1
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Fang H, Dickey B, PerezLaguna D, Ulloa JV, PerezSanchez P, Xu J. Acidothermus cellulolyticus E1 endoglucanase expressed in planta undergoes extensive hydroxyproline-O-glycosylation and exhibits enhanced impact on biomass digestibility. PLANT CELL REPORTS 2024; 43:202. [PMID: 39073636 DOI: 10.1007/s00299-024-03291-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Accepted: 07/20/2024] [Indexed: 07/30/2024]
Abstract
KEY MESSAGE E1 holoenzyme was extensively Hyp-O-glycosylated at the proline rich linker region in plants, which substantially increased the molecular size and improved the enzymatic digestibility of the biomass of transgenic plants. Thermophilic E1 endo-1,4-β-glucanase derived from Acidothermus cellulolyticus has been frequently expressed in planta to reconstruct the plant cell wall to overcome biomass recalcitrance. However, the expressed holoenzyme exhibited a larger molecular size (~ 100 kDa) than the theoretical one (57 kDa), possibly due to posttranslational modifications in the recombinant enzyme within plant cells. This study investigates the glycosylation of the E1 holoenzyme expressed in tobacco plants and determines its impact on enzyme activity and biomass digestibility. The E1 holoenzyme, E1 catalytic domain (E1cd) and E1 linker (E1Lk) were each expressed in tobacco plants and suspension cells. The accumulation of holoenzyme was 2.0- to 2.3- times higher than that of E1cd. The proline-rich E1Lk region was extensively hydroxyproline-O-glycosylated with arabinogalactan polysaccharides. Compared with E1cd, the holoenzyme displayed a broader optimal temperature range (70 to 85 ºC). When grown in greenhouse, the expression of E1 holoenzyme induced notable phenotypic changes in plants, including delayed flowering and leaf variegation post-flowering. However, the final yield of plant biomass was not significantly affected. Finally, plant biomass engineering with E1 holoenzyme showed 1.7- to 1.8-fold higher saccharification efficiency than the E1cd lines and 2.4- to 2.7-fold higher than the wild-type lines, which was ascribed to the synergetic action of the E1Lk and cellulose binding module in reducing cell wall recalcitrance.
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Affiliation(s)
- Hong Fang
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR, 72401, USA
- College of Agriculture, Arkansas State University, Jonesboro, AR, 72401, USA
| | - Berry Dickey
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, 72401, USA
| | - Daniela PerezLaguna
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, 72401, USA
| | | | - Paula PerezSanchez
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR, 72401, USA
| | - Jianfeng Xu
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR, 72401, USA.
- College of Agriculture, Arkansas State University, Jonesboro, AR, 72401, USA.
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2
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Shinde R, Shahi DK, Mahapatra P, Naik SK, Thombare N, Singh AK. Potential of lignocellulose degrading microorganisms for agricultural residue decomposition in soil: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 320:115843. [PMID: 36056484 DOI: 10.1016/j.jenvman.2022.115843] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 07/16/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Lignocellulosic crop residues (LCCRs) hold a significant share of the terrestrial biomass, estimated at 5 billion Mg per annum globally. A massive amount of these LCCRs are burnt in many countries resulting in immense environmental pollution; hence, its proper disposal in a cost-effective and eco-friendly manner is a significant challenge. Among the different options for management of LCCRs, the use of lignocellulose degrading microorganisms (LCDMOs), like fungi and bacteria, has emerged as an eco-friendly and effective way for its on-site disposal. LCDMOs achieve degradation through various mechanisms, including multiple supportive enzymes, causing oxidative attacks by which recalcitrance of lignocellulose material is reduced, paving the way to further activity by depolymerizing enzymes. This improves the physical properties of soil, recycles plant nutrients, promotes plant growth and thus helps improve productivity. Rapid and proper microbial degradation may be achieved through the correct combination of the LCDMOs, supplementing nutrients and controlling different factors affecting microbial activity in the field. The review is a critical discussion of previous studies revealing the potential of individuals or a set of LCDMOs, factors controlling the rate of degradation and the key researchable areas for better understanding of the role of these decomposers for future use.
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Affiliation(s)
- Reshma Shinde
- ICAR- Research Complex for Eastern Region, Farming System Research Centre for Hill and Plateau Region, Ranchi, 834010, Jharkhand, India.
| | | | | | - Sushanta Kumar Naik
- ICAR- Research Complex for Eastern Region, Farming System Research Centre for Hill and Plateau Region, Ranchi, 834010, Jharkhand, India
| | - Nandkishore Thombare
- ICAR- Indian Institute of Natural Resin and Gums, Ranchi, 834010, Jharkhand, India
| | - Arun Kumar Singh
- ICAR- Research Complex for Eastern Region, Farming System Research Centre for Hill and Plateau Region, Ranchi, 834010, Jharkhand, India
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3
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Harindintwali JD, Zhou J, Yu X. Lignocellulosic crop residue composting by cellulolytic nitrogen-fixing bacteria: A novel tool for environmental sustainability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 715:136912. [PMID: 32014770 DOI: 10.1016/j.scitotenv.2020.136912] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/19/2020] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Lignocellulosic crop residue (LCCR) composting is a cost-effective and sustainable approach for addressing environmental pollution associated with open biomass burning and application of chemical fertilizers in agriculture. The value-added bio-product of the composting process contributes to the improvement of the soil properties and plant growth in an environment-friendly way. However, the conventional process employed for composting LCCRs is slow and becomes an impediment for farmers who plant two or three crops a year. This concern has led to the development of different techniques for rapid composting of LCCRs. The use of cellulolytic nitrogen-fixing microorganisms for composting has emerged as a promising method for enhancing LCCR composting and quality of the compost. Therefore, this review addresses the recent progress on the potential use of cellulolytic nitrogen-fixing bacteria (CNFB) for LCCR composting and discusses various applications of nutrient-rich compost for sustainable agriculture to increase crop yields in a nature-friendly way. This knowledge of bacteria with both cellulose-degrading and nitrogen-fixing activities is significant with respect to rapid composting, soil fertility, plant growth and sustainable management of the lignocellulosic agricultural waste and it provides a means for the development of new technology for sustainability.
