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Li J, Fan F, Wang L, Zhan Q, Wu P, Du J, Yang X, Liu Y. Cloning and expression analysis of cinnamoyl-CoA reductase (CCR) genes in sorghum. PeerJ 2016; 4:e2005. [PMID: 27231650 PMCID: PMC4878380 DOI: 10.7717/peerj.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 04/13/2016] [Indexed: 11/20/2022] Open
Abstract
Cinnamoyl-CoA reductase (CCR) is the first enzyme in the monolignol-specific branch of the lignin biosynthetic pathway. In this research, three sorghum CCR genes including SbCCR1, SbCCR2-1 and SbCCR2-2 were cloned and characterized. Analyses of the structure and phylogeny of the three CCR genes showed evolutionary conservation of the functional domains and divergence of function. Transient expression assays in Nicotiana benthamiana leaves demonstrated that the three CCR proteins were localized in the cytoplasm. The expression analysis showed that the three CCR genes were induced by drought. But in 48 h, the expression levels of SbCCR1 and SbCCR2-2 did not differ between CK and the drought treatment; while the expression level of SbCCR2-1 in the drought treatment was higher than in CK. The expression of the SbCCR1 and SbCCR2-1 genes was not induced by sorghum aphid [Melanaphis sacchari (Zehntner)] attack, but SbCCR2-2 was significantly induced by sorghum aphid attack. It is suggested that SbCCR2-2 is involved in the process of pest defense. Absolute quantitative real-time PCR revealed that the three CCR genes were mainly expressed in lignin deposition organs. The gene copy number of SbCCR1 was significantly higher than those of SbCCR2-1 and SbCCR2-2 in the tested tissues, especially in stem. The results provide new insight into the functions of the three CCR genes in sorghum.
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Affiliation(s)
- Jieqin Li
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Feifei Fan
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Lihua Wang
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Qiuwen Zhan
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Peijin Wu
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Junli Du
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Xiaocui Yang
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
| | - Yanlong Liu
- College of Agriculture, Anhui Science and Technology University , Fengyang , China
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Characterization of ubiquitin ligase SlATL31 and proteomic analysis of 14-3-3 targets in tomato fruit tissue (Solanum lycopersicum L.). J Proteomics 2016; 143:254-264. [PMID: 27113132 DOI: 10.1016/j.jprot.2016.04.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/13/2016] [Accepted: 04/18/2016] [Indexed: 02/01/2023]
Abstract
UNLABELLED The 14-3-3 proteins participate in many aspects of plant physiology by interacting with phosphorylated proteins and thereby regulating target protein functions. In Arabidopsis plant, the ubiquitin ligase ATL31 controls 14-3-3 stability via both direct interaction and ubiquitination, and this consequently regulates post-germinative growth in response to carbon and nitrogen nutrient availability. Since 14-3-3 proteins regulate the activities of many key enzymes related to nutrient metabolism, one would anticipate that they should play an essential role not only in vegetative but also in reproductive tissue. Because fruit yield largely depends on carbon and nitrogen availability and their utilization, the function of 14-3-3 proteins was analyzed in tomato fruit tissue. Here, we isolated and characterized an ubiquitin ligase SlATL31 (Solyc03g112340) from tomato and demonstrated that SlATL31 has ubiquitin ligase activity as well as interaction with tomato 14-3-3 proteins, suggesting the possibility that the SlATL31 functions as an ubiquitin ligase for 14-3-3 similarly to its Arabidopsis ortholog. Furthermore, we performed proteomic analysis of 14-3-3 interacting proteins and identified 106 proteins as putative 14-3-3 targets including key enzymes for carbon metabolism and photosynthesis. This 14-3-3 interactome result and available transcriptome profile suggest a considerable yet complex role of 14-3-3 proteins in tomato fruit tissue. BIOLOGICAL SIGNIFICANCE Considerable cumulative evidence exists which implies that 14-3-3 proteins are involved in the regulation of plant primary metabolism. Here we provide the first report of 14-3-3 interactome analysis and identify putative 14-3-3 targets in tomato fruit tissue, which may be highly important given the documented metabolic shifts, which occur during fruit development and ripening. These data open future research avenues by which to understand the regulation of the role of post-translational regulation in tomato fruit development.
