergoing xylogenesis, we designed a custom cDNA microarray to compare expression of highly regulated genes throughout a growing season. This led to identification of candidate genes involved both in wood formation and later cessation of growth and dormancy. Based on homology to orthologous protein groups, the genes were assigned to functional classes. A high proportion of sequences fell into functional classes related to posttranscriptional modification and signal transduction, while transcription factors and genes involved in the metabolism of sugars, cell-wall synthesis and lignification, and cold hardiness were among other classes of genes identified as having a potential role in xylem formation and seasonal wood formation. CONCLUSIONS We obtained 55,051 unique sequences by next-generation sequencing of a cDNA library prepared from cambial meristem and derivative cells. Previous studies on conifers have identified unique sequences expressed in developing xylem, but this is the first comprehensive study utilizing a collection of expressed sequence tags for expression studies related to xylem formation in Japanese cedar, which belongs to a different lineage than the Pinaceae. Our characterization of these sequences should allow comparative studies of genome evolution and functional genetics of wood species.
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Affiliation(s)
| | | | | | | | | | | | | | - Atsushi Watanabe
- Department of Forest Environmental Sciences, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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109
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Chong SL, Virkki L, Maaheimo H, Juvonen M, Derba-Maceluch M, Koutaniemi S, Roach M, Sundberg B, Tuomainen P, Mellerowicz EJ, Tenkanen M. O-Acetylation of glucuronoxylan in Arabidopsis thaliana wild type and its change in xylan biosynthesis mutants. Glycobiology 2014; 24:494-506. [DOI: 10.1093/glycob/cwu017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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110
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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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111
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Wang C, Lv Y, Xu W, Zhang T, Guo W. Aberrant phenotype and transcriptome expression during fiber cell wall thickening caused by the mutation of the Im gene in immature fiber (im) mutant in Gossypium hirsutum L. BMC Genomics 2014; 15:94. [PMID: 24483163 PMCID: PMC3925256 DOI: 10.1186/1471-2164-15-94] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 01/31/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The immature fiber (im) mutant of Gossypium hirsutum L. is a special cotton fiber mutant with non-fluffy fibers. It has low dry weight and fineness of fibers due to developmental defects in fiber secondary cell wall (SCW). RESULTS We compared the cellulose content in fibers, thickness of fiber cell wall and fiber transcriptional profiling during SCW development in im mutant and its near-isogenic wild-type line (NIL) TM-1. The im mutant had lower cellulose content and thinner cell walls than TM-1 at same fiber developmental stage. During 25 ~ 35 day post-anthesis (DPA), sucrose content, an important carbon source for cellulose synthesis, was also significantly lower in im mutant than in TM-1. Comparative analysis of fiber transcriptional profiling from 13 ~ 25 DPA indicated that the largest transcriptional variations between the two lines occurred at the onset of SCW development. TM-1 began SCW biosynthesis approximately at 16 DPA, whereas the same fiber developmental program in im mutant was delayed until 19 DPA, suggesting an asynchronous fiber developmental program between TM-1 and im mutant. Functional classification and enrichment analysis of differentially expressed genes (DEGs) between the two NILs indicated that genes associated with biological processes related to cellulose synthesis, secondary cell wall biogenesis, cell wall thickening and sucrose metabolism, respectively, were significantly up-regulated in TM-1. Twelve genes related to carbohydrate metabolism were validated by quantitative reverse transcription PCR (qRT-PCR) and confirmed a temporal difference at the earlier transition and SCW biosynthesis stages of fiber development between TM-1 and im mutant. CONCLUSIONS We propose that Im is an important regulatory gene influencing temporal differences in expression of genes related to fiber SCW biosynthesis. This study lays a foundation for cloning the Im gene, elucidating molecular mechanism of fiber SCW development and further genetic manipulation for the improvement of fiber fineness and maturity.
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Affiliation(s)
- Cheng Wang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanda Lv
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing 210095, China
| | - Wentin Xu
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing 210095, China
| | - Tianzhen Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing 210095, China
| | - Wangzhen Guo
- State Key Laboratory of Crop Genetics & Germplasm Enhancement, Hybrid Cotton R & D Engineering Research Center, MOE, Nanjing Agricultural University, Nanjing 210095, China
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112
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Chormova D, Messenger DJ, Fry SC. Boron bridging of rhamnogalacturonan-II, monitored by gel electrophoresis, occurs during polysaccharide synthesis and secretion but not post-secretion. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 77:534-46. [PMID: 24320597 PMCID: PMC4171739 DOI: 10.1111/tpj.12403] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 11/20/2013] [Accepted: 11/28/2013] [Indexed: 05/02/2023]
Abstract
The cell-wall pectic domain rhamnogalacturonan-II (RG-II) is cross-linked via borate diester bridges, which influence the expansion, thickness and porosity of the wall. Previously, little was known about the mechanism or subcellular site of this cross-linking. Using polyacrylamide gel electrophoresis (PAGE) to separate monomeric from dimeric (boron-bridged) RG-II, we confirmed that Pb(2+) promotes H3 BO3 -dependent dimerisation in vitro. H3 BO3 concentrations as high as 50 mm did not prevent cross-linking. For in-vivo experiments, we successfully cultured 'Paul's Scarlet' rose (Rosa sp.) cells in boron-free medium: their wall-bound pectin contained monomeric RG-II domains but no detectable dimers. Thus pectins containing RG-II domains can be held in the wall other than via boron bridges. Re-addition of H3 BO3 to 3.3 μm triggered a gradual appearance of RG-II dimer over 24 h but without detectable loss of existing monomers, suggesting that only newly synthesised RG-II was amenable to boron bridging. In agreement with this, Rosa cultures whose polysaccharide biosynthetic machinery had been compromised (by carbon starvation, respiratory inhibitors, anaerobiosis, freezing or boiling) lost the ability to generate RG-II dimers. We conclude that RG-II normally becomes boron-bridged during synthesis or secretion but not post-secretion. Supporting this conclusion, exogenous [(3) H]RG-II was neither dimerised in the medium nor cross-linked to existing wall-associated RG-II domains when added to Rosa cultures. In conclusion, in cultured Rosa cells RG-II domains have a brief window of opportunity for boron-bridging intraprotoplasmically or during secretion, but secretion into the apoplast is a point of no return beyond which additional boron-bridging does not readily occur.
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113
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Zhao X, Ouyang K, Gan S, Zeng W, Song L, Zhao S, Li J, Doblin MS, Bacic A, Chen XY, Marchant A, Deng X, Wu AM. Biochemical and molecular changes associated with heteroxylan biosynthesis in Neolamarckia cadamba (Rubiaceae) during xylogenesis. FRONTIERS IN PLANT SCIENCE 2014; 5:602. [PMID: 25426124 PMCID: PMC4224071 DOI: 10.3389/fpls.2014.00602] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 10/16/2014] [Indexed: 05/07/2023]
Abstract
Wood, derived from plant secondary growth, is a commercially important material. Both cellulose and lignin assembly have been well studied during wood formation (xylogenesis), but heteroxylan biosynthesis is less well defined. Elucidation of the heteroxylan biosynthetic pathway is crucial to understand the mechanism of wood formation. Here, we use Neolamarckia cadamba, a fast-growing tropical tree, as a sample to analyze heteroxylan formation at the biochemical and molecular levels during wood formation. Analysis of the non-cellulosic polysaccharides isolated from N. cadamba stems shows that heteroxylans dominate non-cellulosic polysaccharides and increase with xylogenesis. Microsomes isolated from stems of 1-year-old N. cadamba exhibited UDP-Xyl synthase and xylosyltransferase activities with the highest activity present in the middle and basal stem regions. To further understand the genetic basis of heteroxylan synthesis, RNA sequencing (RNA-seq) was used to generate transcriptomes of N. cadamba during xylogenesis. The RNA-seq results showed that genes related to heteroxylan synthesis had higher expression levels in the middle and basal part of the stem compared to the apical part. Our results describe the heteroxylan distribution and heteroxylan synthesis trait in N. cadamba and give a new example for understanding the mechanism of heteroxylan synthesis in tropical tree species in future.