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Affiliation(s)
- Jean Damascene Harindintwali
- The Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Li-Hu Road, Bin-Hu District, Wuxi 214122, China
| | - Jianli Zhou
- The Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Li-Hu Road, Bin-Hu District, Wuxi 214122, China
| | - Xiaobin Yu
- The Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Li-Hu Road, Bin-Hu District, Wuxi 214122, China.
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4
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Fang H, Wright T, Jinn JR, Guo W, Zhang N, Wang X, Wang YJ, Xu J. Engineering hydroxyproline-O-glycosylated biopolymers to reconstruct the plant cell wall for improved biomass processability. Biotechnol Bioeng 2020; 117:945-958. [PMID: 31930479 DOI: 10.1002/bit.27266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/23/2019] [Accepted: 01/07/2020] [Indexed: 12/19/2022]
Abstract
Reconstructing the chemical and structural characteristics of the plant cell wall represents a promising solution to overcoming lignocellulosic biomass recalcitrance to biochemical deconstruction. This study aims to leverage hydroxyproline (Hyp)-O-glycosylation, a process unique to plant cell wall glycoproteins, as an innovative technology for de novo design and engineering in planta of Hyp-O-glycosylated biopolymers (HypGP) that facilitate plant cell wall reconstruction. HypGP consisting of 18 tandem repeats of "Ser-Hyp-Hyp-Hyp-Hyp" motif or (SP4)18 was designed and engineered into tobacco plants as a fusion peptide with either a reporter protein enhanced green fluorescence protein or the catalytic domain of a thermophilic E1 endoglucanase (E1cd) from Acidothermus cellulolyticus. The engineered (SP4)18 module was extensively Hyp-O-glycosylated with arabino-oligosaccharides, which facilitated the deposition of the fused protein/enzyme in the cell wall matrix and improved the accumulation of the protein/enzyme in planta by 1.5-11-fold. The enzyme activity of the recombinant E1cd was not affected by the fused (SP4)18 module, showing an optimal temperature of 80°C and optimal pH between 5 and 8. The plant biomass engineered with the (SP4)18 -tagged protein/enzyme increased the biomass saccharification efficiency by up to 3.5-fold without having adverse impact on the plant growth.
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Affiliation(s)
- Hong Fang
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, Arkansas
- College of Agriculture, Arkansas State University, Jonesboro, Arkansas
| | - Tristen Wright
- Department of Biological Sciences, Arkansas State University, Jonesboro, Arkansas
| | - Jia-Rong Jinn
- Department of Food Sciences, University of Arkansas, Fayetteville, Arkansas
| | - Wenzheng Guo
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, Arkansas
| | - Ningning Zhang
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, Arkansas
- Department of Biological Sciences, Arkansas State University, Jonesboro, Arkansas
| | - Xiaoting Wang
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, Arkansas
- Department of Biological Sciences, Arkansas State University, Jonesboro, Arkansas
| | - Ya-Jane Wang
- Department of Food Sciences, University of Arkansas, Fayetteville, Arkansas
| | - Jianfeng Xu
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, Arkansas
- College of Agriculture, Arkansas State University, Jonesboro, Arkansas
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5
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Chou HL, Tian L, Fukuda M, Kumamaru T, Okita TW. The Role of RNA-Binding Protein OsTudor-SN in Post-Transcriptional Regulation of Seed Storage Proteins and Endosperm Development. PLANT & CELL PHYSIOLOGY 2019; 60:2193-2205. [PMID: 31198964 DOI: 10.1093/pcp/pcz113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 05/28/2019] [Indexed: 05/28/2023]
Abstract
Tudor-SN is involved in a myriad of transcriptional and post-transcriptional processes due to its modular structure consisting of 4 tandem SN domains (4SN module) and C-terminal Tsn module consisting of Tudor-partial SN domains. We had previously demonstrated that OsTudor-SN is a key player for transporting storage protein mRNAs to specific ER subdomains in developing rice endosperm. Here, we provide genetic evidence that this multifunctional RBP is required for storage protein expression, seed development and protein body formation. The rice EM1084 line, possessing a nonsynonymous mutation in the 4SN module (SN3 domain), exhibited a strong reduction in grain weight and storage protein accumulation, while a mutation in the Tudor domain (47M) or the loss of the Tsn module (43M) had much smaller effects. Immunoelectron microscopic analysis showed the presence of a new protein body type containing glutelin and prolamine inclusions in EM1084, while 43M and 47M exhibited structurally modified prolamine and glutelin protein bodies. Transcriptome analysis indicates that OsTudor-SN also functions in regulating gene expression of transcriptional factors and genes involved in developmental processes and stress responses as well as for storage proteins. Normal protein body formation, grain weight and expression of many genes were partially restored in EM1084 transgenic line complemented with wild-type OsTudor-SN gene. Overall, our study showed that OsTudor-SN possesses multiple functional properties in rice storage protein expression and seed development and that the 4SN and Tsn modules have unique roles in these processes.
