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Ahlawat YK, Biswal AK, Harun S, Harman-Ware AE, Doeppke C, Sharma N, Joshi CP, Hankoua BB. Heterologous expression of Arabidopsis laccase2, laccase4 and peroxidase52 driven under developing xylem specific promoter DX15 improves saccharification in populus. Biotechnol Biofuels Bioprod 2024; 17:5. [PMID: 38218877 PMCID: PMC10787383 DOI: 10.1186/s13068-023-02452-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/19/2023] [Indexed: 01/15/2024]
Abstract
BACKGROUND Secondary cell wall holds considerable potential as it has gained immense momentum to replace the lignocellulosic feedstock into fuels. Lignin one of the components of secondary cell wall tightly holds the polysaccharides thereby enhancing the recalcitrance and complexity in the biomass. Laccases (LAC) and peroxidases (PRX) are the major phenyl-oxidases playing key functions during the polymerization of monolignols into lignin. Yet, the functions of laccase and peroxidases gene families remained largely unknown. Hence, the objective of this conducted study is to understand the role of specific LAC and PRX in Populus wood formation and to further investigate how the altered Lac and Prx expression affects biomass recalcitrance and plant growth. This study of heterologous expression of Arabidopsis Lac and Prx genes was conducted in poplar to avoid any otherwise occurring co-suppression mechanism during the homologous overexpression of highly expressed native genes. In the pursuit of optimizing lignocellulosic biomass for biofuel production, the present study focuses on harnessing the enzymatic potential of Arabidopsis thaliana Laccase2, Laccase4, and Peroxidase52 through heterologous expression. RESULTS We overexpressed selected Arabidopsis laccase2 (AtLac2), laccase4 (AtLac4), and peroxidase52 (AtPrx52) genes, based on their high transcript expression respective to the differentiating xylem tissues in the stem, in hybrid poplar (cv. 717) expressed under the developing xylem tissue-specific promoter, DX15 characterized the transgenic populus for the investigation of growth phenotypes and recalcitrance efficiency. Bioinformatics analyses conducted on AtLac2 and AtLac4 and AtPrx52, revealed the evolutionary relationship between the laccase gene and peroxidase gene homologs, respectively. Transgenic poplar plant lines overexpressing the AtLac2 gene (AtLac2-OE) showed an increase in plant height without a change in biomass yield as compared to the controls; whereas, AtLac4-OE and AtPrx52-OE transgenic lines did not show any such observable growth phenotypes compared to their respective controls. The changes in the levels of lignin content and S/G ratios in the transgenic poplar resulted in a significant increase in the saccharification efficiency as compared to the control plants. CONCLUSIONS Overall, saccharification efficiency was increased by 35-50%, 21-42%, and 8-39% in AtLac2-OE, AtLac4-OE, and AtPrx52-OE transgenic poplar lines, respectively, as compared to their controls. Moreover, the bioengineered plants maintained normal growth and development, underscoring the feasibility of this approach for biomass improvement without compromising overall plant fitness. This study also sheds light on the potential of exploiting regulatory elements of DX15 to drive targeted expression of lignin-modifying enzymes, thereby providing a promising avenue for tailoring biomass for improved biofuel production. These findings contribute to the growing body of knowledge in synthetic biology and plant biotechnology, offering a sustainable solution to address the challenges associated with lignocellulosic biomass recalcitrance.
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Affiliation(s)
- Yogesh K Ahlawat
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA
| | - Ajaya K Biswal
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA30602, USA
| | - Sarahani Harun
- Centre for Bioinformatics Research, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, UKM Bangi, Selangor, Malaysia
| | - Anne E Harman-Ware
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Crissa Doeppke
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Nisha Sharma
- Microbiology Section, Department of Basic Science, Dr. Y.S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India
| | - Chandrashekhar P Joshi
- Department of Biological Sciences, Michigan Technological University, Houghton, MI, 49931, USA.
| | - Bertrand B Hankoua
- Human Ecology Department, College of Agriculture, Science, and Technology (CAST), Food Science and Biotechnology Program, 1200 N. DuPont Highway, Dover, DE, 19901, USA.
