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Panahabadi R, Ahmadikhah A, Farrokhi N. Genetic dissection of monosaccharides contents in rice whole grain using genome-wide association study. THE PLANT GENOME 2023; 16:e20292. [PMID: 36691363 DOI: 10.1002/tpg2.20292] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
The simplest form of carbohydrates are monosaccharides which are the building blocks for the synthesis of polymers or complex carbohydrates. Monosaccharide contents of 197 rice accessions were quantified by HPAEC-PAD in rice (Oryza sativa L.) whole grain (RWG). A genome-wide association study (GWAS) was carried out using 33,812 single nucleotide polymorphisms (SNPs) to identify corresponding genomic regions influencing neutral monosaccharides contents. In total, 49 GWAS signals contained in 17 genomic regions (quantitative trait loci [QTLs]) on seven chromosomes of rice were determined to be associated with monosaccharides contents of whole grain. The QTLs were found for fucose (1), mannose (1), xylose (2), arabinose (2), galactose (4), and rhamnose (7) contents, all of which are novel. Based on co-location of annotated rice genes in the vicinity of GWAS signals, the constituents of the whole grain were associated with the following candidate genes: arabinose content with α-N-arabinofuranosidase, pectinesterase inhibitor, and glucosamine-fructose-6-phosphate aminotransferase 1; xylose content with ZOS1-10 (a C2H2 zinc finger transcription factor [TF]); mannose content with aldose 1-epimerase-like protein and a MYB family TF; galactose content with a GT8 family member (galacturonosyltransferase-like 3), a GRAS family TF, and a GH16 family member (xyloglucan endotransglucosylase/hydrolase xyloglucan 23); fucose content with gibberellin 20 oxidase and a lysine-rich arabinogalactan protein 19, and finally rhamnose content with myo-inositol-1-phosphate synthase, UDP-arabinopyranose mutase, and COBRA-like protein precursor. The results of this study should improve our understanding of the genetic basis of the factors that might be involved in the biosynthesis, regulation, and turnover of monosaccharides in RWG, aiming to enhance the nutritional value of rice grain and impact the related industries.
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Affiliation(s)
- Rahele Panahabadi
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti Univ., Tehran, Iran
| | | | - Naser Farrokhi
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti Univ., Tehran, Iran
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Costa IO, Morais JRF, de Medeiros Dantas JM, Gonçalves LRB, Dos Santos ES, Rios NS. Enzyme immobilization technology as a tool to innovate in the production of biofuels: A special review of the Cross-Linked Enzyme Aggregates (CLEAs) strategy. Enzyme Microb Technol 2023; 170:110300. [PMID: 37523882 DOI: 10.1016/j.enzmictec.2023.110300] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 08/02/2023]
Abstract
This review emphasizes the crucial role of enzyme immobilization technology in advancing the production of two main biofuels, ethanol and biodiesel, with a specific focus on the Cross-linked Enzyme Aggregates (CLEAs) strategy. This method of immobilization has gained attention due to its simplicity and affordability, as it does not initially require a solid support. CLEAs synthesis protocol includes two steps: enzyme precipitation and cross-linking of aggregates using bifunctional agents. We conducted a thorough search for papers detailing the synthesis of CLEAs utilizing amylases, cellulases, and hemicellulases. These key enzymes are involved in breaking down starch or lignocellulosic materials to produce ethanol, both in first and second-generation processes. CLEAs of lipases were included as these enzymes play a crucial role in the enzymatic process of biodiesel production. However, when dealing with large or diverse substrates such as lignocellulosic materials for ethanol production and oils/fats for biodiesel production, the use of individual enzymes may not be the most efficient method. Instead, a system that utilizes a blend of enzymes may prove to be more effective. To innovate in the production of biofuels (ethanol and biodiesel), enzyme co-immobilization using different enzyme species to produce Combi-CLEAs is a promising trend.
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Affiliation(s)
- Isabela Oliveira Costa
- Departamento de Engenharia Química, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | | | | | | | | | - Nathália Saraiva Rios
- Departamento de Engenharia Química, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
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Wang Y, Gui C, Wu J, Gao X, Huang T, Cui F, Liu H, Sethupathy S. Spatio-Temporal Modification of Lignin Biosynthesis in Plants: A Promising Strategy for Lignocellulose Improvement and Lignin Valorization. Front Bioeng Biotechnol 2022; 10:917459. [PMID: 35845403 PMCID: PMC9283729 DOI: 10.3389/fbioe.2022.917459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Lignin is essential for plant growth, structural integrity, biotic/abiotic stress resistance, and water transport. Besides, lignin constitutes 10–30% of lignocellulosic biomass and is difficult to utilize for biofuel production. Over the past few decades, extensive research has uncovered numerous metabolic pathways and genes involved in lignin biosynthesis, several of which have been highlighted as the primary targets for genetic manipulation. However, direct manipulation of lignin biosynthesis is often associated with unexpected abnormalities in plant growth and development for unknown causes, thus limiting the usefulness of genetic engineering for biomass production and utilization. Recent advances in understanding the complex regulatory mechanisms of lignin biosynthesis have revealed new avenues for spatial and temporal modification of lignin in lignocellulosic plants that avoid growth abnormalities. This review explores recent work on utilizing specific transcriptional regulators to modify lignin biosynthesis at both tissue and cellular levels, focusing on using specific promoters paired with functional or regulatory genes to precisely control lignin synthesis and achieve biomass production with desired properties. Further advances in designing more appropriate promoters and other regulators will increase our capacity to modulate lignin content and structure in plants, thus setting the stage for high-value utilization of lignin in the future.