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Affiliation(s)
- Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
| | - Masako Fukuda
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, Japan
| | - Toshihiro Kumamaru
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, DC, USA
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6
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Singh G, Patel AK, Gupta A, Gupta D, Mishra VK. Current Advancements in Recombinant Technology for Industrial Production of Cellulases: Part-II. Fungal Biol 2019. [DOI: 10.1007/978-3-030-14726-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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7
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Fang H, Kandhola G, Rajan K, Djioleu A, Carrier DJ, Hood KR, Hood EE. Effects of Oligosaccharides Isolated From Pinewood Hot Water Pre-hydrolyzates on Recombinant Cellulases. Front Bioeng Biotechnol 2018; 6:55. [PMID: 29868572 PMCID: PMC5962771 DOI: 10.3389/fbioe.2018.00055] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 04/23/2018] [Indexed: 11/29/2022] Open
Abstract
Loblolly pine residues have enormous potential to be the raw material for advanced biofuel production due to extensive sources and high cellulose content. Hot water (HW) pretreatment, while being a relatively economical and clean technology for the deconstruction of lignocellulosic biomass, could also inhibit the ensuing enzymatic hydrolysis process because of the production of inhibitors. In this study, we investigated the effect of oligosaccharide fractions purified from HW pre-hydrolyzate of pinewood using centrifugal partition chromatography (CPC) on three recombinant cellulolytic enzymes (E1, CBHI and CBHII), which were expressed in the transgenic corn grain system. The efficiency of recombinant enzymes was measured using either a 4-methylumbelliferyl-β-D-cellobioside (MUC) or a cellulose-dinitrosalicylic acid (DNS) assay system. The results showed that HW pre-hydrolyzate CPC fractions contain phenolics, furans, and monomeric and oligomeric sugars. Among CPC fractions, oligomers composed of xylan, galactan, and mannan were inhibitory to the three recombinant enzymes and to the commercial cellulase cocktail, reducing the enzymatic efficiency to as low as 10%.
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Affiliation(s)
- Hong Fang
- Department of Biology, Molecular Biosciences Graduate Program, College of Biology, Molecular Biosciences, Arkansas State University, Jonesboro, AR, United States
| | - Gurshagan Kandhola
- Department of Biological & Agricultural Engineering, University of Arkansas, Fayetteville, AR, United States
| | - Kalavathy Rajan
- Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN, United States
| | - Angele Djioleu
- Department of Biological & Agricultural Engineering, University of Arkansas, Fayetteville, AR, United States
| | - Danielle Julie Carrier
- Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN, United States
| | - Kendall R Hood
- Infinite Enzymes, Arkansas State University, Jonesboro, AR, United States
| | - Elizabeth E Hood
- Arkansas State University Biosciences Institute and College of Agriculture and Technology, Arkansas State University, Jonesboro, AR, United States
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8
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Ligaba-Osena A, Hankoua B, DiMarco K, Pace R, Crocker M, McAtee J, Nagachar N, Tien M, Richard TL. Reducing biomass recalcitrance by heterologous expression of a bacterial peroxidase in tobacco (Nicotiana benthamiana). Sci Rep 2017; 7:17104. [PMID: 29213132 PMCID: PMC5719049 DOI: 10.1038/s41598-017-16909-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 10/25/2017] [Indexed: 11/13/2022] Open
Abstract
Commercial scale production of biofuels from lignocellulosic feed stocks has been hampered by the resistance of plant cell walls to enzymatic conversion, primarily owing to lignin. This study investigated whether DypB, the lignin-degrading peroxidase from Rodococcus jostii, depolymerizes lignin and reduces recalcitrance in transgenic tobacco (Nicotiana benthamiana). The protein was targeted to the cytosol or the ER using ER-targeting and retention signal peptides. For each construct, five independent transgenic lines were characterized phenotypically and genotypically. Our findings reveal that expression of DypB in the cytosol and ER does not affect plant development. ER-targeting increased protein accumulation, and extracts from transgenic leaves showed higher activity on classic peroxidase substrates than the control. Intriguingly, in situ DypB activation and subsequent saccharification released nearly 200% more fermentable sugars from transgenic lines than controls, which were not explained by variation in initial structural and non-structural carbohydrates and lignin content. Pyrolysis-GC-MS analysis showed more reduction in the level of lignin associated pyrolysates in the transgenic lines than the control primarily when the enzyme is activated prior to pyrolysis, consistent with increased lignin degradation and improved saccharification. The findings reveal for the first time that accumulation and in situ activation of a peroxidase improves biomass digestibility.
