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Lu H, Yuan G, Strauss SH, Tschaplinski TJ, Tuskan GA, Chen JG, Yang X. Reconfiguring Plant Metabolism for Biodegradable Plastic Production. BIODESIGN RESEARCH 2020; 2020:9078303. [PMID: 37849903 PMCID: PMC10530661 DOI: 10.34133/2020/9078303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/11/2020] [Indexed: 10/19/2023] Open
Abstract
For decades, plants have been the subject of genetic engineering to synthesize novel, value-added compounds. Polyhydroxyalkanoates (PHAs), a large class of biodegradable biopolymers naturally synthesized in eubacteria, are among the novel products that have been introduced to make use of plant acetyl-CoA metabolic pathways. It was hoped that renewable PHA production would help address environmental issues associated with the accumulation of nondegradable plastic wastes. However, after three decades of effort synthesizing PHAs, and in particular the simplest form polyhydroxybutyrate (PHB), and seeking to improve their production in plants, it has proven very difficult to reach a commercially profitable rate in a normally growing plant. This seems to be due to the growth defects associated with PHA production and accumulation in plant cells. Here, we review major breakthroughs that have been made in plant-based PHA synthesis using traditional genetic engineering approaches and discuss challenges that have been encountered. Then, from the point of view of plant synthetic biology, we provide perspectives on reprograming plant acetyl-CoA pathways for PHA production, with the goal of maximizing PHA yield while minimizing growth inhibition. Specifically, we suggest genetic elements that can be considered in genetic circuit design, approaches for nuclear genome and plastome modification, and the use of multiomics and mathematical modeling in understanding and restructuring plant metabolic pathways.
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Affiliation(s)
- Haiwei Lu
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Guoliang Yuan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Steven H. Strauss
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA
| | - Timothy J. Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Gerald A. Tuskan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jin-Gui Chen
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xiaohan Yang
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Gomes de Oliveira Dal'Molin C, Quek LE, Saa PA, Palfreyman R, Nielsen LK. From reconstruction to C 4 metabolic engineering: A case study for overproduction of polyhydroxybutyrate in bioenergy grasses. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 273:50-60. [PMID: 29907309 DOI: 10.1016/j.plantsci.2018.03.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 06/08/2023]
Abstract
The compartmentalization of C4 plants increases photosynthetic efficiency, while constraining how material and energy must flow in leaf tissues. To capture this metabolic phenomenon, a generic plant metabolic reconstruction was replicated into four connected spatiotemporal compartments, namely bundle sheath (B) and mesophyll (M) across the day and night cycle. The C4 leaf model was used to explore how amenable polyhydroxybutyrate (PHB) production is with these four compartments working cooperatively. A strategic pattern of metabolite conversion and exchange emerged from a systems-level network that has very few constraints imposed; mainly the sequential two-step carbon capture in mesophyll, then bundle sheath and photosynthesis during the day only. The building of starch reserves during the day and their mobilization during the night connects day and night metabolism. Flux simulations revealed that PHB production did not require rerouting of metabolic pathways beyond what is already utilised for growth. PHB yield was sensitive to photoassimilation capacity, availability of carbon reserves, ATP maintenance, relative photosynthetic activity of B and M, and type of metabolites exchanged in the plasmodesmata, but not sensitive towards compartmentalization. Hence, the compartmentalization issues currently encountered are likely to be kinetic or thermodynamic limitations rather than stoichiometric.
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Affiliation(s)
- Cristiana Gomes de Oliveira Dal'Molin
- Australian Institute for Bioengineering and Nanotechnology, School of Chemical Engineering, University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Lake-Ee Quek
- School of Mathematics and Statistics, The University of Sydney, New South Wales 2006, Australia
| | - Pedro A Saa
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Casilla 306, Correo 22, Chile; Mathomics, Center for Mathematical Modeling, Universidad de Chile, Santiago, Chile
| | - Robin Palfreyman
- Australian Institute for Bioengineering and Nanotechnology, School of Chemical Engineering, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Lars Keld Nielsen
- Australian Institute for Bioengineering and Nanotechnology, School of Chemical Engineering, University of Queensland, Brisbane, Queensland 4072, Australia; Novo Nordisk Foundation Center for Biosustainability, The Technical University of Denmark, Lyngby, DK-2800, Denmark
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Yao W, Ruan M, Qin L, Yang C, Chen R, Chen B, Zhang M. Field Performance of Transgenic Sugarcane Lines Resistant to Sugarcane Mosaic Virus. FRONTIERS IN PLANT SCIENCE 2017; 8:104. [PMID: 28228765 PMCID: PMC5296345 DOI: 10.3389/fpls.2017.00104] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 01/18/2017] [Indexed: 05/23/2023]
Abstract
Sugarcane mosaic disease is mainly caused by the sugarcane mosaic virus (SCMV), which can significantly reduce stalk yield and sucrose content of sugarcane in the field. Coat protein mediated protection (CPMP) is an effective strategy to improve virus resistance. A 2-year field study was conducted to compare five independent transgenic sugarcane lines carrying the SCMV-CP gene (i.e., B2, B36, B38, B48, and B51) with the wild-type parental clone Badila (WT). Agronomic performance, resistance to SCMV infection, and transgene stability were evaluated and compared with the wild-type parental clone Badila (WT) at four experimental locations in China across two successive seasons, i.e., plant cane (PC) and 1st ratoon cane (1R). All transgenic lines derived from Badila had significantly greater tons of cane per hectare (TCH) and tons of sucrose per hectare (TSH) as well as lower SCMV disease incidence than those from Badila in the PC and 1R crops. The transgenic line B48 was highly resistant to SCMV with less than 3% incidence of infection. The recovery phenotype of transgenic line B36 was infected soon after virus inoculation, but the subsequent leaves showed no symptoms of infection. Most control plants developed symptoms that persisted and spread throughout the plant with more than 50% incidence. B48 recorded an average of 102.72 t/ha, which was 67.2% more than that for Badila. The expression of the transgene was stable over many generations with vegetative propagation. These results show that SCMV-resistant transgenic lines derived from Badila can provide resistant germplasm for sugarcane breeding and can also be used to study virus resistance mechanisms. This is the first report on the development and field performance of transgenic sugarcane plants that are resistant to SCMV infection in China.