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Ligaba-Osena A, Guo W, Choi SC, Limmer MA, Seyfferth AL, Hankoua BB. Silicon Enhances Biomass and Grain Yield in an Ancient Crop Tef [ Eragrostis tef (Zucc.) Trotter]. Front Plant Sci 2020; 11:608503. [PMID: 33329679 PMCID: PMC7732538 DOI: 10.3389/fpls.2020.608503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
Silicon (Si) is one of the beneficial plant mineral nutrients which is known to improve biotic and abiotic stress resilience and productivity in several crops. However, its beneficial role in underutilized or "orphan" crop such as tef [Eragrostis tef (Zucc.) Trotter] has never been studied before. In this study, we investigated the effect of Si application on tef plant performance. Plants were grown in soil with or without exogenous application of Na2SiO3 (0, 1.0, 2.0, 3.0, 4.0, and 5.0 mM), and biomass and grain yield, mineral content, chlorophyll content, plant height, and expression patterns of putative Si transporter genes were studied. Silicon application significantly increased grain yield (100%) at 3.0 mM Si, and aboveground biomass yield by 45% at 5.0 mM Si, while it had no effect on plant height. The observed increase in grain yield appears to be due to enhanced stress resilience and increased total chlorophyll content. Increasing the level of Si increased shoot Si and Na content while it significantly decreased the content of other minerals including K, Ca, Mg, P, S, Fe, and Mn in the shoot, which is likely due to the use of Na containing Si amendment. A slight decrease in grain Ca, P, S, and Mn was also observed with increasing Si treatment. The increase in Si content with increasing Si levels prompted us to analyze the expression of Si transporter genes. The tef genome contains seven putative Si transporters which showed high homology with influx and efflux Lsi transporters reported in various plant species including rice. The tef Lsi homologs were deferentially expressed between tissues (roots, leaves, nodes, and inflorescences) and in response to Si, suggesting that they may play a role in Si uptake and/or translocation. Taken together, these results show that Si application improves stress resilience and yield and regulates the expression of putative Si transporter genes. However, further study is needed to determine the physiological function of the putative Si transporters, and to study the effect of field application of Si on tef productivity.
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Affiliation(s)
- Ayalew Ligaba-Osena
- Laboratory of Molecular Biology and Biotechnology, Department of Biology, The University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Wanli Guo
- Laboratory of Molecular Biology and Biotechnology, Department of Biology, The University of North Carolina at Greensboro, Greensboro, NC, United States
- Department of Biotechnology, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Sang Chul Choi
- Laboratory of Molecular Biology and Biotechnology, Department of Biology, The University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Matthew Alan Limmer
- Department of Plant and Soil Sciences, The University of Delaware, Newark, DE, United States
| | - Angelia L. Seyfferth
- Department of Plant and Soil Sciences, The University of Delaware, Newark, DE, United States
| | - Bertrand B. Hankoua
- Plant Biotechnology Lab, Department of Agriculture and Natural Resources, College of Agriculture, Sciences and Technology, Delaware State University, Dover, DE, United States
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Ligaba-Osena A, Jones J, Donkor E, Chandrayan S, Pole F, Wu CH, Vieille C, Adams MWW, Hankoua BB. Novel Bioengineered Cassava Expressing an Archaeal Starch Degradation System and a Bacterial ADP-Glucose Pyrophosphorylase for Starch Self-Digestibility and Yield Increase. Front Plant Sci 2018; 9:192. [PMID: 29541080 PMCID: PMC5836596 DOI: 10.3389/fpls.2018.00192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/01/2018] [Indexed: 11/06/2023]
Abstract
To address national and global low-carbon fuel targets, there is great interest in alternative plant species such as cassava (Manihot esculenta), which are high-yielding, resilient, and are easily converted to fuels using the existing technology. In this study the genes encoding hyperthermophilic archaeal starch-hydrolyzing enzymes, α-amylase and amylopullulanase from Pyrococcus furiosus and glucoamylase from Sulfolobus solfataricus, together with the gene encoding a modified ADP-glucose pyrophosphorylase (glgC) from Escherichia coli, were simultaneously expressed in cassava roots to enhance starch accumulation and its subsequent hydrolysis to sugar. A total of 13 multigene expressing transgenic lines were generated and characterized phenotypically and genotypically. Gene expression analysis using quantitative RT-PCR showed that the microbial genes are expressed in the transgenic roots. Multigene-expressing transgenic lines produced up to 60% more storage root yield than the non-transgenic control, likely due to glgC expression. Total protein extracted from the transgenic roots showed up to 10-fold higher starch-degrading activity in vitro than the protein extracted from the non-transgenic control. Interestingly, transgenic tubers released threefold more glucose than the non-transgenic control when incubated at 85°C for 21-h without exogenous application of thermostable enzymes, suggesting that the archaeal enzymes produced in planta maintain their activity and thermostability.
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Affiliation(s)
- Ayalew Ligaba-Osena
- College of Agriculture and Related Sciences, Delaware State University, Dover, DE, United States
| | - Jenna Jones
- College of Agriculture and Related Sciences, Delaware State University, Dover, DE, United States
| | - Emmanuel Donkor
- College of Agriculture and Related Sciences, Delaware State University, Dover, DE, United States
| | - Sanjeev Chandrayan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Farris Pole
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Chang-Hao Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Claire Vieille
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Michael W. W. Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Bertrand B. Hankoua
- College of Agriculture and Related Sciences, Delaware State University, Dover, DE, United States
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