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Affiliation(s)
- Ayalew Ligaba-Osena
- College of Agriculture and Related Sciences, Delaware State University, 1200 N DuPont Highway, Dover, DE, 19901, USA
| | - Bertrand Hankoua
- College of Agriculture and Related Sciences, Delaware State University, 1200 N DuPont Highway, Dover, DE, 19901, USA.
| | - Kay DiMarco
- Agricultural and Biological Engineering, Pennsylvania State University, 111 Research Unit A, University Park, Pennsylvania, PA, 16802, USA
| | - Robert Pace
- Center for Applied Energy Research, University of Kentucky, 2540 Research Park Drive, Lexington, KY, 40511, USA
| | - Mark Crocker
- Center for Applied Energy Research, University of Kentucky, 2540 Research Park Drive, Lexington, KY, 40511, USA
| | - Jesse McAtee
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA
| | - Nivedita Nagachar
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, 305 South Frear Laboratory, University Park, Pennsylvania, PA, 16802, USA
| | - Ming Tien
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, 305 South Frear Laboratory, University Park, Pennsylvania, PA, 16802, USA
| | - Tom L Richard
- Agricultural and Biological Engineering, Pennsylvania State University, 111 Research Unit A, University Park, Pennsylvania, PA, 16802, USA
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9
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Song EG, Ryu KH. A pepper mottle virus-based vector enables systemic expression of endoglucanase D in non-transgenic plants. Arch Virol 2017; 162:3717-3726. [PMID: 28864903 DOI: 10.1007/s00705-017-3539-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 08/02/2017] [Indexed: 12/16/2022]
Abstract
Plant-virus-based expression vectors have been used as an alternative to the creation of transgenic plants. Using a virus-based vector, we investigated the feasibility of producing the endoglucanase D (EngD) from Clostridium cellulovorans in Nicotiana benthamiana. This protein has endoglucanase, xylanase, and exoglucanase activities and may be of value for cellulose digestion in the generation of biofuels from plant biomass. The EngD gene was cloned between the nuclear inclusion b (NIb)- and coat protein (CP)-encoding sequences of pSP6PepMoV-Vb1. In vitro transcripts derived from the clone (pSP6PepMoV-Vb1/EngD) were infectious in N. benthamiana but caused milder symptoms than wild-type PepMoV-Vb1. RT-PCR amplification of total RNA from non-inoculated upper leaves infected with PepMoV-Vb1/EngD produced the target band for the CP, partial NIb and EngD-CP regions of PepMoV-V1/EngD, in addition to nonspecific bands. Western blot analysis showed the CP target bands of PepMoV-Vb1/EngD as well as non-target bands. EngD enzymatic activity in infected plants was detected using a glucose assay. The plant leaves showed increased senescence compared with healthy and PepMoV-Vb1-infected plants. Our study suggests the feasibility of using a viral vector for systemic infection of plants for expression of heterologous engD for the purpose of digesting a cellulose substrate in plant cells for biomass production.
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Affiliation(s)
- Eun Gyeong Song
- Plant Virus GenBank, Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women's University, Seoul, Republic of Korea
| | - Ki Hyun Ryu
- Plant Virus GenBank, Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women's University, Seoul, Republic of Korea.
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10
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Chou HL, Tian L, Kumamaru T, Hamada S, Okita TW. Multifunctional RNA Binding Protein OsTudor-SN in Storage Protein mRNA Transport and Localization. PLANT PHYSIOLOGY 2017; 175:1608-1623. [PMID: 29084903 PMCID: PMC5717745 DOI: 10.1104/pp.17.01388] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 10/26/2017] [Indexed: 05/04/2023]
Abstract
The multifunctional RNA-binding protein Tudor-SN plays multiple roles in transcriptional and posttranscriptional processes due to its modular domain structure, consisting of four tandem Staphylococcus nuclease (SN)-like domains (4SN), followed by a carboxyl-terminal Tudor domain, followed by a fifth partial SN sequence (Tsn). In plants, it confers stress tolerance, is a component of stress granules and P-bodies, and may participate in stabilizing and localizing RNAs to specific subdomains of the cortical-endoplasmic reticulum in developing rice (Oryza sativa) endosperm. Here, we show that, in addition to the intact rice OsTudor-SN protein, the 4SN and Tsn modules exist as independent polypeptides, which collectively may coassemble to form a complex population of homodimer and heteroduplex species. The 4SN and Tsn modules exhibit different roles in RNA binding and as a protein scaffold for stress-associated proteins and RNA-binding proteins. Despite their distinct individual properties, mutations in both the 4SN and Tsn modules mislocalize storage protein mRNAs to the cortical endoplasmic reticulum. These results indicate that the two modular peptide regions of OsTudor-SN confer different cellular properties but cooperate in mRNA localization, a process linking its multiple functions in the nucleus and cytoplasm.
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Affiliation(s)
- Hong-Li Chou
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Li Tian
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
| | - Toshihiro Kumamaru
- Plant Genetics Laboratory, Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Shigeki Hamada
- Institute of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340
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11
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Mir BA, Myburg AA, Mizrachi E, Cowan DA. In planta expression of hyperthermophilic enzymes as a strategy for accelerated lignocellulosic digestion. Sci Rep 2017; 7:11462. [PMID: 28904370 PMCID: PMC5597601 DOI: 10.1038/s41598-017-11026-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 06/14/2017] [Indexed: 11/24/2022] Open
Abstract
Conversion of lignocellulosic biomass to biofuels and biomaterials suffers from high production costs associated with biomass pretreatment and enzymatic hydrolysis. In-planta expression of lignocellulose-digesting enzymes is a promising approach to reduce these cost elements. However, this approach faces a number of challenges, including auto-hydrolysis of developing cell walls, plant growth and yield penalties, low expression levels and the limited stability of expressed enzymes at the high temperatures generally used for biomass processing to release fermentable sugars. To overcome these challenges we expressed codon-optimized recombinant hyperthermophilic endoglucanase (EG) and xylanase (Xyn) genes in A. thaliana. Transgenic Arabidopsis lines expressing EG and Xyn enzymes at high levels without any obvious plant growth or yield penalties were selected for further analysis. The highest enzyme activities were observed in the dry stems of transgenic lines, indicating that the enzymes were not degraded during stem senescence and storage. Biomass from transgenic lines exhibited improved saccharification efficiency relative to WT control plants. We conclude that the expression of hyperthermophilic enzymes in plants is a promising approach for combining pretreatment and enzymatic hydrolysis processes in lignocellulosic digestion. This study provides a valid foundation for further studies involving in planta co-expression of core and accessory lignocellulose-digesting enzymes.