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Affiliation(s)
- Yongli Wang
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
- *Correspondence: Yongli Wang, ; Sivasamy Sethupathy,
| | - Cunjin Gui
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Jiangyan Wu
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Xing Gao
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Ting Huang
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Fengjie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China
| | - Huan Liu
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Sivasamy Sethupathy
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
- *Correspondence: Yongli Wang, ; Sivasamy Sethupathy,
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Peng W, Yang Y, Xu J, Peng E, Dai S, Dai L, Wang Y, Yi T, Wang B, Li D, Song N. TALE Transcription Factors in Sweet Orange ( Citrus sinensis): Genome-Wide Identification, Characterization, and Expression in Response to Biotic and Abiotic Stresses. FRONTIERS IN PLANT SCIENCE 2022; 12:814252. [PMID: 35126435 PMCID: PMC8811264 DOI: 10.3389/fpls.2021.814252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Three-amino-acid-loop-extension (TALE) transcription factors comprise one of the largest gene families in plants, in which they contribute to regulation of a wide variety of biological processes, including plant growth and development, as well as governing stress responses. Although sweet orange (Citrus sinensis) is among the most commercially important fruit crops cultivated worldwide, there have been relatively few functional studies on TALE genes in this species. In this study, we investigated 18 CsTALE gene family members with respect to their phylogeny, physicochemical properties, conserved motif/domain sequences, gene structures, chromosomal location, cis-acting regulatory elements, and protein-protein interactions (PPIs). These CsTALE genes were classified into two subfamilies based on sequence homology and phylogenetic analyses, and the classification was equally strongly supported by the highly conserved gene structures and motif/domain compositions. CsTALEs were found to be unevenly distributed on the chromosomes, and duplication analysis revealed that segmental duplication and purifying selection have been major driving force in the evolution of these genes. Expression profile analysis indicated that CsTALE genes exhibit a discernible spatial expression pattern in different tissues and differing expression patterns in response to different biotic/abiotic stresses. Of the 18 CsTALE genes examined, 10 were found to be responsive to high temperature, four to low temperature, eight to salt, and four to wounding. Moreover, the expression of CsTALE3/8/12/16 was induced in response to infection with the fungal pathogen Diaporthe citri and bacterial pathogen Candidatus Liberibacter asiaticus, whereas the expression of CsTALE15/17 was strongly suppressed. The transcriptional activity of CsTALE proteins was also verified in yeast, with yeast two-hybrid assays indicating that CsTALE3/CsTALE8, CsTALE3/CsTALE11, CsTALE10/CsTALE12, CsTALE14/CsTALE8, CsTALE14/CsTALE11 can form respective heterodimers. The findings of this study could lay the foundations for elucidating the biological functions of the TALE family genes in sweet orange and contribute to the breeding of stress-tolerant plants.
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Affiliation(s)
- Weiye Peng
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Yang Yang
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Jing Xu
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Erping Peng
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Suming Dai
- Horticulture College, Hunan Agricultural University, Changsha, China
- National Center for Citrus Improvement Changsha, Changsha, China
| | - Liangying Dai
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Yunsheng Wang
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Tuyong Yi
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Bing Wang
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
| | - Dazhi Li
- Horticulture College, Hunan Agricultural University, Changsha, China
- National Center for Citrus Improvement Changsha, Changsha, China
| | - Na Song
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha, China
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Hodgson-Kratky K, Perlo V, Furtado A, Choudhary H, Gladden JM, Simmons BA, Botha F, Henry RJ. Association of gene expression with syringyl to guaiacyl ratio in sugarcane lignin. PLANT MOLECULAR BIOLOGY 2021; 106:173-192. [PMID: 33738678 DOI: 10.1007/s11103-021-01136-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/02/2021] [Indexed: 05/11/2023]
Abstract
A transcriptome analysis reveals the transcripts and alleles differentially expressed in sugarcane genotypes with contrasting lignin composition. Sugarcane bagasse is a highly abundant resource that may be used as a feedstock for the production of biofuels and bioproducts in order to meet increasing demands for renewable replacements for fossil carbon. However, lignin imparts rigidity to the cell wall that impedes the efficient breakdown of the biomass into fermentable sugars. Altering the ratio of the lignin units, syringyl (S) and guaiacyl (G), which comprise the native lignin polymer in sugarcane, may facilitate the processing of bagasse. This study aimed to identify genes and markers associated with S/G ratio in order to accelerate the development of sugarcane bioenergy varieties with modified lignin composition. The transcriptome sequences of 12 sugarcane genotypes that contrasted for S/G ratio were compared and there were 2019 transcripts identified as differentially expressed (DE) between the high and low S/G ratio groups. These included transcripts encoding possible monolignol biosynthetic pathway enzymes, transporters, dirigent proteins and transcriptional and post-translational regulators. Furthermore, the frequencies of single nucleotide polymorphisms (SNPs) were compared between the low and high S/G ratio groups to identify specific alleles expressed with the phenotype. There were 2063 SNP loci across 787 unique transcripts that showed group-specific expression. Overall, the DE transcripts and SNP alleles identified in this study may be valuable for breeding sugarcane varieties with altered S/G ratio that may provide desirable bioenergy traits.
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Affiliation(s)
- K Hodgson-Kratky
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia
| | - V Perlo
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia
| | - A Furtado
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia
| | - H Choudhary
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Sandia National Laboratories, Livermore, CA, 94550, USA
| | - J M Gladden
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Sandia National Laboratories, Livermore, CA, 94550, USA
| | - B A Simmons
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - F Botha
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia
| | - R J Henry
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, 4072, Australia.
