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Zeng D, Ford B, Doležel J, Karafiátová M, Hayden MJ, Rathjen TM, George TS, Brown LK, Ryan PR, Pettolino FA, Mathesius U, Delhaize E. A conditional mutation in a wheat (Triticum aestivum L.) gene regulating root morphology. Theor Appl Genet 2024; 137:48. [PMID: 38345612 PMCID: PMC10861616 DOI: 10.1007/s00122-024-04555-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024]
Abstract
KEY MESSAGE Characterisation and genetic mapping of a key gene defining root morphology in bread wheat. Root morphology is central to plants for the efficient uptake up of soil water and mineral nutrients. Here we describe a conditional mutant of hexaploid wheat (Triticum aestivum L.) that when grown in soil with high Ca2+ develops a larger rhizosheath accompanied with shorter roots than the wild type. In wheat, rhizosheath size is a reliable surrogate for root hair length and this was verified in the mutant which possessed longer root hairs than the wild type when grown in high Ca2+ soil. We named the mutant Stumpy and showed it to be due to a single semi-dominant mutation. The short root phenotype at high Ca2+ was due to reduced cellular elongation which might also explain the long root hair phenotype. Analysis of root cell walls showed that the polysaccharide composition of Stumpy roots is remodelled when grown at non-permissive (high) Ca2+ concentrations. The mutation mapped to chromosome 7B and sequencing of the 7B chromosomes in both wild type and Stumpy identified a candidate gene underlying the Stumpy mutation. As part of the process to determine whether the candidate gene was causative, we identified wheat lines in a Cadenza TILLING population with large rhizosheaths but accompanied with normal root length. This finding illustrates the potential of manipulating the gene to disconnect root length from root hair length as a means of developing wheat lines with improved efficiency of nutrient and water uptake. The Stumpy mutant will be valuable for understanding the mechanisms that regulate root morphology in wheat.
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Affiliation(s)
- Deying Zeng
- Department of Biological Science, College of Life Sciences, Sichuan Normal University, Chengdu, Sichuan, 610101, China
| | - Brett Ford
- Grains Research and Development Corporation, Barton, ACT, 2600, Australia
- CSIRO Agriculture & Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | - Jaroslav Doležel
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czech Republic
| | - Miroslava Karafiátová
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czech Republic
| | - Mathew J Hayden
- Department of Jobs, Precincts and Regions, Agriculture Victoria Research, AgriBio, Bundoora, VIC, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC, Australia
| | - Tina M Rathjen
- CSIRO Agriculture & Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | | | - Lawrie K Brown
- James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Peter R Ryan
- CSIRO Agriculture & Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | | | - Ulrike Mathesius
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Emmanuel Delhaize
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.
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Conaty WC, Broughton KJ, Egan LM, Li X, Li Z, Liu S, Llewellyn DJ, MacMillan CP, Moncuquet P, Rolland V, Ross B, Sargent D, Zhu QH, Pettolino FA, Stiller WN. Cotton Breeding in Australia: Meeting the Challenges of the 21st Century. Front Plant Sci 2022; 13:904131. [PMID: 35646011 PMCID: PMC9136452 DOI: 10.3389/fpls.2022.904131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023]
Abstract
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) cotton breeding program is the sole breeding effort for cotton in Australia, developing high performing cultivars for the local industry which is worth∼AU$3 billion per annum. The program is supported by Cotton Breeding Australia, a Joint Venture between CSIRO and the program's commercial partner, Cotton Seed Distributors Ltd. (CSD). While the Australian industry is the focus, CSIRO cultivars have global impact in North America, South America, and Europe. The program is unique compared with many other public and commercial breeding programs because it focuses on diverse and integrated research with commercial outcomes. It represents the full research pipeline, supporting extensive long-term fundamental molecular research; native and genetically modified (GM) trait development; germplasm enhancement focused on yield and fiber quality improvements; integration of third-party GM traits; all culminating in the release of new commercial cultivars. This review presents evidence of past breeding successes and outlines current breeding efforts, in the areas of yield and fiber quality improvement, as well as the development of germplasm that is resistant to pests, diseases and abiotic stressors. The success of the program is based on the development of superior germplasm largely through field phenotyping, together with strong commercial partnerships with CSD and Bayer CropScience. These relationships assist in having a shared focus and ensuring commercial impact is maintained, while also providing access to markets, traits, and technology. The historical successes, current foci and future requirements of the CSIRO cotton breeding program have been used to develop a framework designed to augment our breeding system for the future. This will focus on utilizing emerging technologies from the genome to phenome, as well as a panomics approach with data management and integration to develop, test and incorporate new technologies into a breeding program. In addition to streamlining the breeding pipeline for increased genetic gain, this technology will increase the speed of trait and marker identification for use in genome editing, genomic selection and molecular assisted breeding, ultimately producing novel germplasm that will meet the coming challenges of the 21st Century.
