1
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Delmer D, Dixon RA, Keegstra K, Mohnen D. The plant cell wall-dynamic, strong, and adaptable-is a natural shapeshifter. Plant Cell 2024; 36:1257-1311. [PMID: 38301734 PMCID: PMC11062476 DOI: 10.1093/plcell/koad325] [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: 07/17/2023] [Accepted: 12/19/2023] [Indexed: 02/03/2024]
Abstract
Mythology is replete with good and evil shapeshifters, who, by definition, display great adaptability and assume many different forms-with several even turning themselves into trees. Cell walls certainly fit this definition as they can undergo subtle or dramatic changes in structure, assume many shapes, and perform many functions. In this review, we cover the evolution of knowledge of the structures, biosynthesis, and functions of the 5 major cell wall polymer types that range from deceptively simple to fiendishly complex. Along the way, we recognize some of the colorful historical figures who shaped cell wall research over the past 100 years. The shapeshifter analogy emerges more clearly as we examine the evolving proposals for how cell walls are constructed to allow growth while remaining strong, the complex signaling involved in maintaining cell wall integrity and defense against disease, and the ways cell walls adapt as they progress from birth, through growth to maturation, and in the end, often function long after cell death. We predict the next century of progress will include deciphering cell type-specific wall polymers; regulation at all levels of polymer production, crosslinks, and architecture; and how walls respond to developmental and environmental signals to drive plant success in diverse environments.
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Affiliation(s)
- Deborah Delmer
- Section of Plant Biology, University of California Davis, Davis, CA 95616, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Kenneth Keegstra
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA
| | - Debra Mohnen
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
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2
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Dixon RA, Dickinson AJ. A century of studying plant secondary metabolism-From "what?" to "where, how, and why?". Plant Physiol 2024; 195:48-66. [PMID: 38163637 PMCID: PMC11060662 DOI: 10.1093/plphys/kiad596] [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: 07/10/2023] [Accepted: 08/15/2023] [Indexed: 01/03/2024]
Abstract
Over the past century, early advances in understanding the identity of the chemicals that collectively form a living plant have led scientists to deeper investigations exploring where these molecules localize, how they are made, and why they are synthesized in the first place. Many small molecules are specific to the plant kingdom and have been termed plant secondary metabolites, despite the fact that they can play primary and essential roles in plant structure, development, and response to the environment. The past 100 yr have witnessed elucidation of the structure, function, localization, and biosynthesis of selected plant secondary metabolites. Nevertheless, many mysteries remain about the vast diversity of chemicals produced by plants and their roles in plant biology. From early work characterizing unpurified plant extracts, to modern integration of 'omics technology to discover genes in metabolite biosynthesis and perception, research in plant (bio)chemistry has produced knowledge with substantial benefits for society, including human medicine and agricultural biotechnology. Here, we review the history of this work and offer suggestions for future areas of exploration. We also highlight some of the recently developed technologies that are leading to ongoing research advances.
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Affiliation(s)
- Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Alexandra Jazz Dickinson
- Department of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA 92093, USA
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3
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Dainton J, Dixon RA. Guest-editing under the spotlight. Philos Trans A Math Phys Eng Sci 2024; 382:20230374. [PMID: 38219782 PMCID: PMC10788155 DOI: 10.1098/rsta.2023.0374] [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] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 01/16/2024]
Affiliation(s)
- John Dainton
- STFC Daresbury Laboratory, Cockcroft Institute, SciTech Daresbury, Warrington WA4 4AD, UK
- Department of Physics, University of Lancaster, Lancaster LA1 4YB, UK
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
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4
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Dixon RA, Dainton J. Guest-editing under the spotlight. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230478. [PMID: 38186281 PMCID: PMC10772601 DOI: 10.1098/rstb.2023.0478] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 01/09/2024] Open
Affiliation(s)
- Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - John Dainton
- STFC Daresbury Laboratory, Cockcroft Institute, SciTech Daresbury, Warrington WA4 4AD, UK
- Department of Physics, University of Lancaster, Lancaster LA1 4YB, UK
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5
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Lu N, Jun JH, Li Y, Dixon RA. An unconventional proanthocyanidin pathway in maize. Nat Commun 2023; 14:4349. [PMID: 37468488 DOI: 10.1038/s41467-023-40014-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 07/09/2023] [Indexed: 07/21/2023] Open
Abstract
Proanthocyanidins (PAs), flavonoid polymers involved in plant defense, are also beneficial to human health and ruminant nutrition. To date, there is little evidence for accumulation of PAs in maize (Zea mays), although maize makes anthocyanins and possesses the key enzyme of the PA pathway, anthocyanidin reductase (ANR). Here, we explore whether there is a functional PA biosynthesis pathway in maize using a combination of analytical chemistry and genetic approaches. The endogenous PA biosynthetic machinery in maize preferentially produces the unusual PA precursor (+)-epicatechin, as well as 4β-(S-cysteinyl)-catechin, as potential PA starter and extension units. Uncommon procyanidin dimers with (+)-epicatechin as starter unit are also found. Expression of soybean (Glycine max) anthocyanidin reductase 1 (ANR1) in maize seeds increases the levels of 4β-(S-cysteinyl)-epicatechin and procyanidin dimers mainly using (-)-epicatechin as starter units. Introducing a Sorghum bicolor transcription factor (SbTT2) specifically regulating PA biosynthesis into a maize inbred deficient in anthocyanin biosynthesis activates both anthocyanin and PA biosynthesis pathways, suggesting conservation of the PA regulatory machinery across species. Our data support the divergence of PA biosynthesis across plant species and offer perspectives for future agricultrural applications in maize.
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Affiliation(s)
- Nan Lu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
- Children's Research Institute and the Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ying Li
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA.
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6
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Guo Y, Wang S, Yu K, Wang HL, Xu H, Song C, Zhao Y, Wen J, Fu C, Li Y, Wang S, Zhang X, Zhang Y, Cao Y, Shao F, Wang X, Deng X, Chen T, Zhao Q, Li L, Wang G, Grünhofer P, Schreiber L, Li Y, Song G, Dixon RA, Lin J. Manipulating microRNA miR408 enhances both biomass yield and saccharification efficiency in poplar. Nat Commun 2023; 14:4285. [PMID: 37463897 DOI: 10.1038/s41467-023-39930-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 06/30/2023] [Indexed: 07/20/2023] Open
Abstract
The conversion of lignocellulosic feedstocks to fermentable sugar for biofuel production is inefficient, and most strategies to enhance efficiency directly target lignin biosynthesis, with associated negative growth impacts. Here we demonstrate, for both laboratory- and field-grown plants, that expression of Pag-miR408 in poplar (Populus alba × P. glandulosa) significantly enhances saccharification, with no requirement for acid-pretreatment, while promoting plant growth. The overexpression plants show increased accessibility of cell walls to cellulase and scaffoldin cellulose-binding modules. Conversely, Pag-miR408 loss-of-function poplar shows decreased cell wall accessibility. Overexpression of Pag-miR408 targets three Pag-LACCASES, delays lignification, and modestly reduces lignin content, S/G ratio and degree of lignin polymerization. Meanwhile, the LACCASE loss of function mutants exhibit significantly increased growth and cell wall accessibility in xylem. Our study shows how Pag-miR408 regulates lignification and secondary growth, and suggest an effective approach towards enhancing biomass yield and saccharification efficiency in a major bioenergy crop.
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Affiliation(s)
- Yayu Guo
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Shufang Wang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
- Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Keji Yu
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Hou-Ling Wang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Huimin Xu
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
- College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Chengwei Song
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
- College of Agriculture, Henan University of Science and Technology, Luoyang, 471003, China
| | - Yuanyuan Zhao
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Jialong Wen
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083, China
| | - Chunxiang Fu
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Yu Li
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Shuizhong Wang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083, China
| | - Xi Zhang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Yan Zhang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Yuan Cao
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, 100091, China
| | - Fenjuan Shao
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, 100091, China
| | - Xiaohua Wang
- Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xin Deng
- Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Tong Chen
- Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Qiao Zhao
- Shenzhen Key Laboratory of Synthetic Genomics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Lei Li
- School of Life Sciences and School of Advanced Agricultural Sciences, Peking University, Beijing, 100871, China
| | - Guodong Wang
- National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Paul Grünhofer
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Lukas Schreiber
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Yue Li
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
| | - Guoyong Song
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083, China
| | - Richard A Dixon
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, 76203, USA.
| | - Jinxing Lin
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China.
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Ha CM, Escamilla-Trevino L, Zhuo C, Pu Y, Bryant N, Ragauskas AJ, Xiao X, Li Y, Chen F, Dixon RA. Systematic approaches to C-lignin engineering in Medicago truncatula. Biotechnol Biofuels Bioprod 2023; 16:100. [PMID: 37308891 DOI: 10.1186/s13068-023-02339-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/10/2023] [Indexed: 06/14/2023]
Abstract
BACKGROUND C-lignin is a homopolymer of caffeyl alcohol present in the seed coats of a variety of plant species including vanilla orchid, various cacti, and the ornamental plant Cleome hassleriana. Because of its unique chemical and physical properties, there is considerable interest in engineering C-lignin into the cell walls of bioenergy crops as a high-value co-product of bioprocessing. We have used information from a transcriptomic analysis of developing C. hassleriana seed coats to suggest strategies for engineering C-lignin in a heterologous system, using hairy roots of the model legume Medicago truncatula. RESULTS We systematically tested strategies for C-lignin engineering using a combination of gene overexpression and RNAi-mediated knockdown in the caffeic acid/5-hydroxy coniferaldehyde 3/5-O-methyltransferase (comt) mutant background, monitoring the outcomes by analysis of lignin composition and profiling of monolignol pathway metabolites. In all cases, C-lignin accumulation required strong down-regulation of caffeoyl CoA 3-O-methyltransferase (CCoAOMT) paired with loss of function of COMT. Overexpression of the Selaginella moellendorffii ferulate 5-hydroxylase (SmF5H) gene in comt mutant hairy roots resulted in lines that unexpectedly accumulated high levels of S-lignin. CONCLUSION C-Lignin accumulation of up to 15% of total lignin in lines with the greatest reduction in CCoAOMT expression required the strong down-regulation of both COMT and CCoAOMT, but did not require expression of a heterologous laccase, cinnamyl alcohol dehydrogenase (CAD) or cinnamoyl CoA reductase (CCR) with preference for 3,4-dihydroxy-substituted substrates in M. truncatula hairy roots. Cell wall fractionation studies suggested that the engineered C-units are not present in a heteropolymer with the bulk of the G-lignin.
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Affiliation(s)
- Chan Man Ha
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Luis Escamilla-Trevino
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA
| | - Chunliu Zhuo
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Yunqiao Pu
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Nathan Bryant
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Arthur J Ragauskas
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996, USA
| | - Xirong Xiao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Ying Li
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA
| | - Fang Chen
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203-5017, USA.
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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8
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Yu K, Song Y, Lin J, Dixon RA. The complexities of proanthocyanidin biosynthesis and its regulation in plants. Plant Commun 2023; 4:100498. [PMID: 36435967 PMCID: PMC10030370 DOI: 10.1016/j.xplc.2022.100498] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/07/2022] [Accepted: 11/23/2022] [Indexed: 05/04/2023]
Abstract
Proanthocyanidins (PAs) are natural flavan-3-ol polymers that contribute protection to plants under biotic and abiotic stress, benefits to human health, and bitterness and astringency to food products. They are also potential targets for carbon sequestration for climate mitigation. In recent years, from model species to commercial crops, research has moved closer to elucidating the flux control and channeling, subunit biosynthesis and polymerization, transport mechanisms, and regulatory networks involved in plant PA metabolism. This review extends the conventional understanding with recent findings that provide new insights to address lingering questions and focus strategies for manipulating PA traits in plants.
