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Tetreault HM, Gries T, Liu S, Toy J, Xin Z, Vermerris W, Ralph J, Funnell-Harris DL, Sattler SE. The Sorghum ( Sorghum bicolor) Brown Midrib 30 Gene Encodes a Chalcone Isomerase Required for Cell Wall Lignification. FRONTIERS IN PLANT SCIENCE 2021; 12:732307. [PMID: 34925394 PMCID: PMC8674566 DOI: 10.3389/fpls.2021.732307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/19/2021] [Indexed: 06/14/2023]
Abstract
In sorghum (Sorghum bicolor) and other C4 grasses, brown midrib (bmr) mutants have long been associated with plants impaired in their ability to synthesize lignin. The brown midrib 30 (Bmr30) gene, identified using a bulk segregant analysis and next-generation sequencing, was determined to encode a chalcone isomerase (CHI). Two independent mutations within this gene confirmed that loss of its function was responsible for the brown leaf midrib phenotype and reduced lignin concentration. Loss of the Bmr30 gene function, as shown by histochemical staining of leaf midrib and stalk sections, resulted in altered cell wall composition. In the bmr30 mutants, CHI activity was drastically reduced, and the accumulation of total flavonoids and total anthocyanins was impaired, which is consistent with its function in flavonoid biosynthesis. The level of the flavone lignin monomer tricin was reduced 20-fold in the stem relative to wild type, and to undetectable levels in the leaf tissue of the mutants. The bmr30 mutant, therefore, harbors a mutation in a phenylpropanoid biosynthetic gene that is key to the interconnection between flavonoids and monolignols, both of which are utilized for lignin synthesis in the grasses.
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Affiliation(s)
- Hannah M. Tetreault
- Wheat, Sorghum and Forage Research Unit, Agricultural Research Service, United States Department of Agriculture, Lincoln, NE, United States
- Department of Agronomy and Horticulture, University of Nebraska–Lincoln, Lincoln, NE, United States
| | - Tammy Gries
- Wheat, Sorghum and Forage Research Unit, Agricultural Research Service, United States Department of Agriculture, Lincoln, NE, United States
- Department of Agronomy and Horticulture, University of Nebraska–Lincoln, Lincoln, NE, United States
| | - Sarah Liu
- Department of Biochemistry, The DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, Madison, WI, United States
| | - John Toy
- Wheat, Sorghum and Forage Research Unit, Agricultural Research Service, United States Department of Agriculture, Lincoln, NE, United States
- Department of Agronomy and Horticulture, University of Nebraska–Lincoln, Lincoln, NE, United States
| | - Zhanguo Xin
- Plant Stress and Germplasm Development Unit, Agricultural Research Service, United States Department of Agriculture, Lubbock, TX, United States
| | - Wilfred Vermerris
- Department of Microbiology and Cell Science, UF Genetics Institute, University of Florida, Gainesville, FL, United States
| | - John Ralph
- Department of Biochemistry, The DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin, Madison, WI, United States
| | - Deanna L. Funnell-Harris
- Wheat, Sorghum and Forage Research Unit, Agricultural Research Service, United States Department of Agriculture, Lincoln, NE, United States
- Department of Plant Pathology, University of Nebraska–Lincoln, Lincoln, NE, United States
| | - Scott E. Sattler
- Wheat, Sorghum and Forage Research Unit, Agricultural Research Service, United States Department of Agriculture, Lincoln, NE, United States
- Department of Agronomy and Horticulture, University of Nebraska–Lincoln, Lincoln, NE, United States
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Nguyen DT, Gomez LD, Harper A, Halpin C, Waugh R, Simister R, Whitehead C, Oakey H, Nguyen HT, Nguyen TV, Duong TX, McQueen-Mason SJ. Association mapping identifies quantitative trait loci (QTL) for digestibility in rice straw. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:165. [PMID: 33062051 PMCID: PMC7545568 DOI: 10.1186/s13068-020-01807-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The conversion of lignocellulosic biomass from agricultural waste into biofuels and chemicals is considered a promising way to provide sustainable low carbon products without compromising food security. However, the use of lignocellulosic biomass for biofuel and chemical production is limited by the cost-effectiveness of the production process due to its recalcitrance to enzymatic hydrolysis and fermentable sugar release (i.e., saccharification). Rice straw is a particularly attractive feedstock because millions of tons are currently burned in the field each year for disposal. The aim of this study was to explore the underlying natural genetic variation that impacts the recalcitrance of rice (Oryza sativa) straw to enzymatic saccharification. Ultimately, we wanted to investigate whether we could identify genetic markers that could be used in rice breeding to improve commercial cultivars for this trait. Here, we describe the development