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Affiliation(s)
| | | | - Lucy M. Egan
- CSIRO Agriculture and Food, Narrabri, NSW, Australia
| | - Xiaoqing Li
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Zitong Li
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Shiming Liu
- CSIRO Agriculture and Food, Narrabri, NSW, Australia
| | | | | | | | | | - Brett Ross
- Cotton Seed Distributors Ltd., Wee Waa, NSW, Australia
| | - Demi Sargent
- CSIRO Agriculture and Food, Narrabri, NSW, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Qian-Hao Zhu
- CSIRO Agriculture and Food, Canberra, ACT, Australia
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MacMillan CP, Birke H, Chuah A, Brill E, Tsuji Y, Ralph J, Dennis ES, Llewellyn D, Pettolino FA. Correction to: Tissue and cell-specific transcriptomes in cotton reveal the subtleties of gene regulation underlying the diversity of plant secondary cell walls. BMC Genomics 2018; 19:261. [PMID: 29665776 PMCID: PMC5902885 DOI: 10.1186/s12864-018-4634-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 03/27/2018] [Indexed: 11/25/2022] Open
Affiliation(s)
| | - Hannah Birke
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia.,Present address: Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Aaron Chuah
- John Curtin School of Medical Research, The Australian National University, ACT, Canberra, 2601, Australia
| | - Elizabeth Brill
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
| | - Yukiko Tsuji
- Department of Biochemistry and the Department of Energy's Great Lakes BioEnergy Research Center, The Wisconsin Energy Institute, 1552 University Avenue, Madison, WI, 53726-4084, USA
| | - John Ralph
- Department of Biochemistry and the Department of Energy's Great Lakes BioEnergy Research Center, The Wisconsin Energy Institute, 1552 University Avenue, Madison, WI, 53726-4084, USA
| | | | - Danny Llewellyn
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
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4
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MacMillan CP, Birke H, Chuah A, Brill E, Tsuji Y, Ralph J, Dennis ES, Llewellyn D, Pettolino FA. Tissue and cell-specific transcriptomes in cotton reveal the subtleties of gene regulation underlying the diversity of plant secondary cell walls. BMC Genomics 2017; 18:539. [PMID: 28720072 PMCID: PMC5516393 DOI: 10.1186/s12864-017-3902-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Knowledge of plant secondary cell wall (SCW) regulation and deposition is mainly based on the Arabidopsis model of a 'typical' lignocellulosic SCW. However, SCWs in other plants can vary from this. The SCW of mature cotton seed fibres is highly cellulosic and lacks lignification whereas xylem SCWs are lignocellulosic. We used cotton as a model to study different SCWs and the expression of the genes involved in their formation via RNA deep sequencing and chemical analysis of stem and seed fibre. RESULTS Transcriptome comparisons from cotton xylem and pith as well as from a developmental series of seed fibres revealed tissue-specific and developmentally regulated expression of several NAC transcription factors some of which are likely to be important as top tier regulators of SCW formation in xylem and/or seed fibre. A so far undescribed hierarchy was identified between the top tier NAC transcription factors SND1-like and NST1/2 in cotton. Key SCW MYB transcription factors, homologs of Arabidopsis MYB46/83, were practically absent in cotton stem xylem. Lack of expression of other lignin-specific MYBs in seed fibre relative to xylem could account for the lack of lignin deposition in seed fibre. Expression of a MYB103 homolog correlated with temporal expression of SCW CesAs and cellulose synthesis in seed fibres. FLAs were highly expressed and may be important structural components of seed fibre SCWs. Finally, we made the unexpected observation that cell walls in the pith of cotton stems contained lignin and had a higher S:G ratio than in xylem, despite that tissue's lacking many of the gene transcripts normally associated with lignin biosynthesis. CONCLUSIONS Our study in cotton confirmed some features of the currently accepted gene regulatory cascade for 'typical' plant SCWs, but also revealed substantial differences, especially with key downstream NACs and MYBs. The lignocellulosic SCW of cotton xylem appears to be achieved differently from that in Arabidopsis. Pith cell walls in cotton stems are compositionally very different from that reported for other plant species, including Arabidopsis. The current definition of a 'typical' primary or secondary cell wall might not be applicable to all cell types in all plant species.