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Lin CY, Donohoe BS, Bomble YJ, Yang H, Yunes M, Sarai NS, Shollenberger T, Decker SR, Chen X, McCann MC, Tucker MP, Wei H, Himmel ME. Iron incorporation both intra- and extra-cellularly improves the yield and saccharification of switchgrass (Panicum virgatum L.) biomass. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:55. [PMID: 33663584 PMCID: PMC7931346 DOI: 10.1186/s13068-021-01891-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Pretreatments are commonly used to facilitate the deconstruction of lignocellulosic biomass to its component sugars and aromatics. Previously, we showed that iron ions can be used as co-catalysts to reduce the severity of dilute acid pretreatment of biomass. Transgenic iron-accumulating Arabidopsis and rice plants exhibited higher iron content in grains, increased biomass yield, and importantly, enhanced sugar release from the biomass. RESULTS In this study, we used intracellular ferritin (FerIN) alone and in combination with an improved version of cell wall-bound carbohydrate-binding module fused iron-binding peptide (IBPex) specifically targeting switchgrass, a bioenergy crop species. The FerIN switchgrass improved by 15% in height and 65% in yield, whereas the FerIN/IBPex transgenics showed enhancement up to 30% in height and 115% in yield. The FerIN and FerIN/IBPex switchgrass had 27% and 51% higher in planta iron accumulation than the empty vector (EV) control, respectively, under normal growth conditions. Improved pretreatability was observed in FerIN switchgrass (~ 14% more glucose release than the EV), and the FerIN/IBPex plants showed further enhancement in glucose release up to 24%. CONCLUSIONS We conclude that this iron-accumulating strategy can be transferred from model plants and applied to bioenergy crops, such as switchgrass. The intra- and extra-cellular iron incorporation approach improves biomass pretreatability and digestibility, providing upgraded feedstocks for the production of biofuels and bioproducts.
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Affiliation(s)
- Chien-Yuan Lin
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608 USA
- Present Address: Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Haibing Yang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 USA
- Present Address: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Manal Yunes
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Nicholas S. Sarai
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 USA
| | - Todd Shollenberger
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Stephen R. Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Xiaowen Chen
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Maureen C. McCann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 USA
| | - Melvin P. Tucker
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
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Mohapatra S, Mishra SS, Bhalla P, Thatoi H. Engineering grass biomass for sustainable and enhanced bioethanol production. PLANTA 2019; 250:395-412. [PMID: 31236698 DOI: 10.1007/s00425-019-03218-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
Bioethanol from lignocellulosic biomass is a promising step for the future energy requirements. Grass is a potential lignocellulosic biomass which can be utilised for biorefinery-based bioethanol production. Grass biomass is a suitable feedstock for bioethanol production due to its all the year around production, requirement of less fertile land and noninterference with food system. However, the processes involved, i.e. pretreatment, enzymatic hydrolysis and fermentation for bioethanol production from grass biomass, are both time consuming and costly. Developing the grass biomass in planta for enhanced bioethanol production is a promising step for maximum utilisation of this valuable feedstock and, thus, is the focus of the present review. Modern breeding techniques and transgenic processes are attractive methods which can be utilised for development of the feedstock. However, the outcomes are not always predictable and the time period required for obtaining a robust variety is generation dependent. Sophisticated genome editing technologies such as synthetic genetic circuits (SGC) or clustered regularly interspaced short palindromic repeats (CRISPR) systems are advantageous for induction of desired traits/heritable mutations in a foreseeable genome location in the 1st mutant generation. Although, its application in grass biomass for bioethanol is limited, these sophisticated techniques are anticipated to exhibit more flexibility in engineering the expression pattern for qualitative and qualitative traits. Nevertheless, the fundamentals rendered by the genetics of the transgenic crops will remain the basis of such developments for obtaining biorefinery-based bioethanol concepts from grass biomass. Grasses which are abundant and widespread in nature epitomise attractive lignocellulosic feedstocks for bioethanol production. The complexity offered by the grass cell wall in terms of lignin recalcitrance and its binding to polysaccharides forms a barricade for its commercialization as a biofuel feedstock. Inspired by the possibilities for rewiring the genetic makeup of grass biomass for reduced lignin and lignin-polysaccharide linkages along with increase in carbohydrates, innovative approaches for in planta modifications are forging ahead. In this review, we highlight the progress made in the field of transgenic grasses for bioethanol production and focus our understanding on improvements of simple breeding techniques and post-harvest techniques for development in shortening of lignin-carbohydrate and carbohydrate-carbohydrate linkages. Further, we discuss about the designer lignins which are aimed for qualitable lignins and also emphasise on remodelling of polysaccharides and mixed-linkage glucans for enhancing carbohydrate content and in planta saccharification efficiency. As a final point, we discuss the role of synthetic genetic circuits and CRISPR systems in targeted improvement of cell wall components without compromising the plant growth and health. It is anticipated that this review can provide a rational approach towards a better understanding of application of in planta genetic engineering aspects for designing synthetic genetic circuits which can promote grass feedstocks for biorefinery-based bioethanol concepts.
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Affiliation(s)
- Sonali Mohapatra
- Department of Biotechnology, College of Engineering and Technology, Biju Patnaik University of Technology, Bhubaneswar, 751003, India.
| | - Suruchee Samparana Mishra
- Department of Biotechnology, College of Engineering and Technology, Biju Patnaik University of Technology, Bhubaneswar, 751003, India
| | - Prerna Bhalla
- Bhupat and Jyoti Mehta School of Biosciences Building, Indian Institute of Technology Madras, Chennai, India
| | - Hrudayanath Thatoi
- Department of Biotechnology, North Orissa University, Sriram Chandra Vihar, Takatpur, Baripada, 757003, Odisha, India
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Cheng X, Li M, Abdullah M, Li G, Zhang J, Manzoor MA, Wang H, Jin Q, Jiang T, Cai Y, Li D, Lin Y. In Silico Genome-Wide Analysis of the Pear ( Pyrus bretschneideri) KNOX Family and the Functional Characterization of PbKNOX1, an Arabidopsis BREVIPEDICELLUS Orthologue Gene, Involved in Cell Wall and Lignin Biosynthesis. Front Genet 2019; 10:632. [PMID: 31333718 PMCID: PMC6624237 DOI: 10.3389/fgene.2019.00632] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/17/2019] [Indexed: 12/18/2022] Open
Abstract
Stone cells are a characteristic trait of pear fruit, but the contents and sizes of stone cells negatively correlate with fruit texture and flavor. Secondary cell wall thickening and lignification have been established as key steps of stone cell development. KNOTTED-LIKE HOMEOBOX (KNOX) proteins play important roles in plant cell growth and development, including cell wall formation and lignification. Although the characteristics and biological functions of KNOX proteins have been investigated in other plants, this gene family has not been functionally characterized in pear. Eighteen PbKNOX genes were identified in the present study, and all of the identified family members contained the KNOX I and/or KNOX II domains. Based on the phylogenetic tree and chromosomal localization, the 18 PbKNOX genes were divided into five subfamilies [SHOOT MERISTEMLESS (STM)-like, BREVIPEDICELLUS (BP)-like, KNOTTED ARABIDOPSIS THALIANA 2/6 (KNAT2/6)-like, KNAT7-like, and KNAT3-5-like] and were distributed among 10 chromosomes. In addition, we identified 9, 11, and 11 KNOX genes in the genomes of grape, mei, and strawberry, respectively, and the greatest number of collinear KNOX gene pairs formed between pears and peaches. Analyses of the spatiotemporal expression patterns showed that the tissue specificity of PbKNOX gene expression was not very significant and that the level of the PbKNOX1 transcript showed an opposite trend to the levels of stone cells and lignin accumulation. Furthermore, PbKNOX1 has high sequence identity and similarity with Arabidopsis BP. Compared with wild-type Arabidopsis, plants overexpressing PbKNOX1 not only showed an approximately 19% decrease in the secondary cell wall thickness of vessel cells but also exhibited an approximately 13% reduction in the lignin content of inflorescence stems. Moreover, the expression of several genes involved in lignin biosynthesis was downregulated in transgenic lines. Based on our results, PbKNOX1/BP participates in cell wall-thickening and lignin biosynthesis and represses the transcription of key structural genes involved in lignin synthesis, providing genetic evidence for the roles of KNOX in cell wall thickening and lignin biosynthesis in pear.