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Affiliation(s)
- Bilal Ahmad Mir
- Centre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa.,Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa.,Department of Botany, School of Life Sciences, Satellite Campus Kargil, University of Kashmir, Jammu & Kashmir, India
| | - Alexander A Myburg
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa
| | - Eshchar Mizrachi
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Private Bag X20, Pretoria, 0028, South Africa.
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12
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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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13
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Donohoe BS, Wei H, Mittal A, Shollenberger T, Lunin VV, Himmel ME, Brunecky R. Towards an Understanding of Enhanced Biomass Digestibility by In Planta Expression of a Family 5 Glycoside Hydrolase. Sci Rep 2017; 7:4389. [PMID: 28663545 PMCID: PMC5491509 DOI: 10.1038/s41598-017-04502-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 05/17/2017] [Indexed: 12/21/2022] Open
Abstract
In planta expression of a thermophilic endoglucanase (AcCel5A) reduces recalcitrance by creating voids and other irregularities in cell walls of Arabidopsis thaliana that increase enzyme accessibility without negative impacts on plant growth or cell wall composition. Our results suggest that cellulose β-1-4 linkages can be cut sparingly in the assembling wall and that these minimal changes, made at the proper time, have an impact on plant cell wall recalcitrance without negative effects on overall plant development.
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Affiliation(s)
- Bryon S Donohoe
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States
| | - Ashutosh Mittal
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States
| | - Todd Shollenberger
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States
| | - Vladimir V Lunin
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States
| | - Michael E Himmel
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States
| | - Roman Brunecky
- Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado, 80401, United States.
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14
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Tsai AYL, Chan K, Ho CY, Canam T, Capron R, Master ER, Bräutigam K. Transgenic expression of fungal accessory hemicellulases in Arabidopsis thaliana triggers transcriptional patterns related to biotic stress and defense response. PLoS One 2017; 12:e0173094. [PMID: 28253318 PMCID: PMC5333852 DOI: 10.1371/journal.pone.0173094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/15/2017] [Indexed: 11/18/2022] Open
Abstract
The plant cell wall is an abundant and renewable resource for lignocellulosic applications such as the production of biofuel. Due to structural and compositional complexities, the plant cell wall is, however, recalcitrant to hydrolysis and extraction of platform sugars. A cell wall engineering strategy to reduce this recalcitrance makes use of microbial cell wall modifying enzymes that are expressed directly in plants themselves. Previously, we constructed transgenic Arabidopsis thaliana constitutively expressing the fungal hemicellulases: Phanerochaete carnosa glucurnoyl esterase (PcGCE) and Aspergillus nidulans α-arabinofuranosidase (AnAF54). While the PcGCE lines demonstrated improved xylan extractability, they also displayed chlorotic leaves leading to the hypothesis that expression of such enzymes in planta resulted in plant stress. The objective of this study is to investigate the impact of transgenic expression of the aforementioned microbial hemicellulases in planta on the host arabidopsis. More specifically, we investigated transcriptome profiles by short read high throughput sequencing (RNAseq) from developmentally distinct parts of the plant stem. When compared to non-transformed wild-type plants, a subset of genes was identified that showed differential transcript abundance in all transgenic lines and tissues investigated. Intriguingly, this core set of genes was significantly enriched for those involved in plant defense and biotic stress responses. While stress and defense-related genes showed increased transcript abundance in the transgenic plants regardless of tissue or genotype, genes involved in photosynthesis (light harvesting) were decreased in their transcript abundance potentially reflecting wide-spread effects of heterologous microbial transgene expression and the maintenance of plant homeostasis. Additionally, an increase in transcript abundance for genes involved in salicylic acid signaling further substantiates our finding that transgenic expression of microbial cell wall modifying enzymes induces transcriptome responses similar to those observed in defense responses.
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Affiliation(s)
- Alex Yi-Lin Tsai
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Kin Chan
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Chi-Yip Ho
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Thomas Canam
- Department of Biological Sciences, Eastern Illinois University, Charleston, Illinois, United States of America
| | - Resmi Capron
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Emma R. Master
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Katharina Bräutigam
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
- * E-mail:
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15
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Park SH, Ong RG, Sticklen M. Strategies for the production of cell wall-deconstructing enzymes in lignocellulosic biomass and their utilization for biofuel production. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:1329-44. [PMID: 26627868 PMCID: PMC5063159 DOI: 10.1111/pbi.12505] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 10/23/2015] [Accepted: 11/02/2015] [Indexed: 05/18/2023]
Abstract
Microbial cell wall-deconstructing enzymes are widely used in the food, wine, pulp and paper, textile, and detergent industries and will be heavily utilized by cellulosic biorefineries in the production of fuels and chemicals. Due to their ability to use freely available solar energy, genetically engineered bioenergy crops provide an attractive alternative to microbial bioreactors for the production of cell wall-deconstructing enzymes. This review article summarizes the efforts made within the last decade on the production of cell wall-deconstructing enzymes in planta for use in the deconstruction of lignocellulosic biomass. A number of strategies have been employed to increase enzyme yields and limit negative impacts on plant growth and development including targeting heterologous enzymes into specific subcellular compartments using signal peptides, using tissue-specific or inducible promoters to limit the expression of enzymes to certain portions of the plant or certain times, and fusion of amplification sequences upstream of the coding region to enhance expression. We also summarize methods that have been used to access and maintain activity of plant-generated enzymes when used in conjunction with thermochemical pretreatments for the production of lignocellulosic biofuels.