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Affiliation(s)
| | - Hannah Birke
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT, 2601, Australia.,Present address: Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Aaron Chuah
- John Curtin School of Medical Research, The Australian National University, ACT, Canberra, 2601, Australia
| | - Elizabeth Brill
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | - Yukiko Tsuji
- Department of Biochemistry and the Department of Energy's Great Lakes BioEnergy Research Center, The Wisconsin Energy Institute, 1552 University Avenue, Madison, WI, 53726-4084, USA
| | - John Ralph
- Department of Biochemistry and the Department of Energy's Great Lakes BioEnergy Research Center, The Wisconsin Energy Institute, 1552 University Avenue, Madison, WI, 53726-4084, USA
| | | | - Danny Llewellyn
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT, 2601, Australia
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5
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Li Y, Tu L, Pettolino FA, Ji S, Hao J, Yuan D, Deng F, Tan J, Hu H, Wang Q, Llewellyn DJ, Zhang X. GbEXPATR, a species-specific expansin, enhances cotton fibre elongation through cell wall restructuring. Plant Biotechnol J 2016; 14:951-63. [PMID: 26269378 DOI: 10.1111/pbi.12450] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 05/08/2015] [Accepted: 05/26/2015] [Indexed: 05/18/2023]
Abstract
Cotton provides us the most important natural fibre. High fibre quality is the major goal of cotton breeding, and introducing genes conferring longer, finer and stronger fibre from Gossypium barbadense to Gossypium hirsutum is an important breeding strategy. We previously analysed the G. barbadense fibre development mechanism by gene expression profiling and found two homoeologous fibre-specific α-expansins from G. barbadense, GbEXPA2 and GbEXPATR. GbEXPA2 (from the DT genome) is a classical α-expansin, while its homoeolog, GbEXPATR (AT genome), encodes a truncated protein lacking the normal C-terminal polysaccharide-binding domain of other α-expansins and is specifically expressed in G. barbadense. Silencing EXPA in G. hirsutum induced shorter fibres with thicker cell walls. GbEXPA2 overexpression in G. hirsutum had no effect on mature fibre length, but produced fibres with a slightly thicker wall and increased crystalline cellulose content. Interestingly, GbEXPATR overexpression resulted in longer, finer and stronger fibres coupled with significantly thinner cell walls. The longer and thinner fibre was associated with lower expression of a number of secondary wall-associated genes, especially chitinase-like genes, and walls with lower cellulose levels but higher noncellulosic polysaccharides which advocated that a delay in the transition to secondary wall synthesis might be responsible for better fibre. In conclusion, we propose that α-expansins play a critical role in fibre development by loosening the cell wall; furthermore, a truncated form, GbEXPATR, has a more dramatic effect through reorganizing secondary wall synthesis and metabolism and should be a candidate gene for developing G. hirsutum cultivars with superior fibre quality.
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Affiliation(s)
- Yang Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Lili Tu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Filomena A Pettolino
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Plant Industry, Canberra, ACT, Australia
| | - Shengmei Ji
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Juan Hao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Daojun Yuan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Fenglin Deng
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jiafu Tan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Haiyan Hu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Qing Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Danny J Llewellyn
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Plant Industry, Canberra, ACT, Australia
| | - Xianlong Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
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6
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Osabe K, Clement JD, Bedon F, Pettolino FA, Ziolkowski L, Llewellyn DJ, Finnegan EJ, Wilson IW. Genetic and DNA methylation changes in cotton (Gossypium) genotypes and tissues. PLoS One 2014; 9:e86049. [PMID: 24465864 PMCID: PMC3896429 DOI: 10.1371/journal.pone.0086049] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 12/05/2013] [Indexed: 12/19/2022] Open
Abstract
In plants, epigenetic regulation is important in normal development and in modulating some agronomic traits. The potential contribution of DNA methylation mediated gene regulation to phenotypic diversity and development in cotton was investigated between cotton genotypes and various tissues. DNA methylation diversity, genetic diversity, and changes in methylation context were investigated using methylation-sensitive amplified polymorphism (MSAP) assays including a methylation insensitive enzyme (BsiSI), and the total DNA methylation level was measured by high-performance liquid chromatography (HPLC). DNA methylation diversity was greater than the genetic diversity in the selected cotton genotypes and significantly different levels of DNA methylation were identified between tissues, including fibre. The higher DNA methylation diversity (CHG methylation being more diverse than CG methylation) in cotton genotypes suggest epigenetic regulation may be important for cotton, and the change in DNA methylation between fibre and other tissues hints that some genes may be epigenetically regulated for fibre development. The novel approach using BsiSI allowed direct comparison between genetic and epigenetic diversity, and also measured CC methylation level that cannot be detected by conventional MSAP.