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Affiliation(s)
- Xianhai Zhao
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
| | - Kunxi Ouyang
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
| | - Siming Gan
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, BeijingChina
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, GuangzhouChina
| | - Wei Zeng
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, The University of Melbourne, Parkville, VICAustralia
| | - Lili Song
- Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, HangzhouChina
| | - Shuai Zhao
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
| | - Juncheng Li
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
| | - Monika S. Doblin
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, The University of Melbourne, Parkville, VICAustralia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, The University of Melbourne, Parkville, VICAustralia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VICAustralia
| | - Xiao-Yang Chen
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
| | - Alan Marchant
- Centre for Biological Sciences, University of Southampton, SouthamptonUK
| | - Xiaomei Deng
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
- College of Forest, South China Agricultural University, GuangzhouChina
- *Correspondence: Xiaomei Deng and Ai-Min Wu, College of Forest, South China Agricultural University, Guangzhou 510642, China e-mail: ;
| | - Ai-Min Wu
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, GuangzhouChina
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, GuangzhouChina
- College of Forest, South China Agricultural University, GuangzhouChina
- *Correspondence: Xiaomei Deng and Ai-Min Wu, College of Forest, South China Agricultural University, Guangzhou 510642, China e-mail: ;
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Plant Cell Wall Polysaccharides: Structure and Biosynthesis. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_73-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Lee C, Teng Q, Zhong R, Yuan Y, Ye ZH. Functional roles of rice glycosyltransferase family GT43 in xylan biosynthesis. PLANT SIGNALING & BEHAVIOR 2014; 9:e27809. [PMID: 24525904 PMCID: PMC4091335 DOI: 10.4161/psb.27809] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Xylan is the major hemicellulose present in both primary and secondary cell walls of rice vegetative tissues. Since xylan is one of the factors contributing to biomass recalcitrance, understanding how xylan is synthesized in rice will potentially provide tools to modify grass biomass composition better suited for biofuel production. Studies of xylan biosynthesis in Arabidopsis have revealed that family GT43 glycosyltransferases, which form 2 functionally nonredundant groups, IRX9/IRX9 homolog and IRX14/IRX14 homolog, are required for xylan backbone elongation. The rice genome harbors 10 genes encoding family GT43 members and it is currently unknown whether they are all involved in xylan biosynthesis. In this report, we performed biochemical analysis of xylan xylosyltransferase activity in rice stem microsomes and investigated the roles of 4 representative rice GT43 members, OsGT43A (LOC_Os05 g03174), OsGT43E (LOC_Os05 g48600), OsGT43H (LOC_Os04 g01280), and OsGT43J (LOC_Os06 g47340), in xylan biosynthesis. OsGT43 proteins were shown to be localized in the Golgi, where xylan biosynthesis occurs. Complementation analysis by expression of OsGT43s in Arabidopsis irx9 and irx14 mutants demonstrated that OsGT43A and OsGT43E but not OsGT43H and OsGT43J were able to rescue the mutant phenotypes conferred by the irx9 mutation, including defective stem mechanical strength, vessel morphology, xylan content, GlcA side chains, xylan chain length, and xylosyltransferase activity. On the other hand, OsGT43J but not OsGT43A, OsGT43E, and OsGT43H restored the defective xylan phenotype in the irx14 mutant. These results indicate that the rice GT43 family evolved to retain the involvement of 2 functionally nonredundant groups, OsGT43A and OsGT43E (IRX9 homologs) vs. OsGT43J (an IRX14 homolog), in xylan backbone biosynthesis.
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Affiliation(s)
- Chanhui Lee
- Department of Plant Biology; University of Georgia; Athens, GA USA
- Department of Plant and Environmental New Resources; Kyung Hee University; Yongin, South Korea
| | - Quincy Teng
- Department of Pharmaceutical and Biomedical Sciences; University of Georgia; Athens, GA USA
| | - Ruiqin Zhong
- Department of Plant Biology; University of Georgia; Athens, GA USA
| | - Youxi Yuan
- Department of Plant Biology; University of Georgia; Athens, GA USA
| | - Zheng-Hua Ye
- Department of Plant Biology; University of Georgia; Athens, GA USA
- Correspondence to: Zheng-Hua Ye,
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116
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Zhong R, Teng Q, Lee C, Ye ZH. Identification of a disaccharide side chain 2-O-α-D-galactopyranosyl-α-D-glucuronic acid in Arabidopsis xylan. PLANT SIGNALING & BEHAVIOR 2014; 9:e27933. [PMID: 24521940 PMCID: PMC4091222 DOI: 10.4161/psb.27933] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 05/17/2023]
Abstract
Arabidopsis xylan consists of a linear chain of β-1,4-linked D-xylosyl residues, about 10% of which are substituted with single residues of α-D-glucuronic acid (GlcA) or 4-O-methyl-α-D-glucuronic acid (MeGlcA) at O-2. In addition, about 60% of xylosyl residues are acetylated at O-2 and/or O-3. Previous studies have identified a number of genes responsible for elongation of the xylan backbone, addition of the GlcA substituents, and methylation of the GlcA residues. Yuan et al. (2013) have recently reported that the 2-O- and 3-O-monoacetylation of xylosyl residues in Arabidopsis xylan requires a DUF231 domain-containing protein, ESKIMO1 (ESK1), and proposed that ESK1 and its homologs are putative acetyltransferases responsible for xylan acetylation. It was noticed that the (1)H nuclear magnetic resonance (NMR) spectra of the acetylated xylan from the esk1 mutant and the wild-type Arabidopsis exhibited a prominent proton signal peak at 5.42 ppm in addition to resonances corresponding to known acetylated structural groups of xylan. Here, we performed detailed structural investigation of wild-type Arabidopsis acetylated xylan using 2-dimensional (1)H- (1)H and (1)H- (13)C NMR spectroscopy and found that the signal peak at 5.42 ppm in the (1)H NMR spectrum was attributed to GlcA residues substituted at O-2 with α-D-galactose (Gal), indicating the presence of Gal-GlcA disaccharide side chains in Arabidopsis xylan. This finding was further supported by analysis of endoxylanase-digested xylan using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. Our study demonstrates that Arabidopsis xylan contains Gal-GlcA disaccharide side chains in addition to GlcA, MeGlcA, and acetyl substitutions.
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Affiliation(s)
- Ruiqin Zhong
- Department of Plant Biology; University of Georgia; Athens, GA USA
| | - Quincy Teng
- Department of Pharmaceutical and Biomedical Sciences; University of Georgia; Athens, GA USA
| | - Chanhui Lee
- Department of Plant Biology; University of Georgia; Athens, GA USA
- Department of Plant and Environmental New Resources; Kyung Hee University; Yongin, South Korea
| | - Zheng-Hua Ye
- Department of Plant Biology; University of Georgia; Athens, GA USA
- Correspondence to: Zheng-Hua Ye,
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117
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Parsons HT, Weinberg CS, Macdonald LJ, Adams PD, Petzold CJ, Strabala TJ, Wagner A, Heazlewood JL. Golgi enrichment and proteomic analysis of developing Pinus radiata xylem by free-flow electrophoresis. PLoS One 2013; 8:e84669. [PMID: 24416096 PMCID: PMC3887118 DOI: 10.1371/journal.pone.0084669] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 11/17/2013] [Indexed: 01/10/2023] Open
Abstract
Our understanding of the contribution of Golgi proteins to cell wall and wood formation in any woody plant species is limited. Currently, little Golgi proteomics data exists for wood-forming tissues. In this study, we attempted to address this issue by generating and analyzing Golgi-enriched membrane preparations from developing xylem of compression wood from the conifer Pinus radiata. Developing xylem samples from 3-year-old pine trees were harvested for this purpose at a time of active growth and subjected to a combination of density centrifugation followed by free flow electrophoresis, a surface charge separation technique used in the enrichment of Golgi membranes. This combination of techniques was successful in achieving an approximately 200-fold increase in the activity of the Golgi marker galactan synthase and represents a significant improvement for proteomic analyses of the Golgi from conifers. A total of thirty known Golgi proteins were identified by mass spectrometry including glycosyltransferases from gene families involved in glucomannan and glucuronoxylan biosynthesis. The free flow electrophoresis fractions of enriched Golgi were highly abundant in structural proteins (actin and tubulin) indicating a role for the cytoskeleton during compression wood formation. The mass spectrometry proteomics data associated with this study have been deposited to the ProteomeXchange with identifier PXD000557.
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Affiliation(s)
- Harriet T. Parsons
- Joint BioEnergy Institute and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | | | | | - Paul D. Adams
- Joint BioEnergy Institute and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Bioengineering, University of California, Berkeley, California, United States of America
| | - Christopher J. Petzold
- Joint BioEnergy Institute and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | | | | | - Joshua L. Heazlewood
- Joint BioEnergy Institute and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
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118
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Ratnayake S, Beahan CT, Callahan DL, Bacic A. The reducing end sequence of wheat endosperm cell wall arabinoxylans. Carbohydr Res 2013; 386:23-32. [PMID: 24462668 DOI: 10.1016/j.carres.2013.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/11/2013] [Accepted: 12/15/2013] [Indexed: 12/31/2022]
Abstract
Walls from wheat (Triticum aestivum L.) endosperm are composed primarily of hetero-(arabino)xylans (AXs) (70%) and (1→3)(1→4)-β-D-glucans (20%) with minor amounts of cellulose and heteromannans (2% each). To understand the differential solubility properties of the AXs, as well as aspects of their biosynthesis, we are sequencing the xylan backbone and examining the reducing end (RE) sequence(s) of wheat (monocot) AXs. A previous study of grass AXs (switchgrass, rice, Brachypodium, Miscanthus and foxtail millet) concluded that grasses lacked the comparable RE glycosyl sequence (4-β-D-Xylp-(1→4)-β-D-Xylp-(1→3)-α-L-Rhap-(1→2)-α-D-GalpA-(1→4)-D-Xylp) found in dicots and gymnosperms but the actual RE sequence was not determined. Here we report the isolation and structural characterisation of the RE oligosaccharide sequence(s) of wheat endosperm cell wall AXs. Walls were isolated as an alcohol-insoluble residue (AIR) and sequentially extracted with hot water (W-sol Fr) and 1M KOH containing 1% NaBH4 (KOH-sol Fr). Detailed structural analysis of the RE oligosaccharides was performed using a combination of methylation analysis, MALDI-TOF-MS, ESI-QTOF-MS, ESI-MS(n) and enzymic analysis. Analysis of RE oligosaccharides, both 2AB labelled (from W-sol Fr) and glycosyl-alditol (from KOH-sol Fr), revealed that the RE glycosyl sequence of wheat endosperm AX comprises a linear (1→4)-β-D-Xylp backbone which may be mono-substituted with either an α-L-Araf residue at the reducing end β-D-Xylp residue and/or penultimate RE β-D-Xyl residue; β-D-Xylp-(1→4)-[α-L-Araf-(1→3)](+/-)-β-D-Xylp-(1→4)-[α-L-Araf-(1→3)](+/-)-β-D-Xylp and/or an α-D-GlcpA residue at the reducing end β-D-Xylp residue; β-D-Xylp-(1→4)-[α-L-Araf-(1→3)](+/-)-β-D-Xylp-(1→4)-[α-D-GlcAp-(1→2)]-β-D-Xylp. Thus, wheat endosperm AX backbones lacks the RE sequence found in dicot and gymnosperm xylans; a finding consistent with previous reports from other grass species.