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Affiliation(s)
- Sang-Hyuck Park
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Rebecca Garlock Ong
- Department of Chemical Engineering and Materials Science, DOE Great Lakes Bioenergy Research Center, Michigan State University, Lansing, MI, USA
- Department of Chemical Engineering, Michigan Technological University, Houghton, MI, USA
| | - Mariam Sticklen
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
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16
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Willis JD, Mazarei M, Stewart CN. Transgenic Plant-Produced Hydrolytic Enzymes and the Potential of Insect Gut-Derived Hydrolases for Biofuels. FRONTIERS IN PLANT SCIENCE 2016; 7:675. [PMID: 27303411 PMCID: PMC4885837 DOI: 10.3389/fpls.2016.00675] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/02/2016] [Indexed: 05/25/2023]
Abstract
Various perennial C4 grass species have tremendous potential for use as lignocellulosic biofuel feedstocks. Currently available grasses require costly pre-treatment and exogenous hydrolytic enzyme application to break down complex cell wall polymers into sugars that can then be fermented into ethanol. It has long been hypothesized that engineered feedstock production of cell wall degrading (CWD) enzymes would be an efficient production platform for of exogenous hydrolytic enzymes. Most research has focused on plant overexpression of CWD enzyme-coding genes from free-living bacteria and fungi that naturally break down plant cell walls. Recently, it has been found that insect digestive tracts harbor novel sources of lignocellulolytic biocatalysts that might be exploited for biofuel production. These CWD enzyme genes can be located in the insect genomes or in symbiotic microbes. When CWD genes are transformed into plants, negative pleiotropic effects are possible such as unintended cell wall digestion. The use of codon optimization along with organelle and tissue specific targeting improves CWD enzyme yields. The literature teaches several important lessons on strategic deployment of CWD genes in transgenic plants, which is the focus of this review.
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Affiliation(s)
- Jonathan D. Willis
- Department of Plant Sciences, University of TennesseeKnoxville, TN, USA
- Oak Ridge National Laboratory, BioEnergy Science CenterOak Ridge, TN, USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of TennesseeKnoxville, TN, USA
- Oak Ridge National Laboratory, BioEnergy Science CenterOak Ridge, TN, USA
| | - C. Neal Stewart
- Department of Plant Sciences, University of TennesseeKnoxville, TN, USA
- Oak Ridge National Laboratory, BioEnergy Science CenterOak Ridge, TN, USA
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17
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Behera SS, Ray RC. Solid state fermentation for production of microbial cellulases: Recent advances and improvement strategies. Int J Biol Macromol 2016; 86:656-69. [DOI: 10.1016/j.ijbiomac.2015.10.090] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 12/23/2022]
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18
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Shivlata L, Satyanarayana T. Thermophilic and alkaliphilic Actinobacteria: biology and potential applications. Front Microbiol 2015; 6:1014. [PMID: 26441937 PMCID: PMC4585250 DOI: 10.3389/fmicb.2015.01014] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 09/07/2015] [Indexed: 11/13/2022] Open
Abstract
Microbes belonging to the phylum Actinobacteria are prolific sources of antibiotics, clinically useful bioactive compounds and industrially important enzymes. The focus of the current review is on the diversity and potential applications of thermophilic and alkaliphilic actinobacteria, which are highly diverse in their taxonomy and morphology with a variety of adaptations for surviving and thriving in hostile environments. The specific metabolic pathways in these actinobacteria are activated for elaborating pharmaceutically, agriculturally, and biotechnologically relevant biomolecules/bioactive compounds, which find multifarious applications.
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19
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Buanafina MMDO, Dalton S, Langdon T, Timms-Taravella E, Shearer EA, Morris P. Functional co-expression of a fungal ferulic acid esterase and a β-1,4 endoxylanase in Festuca arundinacea (tall fescue) modifies post-harvest cell wall deconstruction. PLANTA 2015; 242:97-111. [PMID: 25854601 DOI: 10.1007/s00425-015-2288-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/25/2015] [Indexed: 06/04/2023]
Abstract
Improved post-harvest cell wall deconstruction of tall fescue leaves has been demonstrated by in-planta co-expression of a constitutively expressed ferulic acid esterase together with a senescence-induced β-1,4 endoxylanase. Tall fescue plants (Festuca arundinacea) constitutively expressing vacuole- or apoplast-targeted ferulic acid esterase from Aspergillus niger were retransformed with a senescence-induced and apoplast-targeted β-1,4 endo-xylanase from Trichoderma reesei. Enzyme activities in co-expressing plants stabilized after repeated vegetative propagation, with xylanase activity in senescent leaves increasing and ferulic acid esterase activity decreasing after tillering. Plants co-expressing both enzymes in the apoplast, with the lowest levels of ferulate monomers and dimers and the lowest levels of cell wall arabinoxylans, released ten times more cell wall hydroxycinnamic acids and five times more arabinoxylan from the cell wall on autodigestion compared to expression of ferulic acid esterase or xylanase alone. These plants also showed a 31 % increase in cellulase-mediated release of reducing sugars, a 5 % point increase in in vitro dry matter digestibility and a 23 % increase in acetyl bromide-soluble lignin. However, plant growth was adversely affected by expressing FAE in the apoplast, giving plants with narrower shorted leaves, and a 71 % decrease in biomass.