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7
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Moller IE, Pettolino FA, Hart C, Lampugnani ER, Willats WGT, Bacic A. Glycan profiling of plant cell wall polymers using microarrays. J Vis Exp 2012:e4238. [PMID: 23271573 DOI: 10.3791/4238] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Plant cell walls are complex matrixes of heterogeneous glycans which play an important role in the physiology and development of plants and provide the raw materials for human societies (e.g. wood, paper, textile and biofuel industries)(1,2). However, understanding the biosynthesis and function of these components remains challenging. Cell wall glycans are chemically and conformationally diverse due to the complexity of their building blocks, the glycosyl residues. These form linkages at multiple positions and differ in ring structure, isomeric or anomeric configuration, and in addition, are substituted with an array of non-sugar residues. Glycan composition varies in different cell and/or tissue types or even sub-domains of a single cell wall(3). Furthermore, their composition is also modified during development(1), or in response to environmental cues(4). In excess of 2,000 genes have Plant cell walls are complex matrixes of heterogeneous glycans been predicted to be involved in cell wall glycan biosynthesis and modification in Arabidopsis(5). However, relatively few of the biosynthetic genes have been functionally characterized (4,5). Reverse genetics approaches are difficult because the genes are often differentially expressed, often at low levels, between cell types(6). Also, mutant studies are often hindered by gene redundancy or compensatory mechanisms to ensure appropriate cell wall function is maintained(7). Thus novel approaches are needed to rapidly characterise the diverse range of glycan structures and to facilitate functional genomics approaches to understanding cell wall biosynthesis and modification. Monoclonal antibodies (mAbs)(8,9) have emerged as an important tool for determining glycan structure and distribution in plants. These recognise distinct epitopes present within major classes of plant cell wall glycans, including pectins, xyloglucans, xylans, mannans, glucans and arabinogalactans. Recently their use has been extended to large-scale screening experiments to determine the relative abundance of glycans in a broad range of plant and tissue types simultaneously(9,10,11). Here we present a microarray-based glycan screening method called Comprehensive Microarray Polymer Profiling (CoMPP) (Figures 1 & 2)(10,11) that enables multiple samples (100 sec) to be screened using a miniaturised microarray platform with reduced reagent and sample volumes. The spot signals on the microarray can be formally quantified to give semi-quantitative data about glycan epitope occurrence. This approach is well suited to tracking glycan changes in complex biological systems(12) and providing a global overview of cell wall composition particularly when prior knowledge of this is unavailable.
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Affiliation(s)
- Isabel E Moller
- Australian Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne.
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8
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Wilson SM, Burton RA, Collins HM, Doblin MS, Pettolino FA, Shirley N, Fincher GB, Bacic A. Pattern of deposition of cell wall polysaccharides and transcript abundance of related cell wall synthesis genes during differentiation in barley endosperm. Plant Physiol 2012; 159:655-70. [PMID: 22510768 PMCID: PMC3375932 DOI: 10.1104/pp.111.192682] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Immunolabeling, combined with chemical analyses and transcript profiling, have provided a comprehensive temporal and spatial picture of the deposition and modification of cell wall polysaccharides during barley (Hordeum vulgare) grain development, from endosperm cellularization at 3 d after pollination (DAP) through differentiation to the mature grain at 38 DAP. (1→3)-β-D-Glucan appears transiently during cellularization but reappears in patches in the subaleurone cell walls around 20 DAP. (1→3, 1→4)-β-Glucan, the most abundant polysaccharide of the mature barley grain, accumulates throughout development. Arabino-(1-4)-β-D-xylan is deposited significantly earlier than we previously reported. This was attributable to the initial deposition of the polysaccharide in a highly substituted form that was not recognized by antibodies commonly used to detect arabino-(1-4)-β-D-xylans in sections of plant material. The epitopes needed for antibody recognition were exposed by pretreatment of sections with α-L-arabinofuranosidase; this procedure showed that arabino-(1-4)-β-D-xylans were deposited as early as 5 DAP and highlighted their changing structures during endosperm development. By 28 DAP labeling of hetero-(1→4)-β-D-mannan is observed in the walls of the starchy endosperm but not in the aleurone walls. Although absent in mature endosperm cell walls we now show that xyloglucan is present transiently from 3 until about 6 DAP and disappears by 8 DAP. Quantitative reverse transcription-polymerase chain reaction of transcripts for GLUCAN SYNTHASE-LIKE, Cellulose Synthase, and CELLULOSE SYNTHASE-LIKE genes were consistent with the patterns of polysaccharide deposition. Transcript profiling of some members from the Carbohydrate-Active Enzymes database glycosyl transferase families GT61, GT47, and GT43, previously implicated in arabino-(1-4)-β-d-xylan biosynthesis, confirms their presence during grain development.