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Affiliation(s)
- Sunil Ratnayake
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Cherie T Beahan
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Damien L Callahan
- Metabolomics Australia, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia; Metabolomics Australia, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia.
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119
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Manabe Y, Verhertbruggen Y, Gille S, Harholt J, Chong SL, Pawar PMA, Mellerowicz EJ, Tenkanen M, Cheng K, Pauly M, Scheller HV. Reduced Wall Acetylation proteins play vital and distinct roles in cell wall O-acetylation in Arabidopsis. PLANT PHYSIOLOGY 2013; 163:1107-17. [PMID: 24019426 PMCID: PMC3813637 DOI: 10.1104/pp.113.225193] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/03/2013] [Indexed: 05/17/2023]
Abstract
The Reduced Wall Acetylation (RWA) proteins are involved in cell wall acetylation in plants. Previously, we described a single mutant, rwa2, which has about 20% lower level of O-acetylation in leaf cell walls and no obvious growth or developmental phenotype. In this study, we generated double, triple, and quadruple loss-of-function mutants of all four members of the RWA family in Arabidopsis (Arabidopsis thaliana). In contrast to rwa2, the triple and quadruple rwa mutants display severe growth phenotypes revealing the importance of wall acetylation for plant growth and development. The quadruple rwa mutant can be completely complemented with the RWA2 protein expressed under 35S promoter, indicating the functional redundancy of the RWA proteins. Nevertheless, the degree of acetylation of xylan, (gluco)mannan, and xyloglucan as well as overall cell wall acetylation is affected differently in different combinations of triple mutants, suggesting their diversity in substrate preference. The overall degree of wall acetylation in the rwa quadruple mutant was reduced by 63% compared with the wild type, and histochemical analysis of the rwa quadruple mutant stem indicates defects in cell differentiation of cell types with secondary cell walls.
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Affiliation(s)
- Yuzuki Manabe
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Yves Verhertbruggen
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | | | - Jesper Harholt
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Sun-Li Chong
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Prashant Mohan-Anupama Pawar
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Ewa J. Mellerowicz
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Maija Tenkanen
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Kun Cheng
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
| | - Markus Pauly
- Joint BioEnergy Institute, Feedstocks Division, Emeryville, California 94608 (Y.M., Y.V., H.V.S.); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (Y.M., Y.V., H.V.S.)
- Energy Biosciences Institute, Berkeley, California 94720 (S.G., K.C., M.P.)
- Department of Plant and Environmental Sciences, University of Copenhagen, DK–1871 Frederiksberg, Denmark (J.H.)
- Department of Food and Environmental Sciences, University of Helsinki, FI–00014 Helsinki, Finland (S.-L.C., M.T.)
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden (P.M.-A.P., E.J.M); and
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720 (M.P., H.V.S.)
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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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Wang L, Wang W, Wang YQ, Liu YY, Wang JX, Zhang XQ, Ye D, Chen LQ. Arabidopsis galacturonosyltransferase (GAUT) 13 and GAUT14 have redundant functions in pollen tube growth. MOLECULAR PLANT 2013; 6:1131-48. [PMID: 23709340 DOI: 10.1093/mp/sst084] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Cell wall biosynthesis is indispensable for pollen tube growth. Despite its importance to sexual reproduction, the molecular mechanisms of pollen tube wall biosynthesis remain poorly understood. Here, we report functional characterization of two putative Arabidopsis galacturonosyltransferase genes, GAUT13 and GAUT14, which are essential for pollen tube growth. GAUT13 and GAUT14 encode the proteins that share a high amino acid sequence identity and are located in the Golgi apparatus. The T-DNA insertion mutants, gaut13 and gaut14, did not exhibit any observable defects, but the gaut13 gaut14 double mutants were defective in pollen tube growth; 35.2-37.3% pollen tubes in the heterozygous double mutants were swollen and defective in elongation. The outer layer of the cell wall did not appear distinctly fibrillar in the double mutant pollen tubes. Furthermore, distribution of homogalacturonan labeled with JIM5 and JIM7 in the double mutant pollen tube wall was significantly altered compared to wild-type. Our results suggest that GAUT13 and GAUT14 function redundantly in pollen tube growth, possibly through participation in pectin biosynthesis of the pollen tube wall.
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Affiliation(s)
- Li Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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122
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Yuan Y, Teng Q, Zhong R, Ye ZH. The Arabidopsis DUF231 domain-containing protein ESK1 mediates 2-O- and 3-O-acetylation of xylosyl residues in xylan. PLANT & CELL PHYSIOLOGY 2013; 54:1186-99. [PMID: 23659919 DOI: 10.1093/pcp/pct070] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Xylan, a major polysaccharide in plant lignocellulosic biomass, is acetylated at O-2 and/or O-3 and its acetylation impedes the use of biomass for biofuel production. Currently, it is not known what genes encode acetyltransferases that are responsible for xylan O-acetylation. In this report, we demonstrate an essential role for the Arabidopsis gene ESKIMO1 (ESK1) in xylan O-acetylation during secondary wall biosynthesis. ESK1 expression was found to be regulated by the secondary wall master regulator SND1 (secondary wall-associated NAC domain protein1) and specifically associated with secondary wall biosynthesis. Its encoded protein was localized in the Golgi, the site of xylan biosynthesis. The esk1 mutation caused reductions in secondary wall thickening and stem mechanical strength. Chemical analyses of cell walls revealed that although the esk1 mutation did not cause apparent alterations in the xylan chain length and the abundance of the reducing end sequence, it resulted in a significant reduction in the degree of xylan acetylation. The reduced acetylation of esk1 xylan rendered it more accessible and digestible by endoxylanase, leading to generation of shorter xylooligomers compared with the wild type. Further structural analysis of xylan showed that the esk1 mutation caused a specific reduction in 2-O- and 3-O-monoacetylation of xylosyl residues but not in 2,3-di-O-acetylation or 3-O-acetylation of xylosyl residues substituted at O-2 with glucuronic acid. Consistent with ESK1's involvement in xylan O-acetylation, an activity assay revealed that the esk1 mutation led to a significant decrease in xylan acetyltransferase activity. Together, these results demonstrate that ESK1 is a putative xylan acetyltransferase required for 2-O- and 3-O-monoacetylation of xylosyl residues and indicate the complexity of the biochemical mechanism underlying xylan O-acetylation.
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Affiliation(s)
- Youxi Yuan
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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Bromley JR, Busse-Wicher M, Tryfona T, Mortimer JC, Zhang Z, Brown DM, Dupree P. GUX1 and GUX2 glucuronyltransferases decorate distinct domains of glucuronoxylan with different substitution patterns. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 74:423-34. [PMID: 23373848 DOI: 10.1111/tpj.12135] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/22/2013] [Accepted: 01/27/2013] [Indexed: 05/17/2023]
Abstract
Xylan comprises up to one-third of plant cell walls, and it influences the properties and processing of biomass. Glucuronoxylan in Arabidopsis is characterized by a linear β-(1,4)-linked backbone of xylosyl residues substituted by glucuronic acid and 4-O-methylglucuronic acid (collectively termed [Me]GlcA). The role of these substitutions remains unclear. GUX1 (glucuronic acid substitution of xylan 1) and GUX2, recently identified as glucuronyltransferases, are both required for substitution of the xylan backbone with [Me]GlcA. Here, we demonstrate clear differences in the pattern of [Me]GlcA substitution generated by each of these glucuronyltransferases. GUX1 decorates xylan with a preference for addition of [Me]GlcA at evenly spaced xylosyl residues. Intervals of eight or 10 residues dominate, but larger intervals are observed. GUX2, in contrast, produces more tightly clustered decorations with most frequent spacing of five, six or seven xylosyl residues, with no preference for odd or even spacing. Moreover, each of these GUX transferases substitutes a distinct domain of secondary cell wall xylan, which we call the major and minor domains. These major and minor xylan domains were not separable from each other by size or charge, a finding that suggests that they are tightly associated. The presence of both differently [Me]GlcA decorated domains may produce a xylan molecule that is heterogeneous in its properties. We speculate that the major and minor domains of xylan may be specialised, such as for interaction with cellulose or lignin. These findings have substantial implications for our understanding of xylan synthesis and structure, and for models of the molecular architecture of the lignocellulosic matrix of plant cell walls.