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Affiliation(s)
- Xi Cheng
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Manli Li
- School of Life Science, Anhui Agricultural University, Hefei, China
| | | | - Guohui Li
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Jingyun Zhang
- School of Life Science, Anhui Agricultural University, Hefei, China.,Horticultural Institute, Anhui Academy of Agricultural Sciences, Hefei, China
| | | | - Han Wang
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Qing Jin
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Taoshan Jiang
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Yongping Cai
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Dahui Li
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Yi Lin
- School of Life Science, Anhui Agricultural University, Hefei, China
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9
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Pazhany AS, Henry RJ. Genetic Modification of Biomass to Alter Lignin Content and Structure. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b01163] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Adhini S. Pazhany
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, 4072 Queensland, Australia
- ICAR - Sugarcane Breeding Institute, Coimbatore, 641 007 Tamil Nadu, India
| | - Robert J. Henry
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, 4072 Queensland, Australia
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10
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Figueiredo R, Araújo P, Llerena JPP, Mazzafera P. Suberin and hemicellulose in sugarcane cell wall architecture and crop digestibility: A biotechnological perspective. Food Energy Secur 2019. [DOI: 10.1002/fes3.163] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Raquel Figueiredo
- Department of Plant Biology Institute of Biology State University of Campinas Campinas Brazil
| | - Pedro Araújo
- Department of Genetics, Evolution and Bioagents Institute of Biology State University of Campinas Campinas Brazil
| | - Juan Pablo P. Llerena
- Department of Plant Biology Institute of Biology State University of Campinas Campinas Brazil
| | - Paulo Mazzafera
- Department of Plant Biology Institute of Biology State University of Campinas Campinas Brazil
- Department of Crop Science College of Agriculture Luiz de Queiroz University of São Paulo Piracicaba Brazil
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11
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Li G, Jones KC, Eudes A, Pidatala VR, Sun J, Xu F, Zhang C, Wei T, Jain R, Birdseye D, Canlas PE, Baidoo EEK, Duong PQ, Sharma MK, Singh S, Ruan D, Keasling JD, Mortimer JC, Loqué D, Bartley LE, Scheller HV, Ronald PC. Overexpression of a rice BAHD acyltransferase gene in switchgrass (Panicum virgatum L.) enhances saccharification. BMC Biotechnol 2018; 18:54. [PMID: 30180895 PMCID: PMC6123914 DOI: 10.1186/s12896-018-0464-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/27/2018] [Indexed: 11/10/2022] Open
Abstract
Background Switchgrass (Panicum virgatum L.) is a promising bioenergy feedstock because it can be grown on marginal land and produces abundant biomass. Recalcitrance of the lignocellulosic components of the switchgrass cell wall to enzymatic degradation into simple sugars impedes efficient biofuel production. We previously demonstrated that overexpression of OsAT10, a BAHD acyltransferase gene, enhances saccharification efficiency in rice. Results Here we show that overexpression of the rice OsAT10 gene in switchgrass decreased the levels of cell wall-bound ferulic acid (FA) in green leaf tissues and to a lesser extent in senesced tissues, and significantly increased levels of cell wall-bound p-coumaric acid (p-CA) in green leaves but decreased its level in senesced tissues of the T0 plants under greenhouse conditions. The engineered switchgrass lines exhibit an approximate 40% increase in saccharification efficiency in green tissues and a 30% increase in senesced tissues. Conclusion Our study demonstrates that overexpression of OsAT10, a rice BAHD acyltransferase gene, enhances saccharification of lignocellulosic biomass in switchgrass. Electronic supplementary material The online version of this article (10.1186/s12896-018-0464-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guotian Li
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Kyle C Jones
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Aymerick Eudes
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | | | - Jian Sun
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Biomass Science and Conversion Technology Department, Sandia National Laboratories, CA94551, Livermore, USA
| | - Feng Xu
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Chengcheng Zhang
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Tong Wei
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Rashmi Jain
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Devon Birdseye
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Patrick E Canlas
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Edward E K Baidoo
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Phat Q Duong
- Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Manoj K Sharma
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA.,School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Seema Singh
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Biomass Science and Conversion Technology Department, Sandia National Laboratories, CA94551, Livermore, USA
| | - Deling Ruan
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA
| | - Jay D Keasling
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Bioengineering and Department of Chemical & Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Jenny C Mortimer
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Dominique Loqué
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Laura E Bartley
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Henrik V Scheller
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Pamela C Ronald
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. .,Department of Plant Pathology and the Genome Center, University of California, Davis, CA, 95616, USA.