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Affiliation(s)
- Sarah M Wilson
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Victoria 3010, Australia.
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9
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Ling NXY, Lee J, Ellis M, Liao ML, Mau SL, Guest D, Janssen PH, Kováč P, Bacic A, Pettolino FA. An exo-β-(1→3)-D-galactanase from Streptomyces sp. provides insights into type II arabinogalactan structure. Carbohydr Res 2012; 352:70-81. [PMID: 22464224 PMCID: PMC3419940 DOI: 10.1016/j.carres.2012.02.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/21/2012] [Accepted: 02/28/2012] [Indexed: 11/29/2022]
Abstract
An exo-β-(1→3)-D-galactanase (SGalase1) that specifically cleaves the β-(1→3)-D-galactan backbone of arabinogalactan-proteins (AGPs) was isolated from culture filtrates of a soil Streptomyces sp. Internal peptide sequence information was used to clone and recombinantly express the gene in E. coli. The molecular mass of the isolated enzyme was ~45 kDa, similar to the 48.2 kDa mass predicted from the amino acid sequence. The pI, pH and temperature optima for the enzyme were ~7.45, 3.8 and 48 °C, respectively. The native and recombinant enzymes specifically hydrolysed β-(1→3)-D-galacto-oligo- or poly-saccharides from the upstream (non-reducing) end, typical of an exo-acting enzyme. A second homologous Streptomyces gene (SGalase2) was also cloned and expressed. SGalase2 was similar in size (47.9 kDa) and enzyme activity to SGalase1 but differed in its pH optimum (pH 5). Both SGalase1 and SGalase2 are predicted to belong to the CAZy glycosyl hydrolase family GH 43 based on activity, sequence homology and phylogenetic analysis. The K(m) and V(max) of the native exo-β-(1→3)-D-galactanase for de-arabinosylated gum arabic (dGA) were 19 mg/ml and 9.7 μmol D-Gal/min/mg protein, respectively. The activity of these enzymes is well suited for the study of type II galactan structures and provides an important tool for the investigation of the biological role of AGPs in plants. De-arabinosylated gum arabic (dGA) was used as a model to investigate the use of these enzymes in defining type II galactan structure. Exhaustive hydrolysis of dGA resulted in a limited number of oligosaccharide products with a trisaccharide of Gal(2)GlcA(1) predominating.
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Affiliation(s)
- Naomi X.-Y. Ling
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Joanne Lee
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Miriam Ellis
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Ming-Long Liao
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Shaio-Lim Mau
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - David Guest
- Faculty of Agriculture, Food and Natural Resources, Biomedical Building C81, The University of Sydney, Eveleigh, NSW 2015, Australia
| | - Peter H. Janssen
- Grasslands Research Centre, AgResearch Ltd, Tennent Drive, Private Bag 11008, Palmerston North 4442, New Zealand
| | - Pavol Kováč
- Laboratory of Bioorganic Chemistry, Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892-0815, USA
| | - Antony Bacic
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Filomena A. Pettolino
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
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10
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Sørensen I, Pettolino FA, Bacic A, Ralph J, Lu F, O'Neill MA, Fei Z, Rose JKC, Domozych DS, Willats WGT. The charophycean green algae provide insights into the early origins of plant cell walls. Plant J 2011; 68:201-11. [PMID: 21707800 DOI: 10.1111/j.1365-313x.2011.04686.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Numerous evolutionary innovations were required to enable freshwater green algae to colonize terrestrial habitats and thereby initiate the evolution of land plants (embryophytes). These adaptations probably included changes in cell-wall composition and architecture that were to become essential for embryophyte development and radiation. However, it is not known to what extent the polymers that are characteristic of embryophyte cell walls, including pectins, hemicelluloses, glycoproteins and lignin, evolved in response to the demands of the terrestrial environment or whether they pre-existed in their algal ancestors. Here we show that members of the advanced charophycean green algae (CGA), including the Charales, Coleochaetales and Zygnematales, but not basal CGA (Klebsormidiales and Chlorokybales), have cell walls that are comparable in several respects to the primary walls of embryophytes. Moreover, we provide both chemical and immunocytochemical evidence that selected Coleochaete species have cell walls that contain small amounts of lignin or lignin-like polymers derived from radical coupling of hydroxycinnamyl alcohols. Thus, the ability to synthesize many of the components that characterize extant embryophyte walls evolved during divergence within CGA. Our study provides new insight into the evolutionary window during which the structurally complex walls of embryophytes originated, and the significance of the advanced CGA during these events.