and characterization of a Vietnamese rice genome-wide association panel, high-throughput analysis of rice straw saccharification and lignin content, and the results from preliminary genome-wide association studies (GWAS) of the combined data sets. We identify both QTL and plausible candidate genes that may have an impact on the saccharification of rice straw. RESULTS We assembled a diversity panel comprising 151 rice genotypes (Indica and Japonica types) from commercial, historical elite cultivars, and traditional landraces grown in Vietnam. The diversity panel was genotyped using genotype by sequencing (GBS) methods yielding a total of 328,915 single nucleotide polymorphisms (SNPs). We collected phenotypic data from stems of these 151 genotypes for biomass saccharification and lignin content. Using GWAS on the indica genotypes over 2 years we identified ten significant QTL for saccharification (digestibility) and seven significant QTL for lignin. One QTL on chromosome 11 occurred in both GWAS for digestibility and for lignin. Seven QTL for digestibility, on CH2, CH6, CH7, CH8, and CH11, were observed in both years of the study. The QTL regions for saccharification include three potential candidate genes that have been previously reported to influence digestibility: OsAT10; OsIRX9; and OsMYB58/63-L. CONCLUSIONS Despite the difficulties associated with multi-phasic analysis of complex traits in novel germplasm, a moderate resolution GWAS successfully identified genetic associations encompassing both known and/or novel genes involved in determining the saccharification potential and lignin content of rice straw. Plausible candidates within QTL regions, in particular those with roles in cell wall biosynthesis, were identified but will require validation to confirm their value for application in rice breeding.
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Affiliation(s)
- Duong T. Nguyen
- Plant Biotechnology Division,, Field Crops Research Institute (FCRI), Hai Duong, Vietnam
- School of Agriculture and Environment, University of Western Australia (UWA), Crawley, WA Australia
| | - Leonardo D. Gomez
- Centre for Novel Agricultural Products (CNAP), University of York (UoY), Wentworth Way, York, UK
| | - Andrea Harper
- Centre for Novel Agricultural Products (CNAP), University of York (UoY), Wentworth Way, York, UK
| | - Claire Halpin
- Division of Plant Sciences, School of Life Sciences, University of Dundee (UoD), Dundee, UK
| | - Robbie Waugh
- Division of Plant Sciences, School of Life Sciences, University of Dundee (UoD), Dundee, UK
- Cell, and Molecular Genetics, The James Hutton Institute (JHI), Invergowrie Dundee, UK
- School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Adelaide, SA Australia
| | - Rachael Simister
- Centre for Novel Agricultural Products (CNAP), University of York (UoY), Wentworth Way, York, UK
| | - Caragh Whitehead
- Centre for Novel Agricultural Products (CNAP), University of York (UoY), Wentworth Way, York, UK
| | - Helena Oakey
- Division of Plant Sciences, School of Life Sciences, University of Dundee (UoD), Dundee, UK
- School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Adelaide, SA Australia
| | - Huong T. Nguyen
- Plant Biotechnology Division,, Field Crops Research Institute (FCRI), Hai Duong, Vietnam
| | - Tuat V. Nguyen
- Vietnam Academy of Agricultural Sciences, Hanoi, Vietnam
| | - Tu X. Duong
- Plant Biotechnology Division,, Field Crops Research Institute (FCRI), Hai Duong, Vietnam
| | - Simon J. McQueen-Mason
- Centre for Novel Agricultural Products (CNAP), University of York (UoY), Wentworth Way, York, UK
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Low Lignin Mutants and Reduction of Lignin Content in Grasses for Increased Utilisation of Lignocellulose. AGRONOMY-BASEL 2019. [DOI: 10.3390/agronomy9050256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Biomass rich in lignocellulose from grasses is a major source for biofuel production and animal feed. However, the presence of lignin in cell walls limits its efficient utilisation such as in its bioconversion to biofuel. Reduction of the lignin content or alteration of its structure in crop plants have been pursued, either by regulating genes encoding enzymes in the lignin biosynthetic pathway using biotechnological techniques or by breeding naturally-occurring low lignin mutant lines. The aim of this review is to provide a summary of these studies, focusing on lignin (monolignol) biosynthesis and composition in grasses and, where possible, the impact on recalcitrance to bioconversion. An overview of transgenic crops of the grass family with regulated gene expression in lignin biosynthesis is presented, including the effect on lignin content and changes in the ratio of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) units. Furthermore, a survey is provided of low-lignin mutants in grasses, including cereals in particular, summarising their origin and phenotypic traits together with genetics and the molecular function of the various genes identified.