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12
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Ambavaram MMR, Ali A, Ryan KP, Peoples O, Snell KD, Somleva MN. Novel transcription factors PvBMY1 and PvBMY3 increase biomass yield in greenhouse-grown switchgrass (Panicum virgatum L.). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 273:100-109. [PMID: 29907302 DOI: 10.1016/j.plantsci.2018.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
Increasing crop yield requires the coordination of multiple metabolic pathways spanning photosynthetic carbon fixation, central carbon metabolism, and finally targeted carbon deposition to end product. In this study, we used a transcriptome-based gene regulatory association network to search for transcription factor genes that could play a role in increasing carbon flow through pathways associated with these processes to increase biomass yield in switchgrass. Two novel switchgrass transcription factors, PvBMY1 (BioMass Yield 1, belonging to the APETALA2/Ethylene Response Factor family of transcription factors) and PvBMY3 (BioMass Yield 3, a member of the Nuclear-Factor Y family of transcription factors), with predicted roles in the regulation of photosynthesis and related metabolism were identified. These genes were overexpressed in switchgrass to determine their impact on biomass yield. A significant increase in both aboveground and root biomass was observed in transgenic greenhouse grown plants compared to wild-type control plants with the best line producing 160% more aboveground biomass than controls. Transgenic lines with elevated electron transport rate of photosystems I and II as well as increased levels of starch and soluble sugars were identified.
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Affiliation(s)
| | - Aminat Ali
- Yield10 Bioscience, Inc., 19 Presidential Way, Woburn, MA 01801, United States
| | - Kieran P Ryan
- Yield10 Bioscience, Inc., 19 Presidential Way, Woburn, MA 01801, United States
| | - Oliver Peoples
- Yield10 Bioscience, Inc., 19 Presidential Way, Woburn, MA 01801, United States
| | - Kristi D Snell
- Yield10 Bioscience, Inc., 19 Presidential Way, Woburn, MA 01801, United States.
| | - Maria N Somleva
- Yield10 Bioscience, Inc., 19 Presidential Way, Woburn, MA 01801, United States
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13
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Liu W, Mazarei M, Ye R, Peng Y, Shao Y, Baxter HL, Sykes RW, Turner GB, Davis MF, Wang ZY, Dixon RA, Stewart CN. Switchgrass ( Panicum virgatum L.) promoters for green tissue-specific expression of the MYB4 transcription factor for reduced-recalcitrance transgenic switchgrass. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:122. [PMID: 29713381 PMCID: PMC5914048 DOI: 10.1186/s13068-018-1119-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 04/16/2018] [Indexed: 05/09/2023]
Abstract
BACKGROUND Genetic engineering of switchgrass (Panicum virgatum L.) for reduced cell wall recalcitrance and improved biofuel production has been a long pursued goal. Up to now, constitutive promoters have been used to direct the expression of cell wall biosynthesis genes toward attaining that goal. While generally sufficient to gauge a transgene's effects in the heterologous host, constitutive overexpression often leads to undesirable plant phenotypic effects. Green tissue-specific promoters from switchgrass are potentially valuable to directly alter cell wall traits exclusively in harvestable aboveground biomass while not changing root phenotypes. RESULTS We identified and functionally characterized three switchgrass green tissue-specific promoters and assessed marker gene expression patterns and intensity in stably transformed rice (Oryza sativa L.), and then used them to direct the expression of the switchgrass MYB4 (PvMYB4) transcription factor gene in transgenic switchgrass to endow reduced recalcitrance in aboveground biomass. These promoters correspond to photosynthesis-related light-harvesting complex II chlorophyll-a/b binding gene (PvLhcb), phosphoenolpyruvate carboxylase (PvPEPC), and the photosystem II 10 kDa R subunit (PvPsbR). Real-time RT-PCR analysis detected their strong expression in the aboveground tissues including leaf blades, leaf sheaths, internodes, inflorescences, and nodes of switchgrass, which was tightly up-regulated by light. Stable transgenic rice expressing the GUS reporter under the control of each promoter (756-2005 bp in length) further confirmed their strong expression patterns in leaves and stems. With the exception of the serial promoter deletions of PvLhcb, all GUS marker patterns under the control of each 5'-end serial promoter deletion were not different from that conveyed by their respective promoters. All of the shortest promoter fragments (199-275 bp in length) conveyed strong green tissue-specific GUS expression in transgenic rice. PvMYB4 is a master repressor of lignin biosynthesis. The green tissue-specific expression of PvMYB4 via each promoter in transgenic switchgrass led to significant gains in saccharification efficiency, decreased lignin, and decreased S/G lignin ratios. In contrast to constitutive overexpression of PvMYB4, which negatively impacts switchgrass root growth, plant growth was not compromised in green tissue-expressed PvMYB4 switchgrass plants in the current study. CONCLUSIONS Each of the newly described green tissue-specific promoters from switchgrass has utility to change cell wall biosynthesis exclusively in aboveground harvestable biomass without altering root systems. The truncated green tissue promoters are very short and should be useful for targeted expression in a number of monocots to improve shoot traits while restricting gene expression from roots. Green tissue-specific expression of PvMYB4 is an effective strategy for improvement of transgenic feedstocks.