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Affiliation(s)
- Keji Yu
- National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Yushuang Song
- National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Jinxing Lin
- National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China.
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China.
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9
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Liu C, Yu H, Voxeur A, Rao X, Dixon RA. FERONIA and wall-associated kinases coordinate defense induced by lignin modification in plant cell walls. Sci Adv 2023; 9:eadf7714. [PMID: 36897948 PMCID: PMC10005186 DOI: 10.1126/sciadv.adf7714] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 02/03/2023] [Indexed: 06/17/2023]
Abstract
Altering the content or composition of the cell wall polymer lignin is a favored approach to valorize lignin toward biomaterial and chemical production in the biorefinery. However, modifying lignin or cellulose in transgenic plants can induce expression of defense responses and negatively affect growth. Through genetic screening for suppressors of defense gene induction in the low lignin ccr1-3 mutant of Arabidopsis thaliana, we found that loss of function of the receptor-like kinase FERONIA, although not restoring growth, affected cell wall remodeling and blocked release of elicitor-active pectic polysaccharides as a result of the ccr1-3 mutation. Loss of function of multiple wall-associated kinases prevented perception of these elicitors. The elicitors are likely heterogeneous, with tri-galacturonic acid the smallest but not necessarily the most active component. Engineering of plant cell walls will require development of ways to bypass endogenous pectin signaling pathways.
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Affiliation(s)
- Chang Liu
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
| | - Hasi Yu
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
| | - Aline Voxeur
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Xiaolan Rao
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, No.368, Friendship Avenue, Wuchang District, Wuhan, Hubei Province 430062, China
| | - Richard A. Dixon
- Department of Biological Sciences, BioDiscovery Institute, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
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10
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Shrestha HK, Fichman Y, Engle NL, Tschaplinski TJ, Mittler R, Dixon RA, Hettich RL, Barros J, Abraham PE. Multi-omic characterization of bifunctional peroxidase 4-coumarate 3-hydroxylase knockdown in Brachypodium distachyon provides insights into lignin modification-associated pleiotropic effects. Front Plant Sci 2022; 13:908649. [PMID: 36247563 PMCID: PMC9554711 DOI: 10.3389/fpls.2022.908649] [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: 03/30/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
A bifunctional peroxidase enzyme, 4-coumarate 3-hydroxylase (C3H/APX), provides a parallel route to the shikimate shunt pathway for the conversion of 4-coumarate to caffeate in the early steps of lignin biosynthesis. Knockdown of C3H/APX (C3H/APX-KD) expression has been shown to reduce the lignin content in Brachypodium distachyon. However, like many other lignin-modified plants, C3H/APX-KDs show unpredictable pleiotropic phenotypes, including stunted growth, delayed senescence, and reduced seed yield. A system-wide level understanding of altered biological processes in lignin-modified plants can help pinpoint the lignin-modification associated growth defects to benefit future studies aiming to negate the yield penalty. Here, a multi-omic approach was used to characterize molecular changes resulting from C3H/APX-KD associated lignin modification and negative growth phenotype in Brachypodium distachyon. Our findings demonstrate that C3H/APX knockdown in Brachypodium stems substantially alters the abundance of enzymes implicated in the phenylpropanoid biosynthetic pathway and disrupt cellular redox homeostasis. Moreover, it elicits plant defense responses associated with intracellular kinases and phytohormone-based signaling to facilitate growth-defense trade-offs. A deeper understanding along with potential targets to mitigate the pleiotropic phenotypes identified in this study could aid to increase the economic feasibility of lignocellulosic biofuel production.
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Affiliation(s)
- Him K. Shrestha
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Genome Science and Technology, University of Tennessee-Knoxville, Knoxville, TN, United States
| | - Yosef Fichman
- Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
| | - Nancy L. Engle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | | | - Ron Mittler
- Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Robert L. Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Jaime Barros
- Division of Plant Sciences and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Paul E. Abraham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
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11
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Gould F, Amasino RM, Brossard D, Buell CR, Dixon RA, Falck-Zepeda JB, Gallo MA, Giller KE, Glenna LL, Griffin T, Magraw D, Mallory-Smith C, Pixley KV, Ransom EP, Stelly DM, Stewart CN. Toward product-based regulation of crops. Science 2022; 377:1051-1053. [PMID: 36048940 DOI: 10.1126/science.abo3034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Current process-based approaches to regulation are no longer fit for purpose.
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Affiliation(s)
- Fred Gould
- The list of author affiliations is available in the supplementary materials
| | - Richard M Amasino
- The list of author affiliations is available in the supplementary materials
| | - Dominique Brossard
- The list of author affiliations is available in the supplementary materials
| | - C Robin Buell
- The list of author affiliations is available in the supplementary materials
| | - Richard A Dixon
- The list of author affiliations is available in the supplementary materials
| | | | - Michael A Gallo
- The list of author affiliations is available in the supplementary materials
| | - Ken E Giller
- The list of author affiliations is available in the supplementary materials
| | - Leland L Glenna
- The list of author affiliations is available in the supplementary materials
| | - Timothy Griffin
- The list of author affiliations is available in the supplementary materials
| | - Daniel Magraw
- The list of author affiliations is available in the supplementary materials
| | | | - Kevin V Pixley
- The list of author affiliations is available in the supplementary materials
| | - Elizabeth P Ransom
- The list of author affiliations is available in the supplementary materials
| | - David M Stelly
- The list of author affiliations is available in the supplementary materials
| | - C Neal Stewart
- The list of author affiliations is available in the supplementary materials
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12
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Adolfo LM, Burks D, Rao X, Alvarez‐Hernandez A, Dixon RA. Evaluation of pathways to the C-glycosyl isoflavone puerarin in roots of kudzu ( Pueraria montana lobata). Plant Direct 2022; 6:e442. [PMID: 36091880 PMCID: PMC9438399 DOI: 10.1002/pld3.442] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 07/21/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Kudzu (Pueraria montana lobata) is used as a traditional medicine in China and Southeast Asia but is a noxious weed in the Southeastern United States. It produces both O- and C-glycosylated isoflavones, with puerarin (C-glucosyl daidzein) as an important bioactive compound. Currently, the stage of the isoflavone pathway at which the C-glycosyl unit is added remains unclear, with a recent report of direct C-glycosylation of daidzein contradicting earlier labeling studies supporting C-glycosylation at the level of chalcone. We have employed comparative mRNA sequencing of the roots from two Pueraria species, one of which produces puerarin (field collected P. montana lobata) and one of which does not (commercial Pueraria phaseoloides), to identify candidate uridine diphosphate glycosyltransferase (UGT) enzymes involved in puerarin biosynthesis. Expression of recombinant UGTs in Escherichia coli and candidate C-glycosyltransferases in Medicago truncatula were used to explore substrate specificities, and gene silencing of UGT and key isoflavone biosynthetic genes in kudzu hairy roots employed to test hypotheses concerning the substrate(s) for C-glycosylation. Our results confirm UGT71T5 as a C-glycosyltransferase of isoflavone biosynthesis in kudzu. Enzymatic, isotope labeling, and genetic analyses suggest that puerarin arises both from the direct action of UGT71T5 on daidzein and via a second route in which the C-glycosidic linkage is introduced to the chalcone isoliquiritigenin.
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Affiliation(s)
- Laci M. Adolfo
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTexasUSA
| | - David Burks
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTexasUSA
| | - Xiaolan Rao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life SciencesHubei UniversityWuhanHubei ProvinceChina
| | | | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTexasUSA
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13
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Lu N, Jun JH, Liu C, Dixon RA. The flexibility of proanthocyanidin biosynthesis in plants. Plant Physiol 2022; 190:202-205. [PMID: 35695780 PMCID: PMC9434147 DOI: 10.1093/plphys/kiac274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/23/2022] [Indexed: 05/20/2023]
Abstract
Plants have evolved different routes for the synthesis and assembly of the building blocks of proanthocyanidins.
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Affiliation(s)
- Nan Lu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton TX 76203, USA
| | | | - Chenggang Liu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton TX 76203, USA
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14
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Barros J, Shrestha HK, Serrani-Yarce JC, Engle NL, Abraham PE, Tschaplinski TJ, Hettich RL, Dixon RA. Proteomic and metabolic disturbances in lignin-modified Brachypodium distachyon. Plant Cell 2022; 34:3339-3363. [PMID: 35670759 PMCID: PMC9421481 DOI: 10.1093/plcell/koac171] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/23/2022] [Indexed: 05/30/2023]
Abstract
Lignin biosynthesis begins with the deamination of phenylalanine and tyrosine (Tyr) as a key branch point between primary and secondary metabolism in land plants. Here, we used a systems biology approach to investigate the global metabolic responses to lignin pathway perturbations in the model grass Brachypodium distachyon. We identified the lignin biosynthetic protein families and found that ammonia-lyases (ALs) are among the most abundant proteins in lignifying tissues in grasses. Integrated metabolomic and proteomic data support a link between lignin biosynthesis and primary metabolism mediated by the ammonia released from ALs that is recycled for the synthesis of amino acids via glutamine. RNA interference knockdown of lignin genes confirmed that the route of the canonical pathway using shikimate ester intermediates is not essential for lignin formation in Brachypodium, and there is an alternative pathway from Tyr via sinapic acid for the synthesis of syringyl lignin involving yet uncharacterized enzymatic steps. Our findings support a model in which plant ALs play a central role in coordinating the allocation of carbon for lignin synthesis and the nitrogen available for plant growth. Collectively, these data also emphasize the value of integrative multiomic analyses to advance our understanding of plant metabolism.
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Affiliation(s)
| | - Him K Shrestha
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37916, USA
| | - Juan C Serrani-Yarce
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201, USA
| | - Nancy L Engle
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Paul E Abraham
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Timothy J Tschaplinski
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Robert L Hettich
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
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15
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Cui X, Jun JH, Rao X, Bahr C, Chapman E, Temple S, Dixon RA. Leaf layer-based transcriptome profiling for discovery of epidermal-selective promoters in Medicago truncatula. Planta 2022; 256:31. [PMID: 35790623 DOI: 10.1007/s00425-022-03920-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 03/17/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Transcriptomics of manually dissected leaf layers from Medicago truncatula identifies genes with preferential expression in upper and/or lower epidermis. The promoters of these genes confer epidermal-specific expression of transgenes. Improving the quality and quantity of proanthocyanidins (PAs) in forage legumes has potential to improve the nitrogen nutrition of ruminant animals and protect them from the risk of pasture bloat, as well as parasites. However, ectopic constitutive accumulation of PAs in plants by genetic engineering can significantly inhibit growth. We selected the leaf epidermis as a candidate tissue for targeted engineering of PAs or other pathways. To identify gene promoters selectively expressed in epidermal tissues, we performed comparative transcriptomic analyses in the model legume Medicago truncatula, using five tissue samples representing upper epidermis, lower epidermis, whole leaf without upper epidermis, whole leaf without lower epidermis, and whole leaf. We identified 52 transcripts preferentially expressed in upper epidermis, most of which encode genes involved in flavonoid biosynthesis, and 53 transcripts from lower epidermis, with the most enriched category being anatomical structure formation. Promoters of the preferentially expressed genes were cloned from the M. truncatula genome and shown to direct tissue-selective promoter activities in transient assays. Expression of the PA pathway transcription factor TaMYB14 under control of several of the promoters in transgenic alfalfa resulted in only modest MYB14 transcript accumulation and low levels of PA production. Activity of a subset of promoters was confirmed by transcript analysis in field-grown alfalfa plants throughout the growing season, and revealed variable but consistent expression, which was generally highest 3-4 weeks after cutting. We conclude that, although the selected promoters show acceptable tissue-specificity, they may not drive high enough transcription factor expression to activate the PA pathway.