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Jiménez-Galindo JC, Ordás B, Butrón A, Samayoa LF, Malvar RA. QTL Mapping for Yield and Resistance against Mediterranean Corn Borer in Maize. FRONTIERS IN PLANT SCIENCE 2017; 8:698. [PMID: 28533785 PMCID: PMC5420578 DOI: 10.3389/fpls.2017.00698] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/18/2017] [Indexed: 05/19/2023]
Abstract
Introduction: The Mediterranean corn borer (MCB), Sesamia nonagrioides, is a major pest of maize, Zea mays, in Mediterranean countries, inflicting significant kernel yield losses. For that reason, it necessary to know the genetic mechanisms that regulate the agronomic and resistance traits. A quantitative trait loci (QTL) mapping study for yield, resistance against MCB attack, and other relevant agronomic traits was performed using a recombinant inbred line (RIL) population derived from the cross A637 × A509 that is expected to segregate for yield, and ear, and stalk resistance to MCB. 171 RILs were evaluated in 2014 and 2015 at Pontevedra, Spain, along with the two parental inbreds A637 and A509 using a 13 × 14 single lattice design with two replications. A genetic map with 285 SNP markers was used for QTL analysis. Our objectives were to detect QTL for resistance to MCB and tolerance-related agronomic traits, to gain insights on the genetic relationship between resistance to MCB attack and yield, and to establish the best way for simultaneously improving yield and resistance to MCB. Results: Twelve significant QTL were detected for agronomic and resistance traits. QTL at bins 1.10 and 5.04 were especially interesting because the same allelic variant at these QTL simultaneously improved yield and insect resistance. In contrast, in the region 8.04-8.05, QTL showed opposite effects for yield and resistance. Several QTL for indexes which combine yield and resistance traits were found especially in the region 10.02-10.03. Conclusions: Selecting genotypes with the favorable allele of QTL on chromosome 5 (bin 5.01) will decrease tunnel length without affect yield, silking and plant height and QTL on the region 5.04 could be used to improve stalk resistance and yield simultaneously. An allele of QTL on bin 9.07 will increase ear resistance to MCB attack but it could produce later varieties while favorable allele in region 1.10 could improve ear and stalk resistance and yield without secondary negative effects. The region 8.03-8.05 mainly but also the region 10.02-10.03 and 5.04 may play an important role to elucidate the association between yield, other agronomic traits and MCB resistance.