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Affiliation(s)
- Iben Sørensen
- Department of Plant Biology and Biotechnology, University of Copenhagen, DK-1871 Copenhagen, Denmark
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Zhang Q, Pettolino FA, Dhugga KS, Rafalski JA, Tingey S, Taylor J, Shirley NJ, Hayes K, Beatty M, Abrams SR, Zaharia LI, Burton RA, Bacic A, Fincher GB. Cell wall modifications in maize pulvini in response to gravitational stress. Plant Physiol 2011; 156:2155-71. [PMID: 21697508 PMCID: PMC3149947 DOI: 10.1104/pp.111.179606] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 06/17/2011] [Indexed: 05/25/2023]
Abstract
Changes in cell wall polysaccharides, transcript abundance, metabolite profiles, and hormone concentrations were monitored in the upper and lower regions of maize (Zea mays) pulvini in response to gravistimulation, during which maize plants placed in a horizontal position returned to the vertical orientation. Heteroxylan levels increased in the lower regions of the pulvini, together with lignin, but xyloglucans and heteromannan contents decreased. The degree of substitution of heteroxylan with arabinofuranosyl residues decreased in the lower pulvini, which exhibited increased mechanical strength as the plants returned to the vertical position. Few or no changes in noncellulosic wall polysaccharides could be detected on the upper side of the pulvinus, and crystalline cellulose content remained essentially constant in both the upper and lower pulvinus. Microarray analyses showed that spatial and temporal changes in transcript profiles were consistent with the changes in wall composition that were observed in the lower regions of the pulvinus. In addition, the microarray analyses indicated that metabolic pathways leading to the biosynthesis of phytohormones were differentially activated in the upper and lower regions of the pulvinus in response to gravistimulation. Metabolite profiles and measured hormone concentrations were consistent with the microarray data, insofar as auxin, physiologically active gibberellic acid, and metabolites potentially involved in lignin biosynthesis increased in the elongating cells of the lower pulvinus.
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Walker M, Tehseen M, Doblin MS, Pettolino FA, Wilson SM, Bacic A, Golz JF. The transcriptional regulator LEUNIG_HOMOLOG regulates mucilage release from the Arabidopsis testa. Plant Physiol 2011; 156:46-60. [PMID: 21402796 PMCID: PMC3091065 DOI: 10.1104/pp.111.172692] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Accepted: 03/12/2011] [Indexed: 05/17/2023]
Abstract
Exposure of the mature Arabidopsis (Arabidopsis thaliana) seed to water results in the rapid release of pectinaceous mucilage from the outer cells of the testa. Once released, mucilage completely envelops the seed in a gel-like capsule. The physical force required to rupture the outer cell wall of the testa comes from the swelling of the mucilage as it expands rapidly following hydration. In this study, we show that mutations in the transcriptional regulator LEUNIG_HOMOLOG (LUH) cause a mucilage extrusion defect due to altered mucilage swelling. Based on sugar linkage and immunomicroscopic analyses, we show that the structure of luh mucilage is altered, having both an increase in substituted rhamnogalacturonan I and in methyl-esterified homogalacturonan. Also correlated with the structural modification of luh mucilage is a significant decrease in MUCILAGE MODIFIED2 (MUM2; a β-galactosidase) expression in the luh seed coat, raising the possibility that reduced activity of this glycosidase is directly responsible for the luh mucilage defects. Consistent with this is the structural similarity between mum2 and luh mucilage as well as the observation that elevating MUM2 expression in luh mutants completely suppresses the mucilage extrusion defect. Suppression of the luh mutant phenotype was also observed when LEUNIG, a transcriptional corepressor closely related to LUH, was introduced in luh mutants under the control of the LUH promoter. Based on these data, we propose a new model for the regulation of pectin biosynthesis during plant growth and development.