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Wang Y, Xiao X, Wang X, Zeng J, Kang H, Fan X, Sha L, Zhang H, Zhou Y. RNA-Seq and iTRAQ Reveal the Dwarfing Mechanism of Dwarf Polish Wheat (Triticum polonicum L.). Int J Biol Sci 2016; 12:653-66. [PMID: 27194943 PMCID: PMC4870709 DOI: 10.7150/ijbs.14577] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/15/2016] [Indexed: 11/05/2022] Open
Abstract
The dwarfing mechanism of Rht-dp in dwarf Polish wheat (DPW) is unknown. Each internode of DPW was significantly shorter than it in high Polish wheat (HPW), and the dwarfism was insensitive to photoperiod, abscisic acid (ABA), gibberellin (GA), cytokinin (CK), auxin and brassinolide (BR). To understand the mechanism, three sets of transcripts, DPW, HPW, and a chimeric set (a combination of DPW and HPW), were constructed using RNA sequencing (RNA-Seq). Based on the chimeric transcripts, 2,446 proteins were identified using isobaric tags for relative and absolute quantification (iTRAQ). A total of 108 unigenes and 12 proteins were considered as dwarfism-related differentially expressed genes (DEGs) and differentially expressed proteins (DEPs), respectively. Among of these DEGs and DEPs, 6 DEGs and 6 DEPs were found to be involved in flavonoid and S-adenosyl-methionine (SAM) metabolisms; 5 DEGs and 3 DEPs were involved in cellulose metabolism, cell wall plasticity and cell expansion; 2 DEGs were auxin transporters; 2 DEPs were histones; 1 DEP was a peroxidase. These DEGs and DEPs reduced lignin and cellulose contents, increased flavonoid content, possibly decreased S-adenosyl-methionine (SAM) and polyamine contents and increased S-adenosyl-L-homocysteine hydrolase (SAHH) content in DPW stems, which could limit auxin transport and reduce extensibility of the cell wall, finally limited cell expansion (the cell size of DPW was significantly smaller than HPW cells) and caused dwarfism in DPW.
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Affiliation(s)
- Yi Wang
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Xue Xiao
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Xiaolu Wang
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Jian Zeng
- 2. College of Resources, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Houyang Kang
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Xing Fan
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Lina Sha
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Haiqin Zhang
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
| | - Yonghong Zhou
- 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang 611130, Sichuan, China
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Scully ED, Gries T, Funnell-Harris DL, Xin Z, Kovacs FA, Vermerris W, Sattler SE. Characterization of novel Brown midrib 6 mutations affecting lignin biosynthesis in sorghum. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:136-49. [PMID: 26172142 DOI: 10.1111/jipb.12375] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/07/2015] [Indexed: 05/23/2023]
Abstract
The presence of lignin reduces the quality of lignocellulosic biomass for forage materials and feedstock for biofuels. In C4 grasses, the brown midrib phenotype has been linked to mutations to genes in the monolignol biosynthesis pathway. For example, the Bmr6 gene in sorghum (Sorghum bicolor) has been previously shown to encode cinnamyl alcohol dehydrogenase (CAD), which catalyzes the final step of the monolignol biosynthesis pathway. Mutations in this gene have been shown to reduce the abundance of lignin, enhance digestibility, and improve saccharification efficiencies and ethanol yields. Nine sorghum lines harboring five different bmr6 alleles were identified in an EMS-mutagenized TILLING population. DNA sequencing of Bmr6 revealed that the majority of the mutations impacted evolutionarily conserved amino acids while three-dimensional structural modeling predicted that all of these alleles interfered with the enzyme's ability to bind with its NADPH cofactor. All of the new alleles reduced in vitro CAD activity levels and enhanced glucose yields following saccharification. Further, many of these lines were associated with higher reductions in acid detergent lignin compared to lines harboring the previously characterized bmr6-ref allele. These bmr6 lines represent new breeding tools for manipulating biomass composition to enhance forage and feedstock quality.