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Affiliation(s)
- Xin Cui
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
| | - Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Children's Research Institute and the Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiaolan Rao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- College of Life Sciences, Hubei University, Wuhan, 430068, Hubei, China
| | - Camille Bahr
- Forage Genetics International, N5292 Gills Coulee Rd S, West Salem, WI, 54669, USA
| | - Elisabeth Chapman
- Forage Genetics International, N5292 Gills Coulee Rd S, West Salem, WI, 54669, USA
| | - Stephen Temple
- Forage Genetics International, N5292 Gills Coulee Rd S, West Salem, WI, 54669, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA.
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16
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Wang R, Lu N, Liu C, Dixon RA, Wu Q, Mao Y, Yang Y, Zheng X, He L, Zhao B, Zhang F, Yang S, Chen H, Jun JH, Li Y, Liu C, Liu Y, Chen J. MtGSTF7, a TT19-like GST gene, is essential for accumulation of anthocyanins, but not proanthocyanins in Medicago truncatula. J Exp Bot 2022; 73:4129-4146. [PMID: 35294003 PMCID: PMC9232208 DOI: 10.1093/jxb/erac112] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 03/12/2022] [Indexed: 05/20/2023]
Abstract
Anthocyanins and proanthocyanins (PAs) are two end products of the flavonoid biosynthesis pathway. They are believed to be synthesized in the endoplasmic reticulum and then sequestered into the vacuole. In Arabidopsis thaliana, TRANSPARENT TESTA 19 (TT19) is necessary for both anthocyanin and PA accumulation. Here, we found that MtGSTF7, a homolog of AtTT19, is essential for anthocyanin accumulation but not required for PA accumulation in Medicago truncatula. MtGSTF7 was induced by the anthocyanin regulator LEGUME ANTHOCYANIN PRODUCTION 1 (LAP1), and its tissue expression pattern correlated with anthocyanin deposition in M. truncatula. Tnt1-insertional mutants of MtGSTF7 lost anthocyanin accumulation in vegetative organs, and introducing a genomic fragment of MtGSTF7 could complement the mutant phenotypes. Additionally, the accumulation of anthocyanins induced by LAP1 was significantly reduced in mtgstf7 mutants. Yeast-one-hybridization and dual-luciferase reporter assays revealed that LAP1 could bind to the MtGSTF7 promoter to activate its expression. Ectopic expression of MtGSTF7 in tt19 mutants could rescue their anthocyanin deficiency, but not their PA defect. Furthermore, PA accumulation was not affected in the mtgstf7 mutants. Taken together, our results show that the mechanism of anthocyanin and PA accumulation in M. truncatula is different from that in A. thaliana, and provide a new target gene for engineering anthocyanins in plants.
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Affiliation(s)
| | | | - Chenggang Liu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Qing Wu
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yawen Mao
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yating Yang
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
- School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoling Zheng
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liangliang He
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Baolin Zhao
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Fan Zhang
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Shengchao Yang
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, Yunnan 650201, China
| | - Haitao Chen
- Sanjie Institute of Forage, Yangling, Shaanxi 712100, China
| | - Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Ying Li
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Changning Liu
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Yu Liu
- CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, CAS Center for Excellence for Molecular Plant Science, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
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17
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Abstract
Proanthocyanidins (PAs) are natural polymers of flavan-3-ols, commonly (+)-catechin and (-)-epicatechin. However, exactly how PA oligomerization proceeds is poorly understood. Here we show, both biochemically and genetically, that ascorbate (AsA) is an alternative "starter unit" to flavan-3-ol monomers for leucocyanidin-derived (+)-catechin subunit extension in the Arabidopsis thaliana anthocyanidin synthase (ans) mutant. These (catechin)n:ascorbate conjugates (AsA-[C]n) also accumulate throughout the phase of active PA biosynthesis in wild-type grape flowers, berry skins and seeds. In the presence of (-)-epicatechin, AsA-[C]n can further provide monomeric or oligomeric PA extension units for non-enzymatic polymerization in vitro, and their role in vivo is inferred from analysis of relative metabolite levels in both Arabidopsis and grape. Our findings advance the knowledge of (+)-catechin-type PA extension and indicate that PA oligomerization does not necessarily proceed by sequential addition of a single extension unit. AsA-[C]n defines a new type of PA intermediate which we term "sub-PAs".
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Affiliation(s)
- Keji Yu
- grid.22935.3f0000 0004 0530 8290Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083 China ,grid.418524.e0000 0004 0369 6250Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing, 100083 China
| | - Richard A. Dixon
- grid.266869.50000 0001 1008 957XBioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Changqing Duan
- grid.22935.3f0000 0004 0530 8290Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, 100083 China ,grid.418524.e0000 0004 0369 6250Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing, 100083 China
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18
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Zhuo C, Wang X, Docampo-Palacios M, Sanders BC, Engle NL, Tschaplinski TJ, Hendry JI, Maranas CD, Chen F, Dixon RA. Developmental changes in lignin composition are driven by both monolignol supply and laccase specificity. Sci Adv 2022; 8:eabm8145. [PMID: 35263134 PMCID: PMC8906750 DOI: 10.1126/sciadv.abm8145] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/17/2022] [Indexed: 05/25/2023]
Abstract
The factors controlling lignin composition remain unclear. Catechyl (C)-lignin is a homopolymer of caffeyl alcohol with unique properties as a biomaterial and precursor of industrial chemicals. The lignin synthesized in the seed coat of Cleome hassleriana switches from guaiacyl (G)- to C-lignin at around 12 to 14 days after pollination (DAP), associated with a rerouting of the monolignol pathway. Lack of synthesis of caffeyl alcohol limits C-lignin formation before around 12 DAP, but coniferyl alcohol is still synthesized and highly accumulated after 14 DAP. We propose a model in which, during C-lignin biosynthesis, caffeyl alcohol noncompetitively inhibits oxidation of coniferyl alcohol by cell wall laccases, a process that might limit movement of coniferyl alcohol to the apoplast. Developmental changes in both substrate availability and laccase specificity together account for the metabolic fates of G- and C-monolignols in the Cleome seed coat.
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Affiliation(s)
- Chunliu Zhuo
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xin Wang
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Maite Docampo-Palacios
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
| | - Brian C. Sanders
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Nancy L. Engle
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Timothy J. Tschaplinski
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - John I. Hendry
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Costas D. Maranas
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Fang Chen
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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19
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Adolfo LM, Rao X, Dixon RA. Identification of Pueraria spp. through DNA barcoding and comparative transcriptomics. BMC Plant Biol 2022; 22:10. [PMID: 34979934 PMCID: PMC8722073 DOI: 10.1186/s12870-021-03383-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 12/05/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Kudzu is a term used generically to describe members of the genus Pueraria. Kudzu roots have been used for centuries in traditional Chinese medicine in view of their high levels of beneficial isoflavones including the unique 8-C-glycoside of daidzein, puerarin. In the US, kudzu is seen as a noxious weed causing ecological and economic damage. However, not all kudzu species make puerarin or are equally invasive. Kudzu remains difficult to identify due to its diverse morphology and inconsistent nomenclature. RESULTS We have generated sequences for the internal transcribed spacer 2 (ITS2) and maturase K (matK) regions of Pueraria montana lobata, P. montana montana, and P. phaseoloides, and identified two accessions previously used for differential analysis of puerarin biosynthesis as P. lobata and P. phaseoloides. Additionally, we have generated root transcriptomes for the puerarin-producing P. m. lobata and the non-puerarin producing P. phaseoloides. Within the transcriptomes, microsatellites were identified to aid in species identification as well as population diversity. CONCLUSIONS The barcode sequences generated will aid in fast and efficient identification of the three kudzu species. Additionally, the microsatellites identified from the transcriptomes will aid in genetic analysis. The root transcriptomes also provide a molecular toolkit for comparative gene expression analysis towards elucidation of the biosynthesis of kudzu phytochemicals.
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Affiliation(s)
- Laci M Adolfo
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203-5017, USA
| | - Xiaolan Rao
- College of Life Sciences, Hubei University, Wuhan, 430068, Hubei Province, China
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX, 76203-5017, USA.
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20
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Guan M, Li C, Shan X, Chen F, Wang S, Dixon RA, Zhao Q. Dual Mechanisms of Coniferyl Alcohol in Phenylpropanoid Pathway Regulation. Front Plant Sci 2022; 13:896540. [PMID: 35599874 PMCID: PMC9121011 DOI: 10.3389/fpls.2022.896540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 03/30/2022] [Indexed: 05/11/2023]
Abstract
Lignin is a complex phenolic polymer that imparts cell wall strength, facilitates water transport and functions as a physical barrier to pathogens in all vascular plants. Lignin biosynthesis is a carbon-consuming, non-reversible process, which requires tight regulation. Here, we report that a major monomer unit of the lignin polymer can function as a signal molecule to trigger proteolysis of the enzyme L-phenylalanine ammonia-lyase, the entry point into the lignin biosynthetic pathway, and feedback regulate the expression levels of lignin biosynthetic genes. These findings highlight the highly complex regulation of lignin biosynthesis and shed light on the biological importance of monolignols as signaling molecules.
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Affiliation(s)
- Mengling Guan
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Changxuan Li
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaotong Shan
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Fang Chen
- Department of Biological Sciences, University of North Texas, Denton, TX, United States
- BioDiscovery Institute, University of North Texas, Denton, TX, United States
| | - Shufang Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
| | - Richard A. Dixon
- Department of Biological Sciences, University of North Texas, Denton, TX, United States
- BioDiscovery Institute, University of North Texas, Denton, TX, United States
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China
| | - Qiao Zhao
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
- *Correspondence: Qiao Zhao,
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21
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Yu H, Liu C, Dixon RA. A gene-editing/complementation strategy for tissue-specific lignin reduction while preserving biomass yield. Biotechnol Biofuels 2021; 14:175. [PMID: 34479620 PMCID: PMC8417962 DOI: 10.1186/s13068-021-02026-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 08/25/2021] [Indexed: 05/08/2023]
Abstract
BACKGROUND Lignification of secondary cell walls is a major factor conferring recalcitrance of lignocellulosic biomass to deconstruction for fuels and chemicals. Genetic modification can reduce lignin content and enhance saccharification efficiency, but usually at the cost of moderate-to-severe growth penalties. We have developed a method, using a single DNA construct that uses CRISPR-Cas9 gene editing to knock-out expression of an endogenous gene of lignin monomer biosynthesis while at the same time expressing a modified version of the gene's open reading frame that escapes cutting by the Cas9 system and complements the introduced mutation in a tissue-specific manner. RESULTS Expressing the complementing open reading frame in vessels allows for the regeneration of Arabidopsis plants with reduced lignin, wild-type biomass yield, and up to fourfold enhancement of cell wall sugar yield per plant. The above phenotypes are seen in both homozygous and bi-allelic heterozygous T1 lines, and are stable over at least four generations. CONCLUSIONS The method provides a rapid approach for generating reduced lignin trees or crops with one single transformation event, and, paired with a range of tissue-specific promoters, provides a general strategy for optimizing loss-of-function traits that are associated with growth penalties. This method should be applicable to any plant species in which transformation and gene editing are feasible and validated vessel-specific promoters are available.
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Affiliation(s)
- Hasi Yu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Chang Liu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA.