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Affiliation(s)
- José C. Jiménez-Galindo
- Misión Biológica de Galicia, Spanish National Research CouncilPontevedra, Spain
- National Institute of Forestry, Agriculture and Livestock ResearchChihuahua, Mexico
- *Correspondence: José C. Jiménez-Galindo
| | - Bernardo Ordás
- Misión Biológica de Galicia, Spanish National Research CouncilPontevedra, Spain
| | - Ana Butrón
- Misión Biológica de Galicia, Spanish National Research CouncilPontevedra, Spain
| | - Luis F. Samayoa
- Department of Crop Science, North Carolina State UniversityRaleigh, NC, USA
| | - Rosa A. Malvar
- Misión Biológica de Galicia, Spanish National Research CouncilPontevedra, Spain
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Abstract
Brown midrib mutants in sorghum are associated with reduced lignin content and increased cell wall digestibility. In this study, we characterized a bmr-6 sorghum mutant, which shows reddish pigment in the midrib and stem after the fifth-leaf stage. Compared to wild type, Kalson lignin content of bmr-6 is decreased significantly. We used histological analysis to determine that the mutant exhibited a modified pattern of lignin staining and found an increased polysaccharide content. We cloned BMR-6 gene, a gene encoded a cinnamyl alcohol dehydrogenase (CAD), using a map-based cloning approach. Genetic complementation confirmed that CAD is responsible for the BMR-6 phenotype. BMR-6 gene was expressed in all tested sorghum tissues, with the highest being in midrib and stem. Transient expression assays in Nicotiana benthamiana leaves demonstrated cytomplasmic localization of BMR-6. We found that the expression level of bmr-6 was significantly decreased in the mutant but expression of SbCAD3 and SbCAD5 were significantly increased. Our results indicate that BMR-6 not only affects the distribution of lignin but also the biosynthesis of lignin in sorghum.
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Santiago R, Malvar RA, Barros-Rios J, Samayoa LF, Butrón A. Hydroxycinnamate Synthesis and Association with Mediterranean Corn Borer Resistance. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:539-51. [PMID: 26690311 DOI: 10.1021/acs.jafc.5b04862] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Previous results suggest a relationship between maize hydroxycinnamate concentration in the pith tissues and resistance to stem tunneling by Mediterranean corn borer (MCB, Sesamia nonagrioides Lef.) larvae. This study performs a more precise experiment, mapping an F2 derived from the cross between two inbreds with contrasting levels for hydroxycinnamates EP125 × PB130. We aimed to co-localize genomic regions involved in hydroxycinnamate synthesis and resistance to MCB and to highlight the particular route for each hydroxycinnamate component in relation to the better known phenylpropanoid pathway. Seven quantitative trait loci (QTLs) for p-coumarate, two QTLs for ferulate, and seven QTLs for total diferulates explained 81.7, 26.9, and 57.8% of the genotypic variance, respectively. In relation to borer resistance, alleles for increased hydroxycinnamate content (affecting one or more hydroxycinnamate compounds) could be associated with favorable effects on stem resistance to MCB, particularly the putative role of p-coumarate in borer resistance.
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Affiliation(s)
- Rogelio Santiago
- Agrobiologı́a Ambiental, Calidad de Suelos y Plantas (UVIGO), Unidad Asociada a la Misión Biológica de Galicia (CSIC); Departamento Biologı́a Vegetal y Ciencias del Suelo, Facultad de Biologı́a, Universidad de Vigo , Campus As Lagoas Marcosende, 36310 Vigo, Spain
| | - Rosa Ana Malvar
- Misión Biológica de Galicia (CSIC) , Apartado 28, 36080 Pontevedra, Spain
| | - Jaime Barros-Rios
- Department of Biological Sciences, University of North Texas , 1155 Union Circle #305220, Denton, Texas 76203, United States
| | | | - Ana Butrón
- Misión Biológica de Galicia (CSIC) , Apartado 28, 36080 Pontevedra, Spain
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Barrière Y, Courtial A, Chateigner-Boutin AL, Denoue D, Grima-Pettenati J. Breeding maize for silage and biofuel production, an illustration of a step forward with the genome sequence. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 242:310-329. [PMID: 26566848 DOI: 10.1016/j.plantsci.2015.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 08/04/2015] [Accepted: 08/13/2015] [Indexed: 05/21/2023]
Abstract
The knowledge of the gene families mostly impacting cell wall digestibility variations would significantly increase the efficiency of marker-assisted selection when breeding maize and grass varieties with improved silage feeding value and/or with better straw fermentability into alcohol or methane. The maize genome sequence of the B73 inbred line was released at the end of 2009, opening up new avenues to identify the genetic determinants of quantitative traits. Colocalizations between a large set of candidate genes putatively involved in secondary cell wall assembly and QTLs for cell wall digestibility (IVNDFD) were then investigated, considering physical positions of both genes and QTLs. Based on available data from six RIL progenies, 59 QTLs corresponding to 38 non-overlapping positions were matched up with a list of 442 genes distributed all over the genome. Altogether, 176 genes colocalized with IVNDFD QTLs and most often, several candidate genes colocalized at each QTL position. Frequent QTL colocalizations were found firstly with genes encoding ZmMYB and ZmNAC transcription factors, and secondly with genes encoding zinc finger, bHLH, and xylogen regulation factors. In contrast, close colocalizations were less frequent with genes involved in monolignol biosynthesis, and found only with the C4H2, CCoAOMT5, and CCR1 genes. Close colocalizations were also infrequent with genes involved in cell wall feruloylation and cross-linkages. Altogether, investigated colocalizations between candidate genes and cell wall digestibility QTLs suggested a prevalent role of regulation factors over constitutive cell wall genes on digestibility variations.