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Affiliation(s)
- Erin D Scully
- Grain, Forage, and Bioenergy Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Tammy Gries
- Grain, Forage, and Bioenergy Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
| | - Deanna L Funnell-Harris
- Grain, Forage, and Bioenergy Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Zhanguo Xin
- Plant Stress and Germplasm Development Unit, USDA-ARS, Lubbock, TX, 79414, USA
| | - Frank A Kovacs
- Department of Chemistry, University of Nebraska-Kearney, Kearney, NE, 68849, USA
| | - Wilfred Vermerris
- Department of Microbiology & Cell Science and UF Genetics Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Scott E Sattler
- Grain, Forage, and Bioenergy Research Unit, USDA-ARS, Lincoln, NE, 68583, USA
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
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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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57
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Lian T, Guo W, Chen M, Li J, Liang Q, Liu F, Meng H, Xu B, Chen J, Zhang C, Jiang L. Genome-wide identification and transcriptional analysis of folate metabolism-related genes in maize kernels. BMC PLANT BIOLOGY 2015; 15:204. [PMID: 26283542 PMCID: PMC4539672 DOI: 10.1186/s12870-015-0578-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 07/23/2015] [Indexed: 05/22/2023]
Abstract
BACKGROUND Maize is a major staple food crop globally and contains various concentrations of vitamins. Folates are essential water-soluble B-vitamins that play an important role as one-carbon (C1) donors and acceptors in organisms. To gain an understanding of folate metabolism in maize, we performed an intensive in silico analysis to screen for genes involved in folate metabolism using publicly available databases, followed by examination of the transcript expression patterns and profiling of the folate derivatives in the kernels of two maize inbred lines. RESULTS A total of 36 candidate genes corresponding to 16 folate metabolism-related enzymes were identified. The maize genome contains all the enzymes required for folate and C1 metabolism, characterized by highly conserved functional domains across all the other species investigated. Phylogenetic analysis revealed that these enzymes in maize are conserved throughout evolution and have a high level of similarity with those in sorghum and millet. The LC-MS analyses of two maize inbred lines demonstrated that 5-methyltetrahydrofolate was the major form of folate derivative in young seeds, while 5-formyltetrahydrofolate in mature seeds. Most of the genes involved in folate and C1 metabolism exhibited similar transcriptional expression patterns between these two maize lines, with the highest transcript abundance detected on day after pollination (DAP) 6 and the decreased transcript abundance on DAP 12 and 18. Compared with the seeds on DAP 30, 5-methyltetrahydrofolate was decreased and 5-formyltetrahydrofolate was increased sharply in the mature dry seeds. CONCLUSIONS The enzymes involved in folate and C1 metabolism are conserved between maize and other plant species. Folate and C1 metabolism is active in young developing maize seeds at transcriptional levels.
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Affiliation(s)
- Tong Lian
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
| | - Wenzhu Guo
- Huazhong Agricultural University, Wuhan, People's Republic of China.
| | - Maoran Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
| | - Jinglai Li
- Beijing Institute of Pharmacology and Toxicology, Beijing, People's Republic of China.
| | - Qiuju Liang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, People's Republic of China.
| | - Fang Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
| | - Hongyan Meng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
| | - Bosi Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
| | - Jinfeng Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
- Southwest University of Science and Technology, Mianyang, People's Republic of China.
| | - Chunyi Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, People's Republic of China.
| | - Ling Jiang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, People's Republic of China.
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58
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Qi G, Wang D, Yu L, Tang X, Chai G, He G, Ma W, Li S, Kong Y, Fu C, Zhou G. Metabolic engineering of 2-phenylethanol pathway producing fragrance chemical and reducing lignin in Arabidopsis. PLANT CELL REPORTS 2015; 34:1331-42. [PMID: 25895734 DOI: 10.1007/s00299-015-1790-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 03/25/2015] [Accepted: 03/31/2015] [Indexed: 05/09/2023]
Abstract
Two 2-phenylethanol biosynthetic pathways were constructed into Arabidopsis ; 2-phenylethanol biosynthesis led to reduced rate of lignin biosynthesis and increased cellulose-to-glucose conversion in the transgenic plants. Lignin is the second most abundant biopolymer on the planet with importance for various agro-industrial activities. The presence of lignin in cell walls, however, impedes biofuel production from lignocellulosic biomass. The phenylpropanoid pathway is responsible for the biosynthesis of lignin and other phenolic metabolites such as 2-phenylethanol. As one of the most used fragrance chemicals, 2-phenylethanol is synthesized in plants from L-phenylalanine which is the first specific intermediate towards lignin biosynthesis. Thus, it is interesting to prove the concept that the phenylpropanoid pathway can be modulated for reduction of lignin as well as production of natural value-added compounds. Here we conferred two 2-phenylethanol biosynthetic pathways constructed from plants and Saccharomyces cerevisiae into Arabidopsis. As anticipated, 2-phenylethanol was accumulated in transgenic plants. Moreover, the transformants showed 12-14% reduction in lignin content and 9-13% increase in cellulose content. Consequently, the glucose yield from cell wall hydrolysis was increased from 37.4% in wild type to 49.9-52.1% in transgenic plants with hot water pretreatment. The transgenic plants had normal development and even enhanced growth relative to the wild type. Our results indicate that the shunt of L-phenylalanine flux to the artificially constructed 2-phenylethanol biosynthetic pathway most likely reduced the rate of lignin biosynthesis in Arabidopsis.