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
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22
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Ha CM, Rao X, Saxena G, Dixon RA. Growth-defense trade-offs and yield loss in plants with engineered cell walls. New Phytol 2021; 231:60-74. [PMID: 33811329 DOI: 10.1111/nph.17383] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [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: 02/08/2021] [Accepted: 03/29/2021] [Indexed: 05/18/2023]
Abstract
As a major component of plant secondary cell walls, lignin provides structural integrity and rigidity, and contributes to primary defense by providing a physical barrier to pathogen ingress. Genetic modification of lignin biosynthesis has been adopted to reduce the recalcitrance of lignified cell walls to improve biofuel production, tree pulping properties and forage digestibility. However, lignin-modification is often, but unpredictably, associated with dwarf phenotypes. Hypotheses suggested to explain this include: collapsed vessels leading to defects in water and solute transport; accumulation of molecule(s) that are inhibitory to plant growth or deficiency of metabolites that are critical for plant growth; activation of defense pathways linked to cell wall integrity sensing. However, there is still no commonly accepted underlying mechanism for the growth defects. Here, we discuss recent data on transcriptional reprogramming in plants with modified lignin content and their corresponding suppressor mutants, and evaluate growth-defense trade-offs as a factor underlying the growth phenotypes. New approaches will be necessary to estimate how gross changes in transcriptional reprogramming may quantitatively affect growth. Better understanding of the basis for yield drag following cell wall engineering is important for the biotechnological exploitation of plants as factories for fuels and chemicals.
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Affiliation(s)
- Chan Man Ha
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Xiaolan Rao
- College of Life Sciences, Hubei University, No. 28 Nanli Road, Hong-shan District, Wuchang, Wuhan, Hubei Province, 430068, China
| | - Garima Saxena
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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23
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Lu N, Rao X, Li Y, Jun JH, Dixon RA. Dissecting the transcriptional regulation of proanthocyanidin and anthocyanin biosynthesis in soybean (Glycine max). Plant Biotechnol J 2021; 19:1429-1442. [PMID: 33539645 PMCID: PMC8313137 DOI: 10.1111/pbi.13562] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [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: 05/15/2020] [Revised: 01/12/2021] [Accepted: 01/29/2021] [Indexed: 05/20/2023]
Abstract
Proanthocyanidins (PAs), also known as condensed tannins, are plant natural products that are beneficial for human and livestock health. As one of the largest grown crops in the world, soybean (Glycine max) is widely used as human food and animal feed. Many cultivated soybeans with yellow seed coats lack PAs or anthocyanins, although some soybean cultivars have coloured seed coats that contain these compounds. Here, we analyse the transcriptional control of PA and anthocyanin biosynthesis in soybean. Ectopic expression of the transcription factors (TFs) GmTT2A, GmTT2B, GmMYB5A or R in soybean hairy roots induced the accumulation of PAs (primarily in phloem tissues) or anthocyanins and led to up-regulation of 1775, 856, 1411 and 1766 genes, respectively, several of which encode enzymes involved in PA biosynthesis. The genes regulated by GmTT2A and GmTT2B partially overlapped, suggesting conserved but potentially divergent roles for these two TFs in regulating PA accumulation in soybean. The two key enzymes anthocyanidin reductase and leucoanthocyanidin reductase were differentially upregulated, by GmTT2A/GmTT2B and GmMYB5A, respectively. Transgenic soybean plants overexpressing GmTT2B or MtLAP1 (a proven up-regulator of the upstream reactions for production of precursors for PA biosynthesis in legumes) showed increased accumulation of PAs and anthocyanins, respectively, associated with transcriptional reprogramming paralleling the RNA-seq data collected in soybean hairy roots. Collectively, our results show that engineered PA biosynthesis in soybean exhibits qualitative and spatial differences from the better-studied model systems Arabidopsis thaliana and Medicago truncatula, and suggest targets for engineering PAs in soybean plants.
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Affiliation(s)
- Nan Lu
- Department of Biological SciencesBioDiscovery InstituteUniversity of North TexasDentonTXUSA
| | - Xiaolan Rao
- Department of Biological SciencesBioDiscovery InstituteUniversity of North TexasDentonTXUSA
| | - Ying Li
- Department of Biological SciencesBioDiscovery InstituteUniversity of North TexasDentonTXUSA
| | - Ji Hyung Jun
- Department of Biological SciencesBioDiscovery InstituteUniversity of North TexasDentonTXUSA
| | - Richard A. Dixon
- Department of Biological SciencesBioDiscovery InstituteUniversity of North TexasDentonTXUSA
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24
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Jun JH, Lu N, Docampo-Palacios M, Wang X, Dixon RA. Dual activity of anthocyanidin reductase supports the dominant plant proanthocyanidin extension unit pathway. Sci Adv 2021; 7:eabg4682. [PMID: 33990337 PMCID: PMC8121424 DOI: 10.1126/sciadv.abg4682] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/25/2021] [Indexed: 05/12/2023]
Abstract
Proanthocyanidins (PAs) are plant natural products important for agriculture and human health. They are polymers of flavan-3-ol subunits, commonly (-)-epicatechin and/or (+)-catechin, but the source of the in planta extension unit that comprises the bulk of the polymer remains unclear, as does how PA composition is determined in different plant species. Anthocyanidin reductase (ANR) can generate 2,3-cis-epicatechin as a PA starter unit from cyanidin, which itself arises from 2,3-trans-leucocyanidin, but ANR proteins from different species produce mixtures of flavan-3-ols with different stereochemistries in vitro. Genetic and biochemical analyses here show that ANR has dual activity and is involved not only in the production of (-)-epicatechin starter units but also in the formation of 2,3-cis-leucocyanidin to serve as (-)-epicatechin extension units. Differences in the product specificities of ANRs account for the presence/absence of PA polymerization and the compositions of PAs across plant species.
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Affiliation(s)
- Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Nan Lu
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Maite Docampo-Palacios
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Xiaoqiang Wang
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
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25
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Adiji OA, Docampo-Palacios ML, Alvarez-Hernandez A, Pasinetti GM, Wang X, Dixon RA. UGT84F9 is the major flavonoid UDP-glucuronosyltransferase in Medicago truncatula. Plant Physiol 2021; 185:1617-1637. [PMID: 33694362 PMCID: PMC8133618 DOI: 10.1093/plphys/kiab016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Mammalian phase II metabolism of dietary plant flavonoid compounds generally involves substitution with glucuronic acid. In contrast, flavonoids mainly exist as glucose conjugates in plants, and few plant UDP-glucuronosyltransferase enzymes have been identified to date. In the model legume Medicago truncatula, the major flavonoid compounds in the aerial parts of the plant are glucuronides of the flavones apigenin and luteolin. Here we show that the M. truncatula glycosyltransferase UGT84F9 is a bi-functional glucosyl/glucuronosyl transferase in vitro, with activity against a wide range of flavonoid acceptor molecules including flavones. However, analysis of metabolite profiles in leaves and roots of M. truncatula ugt84f9 loss of function mutants revealed that the enzyme is essential for formation of flavonoid glucuronides, but not most flavonoid glucosides, in planta. We discuss the use of plant UGATs for the semi-synthesis of flavonoid phase II metabolites for clinical studies.
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Affiliation(s)
- Olubu A Adiji
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
| | - Maite L Docampo-Palacios
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
| | - Anislay Alvarez-Hernandez
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
| | - Giulio M Pasinetti
- Department of Psychiatry, The Mount Sinai School of Medicine, New York City, New York 10029
| | - Xiaoqiang Wang
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
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26
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Serrani-Yarce JC, Escamilla-Trevino L, Barros J, Gallego-Giraldo L, Pu Y, Ragauskas A, Dixon RA. Targeting hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase for lignin modification in Brachypodium distachyon. Biotechnol Biofuels 2021; 14:50. [PMID: 33640016 PMCID: PMC7913460 DOI: 10.1186/s13068-021-01905-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/16/2021] [Indexed: 05/29/2023]
Abstract
BACKGROUND Hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) is a central enzyme of the so-called "esters" pathway to monolignols. As originally envisioned, HCT functions twice in this pathway, to form coumaroyl shikimate and then, in the "reverse" direction, to convert caffeoyl shikimate to caffeoyl CoA. The discovery of a caffeoyl shikimate esterase (CSE) that forms caffeic acid directly from caffeoyl shikimate calls into question the need for the reverse HCT reaction in lignin biosynthesis. Loss of function of HCT gives severe growth phenotypes in several dicot plants, but less so in some monocots, questioning whether this enzyme, and therefore the shikimate shunt, plays the same role in both monocots and dicots. The model grass Brachypodium distachyon has two HCT genes, but lacks a classical CSE gene. This study was therefore conducted to evaluate the utility of HCT as a target for lignin modification in a species with an "incomplete" shikimate shunt. RESULTS The kinetic properties of recombinant B. distachyon HCTs were compared with those from Arabidopsis thaliana, Medicago truncatula, and Panicum virgatum (switchgrass) for both the forward and reverse reactions. Along with two M. truncatula HCTs, B. distachyon HCT2 had the least kinetically unfavorable reverse HCT reaction, and this enzyme is induced when HCT1 is down-regulated. Down regulation of B. distachyon HCT1, or co-down-regulation of HCT1 and HCT2, by RNA interference led to reduced lignin levels, with only modest changes in lignin composition and molecular weight. CONCLUSIONS Down-regulation of HCT1, or co-down-regulation of both HCT genes, in B. distachyon results in less extensive changes in lignin content/composition and cell wall structure than observed following HCT down-regulation in dicots, with little negative impact on biomass yield. Nevertheless, HCT down-regulation leads to significant improvements in biomass saccharification efficiency, making this gene a preferred target for biotechnological improvement of grasses for bioprocessing.
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Affiliation(s)
- Juan Carlos Serrani-Yarce
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, 76203 TX, USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Luis Escamilla-Trevino
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, 76203 TX, USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jaime Barros
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, 76203 TX, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Lina Gallego-Giraldo
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, 76203 TX, USA
| | - Yunqiao Pu
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
- UT-ORNL Joint Institute for Biological Sciences, Oak Ridge, TN, USA
| | - Art Ragauskas
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA
- UT-ORNL Joint Institute for Biological Sciences, Oak Ridge, TN, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, 76203 TX, USA.
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN, USA.
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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27
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Docampo-Palacios ML, Alvarez-Hernández A, Adiji O, Gamiotea-Turro D, Valerino-Diaz AB, Viegas LP, Ndukwe IE, de Fátima Â, Heiss C, Azadi P, Pasinetti GM, Dixon RA. Glucuronidation of Methylated Quercetin Derivatives: Chemical and Biochemical Approaches. J Agric Food Chem 2020; 68:14790-14807. [PMID: 33289379 PMCID: PMC8136248 DOI: 10.1021/acs.jafc.0c04500] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Botanical supplements derived from grapes are functional in animal model systems for the amelioration of neurological conditions, including cognitive impairment. Rats fed with grape extracts accumulate 3'-O-methyl-quercetin-3-O-β-d-glucuronide (3) in their brains, suggesting 3 as a potential therapeutic agent. To develop methods for the synthesis of 3 and the related 4'-O-methyl-quercetin-7-O-β-d-glucuronide (4), 3-O-methyl-quercetin-3'-O-β-d-glucuronide (5), and 4'-O-methyl-quercetin-3'-O-β-d-glucuronide (6), which are not found in the brain, we have evaluated both enzymatic semisynthesis and full chemical synthetic approaches. Biocatalysis by mammalian UDP-glucuronosyltransferases generated multiple glucuronidated products from 4'-O-methylquercetin, and is not cost-effective. Chemical synthetic methods, on the other hand, provided good results; 3, 5, and 6 were obtained in six steps at 12, 18, and 30% overall yield, respectively, while 4 was synthesized in five steps at 34% overall yield. A mechanistic study on the unexpected regioselectivity observed in the quercetin glucuronide synthetic steps is also presented.