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Affiliation(s)
- Jennifer R Bromley
- Department of Biochemistry, University Of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
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Chiniquy D, Varanasi P, Oh T, Harholt J, Katnelson J, Singh S, Auer M, Simmons B, Adams PD, Scheller HV, Ronald PC. Three Novel Rice Genes Closely Related to the Arabidopsis IRX9, IRX9L, and IRX14 Genes and Their Roles in Xylan Biosynthesis. FRONTIERS IN PLANT SCIENCE 2013; 4:83. [PMID: 23596448 PMCID: PMC3622038 DOI: 10.3389/fpls.2013.00083] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 03/21/2013] [Indexed: 05/02/2023]
Abstract
Xylan is the second most abundant polysaccharide on Earth, and represents a major component of both dicot wood and the cell walls of grasses. Much knowledge has been gained from studies of xylan biosynthesis in the model plant, Arabidopsis. In particular, the irregular xylem (irx) mutants, named for their collapsed xylem cells, have been essential in gaining a greater understanding of the genes involved in xylan biosynthesis. In contrast, xylan biosynthesis in grass cell walls is poorly understood. We identified three rice genes Os07g49370 (OsIRX9), Os01g48440 (OsIRX9L), and Os06g47340 (OsIRX14), from glycosyltransferase family 43 as putative orthologs to the putative β-1,4-xylan backbone elongating Arabidopsis IRX9, IRX9L, and IRX14 genes, respectively. We demonstrate that the over-expression of the closely related rice genes, in full or partly complement the two well-characterized Arabidopsis irregular xylem (irx) mutants: irx9 and irx14. Complementation was assessed by measuring dwarfed phenotypes, irregular xylem cells in stem cross sections, xylose content of stems, xylosyltransferase (XylT) activity of stems, and stem strength. The expression of OsIRX9 in the irx9 mutant resulted in XylT activity of stems that was over double that of wild type plants, and the stem strength of this line increased to 124% above that of wild type. Taken together, our results suggest that OsIRX9/OsIRX9L, and OsIRX14, have similar functions to the Arabidopsis IRX9 and IRX14 genes, respectively. Furthermore, our expression data indicate that OsIRX9 and OsIRX9L may function in building the xylan backbone in the secondary and primary cell walls, respectively. Our results provide insight into xylan biosynthesis in rice and how expression of a xylan synthesis gene may be modified to increase stem strength.
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Affiliation(s)
- Dawn Chiniquy
- Department of Plant Pathology, The Genome Center, University of CaliforniaDavis, CA, USA
- Joint BioEnergy InstituteEmeryville, CA, USA
| | - Patanjali Varanasi
- Joint BioEnergy InstituteEmeryville, CA, USA
- Sandia National LabsLivermore, CA, USA
- Physical Biosciences Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA
| | - Taeyun Oh
- Department of Plant Pathology, The Genome Center, University of CaliforniaDavis, CA, USA
| | - Jesper Harholt
- Section for Plant Glycobiology, Department of Plant and Environmental Sciences, VKR Research Centre Pro-Active Plants, University of CopenhagenFrederiksberg C, Denmark
| | | | - Seema Singh
- Joint BioEnergy InstituteEmeryville, CA, USA
- Sandia National LabsLivermore, CA, USA
- Physical Biosciences Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA
| | - Manfred Auer
- Joint BioEnergy InstituteEmeryville, CA, USA
- Life Sciences Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA
| | - Blake Simmons
- Joint BioEnergy InstituteEmeryville, CA, USA
- Sandia National LabsLivermore, CA, USA
- Physical Biosciences Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA
| | | | - Henrik V. Scheller
- Joint BioEnergy InstituteEmeryville, CA, USA
- Physical Biosciences Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA
- Department of Plant and Microbial Biology, University of CaliforniaBerkeley, CA, USA
| | - Pamela C. Ronald
- Department of Plant Pathology, The Genome Center, University of CaliforniaDavis, CA, USA
- Joint BioEnergy InstituteEmeryville, CA, USA
- Department of Plant Molecular Systems Biotechnology and Crop Biotech Institute, Kyung Hee UniversityYongin, Korea
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Xu P, Kong Y, Li X, Li L. Identification of molecular processes needed for vascular formation through transcriptome analysis of different vascular systems. BMC Genomics 2013; 14:217. [PMID: 23548001 PMCID: PMC3620544 DOI: 10.1186/1471-2164-14-217] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 03/22/2013] [Indexed: 11/24/2022] Open
Abstract
Background Vascular system formation has been studied through molecular and genetic approaches in Arabidopsis, a herbaceous dicot that is used as a model system. Different vascular systems have developed in other plants such as crops and trees. Uncovering shared mechanisms underlying vascular development by transcriptome analysis of different vascular systems may help to transfer knowledge acquired from Arabidopsis to other economically important species. Results Conserved vascular genes and biological processes fundamental to vascular development were explored across various plants. Through comparative transcriptome analysis, 226 genes from Arabidopsis, 217 genes from poplar and 281 genes from rice were identified as constituting 107 conserved vascular gene groups. These gene groups are expressed mainly in vascular tissues and form a complex coexpression network with multiple functional connections. To date, only half of the groups have been experimentally investigated. The conserved vascular gene groups were classified into 9 essential processes for vascular development. 18 groups (17%) lack of annotations were classified as having unknown functions. Conclusion The study provides a map of fundamental biological processes conserved across different vascular systems. It identifies gaps in the experimental investigation of pathways active in vascular formation, which if explored, could lead to a more complete understanding of vascular development.
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Affiliation(s)
- Peng Xu
- National Key Laboratory of Plant Molecular Genetics and Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai 200032, China
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Mollet JC, Leroux C, Dardelle F, Lehner A. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth. PLANTS 2013; 2:107-47. [PMID: 27137369 PMCID: PMC4844286 DOI: 10.3390/plants2010107] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/19/2013] [Accepted: 02/19/2013] [Indexed: 01/01/2023]
Abstract
The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.
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Affiliation(s)
- Jean-Claude Mollet
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale, EA4358, IRIB, Normandy University, University of Rouen, 76821 Mont Saint-Aignan, France.
| | - Christelle Leroux
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale, EA4358, IRIB, Normandy University, University of Rouen, 76821 Mont Saint-Aignan, France.
| | - Flavien Dardelle
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale, EA4358, IRIB, Normandy University, University of Rouen, 76821 Mont Saint-Aignan, France.
| | - Arnaud Lehner
- Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale, EA4358, IRIB, Normandy University, University of Rouen, 76821 Mont Saint-Aignan, France.
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Chen X, Vega-Sánchez ME, Verhertbruggen Y, Chiniquy D, Canlas PE, Fagerström A, Prak L, Christensen U, Oikawa A, Chern M, Zuo S, Lin F, Auer M, Willats WGT, Bartley L, Harholt J, Scheller HV, Ronald PC. Inactivation of OsIRX10 leads to decreased xylan content in rice culm cell walls and improved biomass saccharification. MOLECULAR PLANT 2013. [PMID: 23180670 DOI: 10.1093/mp/sss135] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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128
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Hörnblad E, Ulfstedt M, Ronne H, Marchant A. Partial functional conservation of IRX10 homologs in physcomitrella patens and Arabidopsis thaliana indicates an evolutionary step contributing to vascular formation in land plants. BMC PLANT BIOLOGY 2013; 13:3. [PMID: 23286876 PMCID: PMC3543728 DOI: 10.1186/1471-2229-13-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/21/2012] [Indexed: 05/07/2023]
Abstract
BACKGROUND Plant cell walls are complex multicomponent structures that have evolved to fulfil an essential function in providing strength and protection to cells. Hemicelluloses constitute a key component of the cell wall and recently a number of the genes thought to encode the enzymes required for its synthesis have been identified in Arabidopsis. The acquisition of hemicellulose synthesis capability is hypothesised to have been an important step in the evolution of higher plants. RESULTS Analysis of the Physcomitrella patens genome has revealed the presence of homologs for all of the Arabidopsis glycosyltransferases including IRX9, IRX10 and IRX14 required for the synthesis of the glucuronoxylan backbone. The Physcomitrella IRX10 homolog is expressed in a variety of moss tissues which were newly formed or undergoing expansion. There is a high degree of sequence conservation between the Physcomitrella IRX10 and Arabidopsis IRX10 and IRX10-L. Despite this sequence similarity, the Physcomitrella IRX10 gene is only able to partially rescue the Arabidopsis irx10 irx10-L double mutant indicating that there has been a neo- or sub-functionalisation during the evolution of higher plants. Analysis of the monosaccharide composition of stems from the partially rescued Arabidopsis plants does not show any significant change in xylose content compared to the irx10 irx10-L double mutant. Likewise, knockout mutants of the Physcomitrella IRX10 gene do not result in any visible phenotype and there is no significant change in monosaccharide composition of the cell walls. CONCLUSIONS The fact that the Physcomitrella IRX10 (PpGT47A) protein can partially complement an Arabidopsis irx10 irx10-L double mutant suggests that it shares some function with the Arabidopsis proteins, but the lack of a phenotype in knockout lines shows that the function is not required for growth or development under normal conditions in Physcomitrella. In contrast, the Arabidopsis irx10 and irx10 irx10-L mutants have strong phenotypes indicating an important function in growth and development. We conclude that the evolution of vascular plants has been associated with a significant change or adaptation in the function of the IRX10 gene family.