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Affiliation(s)
- Guang Qi
- Key Laboratory of Biofuels and Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China,
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Li L, Hill-Skinner S, Liu S, Beuchle D, Tang HM, Yeh CT, Nettleton D, Schnable PS. The maize brown midrib4 (bm4) gene encodes a functional folylpolyglutamate synthase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:493-504. [PMID: 25495051 PMCID: PMC4329605 DOI: 10.1111/tpj.12745] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/03/2014] [Accepted: 12/08/2014] [Indexed: 05/02/2023]
Abstract
Mutations in the brown midrib4 (bm4) gene affect the accumulation and composition of lignin in maize. Fine-mapping analysis of bm4 narrowed the candidate region to an approximately 105 kb interval on chromosome 9 containing six genes. Only one of these six genes, GRMZM2G393334, showed decreased expression in mutants. At least four of 10 Mu-induced bm4 mutant alleles contain a Mu insertion in the GRMZM2G393334 gene. Based on these results, we concluded that GRMZM2G393334 is the bm4 gene. GRMZM2G393334 encodes a putative folylpolyglutamate synthase (FPGS), which functions in one-carbon (C1) metabolism to polyglutamylate substrates of folate-dependent enzymes. Yeast complementation experiments demonstrated that expression of the maize bm4 gene in FPGS-deficient met7 yeast is able to rescue the yeast mutant phenotype, thus demonstrating that bm4 encodes a functional FPGS. Consistent with earlier studies, bm4 mutants exhibit a modest decrease in lignin concentration and an overall increase in the S:G lignin ratio relative to wild-type. Orthologs of bm4 include at least one paralogous gene in maize and various homologs in other grasses and dicots. Discovery of the gene underlying the bm4 maize phenotype illustrates a role for FPGS in lignin biosynthesis.
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Affiliation(s)
- Li Li
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- College of Agronomy, Northwest Agriculture and Forestry University#3, Taicheng road, Yangling, Shaanxi, 712100, China
| | - Sarah Hill-Skinner
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
| | - Sanzhen Liu
- Department of Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
| | - Danielle Beuchle
- Department of Genetics, Development and Cell Biology, Iowa State University1210 Molecular Biology Building, Ames, IA 50011-3260, USA
| | - Ho Man Tang
- Department of Genetics, Development and Cell Biology, Iowa State University1210 Molecular Biology Building, Ames, IA 50011-3260, 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 Agronomy, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- Department of Genetics, Development and Cell Biology, Iowa State University1210 Molecular Biology Building, Ames, IA 50011-3260, USA
- Center for Plant Genomics, Iowa State University2035 Roy J. Carver Co-Lab, Ames, IA, 50011-3650, USA
- *
For correspondence (e-mail )
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60
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Srivastava AC, Chen F, Ray T, Pattathil S, Peña MJ, Avci U, Li H, Huhman DV, Backe J, Urbanowicz B, Miller JS, Bedair M, Wyman CE, Sumner LW, York WS, Hahn MG, Dixon RA, Blancaflor EB, Tang Y. Loss of function of folylpolyglutamate synthetase 1 reduces lignin content and improves cell wall digestibility in Arabidopsis. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:224. [PMID: 26697113 PMCID: PMC4687376 DOI: 10.1186/s13068-015-0403-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/30/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND One-carbon (C1) metabolism is important for synthesizing a range of biologically important compounds that are essential for life. In plants, the C1 pathway is crucial for the synthesis of a large number of secondary metabolites, including lignin. Tetrahydrofolate and its derivatives, collectively referred to as folates, are crucial co-factors for C1 metabolic pathway enzymes. Given the link between the C1 and phenylpropanoid pathways, we evaluated whether folylpolyglutamate synthetase (FPGS), an enzyme that catalyzes the addition of a glutamate tail to folates to form folylpolyglutamates, can be a viable target for reducing cell wall recalcitrance in plants. RESULTS Consistent with its role in lignocellulosic formation, FPGS1 was preferentially expressed in vascular tissues. Total lignin was low in fpgs1 plants leading to higher saccharification efficiency of the mutant. The decrease in total lignin in fpgs1 was mainly due to lower guaiacyl (G) lignin levels. Glycome profiling revealed subtle alterations in the cell walls of fpgs1. Further analyses of hemicellulosic polysaccharides by NMR showed that the degree of methylation of 4-O-methyl glucuronoxylan was reduced in the fpgs1 mutant. Microarray analysis and real-time qRT-PCR revealed that transcripts of a number of genes in the C1 and lignin pathways had altered expression in fpgs1 mutants. Consistent with the transcript changes of C1-related genes, a significant reduction in S-adenosyl-l-methionine content was detected in the fpgs1 mutant. The modified expression of the various methyltransferases and lignin-related genes indicate possible feedback regulation of C1 pathway-mediated lignin biosynthesis. CONCLUSIONS Our observations provide genetic and biochemical support for the importance of folylpolyglutamates in the lignocellulosic pathway and reinforces previous observations that targeting a single FPGS isoform for down-regulation leads to reduced lignin in plants. Because fpgs1 mutants had no dramatic defects in above ground biomass, selective down-regulation of individual components of C1 metabolism is an approach that should be explored further for the improvement of lignocellulosic feedstocks.