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Affiliation(s)
- Maite L Docampo-Palacios
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton 76203, Texas, United States
| | - Anislay Alvarez-Hernández
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton 76203, Texas, United States
| | - Olubu Adiji
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton 76203, Texas, United States
| | - Daylin Gamiotea-Turro
- Chemistry Institute-Araraquara, UNESP-São Paulo State University, São Paulo 01049-010, Brazil
| | | | - Luís P Viegas
- Coimbra Chemistry Center, Chemistry Department, University of Coimbra, Coimbra 3004-531, Portugal
| | - Ikenna E Ndukwe
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Rd, Athens 30602, Georgia, United States
| | - Ângelo de Fátima
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton 76203, Texas, United States
- Department of Chemistry, Federal University of Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil
| | - Christian Heiss
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Rd, Athens 30602, Georgia, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Rd, Athens 30602, Georgia, United States
| | - Giulio M Pasinetti
- Department of Psychiatry, The Mount Sinai School of Medicine, New York 10029, New York, United States
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton 76203, Texas, United States
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28
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Wang X, Zhuo C, Xiao X, Wang X, Docampo-Palacios M, Chen F, Dixon RA. Substrate Specificity of LACCASE8 Facilitates Polymerization of Caffeyl Alcohol for C-Lignin Biosynthesis in the Seed Coat of Cleome hassleriana. Plant Cell 2020; 32:3825-3845. [PMID: 33037146 PMCID: PMC7721330 DOI: 10.1105/tpc.20.00598] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/24/2020] [Accepted: 10/06/2020] [Indexed: 05/02/2023]
Abstract
Catechyl lignin (C-lignin) is a linear homopolymer of caffeyl alcohol found in the seed coats of diverse plant species. Its properties make it a natural source of carbon fibers and high-value chemicals, but the mechanism of in planta polymerization of caffeyl alcohol remains unclear. In the ornamental plant Cleome hassleriana, lignin biosynthesis in the seed coat switches from guaiacyl lignin to C-lignin at ∼12 d after pollination. Here we found that the transcript profile of the laccase gene ChLAC8 parallels the accumulation of C-lignin during seed coat development. Recombinant ChLAC8 oxidizes caffeyl and sinapyl alcohols, generating their corresponding dimers or trimers in vitro, but cannot oxidize coniferyl alcohol. We propose a basis for this substrate preference based on molecular modeling/docking experiments. Suppression of ChLAC8 expression led to significantly reduced C-lignin content in the seed coats of transgenic Cleome plants. Feeding of 13C-caffeyl alcohol to the Arabidopsis (Arabidopsis thaliana) caffeic acid o-methyltransferase mutant resulted in no incorporation of 13C into C-lignin, but expressing ChLAC8 in this genetic background led to appearance of C-lignin with >40% label incorporation. These results indicate that ChLAC8 is required for C-lignin polymerization and determines lignin composition when caffeyl alcohol is available.
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Affiliation(s)
- Xin Wang
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Chunliu Zhuo
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Xirong Xiao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Xiaoqiang Wang
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
| | - Maite Docampo-Palacios
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Fang Chen
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
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29
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Docampo-Palacios ML, Alvarez-Hernández A, de Fátima Â, Lião LM, Pasinetti GM, Dixon RA. Efficient Chemical Synthesis of (Epi)catechin Glucuronides: Brain-Targeted Metabolites for Treatment of Alzheimer's Disease and Other Neurological Disorders. ACS Omega 2020; 5:30095-30110. [PMID: 33251444 PMCID: PMC7689943 DOI: 10.1021/acsomega.0c04512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/26/2020] [Indexed: 05/03/2023]
Abstract
Grape seed extract (GSE) is rich in flavonoids and has been recognized to possess human health benefits. Our group and others have demonstrated that GSE is able to attenuate the development of Alzheimer's disease (AD). Moreover, our results have disclosed that the anti-Alzheimer's benefits are not directly/solely related to the dietary flavonoids themselves, but rather to their metabolites, particularly to the glucuronidated ones. To facilitate the understanding of regioisomer/stereoisomer-specific biological effects of (epi)catechin glucuronides, we here describe a concise chemical synthesis of authentic standards of catechin and epicatechin metabolites 3-12. The synthesis of glucuronides 9 and 12 is described here for the first time. The key reactions employed in the synthesis of the novel glucuronides 9 and 12 include the regioselective methylation of the 4'-hydroxyl group of (epi)catechin (≤1.0/99.0%; 3'-OMe/4'-OMe) and the regioselective deprotection of the tert-butyldimethylsilyl (TBS) group at position 5 (yielding up to 79%) over the others (3, 7 and 3' or 4').
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Affiliation(s)
- Maite L. Docampo-Palacios
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, United States
- . Phone: +1-214-601-5892. Fax: +1-580-224-6692
| | - Anislay Alvarez-Hernández
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, United States
| | - Ângelo de Fátima
- Department
of Chemistry, Universidade Federal de Minas
Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Luciano Morais Lião
- Institute
of Chemistry, Universidade Federal de Goiás, Goiânia, GO 74690-900, Brazil
| | - Giulio M. Pasinetti
- Department
of Psychiatry, The Mount Sinai School of
Medicine, New York, New York 10029, United States
| | - Richard A. Dixon
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, United States
- . Phone: +1-940-565-2308
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30
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Abstract
Proanthocyanidins are the second most abundant plant phenolic polymer, but, despite intensive investigation, several aspects of their biosynthesis and functions remain unclear.
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Affiliation(s)
- Richard A Dixon
- Hagler Institute for Advanced Study and Department of Biological Sciences, Texas A&M University, College Station, Texas 77843-3572
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203-5017
| | - Sai Sarnala
- Texas Academy of Mathematics and Science, University of North Texas, Denton, Texas 76203-5017
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31
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Chan HC, Chan HC, Liang CJ, Lee HC, Su H, Lee AS, Shiea J, Tsai WC, Ou TT, Wu CC, Chu CS, Dixon RA, Ke LY, Yen JH, Chen CH. Role of Low-Density Lipoprotein in Early Vascular Aging Associated With Systemic Lupus Erythematosus. Arthritis Rheumatol 2020; 72:972-984. [PMID: 31994323 DOI: 10.1002/art.41213] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 01/21/2020] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Patients with systemic lupus erythematosus (SLE) often have atherosclerotic complications at a young age but normal low-density lipoprotein (LDL) levels. This study was undertaken to investigate the role of LDL composition in promoting early vascular aging in SLE patients. METHODS Plasma LDL from 45 SLE patients (SLE-LDL) and from 37 normal healthy controls (N-LDL) was chromatographically divided into 5 subfractions (L1-L5), and the subfraction composition was analyzed. Correlations between subfraction levels and signs of early vascular aging were assessed. Mechanisms of lipid-mediated endothelial dysfunction were explored using in vitro assays and experiments in apoE-/- mice. RESULTS The L5 percentage was increased 3.4 times in the plasma of SLE patients compared with normal controls. This increased percentage of SLE-L5 was positively correlated with the mean blood pressure (r = 0.27, P = 0.04), carotid intima-media thickness (IMT) (right carotid IMT, r = 0.4, P = 0.004; left carotid IMT, r = 0.36, P = 0.01), pulse wave velocity (r = 0.29, P = 0.04), and blood levels of CD16+ monocytes (r = 0.35, P = 0.004) and CX3CL1 cytokines (r = 0.43, P < 0.001) in SLE patients. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry analysis revealed that plasma levels of lysophosphatidylcholine (LPC) and platelet-activating factor (PAF) were increased in SLE-LDL and in the SLE-L5 plasma subfraction. Injecting SLE-LDL, SLE-L5, or LPC into young, male apoE-/- mice caused increases in plasma CX3CL1 levels, aortic fatty-streak areas, aortic vascular aging, and macrophage infiltration into the aortic wall, whereas injection of N-LDL or SLE-L1 had negligible effects (n = 3-8 mice per group). In vitro, SLE-L5 lipid extracts induced increases in CX3CR1 and CD16 expression in human monocytes; synthetic PAF and LPC had similar effects. Furthermore, lipid extracts of SLE-LDL and SLE-L5 induced the expression of CX3CL1 and enhanced monocyte-endothelial cell adhesion in assays with bovine aortic endothelial cells. CONCLUSION An increase in plasma L5 levels, not total LDL concentration, may promote early vascular aging in SLE patients, leading to premature atherosclerosis.
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Affiliation(s)
- Hua-Chen Chan
- Kaohsiung Medical University Hospital and Kaohsiung Medical University, Kaohsiung, Taiwan, and Texas Heart Institute, Houston
| | - Hsiu-Chuan Chan
- Kaohsiung Medical University, Kaohsiung, Taiwan, and Texas Heart Institute, Houston
| | | | - Hsiang-Chun Lee
- Kaohsiung Medical University Hospital and Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hung Su
- National Sun Yat-sen University, Kaohsiung, Taiwan
| | | | | | - Wen-Chan Tsai
- Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Tsan-Teng Ou
- Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Cheng-Chin Wu
- Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Chih-Sheng Chu
- Kaohsiung Medical University Hospital and Kaohsiung Medical University, Kaohsiung, Taiwan
| | | | - Liang-Yin Ke
- Kaohsiung Medical University Hospital and Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jeng-Hsien Yen
- Kaohsiung Medical University Hospital, Kaohsiung Medical University, and National Sun Yat-sen University, Kaohsiung, Taiwan, and National Chiao Tung University, Hsinchu, Taiwan
| | - Chu-Huang Chen
- Kaohsiung Medical University Hospital and Kaohsiung Medical University, Kaohsiung, Taiwan, and Texas Heart Institute, Houston, and New York Heart Research Foundation, Mineola
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32
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Abstract
Aromatic amino acid deaminases are key enzymes mediating carbon flux from primary to secondary metabolism in plants. Recent studies have uncovered a tyrosine ammonia-lyase that contributes to the typical characteristics of grass cell walls and contributes to about 50% of the total lignin synthesized by the plant. Grasses are currently preferred bioenergy feedstocks and lignin is the most important limiting factor in the conversion of plant biomass to liquid biofuels, as well as being an abundant renewable carbon source that can be industrially exploited. Further research on the structure, evolution, regulation, and biological function of functionally distinct ammonia-lyases has multiple implications for improving the economics of the agri-food and biofuel industries.
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Affiliation(s)
- Jaime Barros
- BioDiscovery Institute, University of North Texas, Denton, TX 76203, USA; Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Richard A Dixon
- BioDiscovery Institute, University of North Texas, Denton, TX 76203, USA; Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Abstract
Lignin is a major component of secondarily thickened plant cell walls and is considered to be the second most abundant biopolymer on the planet. At one point believed to be the product of a highly controlled polymerization procedure involving just three potential monomeric components (monolignols), it is becoming increasingly clear that the composition of lignin is quite flexible. Furthermore, the biosynthetic pathways to the major monolignols also appear to exhibit flexibility, particularly as regards the early reactions leading to the formation of caffeic acid from coumaric acid. The operation of parallel pathways to caffeic acid occurring at the level of shikimate esters or free acids may help provide robustness to the pathway under different physiological conditions. Several features of the pathway also appear to link monolignol biosynthesis to both generation and detoxification of hydrogen peroxide, one of the oxidants responsible for creating monolignol radicals for polymerization in the apoplast. Monolignol transport to the apoplast is not well understood. It may involve passive diffusion, although this may be targeted to sites of lignin initiation/polymerization by ordered complexes of both biosynthetic enzymes on the cytosolic side of the plasma membrane and structural anchoring of proteins for monolignol oxidation and polymerization on the apoplastic side. We present several hypothetical models to illustrate these ideas and stimulate further research. These are based primarily on studies in model systems, which may or may not reflect the major lignification process in forest trees.