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Affiliation(s)
- Yves Barrière
- INRA, UR889, Unité de Génétique et d'Amélioration des Plantes Fourragères, 86600 Lusignan, France.
| | - Audrey Courtial
- LRSV, Laboratoire de Recherche en Sciences Végétales, UMR5546, Université Paul Sabatier Toulouse III / CNRS, Auzeville, BP 42617, 31326 Castanet-Tolosan, France; INRA, US1258, Centre National de Ressources Génomiques Végétales, CS 52627, 31326 Castanet-Tolosan, France
| | | | - Dominique Denoue
- INRA, UR889, Unité de Génétique et d'Amélioration des Plantes Fourragères, 86600 Lusignan, France
| | - Jacqueline Grima-Pettenati
- LRSV, Laboratoire de Recherche en Sciences Végétales, UMR5546, Université Paul Sabatier Toulouse III / CNRS, Auzeville, BP 42617, 31326 Castanet-Tolosan, France
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Chen Y, Blanco M, Ji Q, Frei UK, Lübberstedt T. Extensive genetic diversity and low linkage disequilibrium within the COMT locus in maize exotic populations. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 221-222:69-80. [PMID: 24656337 DOI: 10.1016/j.plantsci.2014.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 02/16/2014] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
The caffeic acid 3-O-methytransferase (COMT) gene is a prime candidate for cell wall digestibility improvement based on the characterization of brown midrib-3 mutants. We compared the genetic diversity and linkage disequilibrium at this locus between exotic populations sampled within the Germplasm Enhancement of Maize (GEM) project and 70 inbred lines. In total, we investigated 55 exotic COMT alleles and discovered more than 400 polymorphisms in a 2.2 kb region with pairwise nucleotide diversity (π) up to 0.017, much higher than reported π values of various genes in inbred lines. The ratio of non-synonymous to synonymous SNPs was 3:1 in exotic populations, and significantly higher than the 1:1 ratio for inbred lines. Selection tests detected selection signature in this gene in both pools, but with different evolution patterns. The linkage disequilibrium decay in exotic populations was at least four times more rapid than for inbred lines with r²>0.1 persisting only up to 100 bp. In conclusion, the alleles sampled in the GEM Project offer a valuable genetic resource to broaden genetic variation for the COMT gene, and likely other genes, in inbred background. Moreover, the low linkage disequilibrium makes this material suitable for high resolution association analyses.