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Affiliation(s)
- Marcia M de O Buanafina
- Department of Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, 16802, USA,
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20
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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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21
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Mir BA, Mewalal R, Mizrachi E, Myburg AA, Cowan DA. Recombinant hyperthermophilic enzyme expression in plants: a novel approach for lignocellulose digestion. Trends Biotechnol 2014; 32:281-9. [PMID: 24732021 DOI: 10.1016/j.tibtech.2014.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 02/14/2014] [Accepted: 03/05/2014] [Indexed: 10/25/2022]
Abstract
Plant biomass, as an abundant renewable carbon source, is a promising alternative to fossil fuels. However, the enzymes most commonly used for depolymerization of lignocellulosic biomass are expensive, and the development of cost-effective alternative conversion technologies would be desirable. One possible option is the heterologous expression of genes encoding lignocellulose-digesting enzymes in plant tissues. To overcome simultaneously issues of toxicity and incompatibility with high-temperature steam explosion processes, the use of heterologous genes encoding hyperthermophilic enzymes may be an attractive alternative. This approach could reduce the need for exogenous enzyme additions prior to fermentation, reducing the cost of the complete processing operation. This review highlights recent advances and future prospects for using hyperthermophilic enzymes in the biofuels industry.
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Affiliation(s)
- Bilal Ahmad Mir
- Center for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Private bag X20, Pretoria 0028, South Africa; Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Pretoria 0028, South Africa
| | - Ritesh Mewalal
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Pretoria 0028, South Africa
| | - Eshchar Mizrachi
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Pretoria 0028, South Africa
| | - Alexander A Myburg
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Pretoria 0028, South Africa
| | - Don A Cowan
- Center for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Private bag X20, Pretoria 0028, South Africa.
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22
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Wu Z, Zhang M, Wang L, Tu Y, Zhang J, Xie G, Zou W, Li F, Guo K, Li Q, Gao C, Peng L. Biomass digestibility is predominantly affected by three factors of wall polymer features distinctive in wheat accessions and rice mutants. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:183. [PMID: 24341349 PMCID: PMC3878626 DOI: 10.1186/1754-6834-6-183] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/26/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND Wheat and rice are important food crops with enormous biomass residues for biofuels. However, lignocellulosic recalcitrance becomes a crucial factor on biomass process. Plant cell walls greatly determine biomass recalcitrance, thus it is essential to identify their key factors on lignocellulose saccharification. Despite it has been reported about cell wall factors on biomass digestions, little is known in wheat and rice. In this study, we analyzed nine typical pairs of wheat and rice samples that exhibited distinct cell wall compositions, and identified three major factors of wall polymer features that affected biomass digestibility. RESULTS Based on cell wall compositions, ten wheat accessions and three rice mutants were classified into three distinct groups each with three typical pairs. In terms of group I that displayed single wall polymer alternations in wheat, we found that three wall polymer levels (cellulose, hemicelluloses and lignin) each had a negative effect on biomass digestibility at similar rates under pretreatments of NaOH and H2SO4 with three concentrations. However, analysis of six pairs of wheat and rice samples in groups II and III that each exhibited a similar cell wall composition, indicated that three wall polymer levels were not the major factors on biomass saccharification. Furthermore, in-depth detection of the wall polymer features distinctive in rice mutants, demonstrated that biomass digestibility was remarkably affected either negatively by cellulose crystallinity (CrI) of raw biomass materials, or positively by both Ara substitution degree of non-KOH-extractable hemicelluloses (reverse Xyl/Ara) and p-coumaryl alcohol relative proportion of KOH-extractable lignin (H/G). Correlation analysis indicated that Ara substitution degree and H/G ratio negatively affected cellulose crystallinity for high biomass enzymatic digestion. It was also suggested to determine whether Ara and H monomer have an interlinking with cellulose chains in the future. CONCLUSIONS Using nine typical pairs of wheat and rice samples having distinct cell wall compositions and wide biomass saccharification, Ara substitution degree and monolignin H proportion have been revealed to be the dominant factors positively determining biomass digestibility upon various chemical pretreatments. The results demonstrated the potential of genetic modification of plant cell walls for high biomass saccharification in bioenergy crops.