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Affiliation(s)
- Richard A. Dixon
- Hagler Institute for Advanced Studies and Department of Biological Sciences, Texas A&M University, College Station, TX, USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203-5017, USA
| | - Jaime Barros
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX 76203-5017, USA
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Rao X, Dixon RA. Co-expression networks for plant biology: why and how. Acta Biochim Biophys Sin (Shanghai) 2019; 51:981-988. [PMID: 31436787 DOI: 10.1093/abbs/gmz080] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/20/2019] [Accepted: 07/01/2019] [Indexed: 12/29/2022] Open
Abstract
Co-expression network analysis is one of the most powerful approaches for interpretation of large transcriptomic datasets. It enables characterization of modules of co-expressed genes that may share biological functional linkages. Such networks provide an initial way to explore functional associations from gene expression profiling and can be applied to various aspects of plant biology. This review presents the applications of co-expression network analysis in plant biology and addresses optimized strategies from the recent literature for performing co-expression analysis on plant biological systems. Additionally, we describe the combined interpretation of co-expression analysis with other genomic data to enhance the generation of biologically relevant information.
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Affiliation(s)
- Xiaolan Rao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA
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Man Ha C, Fine D, Bhatia A, Rao X, Martin MZ, Engle NL, Wherritt DJ, Tschaplinski TJ, Sumner LW, Dixon RA. Ectopic Defense Gene Expression Is Associated with Growth Defects in Medicago truncatula Lignin Pathway Mutants. Plant Physiol 2019; 181:63-84. [PMID: 31289215 PMCID: PMC6716239 DOI: 10.1104/pp.19.00533] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 06/26/2019] [Indexed: 05/04/2023]
Abstract
Lignin provides essential mechanical support for plant cell walls but decreases the digestibility of forage crops and increases the recalcitrance of biofuel crops. Attempts to modify lignin content and/or composition by genetic modification often result in negative growth effects. Although several studies have attempted to address the basis for such effects in individual transgenic lines, no common mechanism linking lignin modification with perturbations in plant growth and development has yet been identified. To address whether a common mechanism exists, we have analyzed transposon insertion mutants resulting in independent loss of function of five enzymes of the monolignol pathway, as well as one double mutant, in the model legume Medicago truncatula These plants exhibit growth phenotypes from essentially wild type to severely retarded. Extensive phenotypic, transcriptomic, and metabolomics analyses, including structural characterization of differentially expressed compounds, revealed diverse phenotypic consequences of lignin pathway perturbation that were perceived early in plant development but were not predicted by lignin content or composition alone. Notable phenotypes among the mutants with severe growth impairment were increased trichome numbers, accumulation of a variety of triterpene saponins, and extensive but differential ectopic expression of defense response genes. No currently proposed model explains the observed phenotypes across all lines. We propose that reallocation of resources into defense pathways is linked to the severity of the final growth phenotype in monolignol pathway mutants of M. truncatula, although it remains unclear whether this is a cause or an effect of the growth impairment.
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Affiliation(s)
- Chan Man Ha
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Dennis Fine
- Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Anil Bhatia
- Department of Biochemistry and MU Metabolomics Center, University of Missouri, Columbia, Missouri 65201
| | - Xiaolan Rao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201
- Bioenergy Sciences Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Madhavi Z Martin
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- Bioenergy Sciences Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- BioSciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Nancy L Engle
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- Bioenergy Sciences Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- BioSciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Daniel J Wherritt
- Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
- University of Texas at San Antonio, San Antonio, Texas 78249
| | - Timothy J Tschaplinski
- Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
- University of Texas at San Antonio, San Antonio, Texas 78249
| | - Lloyd W Sumner
- Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
- Department of Biochemistry and MU Metabolomics Center, University of Missouri, Columbia, Missouri 65201
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76201
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- Bioenergy Sciences Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
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Zhuo C, Rao X, Azad R, Pandey R, Xiao X, Harkelroad A, Wang X, Chen F, Dixon RA. Enzymatic basis for C-lignin monomer biosynthesis in the seed coat of Cleome hassleriana. Plant J 2019; 99:506-520. [PMID: 31002459 DOI: 10.1111/tpj.14340] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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: 12/07/2018] [Revised: 03/05/2019] [Accepted: 03/28/2019] [Indexed: 06/09/2023]
Abstract
C-lignin is a linear polymer of caffeyl alcohol, found in the seed coats of several exotic plant species, with promising properties for generation of carbon fibers and high value chemicals. In the ornamental plant Cleome hassleriana, guaiacyl (G) lignin is deposited in the seed coat for the first 6-12 days after pollination, after which G-lignin deposition ceases and C-lignin accumulates, providing an excellent model system to study C-lignin biosynthesis. We performed RNA sequencing of seed coats harvested at 2-day intervals throughout development. Bioinformatic analysis identified a complete set of lignin biosynthesis genes for Cleome. Transcript analysis coupled with kinetic analysis of recombinant enzymes in Escherichia coli revealed that the switch to C-lignin formation was accompanied by down-regulation of transcripts encoding functional caffeoyl CoA- and caffeic acid 3-O-methyltransferases (CCoAOMT and COMT) and a form of cinnamyl alcohol dehydrogenase (ChCAD4) with preference for coniferaldehyde as substrate, and up-regulation of a form of CAD (ChCAD5) with preference for caffealdehyde. Based on these analyses, blockage of lignin monomer methylation by down-regulation of both O-methyltransferases (OMTs) and methionine synthase (for provision of C1 units) appears to be the major factor in diversion of flux to C-lignin in the Cleome seed coat, although the change in CAD specificity also contributes based on the reduction of C-lignin levels in transgenic Cleome with down-regulation of ChCAD5. Structure modeling and mutational analysis identified amino acid residues important for the preference of ChCAD5 for caffealdehyde.
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Affiliation(s)
- Chunliu Zhuo
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
| | - Xiaolan Rao
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
| | - Rajeev Azad
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
- Department of Mathematics, University of North Texas, Denton, TX, USA
| | - Ravi Pandey
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
| | - Xirong Xiao
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TX, USA
| | - Aaron Harkelroad
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
| | - Xiaoqiang Wang
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
| | - Fang Chen
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TX, USA
| | - Richard A Dixon
- BioDiscovery Institute, University of North Texas, Denton, TX, USA
- Department of Biological Science, University of North Texas, Denton, TX, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TX, USA
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Yu K, Jun JH, Duan C, Dixon RA. VvLAR1 and VvLAR2 Are Bifunctional Enzymes for Proanthocyanidin Biosynthesis in Grapevine. Plant Physiol 2019; 180:1362-1374. [PMID: 31092697 PMCID: PMC6752904 DOI: 10.1104/pp.19.00447] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/08/2019] [Indexed: 05/18/2023]
Abstract
Proanthocyanidins (PAs) in grapevine (Vitis vinifera) are found mainly in berries, and their content and degree of polymerization are important for the mouth feel of red wine. However, the mechanism of PA polymerization in grapevine remains unclear. Previous studies in the model legume Medicago truncatula showed that 4β-(S-cysteinyl)-epicatechin (Cys-EC) is an epicatechin-type extension unit for nonenzymatic PA polymerization, and that leucoanthocyanidin reductase (LAR) converts Cys-EC into epicatechin starter unit to control PA extension. Grapevine possesses two LAR genes, but their functions are not clear. Here, we show that both Cys-EC and 4β-(S-cysteinyl)-catechin (Cys-C) are present in grapevine. Recombinant VvLAR1 and VvLAR2 convert Cys-C and Cys-EC into (+)-catechin and (-)-epicatechin, respectively, in vitro. The kinetic parameters of VvLARs are similar, with both enzymes being more efficient with Cys-C than with Cys-EC, the 2,3-cis conformation of which results in steric hindrance in the active site. Both VvLARs also produce (+)-catechin from leucocyanidin, and an inactive VvLAR2 allele reported previously is the result of a single amino acid mutation in the N terminus critical for all NADPH-dependent activities of the enzyme. VvLAR1 or VvLAR2 complement the M. truncatula lar:ldox double mutant that also lacks the leucoanthocyanidin dioxygenase (LDOX) required for epicatechin starter unit formation, resulting in increased soluble PA levels, decreased insoluble PA levels, and reduced levels of Cys-C and Cys-EC when compared to the double mutant, and the appearance of catechin, epicatechin, and PA dimers characteristic of the ldox single mutant in young pods. These data advance our knowledge of PA building blocks and LAR function and provide targets for grapevine breeding to alter PA composition.
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Affiliation(s)
- Keji Yu
- Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, China 100083
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing, China 100083
| | - Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
| | - Changqing Duan
- Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing, China 100083
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing, China 100083
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203
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de Fátima Â, Docampo-Palacios M, Alvarez-Hernandez A, Pasinetti GM, Dixon RA. Correction to "An Efficient Synthesis of Deoxyrhapontigenin-3- O-β-d-glucuronide, a Brain-Targeted Derivative of Dietary Resveratrol, and Its Precursor 4'- O-Me-Resveratrol". ACS Omega 2019; 4:10301. [PMID: 31460122 PMCID: PMC6648519 DOI: 10.1021/acsomega.9b01516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Indexed: 06/10/2023]
Abstract
[This corrects the article DOI: 10.1021/acsomega.9b00722.].
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39
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de
Fátima Â, Docampo-Palacios M, Alvarez-Hernandez A, Pasinetti GM, Dixon RA. An Efficient Synthesis of Deoxyrhapontigenin-3- O- β-D-glucuronide, a Brain-targeted Derivative of Dietary Resveratrol, and its Precursor 4'- O-Me-Resveratrol. ACS Omega 2019; 4:8222-8330. [PMID: 31236526 PMCID: PMC6590917 DOI: 10.1021/acsomega.9b00722] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 04/18/2019] [Indexed: 05/21/2023]
Abstract
Bioactive dietary polyphenols have health benefits against a variety of disorders, but some benefits of polyphenols may be not directly related to them, but rather to their metabolites. Recently, we have identified the brain-available phenol glucuronide metabolite deoxyrhapontigenin-3-O-β-D-glucuronide (5) in perfused rat brains following sub-acute treatment with the stilbene resveratrol (1). However, the role of such a metabolite in the neuroprotective activity of resveratrol (1) is not understood, in part due to the non-commercial availability of 5 for performing biological evaluation in animal models of Alzheimer's disease or other neurological disorders. Here, we describe a concise chemical synthesis of deoxyrhapontigenin-3-O-β-D-glucuronide (5) and its precursor, 4-O-Me-resveratrol (2), accomplished in 4 and 6 steps with 74% and 21% overall yields, respectively, starting from commercially available 3,5-dihydroxybenzaldehyde. Pivotal reactions employed in the synthesis include the palladium-catalyzed C-C coupling between 3,5-di-tert-butyldiphenylsilyloxystyrene and p-iodoanisole in the presence of tributylamine and the acid-catalysed glucuronidation between the trichloroacetimidate-activated glucuronic acid and 4-O-Me-resveratrol.