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Affiliation(s)
- Emma Hörnblad
- UPSC, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-90183, Sweden
| | - Mikael Ulfstedt
- Department of Microbiology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Box 7025, Uppsala, SE-750 07, Sweden
| | - Hans Ronne
- Department of Microbiology, Uppsala Biocenter, Swedish University of Agricultural Sciences, Box 7025, Uppsala, SE-750 07, Sweden
| | - Alan Marchant
- UPSC, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-90183, Sweden
- Centre for Biological Sciences, Life Sciences Building 85, University of Southampton, Southampton, SO17 1BJ, UK
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Jensen JK, Johnson N, Wilkerson CG. Discovery of diversity in xylan biosynthetic genes by transcriptional profiling of a heteroxylan containing mucilaginous tissue. FRONTIERS IN PLANT SCIENCE 2013; 4:183. [PMID: 23761806 PMCID: PMC3675317 DOI: 10.3389/fpls.2013.00183] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/20/2013] [Indexed: 05/07/2023]
Abstract
The exact biochemical steps of xylan backbone synthesis remain elusive. In Arabidopsis, three non-redundant genes from two glycosyltransferase (GT) families, IRX9 and IRX14 from GT43 and IRX10 from GT47, are candidates for forming the xylan backbone. In other plants, evidence exists that different tissues express these three genes at widely different levels, which suggests that diversity in the makeup of the xylan synthase complex exists. Recently we have profiled the transcripts present in the developing mucilaginous tissue of psyllium (Plantago ovata Forsk). This tissue was found to have high expression levels of an IRX10 homolog, but very low levels of the two GT43 family members. This contrasts with recent wheat endosperm tissue profiling that found a relatively high abundance of the GT43 family members. We have performed an in-depth analysis of all GTs genes expressed in four developmental stages of the psyllium mucilagenous layer and in a single stage of the psyllium stem using RNA-Seq. This analysis revealed several IRX10 homologs, an expansion in GT61 (homologs of At3g18170/At3g18180), and several GTs from other GT families that are highly abundant and specifically expressed in the mucilaginous tissue. Our current hypothesis is that the four IRX10 genes present in the mucilagenous tissues have evolved to function without the GT43 genes. These four genes represent some of the most divergent IRX10 genes identified to date. Conversely, those present in the psyllium stem are very similar to those in other eudicots. This suggests these genes are under selective pressure, likely due to the synthesis of the various xylan structures present in mucilage that has a different biochemical role than that present in secondary walls. The numerous GT61 family members also show a wide sequence diversity and may be responsible for the larger number of side chain structures present in the psyllium mucilage.
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Affiliation(s)
- Jacob K. Jensen
- Department of Plant Biology, Michigan State UniversityEast Lansing, MI, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State UniversityEast Lansing, MI, USA
| | - Nathan Johnson
- Department of Plant Biology, Michigan State UniversityEast Lansing, MI, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State UniversityEast Lansing, MI, USA
| | - Curtis G. Wilkerson
- Department of Plant Biology, Michigan State UniversityEast Lansing, MI, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State UniversityEast Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast Lansing, MI, USA
- *Correspondence: Curtis G. Wilkerson, Department of Plant Biology, Michigan State University, 612 Wilson Rd., Room 122, East Lansing, MI 48824-1312 USA e-mail:
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Abstract
Recent progress in the identification and characterization of pectin biosynthetic proteins and the discovery of pectin domain-containing proteoglycans are changing our view of how pectin, the most complex family of plant cell wall polysaccharides, is synthesized. The functional confirmation of four types of pectin biosynthetic glycosyltransferases, the identification of multiple putative pectin glycosyl- and methyltransferases, and the characteristics of the GAUT1:GAUT7 homogalacturonan biosynthetic complex with its novel mechanism for retaining catalytic subunits in the Golgi apparatus and its 12 putative interacting proteins are beginning to provide a framework for the pectin biosynthetic process. We propose two partially overlapping hypothetical and testable models for pectin synthesis: the consecutive glycosyltransferase model and the domain synthesis model.
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Affiliation(s)
- Melani A Atmodjo
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602-4712, USA.
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“Plant Cell Wall Structure-Pretreatment” the Critical Relationship in Biomass Conversion to Fermentable Sugars. SPRINGERBRIEFS IN MOLECULAR SCIENCE 2013. [DOI: 10.1007/978-94-007-6052-3_1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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132
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Schuetz M, Smith R, Ellis B. Xylem tissue specification, patterning, and differentiation mechanisms. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:11-31. [PMID: 23162114 DOI: 10.1093/jxb/ers287] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Vascular plants (Tracheophytes) have adapted to a variety of environments ranging from arid deserts to tropical rainforests, and now comprise >250,000 species. While they differ widely in appearance and growth habit, all of them share a similar specialized tissue system (vascular tissue) for transporting water and nutrients throughout the organism. Plant vascular systems connect all plant organs from the shoot to the root, and are comprised of two main tissue types, xylem and phloem. In this review we examine the current state of knowledge concerning the process of vascular tissue formation, and highlight important mechanisms underlying key steps in vascular cell type specification, xylem and phloem tissue patterning, and, finally, the differentiation and maturation of specific xylem cell types.
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Affiliation(s)
- Mathias Schuetz
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada
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133
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Identification of glycosyltransferases involved in cell wall synthesis of wheat endosperm. J Proteomics 2013; 78:508-21. [DOI: 10.1016/j.jprot.2012.10.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 10/24/2012] [Accepted: 10/26/2012] [Indexed: 01/05/2023]
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Tsai AYL, Canam T, Gorzsás A, Mellerowicz EJ, Campbell MM, Master ER. Constitutive expression of a fungal glucuronoyl esterase in Arabidopsis reveals altered cell wall composition and structure. PLANT BIOTECHNOLOGY JOURNAL 2012; 10:1077-87. [PMID: 22924998 DOI: 10.1111/j.1467-7652.2012.00735.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A family 15 carbohydrate esterase (CE15) from the white-rot basidiomycete, Phanerochaete carnosa (PcGCE), was transformed into Arabidopsis thaliana Col-0 and was expressed from the constitutive cauliflower mosaic virus 35S promoter. Like other CE15 enzymes, PcGCE hydrolyzed methyl-4-O-methyl-d-glucopyranuronate and could target ester linkages that contribute to lignin-carbohydrate complexes that form in plant cell walls. Three independently transformed Arabidopsis lines were evaluated in terms of nine morphometric parameters, total sugar and lignin composition, cell wall anatomy, enzymatic saccharification and xylan extractability. The transgenic lines consistently displayed a leaf-yellowing phenotype, as well as reduced glucose and xylose content by as much as 30% and 35%, respectively. Histological analysis revealed 50% reduction in cell wall thickness in the interfascicular fibres of transgenic plants, and FT-IR microspectroscopy of interfascicular fibre walls indicated reduction in lignin cross-linking in plants overexpressing PcGCE. Notably, these characteristics could be correlated with improved xylose recovery in transgenic plants, up to 15%. The current analysis represents the first example whereby a fungal glucuronoyl esterase is expressed in Arabidopsis and shows that the promotion of glucuronoyl esterase activity in plants can alter the extent of intermolecular cross-linking within plant cell walls.
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Affiliation(s)
- Alex Y-L Tsai
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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135
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Petersen PD, Lau J, Ebert B, Yang F, Verhertbruggen Y, Kim JS, Varanasi P, Suttangkakul A, Auer M, Loqué D, Scheller HV. Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants. BIOTECHNOLOGY FOR BIOFUELS 2012; 5. [PMID: 23181474 PMCID: PMC3537538 DOI: 10.1186/1754-6834-5-84] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production. RESULTS Xylan is the major non-cellulosic polysaccharide in secondary cell walls, and the xylan deficient irregular xylem (irx) mutants irx7, irx8 and irx9 exhibit severe dwarf growth phenotypes. The main reason for the growth phenotype appears to be xylem vessel collapse and the resulting impaired transport of water and nutrients. We developed a xylan-engineering approach to reintroduce xylan biosynthesis specifically into the xylem vessels in the Arabidopsis irx7, irx8 and irx9 mutant backgrounds by driving the expression of the respective glycosyltransferases with the vessel-specific promoters of the VND6 and VND7 transcription factor genes. The growth phenotype, stem breaking strength, and irx morphology was recovered to varying degrees. Some of the plants even exhibited increased stem strength compared to the wild type. We obtained Arabidopsis plants with up to 23% reduction in xylose levels and 18% reduction in lignin content compared to wild-type plants, while exhibiting wild-type growth patterns and morphology, as well as normal xylem vessels. These plants showed a 42% increase in saccharification yield after hot water pretreatment. The VND7 promoter yielded a more complete complementation of the irx phenotype than the VND6 promoter. CONCLUSIONS Spatial and temporal deposition of xylan in the secondary cell wall of Arabidopsis can be manipulated by using the promoter regions of vessel-specific genes to express xylan biosynthetic genes. The expression of xylan specifically in the xylem vessels is sufficient to complement the irx phenotype of xylan deficient mutants, while maintaining low overall amounts of xylan and lignin in the cell wall. This engineering approach has the potential to yield bioenergy crop plants that are more easily deconstructed and fermented into biofuels.