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Affiliation(s)
- Wusheng Liu
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- Department of Horticultural Science, North Carolina State University, Raleigh, NC USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Rongjian Ye
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
| | - Yanhui Peng
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
| | - Yuanhua Shao
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
| | - Holly L. Baxter
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Robert W. Sykes
- National Renewable Energy Laboratory, Golden, CO USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Geoffrey B. Turner
- National Renewable Energy Laboratory, Golden, CO USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Mark F. Davis
- National Renewable Energy Laboratory, Golden, CO USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Zeng-Yu Wang
- Noble Research Institute, Ardmore, OK USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
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14
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Xu W, Liu W, Ye R, Mazarei M, Huang D, Zhang X, Stewart CN. A profilin gene promoter from switchgrass (Panicum virgatum L.) directs strong and specific transgene expression to vascular bundles in rice. PLANT CELL REPORTS 2018; 37:587-597. [PMID: 29340787 DOI: 10.1007/s00299-018-2253-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/05/2018] [Indexed: 05/25/2023]
Abstract
A switchgrass vascular tissue-specific promoter (PvPfn2) and its 5'-end serial deletions drive high levels of vascular bundle transgene expression in transgenic rice. Constitutive promoters are widely used for crop genetic engineering, which can result in multiple off-target effects, including suboptimal growth and epigenetic gene silencing. These problems can be potentially avoided using tissue-specific promoters for targeted transgene expression. One particularly urgent need for targeted cell wall modification in bioenergy crops, such as switchgrass (Panicum virgatum L.), is the development of vasculature-active promoters to express cell wall-affective genes only in the specific tissues, i.e., xylem and phloem. From a switchgrass expression atlas we identified promoter sequence upstream of a vasculature-specific switchgrass profilin gene (PvPfn2), especially in roots, nodes and inflorescences. When the putative full-length (1715 bp) and 5'-end serial deletions of the PvPfn2 promoter (shortest was 413 bp) were used to drive the GUS reporter expression in stably transformed rice (Oryza sativa L.), strong vasculature-specificity was observed in various tissues including leaves, leaf sheaths, stems, and flowers. The promoters were active in both phloem and xylem. It is interesting to note that the promoter was active in many more tissues in the heterologous rice system than in switchgrass. Surprisingly, all four 5'-end promoter deletions, including the shortest fragment, had the same expression patterns as the full-length promoter and with no attenuation in GUS expression in rice. These results indicated that the PvPfn2 promoter variants are new tools to direct transgene expression specifically to vascular tissues in monocots. Of special interest is the very compact version of the promoter, which could be of use for vasculature-specific genetic engineering in monocots.
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Affiliation(s)
- Wenzhi Xu
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
- Department of Grassland Science, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Wusheng Liu
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
- Department of Horticultural Science, North Carolina State University, Raleigh, NC, USA
| | - Rongjian Ye
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Debao Huang
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Xinquan Zhang
- Department of Grassland Science, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA.
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15
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Kulkarni KP, Patil G, Valliyodan B, Vuong TD, Shannon JG, Nguyen HT, Lee JD. Comparative genome analysis to identify SNPs associated with high oleic acid and elevated protein content in soybean. Genome 2018; 61:217-222. [PMID: 29365289 DOI: 10.1139/gen-2017-0158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
The objective of this study was to determine the genetic relationship between the oleic acid and protein content. The genotypes having high oleic acid and elevated protein (HOEP) content were crossed with five elite lines having normal oleic acid and average protein (NOAP) content. The selected accessions were grown at six environments in three different locations and phenotyped for protein, oil, and fatty acid components. The mean protein content of parents, HOEP, and NOAP lines was 34.6%, 38%, and 34.9%, respectively. The oleic acid concentration of parents, HOEP, and NOAP lines was 21.7%, 80.5%, and 20.8%, respectively. The HOEP plants carried both FAD2-1A (S117N) and FAD2-1B (P137R) mutant alleles contributing to the high oleic acid phenotype. Comparative genome analysis using whole-genome resequencing data identified six genes having single nucleotide polymorphism (SNP) significantly associated with the traits analyzed. A single SNP in the putative gene Glyma.10G275800 was associated with the elevated protein content, and palmitic, oleic, and linoleic acids. The genes from the marker intervals of previously identified QTL did not carry SNPs associated with protein content and fatty acid composition in the lines used in this study, indicating that all the genes except Glyma.10G278000 may be the new genes associated with the respective traits.
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Affiliation(s)
- Krishnanand P Kulkarni
- a School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Gunvant Patil
- b Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Babu Valliyodan
- b Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Tri D Vuong
- b Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - J Grover Shannon
- b Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Henry T Nguyen
- b Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Jeong-Dong Lee
- a School of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea
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16
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Physico-Chemical Conversion of Lignocellulose: Inhibitor Effects and Detoxification Strategies: A Mini Review. Molecules 2018; 23:molecules23020309. [PMID: 29389875 PMCID: PMC6017906 DOI: 10.3390/molecules23020309] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/18/2018] [Accepted: 01/30/2018] [Indexed: 11/20/2022] Open
Abstract
A pretreatment of lignocellulosic biomass to produce biofuels, polymers, and other chemicals plays a vital role in the biochemical conversion process toward disrupting the closely associated structures of the cellulose-hemicellulose-lignin molecules. Various pretreatment steps alter the chemical/physical structure of lignocellulosic materials by solubilizing hemicellulose and/or lignin, decreasing the particle sizes of substrate and the crystalline portions of cellulose, and increasing the surface area of biomass. These modifications enhance the hydrolysis of cellulose by increasing accessibilities of acids or enzymes onto the surface of cellulose. However, lignocellulose-derived byproducts, which can inhibit and/or deactivate enzyme and microbial biocatalysts, are formed, including furan derivatives, lignin-derived phenolics, and carboxylic acids. These generation of compounds during pretreatment with inhibitory effects can lead to negative effects on subsequent steps in sugar flat-form processes. A number of physico-chemical pretreatment methods such as steam explosion, ammonia fiber explosion (AFEX), and liquid hot water (LHW) have been suggested and developed for minimizing formation of inhibitory compounds and alleviating their effects on ethanol production processes. This work reviews the physico-chemical pretreatment methods used for various biomass sources, formation of lignocellulose-derived inhibitors, and their contributions to enzymatic hydrolysis and microbial activities. Furthermore, we provide an overview of the current strategies to alleviate inhibitory compounds present in the hydrolysates or slurries.