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Affiliation(s)
- Ângelo de
Fátima
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, Texas 76203-5017, United States
- Department
of Chemistry, Universidade Federal de Minas
Gerais, Avenida Presidente
Antônio Carlos 6627, Campus Pampulha, Belo Horizonte, Minas Gerais 31270-901, Brazil
- E-mail: (A.d.F.)
| | - Maite Docampo-Palacios
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, Texas 76203-5017, United States
| | - Anislay Alvarez-Hernandez
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, Texas 76203-5017, United States
| | - Giulio M. Pasinetti
- Department
of Neurology, Icahn School of Medicine at
Mount Sinai, One Gustave L. Levy Place, P.O. Box 1230, New York, New York 10029, United States
| | - Richard A. Dixon
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, Texas 76203-5017, United States
- E-mail: (R.A.D)
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40
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Xie H, Engle NL, Venketachalam S, Yoo CG, Barros J, Lecoultre M, Howard N, Li G, Sun L, Srivastava AC, Pattathil S, Pu Y, Hahn MG, Ragauskas AJ, Nelson RS, Dixon RA, Tschaplinski TJ, Blancaflor EB, Tang Y. Combining loss of function of FOLYLPOLYGLUTAMATE SYNTHETASE1 and CAFFEOYL- COA 3- O- METHYLTRANSFERASE1 for lignin reduction and improved saccharification efficiency in Arabidopsis thaliana. Biotechnol Biofuels 2019; 12:108. [PMID: 31073332 PMCID: PMC6498598 DOI: 10.1186/s13068-019-1446-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 04/20/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Downregulation of genes involved in lignin biosynthesis and related biochemical pathways has been used as a strategy to improve biofuel production. Plant C1 metabolism provides the methyl units used for the methylation reactions carried out by two methyltransferases in the lignin biosynthetic pathway: caffeic acid 3-O-methyltransferase (COMT) and caffeoyl-CoA 3-O-methyltransferase (CCoAOMT). Mutations in these genes resulted in lower lignin levels and altered lignin compositions. Reduced lignin levels can also be achieved by mutations in the C1 pathway gene, folylpolyglutamate synthetase1 (FPGS1), in both monocotyledons and dicotyledons, indicating a link between the C1 and lignin biosynthetic pathways. To test if lignin content can be further reduced by combining genetic mutations in C1 metabolism and the lignin biosynthetic pathway, fpgs1ccoaomt1 double mutants were generated and functionally characterized. RESULTS Double fpgs1ccoaomt1 mutants had lower thioacidolysis lignin monomer yield and acetyl bromide lignin content than the ccoaomt1 or fpgs1 mutants and the plants themselves displayed no obvious long-term negative growth phenotypes. Moreover, extracts from the double mutants had dramatically improved enzymatic polysaccharide hydrolysis efficiencies than the single mutants: 15.1% and 20.7% higher than ccoaomt1 and fpgs1, respectively. The reduced lignin and improved sugar release of fpgs1ccoaomt1 was coupled with changes in cell-wall composition, metabolite profiles, and changes in expression of genes involved in cell-wall and lignin biosynthesis. CONCLUSION Our observations demonstrate that additional reduction in lignin content and improved sugar release can be achieved by simultaneous downregulation of a gene in the C1 (FPGS1) and lignin biosynthetic (CCOAOMT) pathways. These improvements in sugar accessibility were achieved without introducing unwanted long-term plant growth and developmental defects.
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Affiliation(s)
- Hongli Xie
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Nancy L. Engle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Sivasankari Venketachalam
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Chang Geun Yoo
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Jaime Barros
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Mitch Lecoultre
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Nikki Howard
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Guifen Li
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
| | - Liang Sun
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
| | - Avinash C. Srivastava
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Sivakumar Pattathil
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Yunqiao Pu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Michael G. Hahn
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Arthur J. Ragauskas
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Richard S. Nelson
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Timothy J. Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- The Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Elison B. Blancaflor
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Yuhong Tang
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401 USA
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
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Abstract
Proanthocyanidins (PAs) are oligomeric plant natural products mostly derived from epicatechin and/or catechin monomers. In studies aimed at engineering PAs into plant tissues that do not naturally make these compounds, we have expressed PA biosynthetic and regulatory genes in tobacco, alfalfa ( Medicago sativa) and the model legume Medicago truncatula. Because engineered tannins may be produced in small quantities and it is often necessary to screen many independent plant lines, we have developed an improved, highly sensitive method to quantify and determine the composition of oligomeric PAs in plant extracts. The method involves normal-phase HPLC separation of semi-purified PAs followed by post-column reaction with the PA-specific reagent DMACA (dimethylaminocinnamaldehyde). This procedure allows for accurate and sensitive quantification of individual oligomeric PAs and, unlike currently used methods, does not require exhaustive sample preparation and clean-up. Compositional data are shown for genetically engineered PAs in tobacco and alfalfa.
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Affiliation(s)
- Gregory J. Peel
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore Oklahoma 73401, USA
| | - Richard A. Dixon
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore Oklahoma 73401, USA
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Rao X, Dixon RA. Corrigendum: The Differences between NAD-ME and NADP-ME Subtypes of C 4 Photosynthesis: More than Decarboxylating Enzymes. Front Plant Sci 2019; 10:247. [PMID: 30906304 PMCID: PMC6418413 DOI: 10.3389/fpls.2019.00247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 02/14/2019] [Indexed: 05/26/2023]
Abstract
[This corrects the article DOI: 10.3389/fpls.2016.01525.].
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Affiliation(s)
- Xiaolan Rao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
- BioEnergy Science Center, US Department of Energy, Oak Ridge, TN, United States
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
- BioEnergy Science Center, US Department of Energy, Oak Ridge, TN, United States
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43
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Rao X, Chen X, Shen H, Ma Q, Li G, Tang Y, Pena M, York W, Frazier TP, Lenaghan S, Xiao X, Chen F, Dixon RA. Gene regulatory networks for lignin biosynthesis in switchgrass (Panicum virgatum). Plant Biotechnol J 2019; 17:580-593. [PMID: 30133139 PMCID: PMC6381781 DOI: 10.1111/pbi.13000] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/24/2018] [Accepted: 08/18/2018] [Indexed: 05/17/2023]
Abstract
Cell wall recalcitrance is the major challenge to improving saccharification efficiency in converting lignocellulose into biofuels. However, information regarding the transcriptional regulation of secondary cell wall biogenesis remains poor in switchgrass (Panicum virgatum), which has been selected as a biofuel crop in the United States. In this study, we present a combination of computational and experimental approaches to develop gene regulatory networks for lignin formation in switchgrass. To screen transcription factors (TFs) involved in lignin biosynthesis, we developed a modified method to perform co-expression network analysis using 14 lignin biosynthesis genes as bait (target) genes. The switchgrass lignin co-expression network was further extended by adding 14 TFs identified in this study, and seven TFs identified in previous studies, as bait genes. Six TFs (PvMYB58/63, PvMYB42/85, PvMYB4, PvWRKY12, PvSND2 and PvSWN2) were targeted to generate overexpressing and/or down-regulated transgenic switchgrass lines. The alteration of lignin content, cell wall composition and/or plant growth in the transgenic plants supported the role of the TFs in controlling secondary wall formation. RNA-seq analysis of four of the transgenic switchgrass lines revealed downstream target genes of the secondary wall-related TFs and crosstalk with other biological pathways. In vitro transactivation assays further confirmed the regulation of specific lignin pathway genes by four of the TFs. Our meta-analysis provides a hierarchical network of TFs and their potential target genes for future manipulation of secondary cell wall formation for lignin modification in switchgrass.
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Affiliation(s)
- Xiaolan Rao
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
| | - Xin Chen
- Center for Applied MathematicsTianjin UniversityTianjinChina
| | - Hui Shen
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
- Present address:
Marker‐assisted Breeding and TraitsChromatin IncLubbockTX79404USA
| | - Qin Ma
- Department of Agronomy, Horticulture, and Plant Science and Department of Mathematics and StatisticsSouth Dakota State UniversityBrookingsSDUSA
| | - Guifen Li
- Noble Research InstituteArdmoreOKUSA
| | - Yuhong Tang
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
- Noble Research InstituteArdmoreOKUSA
| | - Maria Pena
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular BiologyUniversity of GeorgiaAthensGAUSA
| | - William York
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular BiologyUniversity of GeorgiaAthensGAUSA
| | | | - Scott Lenaghan
- Department of Food ScienceUniversity of TennesseeKnoxvilleTNUSA
| | - Xirong Xiao
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
| | - Fang Chen
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
- Center for Bioenergy Innovation (CBI)Oak Ridge National LaboratoryOak RidgeTNUSA
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological SciencesUniversity of North TexasDentonTXUSA
- BioEnergy Science Center (BESC)Oak Ridge National LaboratoryOak RidgeTNUSA
- Center for Bioenergy Innovation (CBI)Oak Ridge National LaboratoryOak RidgeTNUSA
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Holwerda EK, Worthen RS, Kothari N, Lasky RC, Davison BH, Fu C, Wang ZY, Dixon RA, Biswal AK, Mohnen D, Nelson RS, Baxter HL, Mazarei M, Stewart CN, Muchero W, Tuskan GA, Cai CM, Gjersing EE, Davis MF, Himmel ME, Wyman CE, Gilna P, Lynd LR. Correction to: Multiple levers for overcoming the recalcitrance of lignocellulosic biomass. Biotechnol Biofuels 2019; 12:25. [PMID: 30774713 PMCID: PMC6368767 DOI: 10.1186/s13068-019-1363-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/04/2019] [Indexed: 06/09/2023]
Abstract
[This corrects the article DOI: 10.1186/s13068-019-1353-7.].
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Affiliation(s)
- Evert K. Holwerda
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Robert S. Worthen
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Ninad Kothari
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521 USA
| | - Ronald C. Lasky
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
| | - Brian H. Davison
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Chunxiang Fu
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Genomics Division, Noble Research Institute, Ardmore, OK 73401 USA
| | - Zeng-Yu Wang
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Genomics Division, Noble Research Institute, Ardmore, OK 73401 USA
| | - Richard A. Dixon
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Ajaya K. Biswal
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Debra Mohnen
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Richard S. Nelson
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Genomics Division, Noble Research Institute, Ardmore, OK 73401 USA
| | - Holly L. Baxter
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Plant Sciences, University of Tennessee at Knoxville, Knoxville, TN 37996 USA
| | - Mitra Mazarei
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Plant Sciences, University of Tennessee at Knoxville, Knoxville, TN 37996 USA
| | - C. Neal Stewart
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Plant Sciences, University of Tennessee at Knoxville, Knoxville, TN 37996 USA
| | - Wellington Muchero
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Gerald A. Tuskan
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Charles M. Cai
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521 USA
| | - Erica E. Gjersing
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Bioenergy Science and Technology, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Mark F. Davis
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Bioenergy Science and Technology, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Michael E. Himmel
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Bioenergy Science and Technology, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Charles E. Wyman
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521 USA
| | - Paul Gilna
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Lee R. Lynd
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
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Furches A, Kainer D, Weighill D, Large A, Jones P, Walker AM, Romero J, Gazolla JGFM, Joubert W, Shah M, Streich J, Ranjan P, Schmutz J, Sreedasyam A, Macaya-Sanz D, Zhao N, Martin MZ, Rao X, Dixon RA, DiFazio S, Tschaplinski TJ, Chen JG, Tuskan GA, Jacobson D. Finding New Cell Wall Regulatory Genes in Populus trichocarpa Using Multiple Lines of Evidence. Front Plant Sci 2019; 10:1249. [PMID: 31649710 PMCID: PMC6791931 DOI: 10.3389/fpls.2019.01249] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 09/09/2019] [Indexed: 05/05/2023]
Abstract
Understanding the regulatory network controlling cell wall biosynthesis is of great interest in Populus trichocarpa, both because of its status as a model woody perennial and its importance for lignocellulosic products. We searched for genes with putatively unknown roles in regulating cell wall biosynthesis using an extended network-based Lines of Evidence (LOE) pipeline to combine multiple omics data sets in P. trichocarpa, including gene coexpression, gene comethylation, population level pairwise SNP correlations, and two distinct SNP-metabolite Genome Wide Association Study (GWAS) layers. By incorporating validation, ranking, and filtering approaches we produced a list of nine high priority gene candidates for involvement in the regulation of cell wall biosynthesis. We subsequently performed a detailed investigation of candidate gene GROWTH-REGULATING FACTOR 9 (PtGRF9). To investigate the role of PtGRF9 in regulating cell wall biosynthesis, we assessed the genome-wide connections of PtGRF9 and a paralog across data layers with functional enrichment analyses, predictive transcription factor binding site analysis, and an independent comparison to eQTN data. Our findings indicate that PtGRF9 likely affects the cell wall by directly repressing genes involved in cell wall biosynthesis, such as PtCCoAOMT and PtMYB.41, and indirectly by regulating homeobox genes. Furthermore, evidence suggests that PtGRF9 paralogs may act as transcriptional co-regulators that direct the global energy usage of the plant. Using our extended pipeline, we show multiple lines of evidence implicating the involvement of these genes in cell wall regulatory functions and demonstrate the value of this method for prioritizing candidate genes for experimental validation.