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Affiliation(s)
- Zhiliang Wu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Mingliang Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Lingqiang Wang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yuanyuan Tu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Jing Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Guosheng Xie
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Weihua Zou
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Fengcheng Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Kai Guo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qing Li
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Chunbao Gao
- Institute of Food Crops, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Liangcai Peng
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan 430070, China
- College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China
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23
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Jung S, Lee DS, Kim YO, Joshi CP, Bae HJ. Improved recombinant cellulase expression in chloroplast of tobacco through promoter engineering and 5' amplification promoting sequence. PLANT MOLECULAR BIOLOGY 2013; 83:317-28. [PMID: 23771581 DOI: 10.1007/s11103-013-0088-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Accepted: 06/03/2013] [Indexed: 05/07/2023]
Abstract
Economical production of bioethanol from lignocellulosic biomass still faces many technical limitations. Cost-effective production of fermentable sugars is still not practical for large-scale production of bioethanol due to high costs of lignocellulolytic enzymes. Therefore, plant molecular farming, where plants are used as bioreactors, was developed for the mass production of cell wall degrading enzymes that will help reduce costs. Subcellular targeting is also potentially more suitable for the accumulation of recombinant cellulases. Herein, we generated transgenic tobacco plants (Nicotiana tabacum cv. SR1) that accumulated Thermotoga maritima BglB cellulase, which was driven by the alfalfa RbcsK-1A promoter and contained a small subunit of the rubisco complex transit peptide. The generated transformants possessed high specific BglB activity and did not show any abnormal phenotypes. Furthermore, we genetically engineered the RbcsK-1A promoter (MRbcsK-1A) and fused the amplification promoting sequence (aps) to MRbcsK-1A promoter to obtain high expression of BglB in transgenic plants. AMRsB plant lines with aps-MRbcsK-1A promoter showed the highest specific activity of BglB, and the accumulated BglB protein represented up to 9.3 % of total soluble protein. When BglB was expressed in Arabidopsis and tobacco plants, the maximal production capacity of recombinant BglB was 0.59 and 1.42 mg/g wet weight, respectively. These results suggests that suitable recombinant expression of cellulases in subcellular compartments such as chloroplasts will contribute to the cost-effective production of enzymes, and will serve as the solid foundation for the future commercialization of bioethanol production via plant molecular farming.
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Affiliation(s)
- Sera Jung
- Department of Forest Products and Technology, Chonnam National University, Kwangju, 500-757, Republic of Korea
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24
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Garvey M, Klose H, Fischer R, Lambertz C, Commandeur U. Cellulases for biomass degradation: comparing recombinant cellulase expression platforms. Trends Biotechnol 2013; 31:581-93. [DOI: 10.1016/j.tibtech.2013.06.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/21/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
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Yennamalli RM, Rader AJ, Kenny AJ, Wolt JD, Sen TZ. Endoglucanases: insights into thermostability for biofuel applications. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:136. [PMID: 24070146 PMCID: PMC3856469 DOI: 10.1186/1754-6834-6-136] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 09/24/2013] [Indexed: 05/03/2023]
Abstract
Obtaining bioethanol from cellulosic biomass involves numerous steps, among which the enzymatic conversion of the polymer to individual sugar units has been a main focus of the biotechnology industry. Among the cellulases that break down the polymeric cellulose are endoglucanases that act synergistically for subsequent hydrolytic reactions. The endoglucanases that have garnered relatively more attention are those that can withstand high temperatures, i.e., are thermostable. Although our understanding of thermostability in endoglucanases is incomplete, some molecular features that are responsible for increased thermostability have been recently identified. This review focuses on the investigations of endoglucanases and their implications for biofuel applications.
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Affiliation(s)
- Ragothaman M Yennamalli
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames 50011, IA, USA
- Present Address: Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Andrew J Rader
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis 46202, IN, USA
- Present Address: State Farm Insurance, Indianapolis 46240, IN, USA
| | - Adam J Kenny
- Biosafety Institute for Genetically Modified Agricultural Products and Department of Agronomy, Iowa State University, Ames 50011, IA, USA
- Present Address: Brownells, Inc, Montezuma, IA 50171, USA
| | - Jeffrey D Wolt
- Biosafety Institute for Genetically Modified Agricultural Products and Department of Agronomy, Iowa State University, Ames 50011, IA, USA
| | - Taner Z Sen
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames 50011, IA, USA
- Bioinformatics and Computational Biology Program, Iowa State University, Ames 50011, IA, USA
- 1025 Crop Genome Informatics Lab, Iowa State University, Ames 50011, IA, USA
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Klose H, Günl M, Usadel B, Fischer R, Commandeur U. Ethanol inducible expression of a mesophilic cellulase avoids adverse effects on plant development. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:53. [PMID: 23587418 PMCID: PMC3643885 DOI: 10.1186/1754-6834-6-53] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/12/2013] [Indexed: 05/07/2023]
Abstract
BACKGROUND Plant-produced biomass-degrading enzymes are promising tools for the processing of lignocellulose to fermentable sugars. A major limitation of in planta production is that high-level expression of such enzymes could potentially affect the structure and integrity of the plant cell wall and negatively influence plant growth and development. RESULTS Here, we evaluate the impact on tobacco plant development of constitutive versus alcohol-inducible expression of the endoglucanase TrCel5A from the mesophilic fungus Trichoderma reesei. Using this system, we are able to demonstrate that constitutive expression of the enzyme, controlled by the doubled Cauliflower Mosaic Virus promoter, leads to lower cellulose content of the plant combined with severe effects on plant growth. However, using an alcohol-inducible expression of the endoglucanase in the plant leaves, we achieved similar enzymatic expression levels with no changes in the crystalline cellulose content. CONCLUSION We were able to produce significant amounts of cellulase in the plant leaves without detrimental effects to plant development. These results demonstrate the potential feasibility of an inducible expression system for producing biomass degrading enzymes in plants.
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Affiliation(s)
- Holger Klose
- Institute for Molecular Biotechnology (Biology VII), RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
| | - Markus Günl
- Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich, Leo-Brandt-Straße, Jülich, 52425, Germany
| | - Björn Usadel
- Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich, Leo-Brandt-Straße, Jülich, 52425, Germany
- Institute of Biology I, RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
| | - Rainer Fischer
- Institute for Molecular Biotechnology (Biology VII), RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Forckenbeckstrasse 6, Aachen, 52074, Germany
| | - Ulrich Commandeur
- Institute for Molecular Biotechnology (Biology VII), RWTH Aachen University, Worringerweg 1, Aachen, 52074, Germany
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