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17
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Rao X, Dixon RA. Current Models for Transcriptional Regulation of Secondary Cell Wall Biosynthesis in Grasses. FRONTIERS IN PLANT SCIENCE 2018; 9:399. [PMID: 29670638 PMCID: PMC5893761 DOI: 10.3389/fpls.2018.00399] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 03/13/2018] [Indexed: 05/17/2023]
Abstract
Secondary cell walls mediate many crucial biological processes in plants including mechanical support, water and nutrient transport and stress management. They also provide an abundant resource of renewable feed, fiber, and fuel. The grass family contains the most important food, forage, and biofuel crops. Understanding the regulatory mechanism of secondary wall formation in grasses is necessary for exploiting these plants for agriculture and industry. Previous research has established a detailed model of the secondary wall regulatory network in the dicot model species Arabidopsis thaliana. Grasses, branching off from the dicot ancestor 140-150 million years ago, display distinct cell wall morphology and composition, suggesting potential for a different secondary wall regulation program from that established for dicots. Recently, combined application of molecular, genetic and bioinformatics approaches have revealed more transcription factors involved in secondary cell wall biosynthesis in grasses. Compared with the dicots, grasses exhibit a relatively conserved but nevertheless divergent transcriptional regulatory program to activate their secondary cell wall development and to coordinate secondary wall biosynthesis with other physiological processes.
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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, United States Department of Energy, Oak Ridge, TN, United States
- *Correspondence: Xiaolan Rao,
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX, United States
- BioEnergy Science Center, United States Department of Energy, Oak Ridge, TN, United States
- Center for Bioenergy Innovation, United States Department of Energy, Oak Ridge, TN, United States
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18
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Bhatia R, Gallagher JA, Gomez LD, Bosch M. Genetic engineering of grass cell wall polysaccharides for biorefining. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1071-1092. [PMID: 28557198 PMCID: PMC5552484 DOI: 10.1111/pbi.12764] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 05/17/2017] [Accepted: 05/24/2017] [Indexed: 05/10/2023]
Abstract
Grasses represent an abundant and widespread source of lignocellulosic biomass, which has yet to fulfil its potential as a feedstock for biorefining into renewable and sustainable biofuels and commodity chemicals. The inherent recalcitrance of lignocellulosic materials to deconstruction is the most crucial limitation for the commercial viability and economic feasibility of biomass biorefining. Over the last decade, the targeted genetic engineering of grasses has become more proficient, enabling rational approaches to modify lignocellulose with the aim of making it more amenable to bioconversion. In this review, we provide an overview of transgenic strategies and targets to tailor grass cell wall polysaccharides for biorefining applications. The bioengineering efforts and opportunities summarized here rely primarily on (A) reprogramming gene regulatory networks responsible for the biosynthesis of lignocellulose, (B) remodelling the chemical structure and substitution patterns of cell wall polysaccharides and (C) expressing lignocellulose degrading and/or modifying enzymes in planta. It is anticipated that outputs from the rational engineering of grass cell wall polysaccharides by such strategies could help in realizing an economically sustainable, grass-derived lignocellulose processing industry.
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Affiliation(s)
- Rakesh Bhatia
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityAberystwythUK
| | - Joe A. Gallagher
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityAberystwythUK
| | | | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityAberystwythUK
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19
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Hu R, Xu Y, Yu C, He K, Tang Q, Jia C, He G, Wang X, Kong Y, Zhou G. Transcriptome analysis of genes involved in secondary cell wall biosynthesis in developing internodes of Miscanthus lutarioriparius. Sci Rep 2017; 7:9034. [PMID: 28831170 PMCID: PMC5567372 DOI: 10.1038/s41598-017-08690-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 07/12/2017] [Indexed: 11/08/2022] Open
Abstract
Miscanthus is a promising lignocellulosic bioenergy crop for bioethanol production. To identify candidate genes and regulation networks involved in secondary cell wall (SCW) development in Miscanthus, we performed de novo transcriptome analysis of a developing internode. According to the histological and in-situ histochemical analysis, an elongating internode of M. lutarioriparius can be divided into three distinct segments, the upper internode (UI), middle internode (MI) and basal internode (BI), each representing a different stage of SCW development. The transcriptome analysis generated approximately 300 million clean reads, which were de novo assembled into 79,705 unigenes. Nearly 65% of unigenes was annotated in seven public databases. Comparative profiling among the UI, MI and BI revealed four distinct clusters. Moreover, detailed expression profiling was analyzed for gene families and transcription factors (TFs) involved in SCW biosynthesis, assembly and modification. Based on the co-expression patterns, putative regulatory networks between TFs and SCW-associated genes were constructed. The work provided the first transcriptome analysis of SCW development in M. lutarioriparius. The results obtained provide novel insights into the biosynthesis and regulation of SCW in Miscanthus. In addition, the genes identified represent good candidates for further functional studies to unravel their roles in SCW biosynthesis and modification.
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Affiliation(s)
- Ruibo Hu
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Yan Xu
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Changjiang Yu
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Kang He
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Qi Tang
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Chunlin Jia
- Shandong Institute of Agricultural Sustainable Development, Jinan, 250100, P. R. China
| | - Guo He
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Xiaoyu Wang
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China
| | - Yingzhen Kong
- Key laboratory of Tobacco Genetic Improvement and Biotechnology, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, 266101, P. R. China
| | - Gongke Zhou
- Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, P. R. China.