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13
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Dagley MJ, Gentle IE, Beilharz TH, Pettolino FA, Djordjevic JT, Lo TL, Uwamahoro N, Rupasinghe T, Tull DL, McConville M, Beaurepaire C, Nantel A, Lithgow T, Mitchell AP, Traven A. Cell wall integrity is linked to mitochondria and phospholipid homeostasis in Candida albicans through the activity of the post-transcriptional regulator Ccr4-Pop2. Mol Microbiol 2010; 79:968-89. [PMID: 21299651 DOI: 10.1111/j.1365-2958.2010.07503.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cell wall is essential for viability of fungi and is an effective drug target in pathogens such as Candida albicans. The contribution of post-transcriptional gene regulators to cell wall integrity in C. albicans is unknown. We show that the C. albicans Ccr4-Pop2 mRNA deadenylase, a regulator of mRNA stability and translation, is required for cell wall integrity. The ccr4/pop2 mutants display reduced wall β-glucans and sensitivity to the echinocandin caspofungin. Moreover, the deadenylase mutants are compromised for filamentation and virulence. We demonstrate that defective cell walls in the ccr4/pop2 mutants are linked to dysfunctional mitochondria and phospholipid imbalance. To further understand mitochondrial function in cell wall integrity, we screened a Saccharomyces cerevisiae collection of mitochondrial mutants. We identify several mitochondrial proteins required for caspofungin tolerance and find a connection between mitochondrial phospholipid homeostasis and caspofungin sensitivity. We focus on the mitochondrial outer membrane SAM complex subunit Sam37, demonstrating that it is required for both trafficking of phospholipids between the ER and mitochondria and cell wall integrity. Moreover, in C. albicans also Sam37 is essential for caspofungin tolerance. Our study provides the basis for an integrative view of mitochondrial function in fungal cell wall biogenesis and resistance to echinocandin antifungal drugs.
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Affiliation(s)
- Michael J Dagley
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia
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14
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Doblin MS, Pettolino FA, Wilson SM, Campbell R, Burton RA, Fincher GB, Newbigin E, Bacic A. A barley cellulose synthase-like CSLH gene mediates (1,3;1,4)-beta-D-glucan synthesis in transgenic Arabidopsis. Proc Natl Acad Sci U S A 2009; 106:5996-6001. [PMID: 19321749 PMCID: PMC2667043 DOI: 10.1073/pnas.0902019106] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Indexed: 11/18/2022] Open
Abstract
The walls of grasses and related members of the Poales are characterized by the presence of the polysaccharide (1,3, 1,4)-beta-D-glucan (beta-glucan). To date, only members of the grass-specific cellulose synthase-like F (CSLF) gene family have been implicated in its synthesis. Assuming that other grass-specific CSL genes also might encode synthases for this polysaccharide, we cloned HvCSLH1, a CSLH gene from barley (Hordeum vulgare L.), and expressed an epitope-tagged version of the cDNA in Arabidopsis, a species with no CSLH genes and no beta-glucan in its walls. Transgenic Arabidopsis lines that had detectable amounts of the epitope-tagged HvCSLH1 protein accumulated beta-glucan in their walls. The presence of beta-glucan was confirmed by immunoelectron microscopy (immuno-EM) of sectioned tissues and chemical analysis of wall extracts. In the chemical analysis, characteristic tri- and tetra-saccharides were identified by high-performance anion-exchange chromatography and MALDI-TOF MS following their release from transgenic Arabidopsis walls by a specific beta-glucan hydrolase. Immuno-EM also was used to show that the epitope-tagged HvCSLH1 protein was in the endoplasmic reticulum and Golgi-associated vesicles, but not in the plasma membrane. In barley, HvCSLH1 was expressed at very low levels in leaf, floral tissues, and the developing grain. In leaf, expression was highest in xylem and interfascicular fiber cells that have walls with secondary thickenings containing beta-glucan. Thus both the CSLH and CSLF families contribute to beta-glucan synthesis in grasses and probably do so independently of each other, because there is no significant transcriptional correlation between these genes in the barley tissues surveyed.