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Affiliation(s)
- Yongsheng Chen
- Department of Agronomy, Iowa State University, Ames, IA 50011, USA; Interdepartmental Genetics Program, Iowa State University, Ames, IA 50011, USA
| | - Michael Blanco
- USDA-ARS, Plant Introduction Research Unit, Ames, IA 50011, USA
| | - Qing Ji
- Department of Agronomy, Iowa State University, Ames, IA 50011, USA
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Tang HM, Liu S, Hill-Skinner S, Wu W, Reed D, Yeh CT, Nettleton D, Schnable PS. The maize brown midrib2 (bm2) gene encodes a methylenetetrahydrofolate reductase that contributes to lignin accumulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 77:380-92. [PMID: 24286468 PMCID: PMC4282534 DOI: 10.1111/tpj.12394] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 10/31/2013] [Accepted: 11/20/2013] [Indexed: 05/02/2023]
Abstract
The midribs of maize brown midrib (bm) mutants exhibit a reddish-brown color associated with reductions in lignin concentration and alterations in lignin composition. Here, we report the mapping, cloning, and functional and biochemical analyses of the bm2 gene. The bm2 gene was mapped to a small region of chromosome 1 that contains a putative methylenetetrahydrofolate reductase (MTHFR) gene, which is down-regulated in bm2 mutant plants. Analyses of multiple Mu-induced bm2-Mu mutant alleles confirmed that this constitutively expressed gene is bm2. Yeast complementation experiments and a previously published biochemical characterization show that the bm2 gene encodes a functional MTHFR. Quantitative RT-PCR analyses demonstrated that the bm2 mutants accumulate substantially reduced levels of bm2 transcript. Alteration of MTHFR function is expected to influence accumulation of the methyl donor S-adenosyl-L-methionine (SAM). Because SAM is consumed by two methyltransferases in the lignin pathway (Ye et al., ), the finding that bm2 encodes a functional MTHFR is consistent with its lignin phenotype. Consistent with this functional assignment of bm2, the expression patterns of genes in a variety of SAM-dependent or -related pathways, including lignin biosynthesis, are altered in the bm2 mutant. Biochemical assays confirmed that bm2 mutants accumulate reduced levels of lignin with altered composition compared to wild-type. Hence, this study demonstrates a role for MTHFR in lignin biosynthesis.
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Affiliation(s)
- Ho Man Tang
- Department of Genetics, Development and Cell Biology, Iowa State UniversityAmes, IA, 50011, USA
- †Center for Cell Dynamics, Department of Biological Chemistry, Johns Hopkins University School of MedicineBaltimore, MD, 21205, USA
| | - Sanzhen Liu
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- *For correspondence (e-mails (SL) or (PSS))
| | - Sarah Hill-Skinner
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
| | - Wei Wu
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- Center for Plant Genomics, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- §Pioneer Hi-Bred International Inc.Johnston, IA, 50131, USA
| | - Danielle Reed
- Department of Genetics, Development and Cell Biology, Iowa State UniversityAmes, IA, 50011, USA
- §Pioneer Hi-Bred International Inc.Johnston, IA, 50131, USA
| | - Cheng-Ting Yeh
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
| | - Dan Nettleton
- Center for Plant Genomics, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- Department of Statistics, Iowa State University2115 Snedecor, Ames, IA, 50011, USA
| | - Patrick S Schnable
- Department of Genetics, Development and Cell Biology, Iowa State UniversityAmes, IA, 50011, USA
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- Center for Plant Genomics, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- *For correspondence (e-mails (SL) or (PSS))
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Frei M. Lignin: characterization of a multifaceted crop component. ScientificWorldJournal 2013; 2013:436517. [PMID: 24348159 PMCID: PMC3848262 DOI: 10.1155/2013/436517] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/24/2013] [Indexed: 11/17/2022] Open
Abstract
Lignin is a plant component with important implications for various agricultural disciplines. It confers rigidity to cell walls, and is therefore associated with tolerance to abiotic and biotic stresses and the mechanical stability of plants. In animal nutrition, lignin is considered an antinutritive component of forages as it cannot be readily fermented by rumen microbes. In terms of energy yield from biomass, the role of lignin depends on the conversion process. It contains more gross energy than other cell wall components and therefore confers enhanced heat value in thermochemical processes such as direct combustion. Conversely, it negatively affects biological energy conversion processes such as bioethanol or biogas production, as it inhibits microbial fermentation of the cell wall. Lignin from crop residues plays an important role in the soil organic carbon cycling, as it constitutes a recalcitrant carbon pool affecting nutrient mineralization and carbon sequestration. Due to the significance of lignin in several agricultural disciplines, the modification of lignin content and composition by breeding is becoming increasingly important. Both mapping of quantitative trait loci and transgenic approaches have been adopted to modify lignin in crops. However, breeding goals must be defined considering the conflicting role of lignin in different agricultural disciplines.
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Affiliation(s)
- Michael Frei
- Division of Abiotic Stress Tolerance in Crops, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Karlrobert-Kreiten Straße 13, 53115 Bonn, Germany
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