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Affiliation(s)
- Avinash C. Srivastava
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Fang Chen
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Tui Ray
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - Sivakumar Pattathil
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- />Department of Plant Biology, University of Georgia, Athens, GA 30602 USA
| | - Maria J. Peña
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Utku Avci
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- />Department of Plant Biology, University of Georgia, Athens, GA 30602 USA
| | - Hongjia Li
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, CA 92507 USA
| | - David V. Huhman
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - Jason Backe
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Breeanna Urbanowicz
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Jeffrey S. Miller
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Mohamed Bedair
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - Charles E. Wyman
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, CA 92507 USA
| | - Lloyd W. Sumner
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
| | - William S. York
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- />Department of Plant Biology, University of Georgia, Athens, GA 30602 USA
| | - Michael G. Hahn
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- />Department of Plant Biology, University of Georgia, Athens, GA 30602 USA
| | - Richard A. Dixon
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
- />Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Elison B. Blancaflor
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
| | - Yuhong Tang
- />Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401 USA
- />BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN 37831 USA
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Li Q, Song J, Peng S, Wang JP, Qu GZ, Sederoff RR, Chiang VL. Plant biotechnology for lignocellulosic biofuel production. PLANT BIOTECHNOLOGY JOURNAL 2014; 12:1174-92. [PMID: 25330253 DOI: 10.1111/pbi.12273] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 08/11/2014] [Accepted: 09/05/2014] [Indexed: 05/18/2023]
Abstract
Lignocelluloses from plant cell walls are attractive resources for sustainable biofuel production. However, conversion of lignocellulose to biofuel is more expensive than other current technologies, due to the costs of chemical pretreatment and enzyme hydrolysis for cell wall deconstruction. Recalcitrance of cell walls to deconstruction has been reduced in many plant species by modifying plant cell walls through biotechnology. These results have been achieved by reducing lignin content and altering its composition and structure. Reduction of recalcitrance has also been achieved by manipulating hemicellulose biosynthesis and by overexpression of bacterial enzymes in plants to disrupt linkages in the lignin-carbohydrate complexes. These modified plants often have improved saccharification yield and higher ethanol production. Cell wall-degrading (CWD) enzymes from bacteria and fungi have been expressed at high levels in plants to increase the efficiency of saccharification compared with exogenous addition of cellulolytic enzymes. In planta expression of heat-stable CWD enzymes from bacterial thermophiles has made autohydrolysis possible. Transgenic plants can be engineered to reduce recalcitrance without any yield penalty, indicating that successful cell wall modification can be achieved without impacting cell wall integrity or plant development. A more complete understanding of cell wall formation and structure should greatly improve lignocellulosic feedstocks and reduce the cost of biofuel production.
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Affiliation(s)
- Quanzi Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
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Characterization of novel Sorghum brown midrib mutants from an EMS-mutagenized population. G3-GENES GENOMES GENETICS 2014; 4:2115-24. [PMID: 25187038 PMCID: PMC4232537 DOI: 10.1534/g3.114.014001] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr mutants were identified that were not allelic to these previously described loci. Further allelism testing among these six bmr mutants showed that they represented four novel bmr loci. Based on this study, the number of bmr loci uncovered in sorghum has doubled. The impact of these lines on agronomic traits and lignocellulosic composition was assessed in a 2-yr field study. Overall, most of the identified bmr lines showed reduced lignin concentration of their biomass relative to wild-type (WT). Effects of the six new bmr mutants on enzymatic saccharification of lignocellulosic materials were determined, but the amount of glucose released from the stover was similar to WT in all cases. Like bmr2, bmr6, and bmr12, these mutants may affect monolignol biosynthesis and may be useful for bioenergy and forage improvement when stacked together or in combination with the three previously described bmr alleles.
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