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Affiliation(s)
- Pia Damm Petersen
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
- Department of Plant Biology and Biotechnology, University of Copenhagen, 40 Thorvaldsensvej, Frederiksberg C, DK-1871, Denmark
| | - Jane Lau
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Berit Ebert
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Fan Yang
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Yves Verhertbruggen
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Jin Sun Kim
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Patanjali Varanasi
- Technology Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Sandia National Laboratories, 7011 East Avenue, Livermore, CA, 94550, USA
| | - Anongpat Suttangkakul
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand
| | - Manfred Auer
- Technology Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Dominique Loqué
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Henrik Vibe Scheller
- Feedstocks Division, Joint Bioenergy Institute, 5885 Hollis St, Emeryville, CA, 94608, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
- Department of Plant & Microbial Biology, University of California, Berkeley, CA, 94720, USA
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136
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Lee C, Teng Q, Zhong R, Yuan Y, Haghighat M, Ye ZH. Three Arabidopsis DUF579 domain-containing GXM proteins are methyltransferases catalyzing 4-o-methylation of glucuronic acid on xylan. PLANT & CELL PHYSIOLOGY 2012; 53:1934-49. [PMID: 23045523 DOI: 10.1093/pcp/pcs138] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Xylan is made of a linear chain of β-1,4-linked xylosyl residues, some of which are substituted with side chains, such as glucuronic acid (GlcA), methylglucuronic acid (MeGlcA) and arabinose, depending on the source of xylan. Although past studies have revealed a number of genes involved in the elongation of the xylan backbone and the addition of GlcA and arabinosyl side chains, no genes have been shown to be implicated in glucuronoxylan methylation. In this report, we investigated the roles of three Arabidopsis genes, namely GLUCURONOXYLAN METHYLTRANSFERASE1 (GXM1), GXM2 and GXM3, in xylan biosynthesis. The GXM1/2/3 genes were found to be expressed in secondary wall-forming cells and their expression was regulated by SND1, a secondary wall master transcriptional switch. Their encoded proteins were shown to be located in the Golgi, where xylan biosynthesis occurs. Chemical analysis of cell wall sugars from single and double mutants of these genes revealed that although no alterations in the amount of xylose were observed, a significant reduction in the level of MeGlcA was evident in the gxm3 single mutant and the gxm double mutants. Structural analysis of xylan demonstrated that the gxm mutations caused a specific defect in GlcA methylation on xylan without affecting the frequency of xylan substitution. Only about 10% of the GlcA residues on xylan were methylated in the gxm2/3 double mutant, whereas in the wild type 60% of the GlcA residues were methylated. Furthermore, an activity assay demonstrated that recombinant GXM proteins exhibited a methyltransferase activity capable of transferring the methyl group from S-adenosylmethionine onto GlcA-substituted xylooligomers and simultaneous mutations of GXM2/3 genes caused a loss of such a methyltransferase activity. Taken together, our results provide the first line of genetic and biochemical evidence that the three DUF579 domain-containing proteins, GXM1, GXM2 and GXM3, are methyltransferases catalyzing 4-O-methylation of GlcA side chains on xylan.
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Affiliation(s)
- Chanhui Lee
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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137
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Chiniquy D, Sharma V, Schultink A, Baidoo EE, Rautengarten C, Cheng K, Carroll A, Ulvskov P, Harholt J, Keasling JD, Pauly M, Scheller HV, Ronald PC. XAX1 from glycosyltransferase family 61 mediates xylosyltransfer to rice xylan. Proc Natl Acad Sci U S A 2012; 109:17117-22. [PMID: 23027943 PMCID: PMC3479505 DOI: 10.1073/pnas.1202079109] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Xylan is the second most abundant polysaccharide on Earth and represents an immense quantity of stored energy for biofuel production. Despite its importance, most of the enzymes that synthesize xylan have yet to be identified. Xylans have a backbone of β-1,4-linked xylose residues with substitutions that include α-(1→2)-linked glucuronosyl, 4-O-methyl glucuronosyl, and α-1,2- and α-1,3-arabinofuranosyl residues. The substitutions are structurally diverse and vary by taxonomy, with grass xylan representing a unique composition distinct from dicots and other monocots. To date, no enzyme has yet been identified that is specific to grass xylan synthesis. We identified a xylose-deficient loss-of-function rice mutant in Os02g22380, a putative glycosyltransferase in a grass-specific subfamily of family GT61. We designate the mutant xax1 for xylosyl arabinosyl substitution of xylan 1. Enzymatic fingerprinting of xylan showed the specific absence in the mutant of a peak, which was isolated and determined by (1)H-NMR to be (β-1,4-Xyl)(4) with a β-Xylp-(1→2)-α-Araf-(1→3). Rice xax1 mutant plants are deficient in ferulic and coumaric acid, aromatic compounds known to be attached to arabinosyl residues in xylan substituted with xylosyl residues. The xax1 mutant plants exhibit an increased extractability of xylan and increased saccharification, probably reflecting a lower degree of diferulic cross-links. Activity assays with microsomes isolated from tobacco plants transiently expressing XAX1 demonstrated xylosyltransferase activity onto endogenous acceptors. Our results provide insight into grass xylan synthesis and how substitutions may be modified for increased saccharification for biofuel generation.
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Affiliation(s)
- Dawn Chiniquy
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA 95616
- Joint BioEnergy Institute, Emeryville, CA 94608
| | | | - Alex Schultink
- Department of Plant and Microbial Biology
- Energy Biosciences Institute, and
| | - Edward E. Baidoo
- Joint BioEnergy Institute, Emeryville, CA 94608
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | | | - Kun Cheng
- Department of Plant and Microbial Biology
- Energy Biosciences Institute, and
| | | | - Peter Ulvskov
- Department of Plant Biology and Biotechnology, University of Copenhagen, DK-1871 Frederiksberg C, Denmark; and
| | - Jesper Harholt
- Department of Plant Biology and Biotechnology, University of Copenhagen, DK-1871 Frederiksberg C, Denmark; and
| | - Jay D. Keasling
- Joint BioEnergy Institute, Emeryville, CA 94608
- Department of Chemical and Biomolecular Engineering, Department of Bioengineering, University of California, Berkeley, CA 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Markus Pauly
- Department of Plant and Microbial Biology
- Energy Biosciences Institute, and
| | - Henrik V. Scheller
- Joint BioEnergy Institute, Emeryville, CA 94608
- Department of Plant and Microbial Biology
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Pamela C. Ronald
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA 95616
- Joint BioEnergy Institute, Emeryville, CA 94608
- Department of Plant Molecular Systems Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea
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138
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Kim JS, Daniel G. Immunolocalization of hemicelluloses in Arabidopsis thaliana stem. Part I: temporal and spatial distribution of xylans. PLANTA 2012; 236:1275-88. [PMID: 22711286 DOI: 10.1007/s00425-012-1686-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 06/01/2012] [Indexed: 05/11/2023]
Abstract
We investigated the microdistribution of xylans in different cell types of Arabidopsis stem using immunolocalization methods with LM10 and LM11 antibodies. Xylan labeling in xylary fibers (fibers) was initially detected at the cell corner of the S(1) layer and increased gradually during fiber maturation, showing correlation between xylan labeling and general secondary cell wall formation processes in fibers. Metaxylem vessels (vessels) showed earlier development of secondary cell walls than fibers, but revealed almost identical labeling patterns to fibers during maturation. No difference in labeling patterns and intensity was detected in the cell wall of fibers, vessels and protoxylem vessels (proto-vessels) between LM10 and LM11, indicating that vascular bundle cells may be chemically composed of a highly homogeneous xylan type. Interestingly, interfascicular fibers (If-fibers) showed different labeling patterns between the two antibodies and also between different developmental stages. LM10 showed no labeling in primary cell walls and intercellular layers of If-fibers at the S(1) formation stage, but some labeling was detected in middle lamella cell corner regions at the S(2) formation stage. In contrast, LM11 revealed uniform labeling across the If-fiber cell wall during all developmental stages. These results suggest that If-fibers have different xylan deposition processes and patterns from vascular bundle cells. The presence of xylan was also confirmed in parenchyma cells following pectinase treatment. Together our results indicate that there are temporal and spatial differences in xylan labeling between cell types in Arabidopsis stem. Differences in xylan labeling between Arabidopsis stem and poplar are also discussed.
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Affiliation(s)
- Jong Sik Kim
- Wood Science, Department of Forest Products, Swedish University of Agricultural Sciences, PO Box 7008, 750 07 Uppsala, Sweden.