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Affiliation(s)
- Anna Furches
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, United States
| | - David Kainer
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Deborah Weighill
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, United States
| | - Annabel Large
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Oak Ridge Associated Universities (ORAU), Oak Ridge, TN, United States
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, United States
| | - Piet Jones
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, United States
| | - Angelica M. Walker
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Oak Ridge Associated Universities (ORAU), Oak Ridge, TN, United States
- Department of Computer Science, Johns Hopkins University, Baltimore, MD, United States
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Jonathon Romero
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, United States
| | | | - Wayne Joubert
- Oak Ridge Leadership Computing Facility, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Manesh Shah
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Jared Streich
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Priya Ranjan
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Department of Plant Sciences, The University of Tennessee Institute of Agriculture, University of Tennessee, Knoxville, TN, United States
| | - Jeremy Schmutz
- Joint Genome Institute, Walnut Creek, CA, United States
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, United States
| | | | - David Macaya-Sanz
- Department of Biology, West Virginia University, Morgantown, WV, United States
| | - Nan Zhao
- Department of Plant Sciences, The University of Tennessee Institute of Agriculture, University of Tennessee, Knoxville, TN, United States
| | - Madhavi Z. Martin
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Xiaolan Rao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
| | - Stephen DiFazio
- Department of Biology, West Virginia University, Morgantown, WV, United States
| | - Timothy J. Tschaplinski
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Jin-Gui Chen
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Gerald A. Tuskan
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Daniel Jacobson
- Biosciences Division, and The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, United States
- *Correspondence: Daniel Jacobson,
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46
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Holwerda EK, Worthen RS, Kothari N, Lasky RC, Davison BH, Fu C, Wang ZY, Dixon RA, Biswal AK, Mohnen D, Nelson RS, Baxter HL, Mazarei M, Muchero W, Tuskan GA, Cai CM, Gjersing EE, Davis MF, Himmel ME, Wyman CE, Gilna P, Lynd LR. Multiple levers for overcoming the recalcitrance of lignocellulosic biomass. Biotechnol Biofuels 2019; 12:15. [PMID: 30675183 PMCID: PMC6335785 DOI: 10.1186/s13068-019-1353-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/04/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND The recalcitrance of cellulosic biomass is widely recognized as a key barrier to cost-effective biological processing to fuels and chemicals, but the relative impacts of physical, chemical and genetic interventions to improve biomass processing singly and in combination have yet to be evaluated systematically. Solubilization of plant cell walls can be enhanced by non-biological augmentation including physical cotreatment and thermochemical pretreatment, the choice of biocatalyst, the choice of plant feedstock, genetic engineering of plants, and choosing feedstocks that are less recalcitrant natural variants. A two-tiered combinatoric investigation of lignocellulosic biomass deconstruction was undertaken with three biocatalysts (Clostridium thermocellum, Caldicellulosiruptor bescii, Novozymes Cellic® Ctec2 and Htec2), three transgenic switchgrass plant lines (COMT, MYB4, GAUT4) and their respective nontransgenic controls, two Populus natural variants, and augmentation of biological attack using either mechanical cotreatment or cosolvent-enhanced lignocellulosic fractionation (CELF) pretreatment. RESULTS In the absence of augmentation and under the conditions tested, increased total carbohydrate solubilization (TCS) was observed for 8 of the 9 combinations of switchgrass modifications and biocatalysts tested, and statistically significant for five of the combinations. Our results indicate that recalcitrance is not a trait determined by the feedstock only, but instead is coequally determined by the choice of biocatalyst. TCS with C. thermocellum was significantly higher than with the other two biocatalysts. Both CELF pretreatment and cotreatment via continuous ball milling enabled TCS in excess of 90%. CONCLUSION Based on our results as well as literature studies, it appears that some form of non-biological augmentation will likely be necessary for the foreseeable future to achieve high TCS for most cellulosic feedstocks. However, our results show that this need not necessarily involve thermochemical processing, and need not necessarily occur prior to biological conversion. Under the conditions tested, the relative magnitude of TCS increase was augmentation > biocatalyst choice > plant choice > plant modification > plant natural variants. In the presence of augmentation, plant modification, plant natural variation, and plant choice exhibited a small, statistically non-significant impact on TCS.
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Affiliation(s)
- Evert K. Holwerda
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Robert S. Worthen
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Ninad Kothari
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521 USA
| | - Ronald C. Lasky
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
| | - Brian H. Davison
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Chunxiang Fu
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Genomics Division, Noble Research Institute, Ardmore, OK 73401 USA
| | - Zeng-Yu Wang
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Genomics Division, Noble Research Institute, Ardmore, OK 73401 USA
| | - Richard A. Dixon
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Ajaya K. Biswal
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Debra Mohnen
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Richard S. Nelson
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Genomics Division, Noble Research Institute, Ardmore, OK 73401 USA
| | - Holly L. Baxter
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Plant Sciences, University of Tennessee at Knoxville, Knoxville, TN 37996 USA
| | - Mitra Mazarei
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Plant Sciences, University of Tennessee at Knoxville, Knoxville, TN 37996 USA
| | - Wellington Muchero
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Gerald A. Tuskan
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Charles M. Cai
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521 USA
| | - Erica E. Gjersing
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Bioenergy Science and Technology, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Mark F. Davis
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Bioenergy Science and Technology, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Michael E. Himmel
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Bioenergy Science and Technology, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Charles E. Wyman
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Chemical and Environmental Engineering and Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, Riverside, CA 92521 USA
| | - Paul Gilna
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Lee R. Lynd
- Thayer School of Engineering, Dartmouth College, 14 Engineering drive, Hanover, NH 03755 USA
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
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47
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Jun JH, Xiao X, Rao X, Dixon RA. Proanthocyanidin subunit composition determined by functionally diverged dioxygenases. Nat Plants 2018; 4:1034-1043. [PMID: 30478357 DOI: 10.1038/s41477-018-0292-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/27/2018] [Indexed: 05/14/2023]
Abstract
Proanthocyanidins (PAs) are primarily composed of the flavan-3-ol subunits (-)-epicatechin and/or (+)-catechin, but the basis for their different starter and extension unit compositions remains unclear. Genetic and biochemical analyses show that, in the model legume Medicago truncatula, two 2-oxoglutarate-dependent dioxygenases, anthocyanidin synthase (ANS) and its homologue leucoanthocyanidin dioxygenase (LDOX), are involved in parallel pathways to generate, respectively, the (-)-epicatechin extension and starter units of PAs, with (+) catechin being an intermediate in the formation of the (-)-epicatechin starter unit. The presence/absence of the LDOX pathway accounts for natural differences in PA compositions across species, and engineering loss of function of ANS or LDOX provides a means to obtain PAs with different compositions and degrees of polymerization for use in food and feed.
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Affiliation(s)
- Ji Hyung Jun
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Xirong Xiao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Xiaolan Rao
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, USA.
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Lukyn T, Dixon RA, MacDonald SWS. VARIABILITY MEASURES UNLOCK THE CLINICAL UTILITY OF GAITRITE ASSESSMENT FOR PREDICTING MILD COGNITIVE IMPAIRMENT. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.2790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- T Lukyn
- University of Victoria, Victoria, British Columbia, Canada
| | - R A Dixon
- Department of Psychology, University of Alberta, Neuroscience and Mental Health Institute, University of Alberta
| | - S W S MacDonald
- Department of Psychology, University of Victoria, Institute of Aging and Lifelong Health, Universtiy of Victoria
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49
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Barros J, Temple S, Dixon RA. Development and commercialization of reduced lignin alfalfa. Curr Opin Biotechnol 2018; 56:48-54. [PMID: 30268938 DOI: 10.1016/j.copbio.2018.09.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 10/28/2022]
Abstract
Reducing lignin content in forage legumes can improve digestibility and, correspondingly, animal performance, and alfalfa (Medicago sativa) is the first genetically engineered crop commercialized for improved forage digestibility. Lignin reduction was achieved by downregulating the gene encoding caffeoyl-CoA 3-O-methyltransferase (CCoAOMT), and development of the commercial product, branded as HarvXtra, required the coordination of two research institutions and two companies, and more than 15 years of research and field trials. Lignin modification has positive impacts on forage management. Future developments will likely stack lignin modification with additional forage quality traits.
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Affiliation(s)
- Jaime Barros
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, United States; Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
| | - Stephen Temple
- Forage Genetics International, West Salem, WI 54669, United States
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203, United States; Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States.
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50
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Faraji M, Fonseca LL, Escamilla-Treviño L, Barros-Rios J, Engle NL, Yang ZK, Tschaplinski TJ, Dixon RA, Voit EO. A dynamic model of lignin biosynthesis in Brachypodium distachyon. Biotechnol Biofuels 2018; 11:253. [PMID: 30250505 PMCID: PMC6145374 DOI: 10.1186/s13068-018-1241-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/27/2018] [Indexed: 05/31/2023]
Abstract
BACKGROUND Lignin is a crucial molecule for terrestrial plants, as it offers structural support and permits the transport of water over long distances. The hardness of lignin reduces plant digestibility by cattle and sheep; it also makes inedible plant materials recalcitrant toward the enzymatic fermentation of cellulose, which is a potentially valuable substrate for sustainable biofuels. Targeted attempts to change the amount or composition of lignin in relevant plant species have been hampered by the fact that the lignin biosynthetic pathway is difficult to understand, because it uses several enzymes for the same substrates, is regulated in an ill-characterized manner, may operate in different locations within cells, and contains metabolic channels, which the plant may use to funnel initial substrates into specific monolignols. RESULTS We propose a dynamic mathematical model that integrates various datasets and other information regarding the lignin pathway in Brachypodium distachyon and permits explanations for some counterintuitive observations. The model predicts the lignin composition and label distribution in a BdPTAL knockdown strain, with results that are quite similar to experimental data. CONCLUSION Given the present scarcity of available data, the model resulting from our analysis is presumably not final. However, it offers proof of concept for how one may design integrative pathway models of this type, which are necessary tools for predicting the consequences of genomic or other alterations toward plants with lignin features that are more desirable than in their wild-type counterparts.
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Affiliation(s)
- Mojdeh Faraji
- The Wallace H. Coulter, Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Drive, Atlanta, GA 30332-2000 USA
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
| | - Luis L. Fonseca
- The Wallace H. Coulter, Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Drive, Atlanta, GA 30332-2000 USA
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
| | - Luis Escamilla-Treviño
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203-5017 USA
| | - Jaime Barros-Rios
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203-5017 USA
| | - Nancy L. Engle
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 USA
| | - Zamin K. Yang
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 USA
| | - Timothy J. Tschaplinski
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 USA
| | - Richard A. Dixon
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203-5017 USA
| | - Eberhard O. Voit
- The Wallace H. Coulter, Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Drive, Atlanta, GA 30332-2000 USA
- BioEnergy Sciences Center (BESC), Oak Ridge National Lab, Oak Ridge, TN USA
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