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Affiliation(s)
- Monika S. Doblin
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Filomena A. Pettolino
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Sarah M. Wilson
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Rebecca Campbell
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Rachel A. Burton
- Australian Centre for Plant Functional Genomics, School of Agriculture and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia; and
| | - Geoffrey B. Fincher
- Australian Centre for Plant Functional Genomics, School of Agriculture and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia; and
| | - Ed Newbigin
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Antony Bacic
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
- Australian Centre for Plant Functional Genomics, School of Botany, University of Melbourne, Victoria 3010, Australia
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15
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Sørensen I, Pettolino FA, Wilson SM, Doblin MS, Johansen B, Bacic A, Willats WGT. Mixed-linkage (1-->3),(1-->4)-beta-D-glucan is not unique to the Poales and is an abundant component of Equisetum arvense cell walls. Plant J 2008; 54:510-21. [PMID: 18284587 DOI: 10.1111/j.1365-313x.2008.03453.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mixed-linkage (1-->3),(1-->4)-beta-D-glucan (MLG) is widely considered to be a defining feature of the cell walls of plants in the Poales order. However, we conducted an extensive survey of cell-wall composition in diverse land plants and discovered that MLG is also abundant in the walls of the horsetail Equisetum arvense. MALDI-TOF MS and monosaccharide linkage analysis revealed that MLG in E. arvense is an unbranched homopolymer that consists of short blocks of contiguous 1,4-beta-linked glucose residues joined by 1,3-beta linkages. However, in contrast to Poaceae species, MLG in E. arvense consists mostly of cellotetraose rather than cellotetriose, and lacks long 1,4-beta-linked glucan blocks. Monosaccharide linkage analyses and immunochemical profiling indicated that, in E. arvense, MLG is a component of cell walls that have a novel architecture that differs significantly from that of the generally recognized type I and II cell walls. Unlike in type II walls, MLG in E. arvense does not appear to be co-extensive with glucuroarabinoxylans but occurs in walls that are rich in pectin. Immunofluorescence and immunogold localization showed that MLG occurs in both young and old regions of E. arvense stems, and is present in most cell types apart from cells in the vascular tissues. These findings have important implications for our understanding of cell-wall evolution, and also demonstrate that plant cell walls can be constructed in a way not previously envisaged.
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Affiliation(s)
- Iben Sørensen
- Department of Biology, The University of Copenhagen, Ole Maaløes vej 5, Copenhagen DK-2200, Denmark
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16
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Webster JM, Oxley D, Pettolino FA, Bacic A. Characterisation of secreted polysaccharides and (glyco)proteins from suspension cultures of Pyrus communis. Phytochemistry 2008; 69:873-81. [PMID: 18037144 DOI: 10.1016/j.phytochem.2007.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 08/21/2007] [Accepted: 10/05/2007] [Indexed: 05/24/2023]
Abstract
High molecular weight material recovered from the culture filtrate of cell suspension cultured Pyrus communis was composed of 81% carbohydrate, 13% protein and 5% inorganic material. This material was separated into three fractions (one neutral (Fraction A) and two acidic (Fractions B and C)), by anion-exchange chromatography on DEAE-Sepharose CL-6B using a gradient of imidazole-HCl at pH 7.0. The monosaccharide and linkage composition of each fraction was determined after carboxyl reduction of uronic acid residues. From the combined results of the carbohydrate analyses, we conclude that the high molecular weight extracellular material consists of three major and two minor polysaccharides: a (fucogalacto)xyloglucan (36%) in the unbound neutral Fraction A; a type II arabinogalactan (as an arabinogalactan-protein, 29%) and an acidic (glucurono)arabinoxylan (2%) in Fraction B; and a galacturonan (33%) and a trace of heteromannan in Fraction C. The main amino acids in the proteins were Glx, Thr, Ser, Hyp/Pro and Gly. Further separation of Fraction B by solvent partition, SDS-PAGE and analysis by LC-MS/MS identified the major proteins as two chitanases, two thaumatin-like proteins, a beta-1,3-glucanase, an extracellular dermal glycoprotein and a pathogenesis-related protein.
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Affiliation(s)
- Judith M Webster
- CRC for Bioproducts, School of Botany, University of Melbourne, Victoria 3010, Australia
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17
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Pettolino FA, Hoogenraad NJ, Ferguson C, Bacic A, Johnson E, Stone BA. A (1-->4)-beta-mannan-specific monoclonal antibody and its use in the immunocytochemical location of galactomannans. Planta 2001; 214:235-42. [PMID: 11800387 DOI: 10.1007/s004250100606] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Galactomannan was coupled to a protein carrier for the preparation of monoclonal antibodies. The monoclonal antibodies generated bound to galactomannans from different sources as well as to glucomannan and galactoglucomannan. One monoclonal antibody, BGM C6, was characterised and found to be specific for (1-->4)-beta-linked mannopyranosyl residues; it had a binding affinity estimated at 1x10(-6) M for the (1-->4)-beta-linked mannohexaose. BGM C6 was used in immunogold labelling studies to locate galactomannans in the endosperm walls of normal coconuts (Cocos nucifera L.) and those of the mutant makapuno at two different developmental stages. The pattern and intensity of antibody labelling varied for each type of coconut at the mature and immature stages, indicating differences in the galactomannan composition of the endosperm walls.
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Affiliation(s)
- F A Pettolino
- Department of Biochemistry, La Trobe University, Victoria, Australia
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