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139
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4-O-methylation of glucuronic acid in Arabidopsis glucuronoxylan is catalyzed by a domain of unknown function family 579 protein. Proc Natl Acad Sci U S A 2012; 109:14253-8. [PMID: 22893684 DOI: 10.1073/pnas.1208097109] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The hemicellulose 4-O-methyl glucuronoxylan is one of the principle components present in the secondary cell walls of eudicotyledonous plants. However, the biochemical mechanisms leading to the formation of this polysaccharide and the effects of modulating its structure on the physical properties of the cell wall are poorly understood. We have identified and functionally characterized an Arabidopsis glucuronoxylan methyltransferase (GXMT) that catalyzes 4-O-methylation of the glucuronic acid substituents of this polysaccharide. AtGXMT1, which was previously classified as a domain of unknown function (DUF) 579 protein, specifically transfers the methyl group from S-adenosyl-L-methionine to O-4 of α-D-glucopyranosyluronic acid residues that are linked to O-2 of the xylan backbone. Biochemical characterization of the recombinant enzyme indicates that GXMT1 is localized in the Golgi apparatus and requires Co(2+) for optimal activity in vitro. Plants lacking GXMT1 synthesize glucuronoxylan in which the degree of 4-O-methylation is reduced by 75%. This result is correlated to a change in lignin monomer composition and an increase in glucuronoxylan release during hydrothermal treatment of secondary cell walls. We propose that the DUF579 proteins constitute a previously undescribed family of cation-dependent, polysaccharide-specific O-methyl-transferases. This knowledge provides new opportunities to selectively manipulate polysaccharide O-methylation and extends the portfolio of structural targets that can be modified either alone or in combination to modulate biopolymer interactions in the plant cell wall.
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140
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Neumetzler L, Humphrey T, Lumba S, Snyder S, Yeats TH, Usadel B, Vasilevski A, Patel J, Rose JKC, Persson S, Bonetta D. The FRIABLE1 gene product affects cell adhesion in Arabidopsis. PLoS One 2012; 7:e42914. [PMID: 22916179 PMCID: PMC3419242 DOI: 10.1371/journal.pone.0042914] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 07/15/2012] [Indexed: 11/18/2022] Open
Abstract
Cell adhesion in plants is mediated predominantly by pectins, a group of complex cell wall associated polysaccharides. An Arabidopsis mutant, friable1 (frb1), was identified through a screen of T-DNA insertion lines that exhibited defective cell adhesion. Interestingly, the frb1 plants displayed both cell and organ dissociations and also ectopic defects in organ separation. The FRB1 gene encodes a Golgi-localized, plant specific protein with only weak sequence similarities to known proteins (DUF246). Unlike other cell adhesion deficient mutants, frb1 mutants do not have reduced levels of adhesion related cell wall polymers, such as pectins. Instead, FRB1 affects the abundance of galactose- and arabinose-containing oligosaccharides in the Golgi. Furthermore, frb1 mutants displayed alteration in pectin methylesterification, cell wall associated extensins and xyloglucan microstructure. We propose that abnormal FRB1 action has pleiotropic consequences on wall architecture, affecting both the extensin and pectin matrices, with consequent changes to the biomechanical properties of the wall and middle lamella, thereby influencing cell-cell adhesion.
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Affiliation(s)
- Lutz Neumetzler
- Max Planck Institute of Molecular Plant Physiology, Golm/Potsdam, Germany
| | - Tania Humphrey
- Vineland Research and Innovation Centre, Vineland Station, Ontario, Canada
| | - Shelley Lumba
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Stephen Snyder
- Department of Plant Biology, Cornell University, Ithaca, New York, United States of America
| | - Trevor H. Yeats
- Department of Plant Biology, Cornell University, Ithaca, New York, United States of America
| | - Björn Usadel
- Max Planck Institute of Molecular Plant Physiology, Golm/Potsdam, Germany
| | | | - Jignasha Patel
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Jocelyn K. C. Rose
- Department of Plant Biology, Cornell University, Ithaca, New York, United States of America
| | - Staffan Persson
- Max Planck Institute of Molecular Plant Physiology, Golm/Potsdam, Germany
| | - Dario Bonetta
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
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141
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Lee C, Teng Q, Zhong R, Ye ZH. Arabidopsis GUX proteins are glucuronyltransferases responsible for the addition of glucuronic acid side chains onto xylan. PLANT & CELL PHYSIOLOGY 2012; 53:1204-16. [PMID: 22537759 DOI: 10.1093/pcp/pcs064] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Xylan, the second most abundant cell wall polysaccharide, is composed of a linear backbone of β-(1,4)-linked xylosyl residues that are often substituted with sugar side chains, such as glucuronic acid (GlcA) and methylglucuronic acid (MeGlcA). It has recently been shown that mutations of two Arabidopsis family GT8 genes, GUX1 and GUX2, affect the addition of GlcA and MeGlcA to xylan, but it is not known whether they encode glucuronyltransferases (GlcATs) or indirectly regulate the GlcAT activity. In this study, we performed biochemical and genetic analyses of three Arabidopsis GUX genes to determine their roles in the GlcA substitution of xylan and secondary wall deposition. The GUX1/2/3 genes were found to be expressed in interfascicular fibers and xylem cells, the two major types of secondary wall-containing cells that have abundant xylan. When expressed in tobacco BY2 cells, the GUX1/2/3 proteins exhibited an activity capable of transferring GlcA residues from the UDP-GlcA donor onto xylooligomer acceptors, demonstrating that these GUX proteins possess xylan GlcAT activity. Analyses of the single, double and triple gux mutants revealed that simultaneous mutations of all three GUX genes led to a complete loss of GlcA and MeGlcA side chains on xylan, indicating that all three GUX proteins are involved in the GlcA substitution of xylan. Furthermore, a complete loss of GlcA and MeGlcA side chains in the gux1/2/3 triple mutant resulted in reduced secondary wall thickening, collapsed vessel morphology and reduced plant growth. Together, our results provide biochemical and genetic evidence that GUX1/2/3 are GlcATs responsible for the GlcA substitution of xylan, which is essential for normal secondary wall deposition and plant development.
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Affiliation(s)
- Chanhui Lee
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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142
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143
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Affiliation(s)
- Anett Doering
- Max-Planck-Institute for Molecular Plant Physiology, Potsdam, Germany
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144
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The glycosyltransferase repertoire of the spikemoss Selaginella moellendorffii and a comparative study of its cell wall. PLoS One 2012; 7:e35846. [PMID: 22567114 PMCID: PMC3342304 DOI: 10.1371/journal.pone.0035846] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 03/26/2012] [Indexed: 01/28/2023] Open
Abstract
Spike mosses are among the most basal vascular plants, and one species, Selaginella moellendorffii, was recently selected for full genome sequencing by the Joint Genome Institute (JGI). Glycosyltransferases (GTs) are involved in many aspects of a plant life, including cell wall biosynthesis, protein glycosylation, primary and secondary metabolism. Here, we present a comparative study of the S. moellendorffii genome across 92 GT families and an additional family (DUF266) likely to include GTs. The study encompasses the moss Physcomitrella patens, a non-vascular land plant, while rice and Arabidopsis represent commelinid and non-commelinid seed plants. Analysis of the subset of GT-families particularly relevant to cell wall polysaccharide biosynthesis was complemented by a detailed analysis of S. moellendorffii cell walls. The S. moellendorffii cell wall contains many of the same components as seed plant cell walls, but appears to differ somewhat in its detailed architecture. The S. moellendorffii genome encodes fewer GTs (287 GTs including DUF266s) than the reference genomes. In a few families, notably GT51 and GT78, S. moellendorffii GTs have no higher plant orthologs, but in most families S. moellendorffii GTs have clear orthologies with Arabidopsis and rice. A gene naming convention of GTs is proposed which takes orthologies and GT-family membership into account. The evolutionary significance of apparently modern and ancient traits in S. moellendorffii is discussed, as is its use as a reference organism for functional annotation of GTs.
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145
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Mizrachi E, Mansfield SD, Myburg AA. Cellulose factories: advancing bioenergy production from forest trees. THE NEW PHYTOLOGIST 2012; 194:54-62. [PMID: 22474687 DOI: 10.1111/j.1469-8137.2011.03971.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Fast-growing, short-rotation forest trees, such as Populus and Eucalyptus, produce large amounts of cellulose-rich biomass that could be utilized for bioenergy and biopolymer production. Major obstacles need to be overcome before the deployment of these genera as energy crops, including the effective removal of lignin and the subsequent liberation of carbohydrate constituents from wood cell walls. However, significant opportunities exist to both select for and engineer the structure and interaction of cell wall biopolymers, which could afford a means to improve processing and product development. The molecular underpinnings and regulation of cell wall carbohydrate biosynthesis are rapidly being elucidated, and are providing tools to strategically develop and guide the targeted modification required to adapt forest trees for the emerging bioeconomy. Much insight has already been gained from the perturbation of individual genes and pathways, but it is not known to what extent the natural variation in the sequence and expression of these same genes underlies the inherent variation in wood properties of field-grown trees. The integration of data from next-generation genomic technologies applied in natural and experimental populations will enable a systems genetics approach to study cell wall carbohydrate production in trees, and should advance the development of future woody bioenergy and biopolymer crops.