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20
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Millwood R, Nageswara-Rao M, Ye R, Terry-Emert E, Johnson CR, Hanson M, Burris JN, Kwit C, Stewart CN. Pollen-mediated gene flow from transgenic to non-transgenic switchgrass (Panicum virgatum L.) in the field. BMC Biotechnol 2017; 17:40. [PMID: 28464851 PMCID: PMC5414321 DOI: 10.1186/s12896-017-0363-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/25/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Switchgrass is C4 perennial grass species that is being developed as a cellulosic bioenergy feedstock. It is wind-pollinated and considered to be an obligate outcrosser. Genetic engineering has been used to alter cell walls for more facile bioprocessing and biofuel yield. Gene flow from transgenic cultivars would likely be of regulatory concern. In this study we investigated pollen-mediated gene flow from transgenic to nontransgenic switchgrass in a 3-year field experiment performed in Oliver Springs, Tennessee, U.S.A. using a modified Nelder wheel design. The planted area (0.6 ha) contained sexually compatible pollen source and pollen receptor switchgrass plants. One hundred clonal switchgrass 'Alamo' plants transgenic for an orange-fluorescent protein (OFP) and hygromycin resistance were used as the pollen source; whole plants, including pollen, were orange-fluorescent. To assess pollen movement, pollen traps were placed at 10 m intervals from the pollen-source plot in the four cardinal directions extending to 20 m, 30 m, 30 m, and 100 m to the north, south, west, and east, respectively. To assess pollination rates, nontransgenic 'Alamo 2' switchgrass clones were planted in pairs adjacent to pollen traps. RESULTS In the eastward direction there was a 98% decrease in OFP pollen grains from 10 to 100 m from the pollen-source plot (Poisson regression, F1,8 = 288.38, P < 0.0001). At the end of the second and third year, 1,820 F1 seeds were collected from pollen recipient-plots of which 962 (52.9%) germinated and analyzed for their transgenic status. Transgenic progeny production detected in each pollen-recipient plot decreased with increased distance from the edge of the transgenic plot (Poisson regression, F1,15 = 12.98, P < 0.003). The frequency of transgenic progeny detected in the eastward plots (the direction of the prevailing wind) ranged from 79.2% at 10 m to 9.3% at 100 m. CONCLUSIONS In these experiments we found transgenic pollen movement and hybridization rates to be inversely associated with distance. However, these data suggest pollen-mediated gene flow is likely to occur up to, at least, 100 m. This study gives baseline data useful to determine isolation distances and other management practices should transgenic switchgrass be grown commercially in relevant environments.
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Affiliation(s)
- Reginald Millwood
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - Madhugiri Nageswara-Rao
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA.,Department of Biology, New Mexico State University, PO Box 30001, MSC 3AF, Las Cruces, NM, USA
| | - Rongjian Ye
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - Ellie Terry-Emert
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - Chelsea R Johnson
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - Micaha Hanson
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - Jason N Burris
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - Charles Kwit
- Department of Forestry, Wildlife and Fisheries, University of Tennessee, 274 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, 252 Ellington Plant Sciences, 2431 Joe Johnson Dr., Knoxville, TN, 37996, USA.
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Nelson RS, Stewart CN, Gou J, Holladay S, Gallego-Giraldo L, Flanagan A, Mann DGJ, Hisano H, Wuddineh WA, Poovaiah CR, Srivastava A, Biswal AK, Shen H, Escamilla-Treviño LL, Yang J, Hardin CF, Nandakumar R, Fu C, Zhang J, Xiao X, Percifield R, Chen F, Bennetzen JL, Udvardi M, Mazarei M, Dixon RA, Wang ZY, Tang Y, Mohnen D, Davison BH. Development and use of a switchgrass ( Panicum virgatum L.) transformation pipeline by the BioEnergy Science Center to evaluate plants for reduced cell wall recalcitrance. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:309. [PMID: 29299059 PMCID: PMC5740764 DOI: 10.1186/s13068-017-0991-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/05/2017] [Indexed: 05/02/2023]
Abstract
BACKGROUND The mission of the BioEnergy Science Center (BESC) was to enable efficient lignocellulosic-based biofuel production. One BESC goal was to decrease poplar and switchgrass biomass recalcitrance to biofuel conversion while not affecting plant growth. A transformation pipeline (TP), to express transgenes or transgene fragments (constructs) in these feedstocks with the goal of understanding and decreasing recalcitrance, was considered essential for this goal. Centralized data storage for access by BESC members and later the public also was essential. RESULTS A BESC committee was established to codify procedures to evaluate and accept genes into the TP. A laboratory information management system (LIMS) was organized to catalog constructs, plant lines and results from their analyses. One hundred twenty-eight constructs were accepted into the TP for expression in switchgrass in the first 5 years of BESC. Here we provide information on 53 of these constructs and the BESC TP process. Eleven of the constructs could not be cloned into an expression vector for transformation. Of the remaining constructs, 22 modified expression of the gene target. Transgenic lines representing some constructs displayed decreased recalcitrance in the field and publications describing these results are tabulated here. Transcript levels of target genes and detailed wall analyses from transgenic lines expressing six additional tabulated constructs aimed toward modifying expression of genes associated with wall structure (xyloglucan and lignin components) are provided. Altered expression of xyloglucan endotransglucosylase/hydrolases did not modify lignin content in transgenic plants. Simultaneous silencing of two hydroxycinnamoyl CoA:shikimate hydroxycinnamoyl transferases was necessary to decrease G and S lignin monomer and total lignin contents, but this reduced plant growth. CONCLUSIONS A TP to produce plants with decreased recalcitrance and a LIMS for data compilation from these plants were created. While many genes accepted into the TP resulted in transgenic switchgrass without modified lignin or biomass content, a group of genes with potential to improve lignocellulosic biofuel yields was identified. Results from transgenic lines targeting xyloglucan and lignin structure provide examples of the types of information available on switchgrass lines produced within BESC. This report supplies useful information when developing coordinated, large-scale, multi-institutional reverse genetic pipelines to improve crop traits.
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Affiliation(s)
- Richard S. Nelson
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Jiqing Gou
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Susan Holladay
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Lina Gallego-Giraldo
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Amy Flanagan
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - David G. J. Mann
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Hiroshi Hisano
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Wegi A. Wuddineh
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Charleson R. Poovaiah
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Avinash Srivastava
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Ajaya K. Biswal
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602 USA
| | - Hui Shen
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Luis L. Escamilla-Treviño
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Jiading Yang
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - C. Frank Hardin
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Rangaraj Nandakumar
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Chunxiang Fu
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Jiyi Zhang
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Xirong Xiao
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Ryan Percifield
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Genetics, University of Georgia, Athens, GA 30602 USA
| | - Fang Chen
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Jeffrey L. Bennetzen
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Department of Genetics, University of Georgia, Athens, GA 30602 USA
| | - Michael Udvardi
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Richard A. Dixon
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX 76203 USA
| | - Zeng-Yu Wang
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Yuhong Tang
- Noble Research Institute, LLC, Ardmore, OK 73401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Debra Mohnen
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602 USA
| | - Brian H. Davison
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
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