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Affiliation(s)
- Eshchar Mizrachi
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
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146
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Søgaard C, Stenbæk A, Bernard S, Hadi M, Driouich A, Scheller HV, Sakuragi Y. GO-PROMTO illuminates protein membrane topologies of glycan biosynthetic enzymes in the Golgi apparatus of living tissues. PLoS One 2012; 7:e31324. [PMID: 22363620 PMCID: PMC3283625 DOI: 10.1371/journal.pone.0031324] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 01/05/2012] [Indexed: 12/27/2022] Open
Abstract
The Golgi apparatus is the main site of glycan biosynthesis in eukaryotes. Better understanding of the membrane topology of the proteins and enzymes involved can impart new mechanistic insights into these processes. Publically available bioinformatic tools provide highly variable predictions of membrane topologies for given proteins. Therefore we devised a non-invasive experimental method by which the membrane topologies of Golgi-resident proteins can be determined in the Golgi apparatus in living tissues. A Golgi marker was used to construct a series of reporters based on the principle of bimolecular fluorescence complementation. The reporters and proteins of interest were recombinantly fused to split halves of yellow fluorescent protein (YFP) and transiently co-expressed with the reporters in the Nicotiana benthamiana leaf tissue. Output signals were binary, showing either the presence or absence of fluorescence with signal morphologies characteristic of the Golgi apparatus and endoplasmic reticulum (ER). The method allows prompt and robust determinations of membrane topologies of Golgi-resident proteins and is termed GO-PROMTO (for GOlgi PROtein Membrane TOpology). We applied GO-PROMTO to examine the topologies of proteins involved in the biosynthesis of plant cell wall polysaccharides including xyloglucan and arabinan. The results suggest the existence of novel biosynthetic mechanisms involving transports of intermediates across Golgi membranes.
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Affiliation(s)
- Casper Søgaard
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark
- Villum Kann Rasmussen Centre for ProActive Plants, Frederiksberg, Denmark
| | - Anne Stenbæk
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark
- Villum Kann Rasmussen Centre for ProActive Plants, Frederiksberg, Denmark
| | - Sophie Bernard
- Laboratoire de Glycobiologie et Matrice Extracellulaire-EA 4358, University of Rouen, Mont Saint Aignan, France
| | - Masood Hadi
- Technologies Division, Joint BioEnergy Institute, Sandia National Laboratory, Emeryville, California, United States of America
| | - Azeddine Driouich
- Laboratoire de Glycobiologie et Matrice Extracellulaire-EA 4358, University of Rouen, Mont Saint Aignan, France
| | - Henrik Vibe Scheller
- Feedstocks Division, Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, California, United States of America
| | - Yumiko Sakuragi
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark
- Villum Kann Rasmussen Centre for ProActive Plants, Frederiksberg, Denmark
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147
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Dhugga KS. Biosynthesis of non-cellulosic polysaccharides of plant cell walls. PHYTOCHEMISTRY 2012; 74:8-19. [PMID: 22137036 DOI: 10.1016/j.phytochem.2011.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 10/08/2011] [Indexed: 05/25/2023]
Abstract
Enzymes that make the polymer backbones of plant cell wall polysaccharides have proven to be recalcitrant to biochemical purification. Availability of mutational genetics and genomic tools paved the way for rapid progress in identifying genes encoding various cell wall glycan synthases. Mutational genetics, the primary tool used in unraveling cellulose biosynthesis, was ineffective in assigning function to any of the hemicellulosic, polymerizing glycan synthases. A combination of comparative genomics and functional expression in a heterologous system allowed identification of various cellulose synthase-like (Csl) sequences as being involved in the formation of β-1,4-mannan, β-1,4-glucan, and mixed-linked glucan. A number of xylose-deficient mutants have led to a variety of genes, none of which thus far possesses the motifs known to be conserved among polymerizing β-glycan synthases. Except for xylan synthase, which appears to be an agglomerate of proteins just like cellulose synthase, Golgi glycan synthases already identified suggest that the catalytic polypeptide by itself is sufficient for enzyme activity, most likely as a homodimer. Several of the Csl genes remain to be assigned a function. The possibility of the involvement of various Csl genes in making more than one product remains.
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Affiliation(s)
- Kanwarpal S Dhugga
- Genetic Discovery, DuPont Agricultural Biotechnology, Pioneer Hi-Bred International, Johnston, IA 50131, United States.
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148
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Cook CM, Daudi A, Millar DJ, Bindschedler LV, Khan S, Bolwell GP, Devoto A. Transcriptional changes related to secondary wall formation in xylem of transgenic lines of tobacco altered for lignin or xylan content which show improved saccharification. PHYTOCHEMISTRY 2012; 74:79-89. [PMID: 22119077 PMCID: PMC3657182 DOI: 10.1016/j.phytochem.2011.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 07/22/2011] [Accepted: 10/14/2011] [Indexed: 05/04/2023]
Abstract
In this study, an EST library (EH663598-EH666265) obtained from xylogenic tissue cultures of tobacco that had been previously generated was annotated. The library proved to be enriched in transcripts related to the synthesis and modification of secondary cell walls. The xylem-specific transcripts for most of the genes of the lignification and xylan pathways were identified and several full-length sequences obtained. Gene expression was determined in available tobacco lines down-regulated for enzymes of the phenylpropanoid pathway: CINNAMATE 4-HYDROXYLASE (sc4h), CINNAMOYL-COA REDUCTASE (asccr) and lignification-specific peroxidase (asprx). In addition, lines down-regulated in the nucleotide-sugar pathway to xylan formation through antisense expression of UDP-GLUCURONIC ACID DECARBOXYLASE (asuxs) were also analysed. It is shown herein that most transcripts were down-regulated for both lignin and xylan synthesis pathways in these lines, while CELLULOSE SYNTHASE A3 was up-regulated in lignin-modified lines. The analysis indicates the existence of interdependence between lignin and xylan pathways at the transcriptional level and also shows that levels of cellulose, xylan and lignin are not necessarily directly correlated to differences in transcription of the genes involved upstream, as shown by cell wall fractionation and sugar analysis. It is therefore suggested that cell wall biosynthesis regulation occurs at different levels, and not merely at the transcriptional level. In addition, all lines analyzed showed improved enzymic saccharification of secondary but not primary walls. Nevertheless, this demonstrates potential industrial applicability for the approach undertaken to improve biomass utility.
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Key Words
- adh, bifunctional alcohol/udp glucose dehydrogenase
- aim, acetone-insoluble material
- cesa3, cellulose synthase
- csld, cellulose synthase-like d
- pal, phenylalanine ammonia lyase
- c4h, cinnamate 4-hydroxylase
- c3h, coumaroyl-ester-3-hydroxylase
- comt, caffeic acid o-methyl transferase
- ccomt, caffeoyl-coa methyl-transferase
- ccr, cinnamoyl-coa reductase
- cad, cinnamyl alcohol dehydrogenase
- hqt, hydroxycinnamoyl-coa:quinate hydroxycinnamoyltransferase
- susy, sucrose synthase
- ugd, udp-glucose dehydrogenase
- uxs, udp-glucuronate decarboxylase
- tobacco
- nicotiana tabacum
- solanaceae
- cell wall
- lignin
- xylan
- antisense
- saccharification
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Affiliation(s)
- Charis M. Cook
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
| | - Arsalan Daudi
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
| | - David J. Millar
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
- Department of Medicine, Royal Free & University College Medical School, University College London, Rowland Hill Street, London NW3 2PF, UK
| | - Laurence V. Bindschedler
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
- Department of chemistry, University of Reading, Whiteknights, Reading RG6 6AS, UK
| | - Safina Khan
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
| | - G. Paul Bolwell
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
| | - Alessandra Devoto
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
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149
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Abstract
This account gives a brief overview of various directions in current solar fuels research. On that basis, the necessity for an interdisciplinary approach is argued, and an institutional way for promoting this development is presented using the example of the Chemistry Biology Centre (KBC) at Umeå University in Sweden.
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150
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Zhang SJ, Song XQ, Yu BS, Zhang BC, Sun CQ, Knox JP, Zhou YH. Identification of quantitative trait loci affecting hemicellulose characteristics based on cell wall composition in a wild and cultivated rice species. MOLECULAR PLANT 2012; 5:162-75. [PMID: 21914650 DOI: 10.1093/mp/ssr076] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Cell wall hemicellulosic polysaccharides are structurally complex and diverse. Knowledge about the synthesis of cell wall hemicelluloses and their biological roles is limited. Quantitative trait loci (QTL) mapping is a helpful tool for the dissection of complex phenotypes for gene identification. In this study, we exploited the natural variation in cell wall monosaccharide levels between a common wild rice, Yuanj, and an elite indica cultivar, Teqing, and performed QTL mapping with their introgression lines (ILs). Chemical analyses conducted on the culms of Yuanj and Teqing showed that the major alterations are found in glucose and xylose levels, which are correlated with specific hemicellulosic polymers. Glycosidic linkage examination revealed that, in Yuanj, an increase in glucose content results from a higher level of mixed linkage β-glucan (MLG), whereas a reduction in xylose content reflects a low level of xylan backbone and a varied arabinoxylan (AX) structure. Seventeen QTLs for monosaccharides have been identified through composition analysis of the culm residues of 95 core ILs. Four major QTLs affecting xylose and glucose levels are responsible for 19 and 21% of the phenotypic variance, respectively. This study provides a unique resource for the genetic dissection of rice cell wall formation and remodeling in the vegetative organs.
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Affiliation(s)
- Si-Ju Zhang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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