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Affiliation(s)
- Wei Yao
- State Key Laboratory of Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi UniversityNanning, China
- Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Miaohong Ruan
- Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Lifang Qin
- State Key Laboratory of Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi UniversityNanning, China
| | - Chuanyu Yang
- State Key Laboratory of Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi UniversityNanning, China
| | - Rukai Chen
- Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Baoshan Chen
- State Key Laboratory of Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi UniversityNanning, China
| | - Muqing Zhang
- State Key Laboratory of Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi UniversityNanning, China
- Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry UniversityFuzhou, China
- IRREC-IFAS, University of FloridaFort Pierce, FL, USA
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Biological System as Reactor for the Production of Biodegradable Thermoplastics, Polyhydroxyalkanoates. Ind Biotechnol (New Rochelle N Y) 2016. [DOI: 10.1201/b19347-12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] Open
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Abstract
This review is a short synopsis of some of the latest breakthroughs in the areas of lignocellulosic conversion to fuels and utilization of oils for biodiesel. Although four lignocellulosic ethanol factories have opened in the USA and hundreds of biodiesel installations are active worldwide, technological improvements are being discovered that will rapidly evolve the biofuels industry into a new paradigm. These discoveries involve the feedstocks as well as the technologies to process them.
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Affiliation(s)
- Elizabeth E Hood
- College of Agriculture and Technology, Arkansas State University, Arkanas, AR, USA
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McQualter RB, Bellasio C, Gebbie LK, Petrasovits LA, Palfreyman RW, Hodson MP, Plan MR, Blackman DM, Brumbley SM, Nielsen LK. Systems biology and metabolic modelling unveils limitations to polyhydroxybutyrate accumulation in sugarcane leaves; lessons for C4 engineering. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:567-580. [PMID: 26015295 DOI: 10.1111/pbi.12399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/07/2015] [Accepted: 04/16/2015] [Indexed: 05/28/2023]
Abstract
In planta production of the bioplastic polyhydroxybutyrate (PHB) is one important way in which plant biotechnology can address environmental problems and emerging issues related to peak oil. However, high biomass C4 plants such as maize, switch grass and sugarcane develop adverse phenotypes including stunting, chlorosis and reduced biomass as PHB levels in leaves increase. In this study, we explore limitations to PHB accumulation in sugarcane chloroplasts using a systems biology approach, coupled with a metabolic model of C4 photosynthesis. Decreased assimilation was evident in high PHB-producing sugarcane plants, which also showed a dramatic decrease in sucrose and starch content of leaves. A subtle decrease in the C/N ratio was found which was not associated with a decrease in total protein content. An increase in amino acids used for nitrogen recapture was also observed. Based on the accumulation of substrates of ATP-dependent reactions, we hypothesized ATP starvation in bundle sheath chloroplasts. This was supported by mRNA differential expression patterns. The disruption in ATP supply in bundle sheath cells appears to be linked to the physical presence of the PHB polymer which may disrupt photosynthesis by scattering photosynthetically active radiation and/or physically disrupting thylakoid membranes.
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Affiliation(s)
- Richard B McQualter
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Chandra Bellasio
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, UK
| | - Leigh K Gebbie
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Lars A Petrasovits
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Robin W Palfreyman
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Mark P Hodson
- Metabolomics Australia Queensland Node, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Manuel R Plan
- Metabolomics Australia Queensland Node, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Deborah M Blackman
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Stevens M Brumbley
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
| | - Lars K Nielsen
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia
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McQualter RB, Petrasovits LA, Gebbie LK, Schweitzer D, Blackman DM, Chrysanthopoulos P, Hodson MP, Plan MR, Riches JD, Snell KD, Brumbley SM, Nielsen LK. The use of an acetoacetyl-CoA synthase in place of a β-ketothiolase enhances poly-3-hydroxybutyrate production in sugarcane mesophyll cells. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:700-707. [PMID: 25532451 DOI: 10.1111/pbi.12298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 10/10/2014] [Accepted: 10/21/2014] [Indexed: 06/04/2023]
Abstract
Engineering the production of polyhydroxyalkanoates (PHAs) into high biomass bioenergy crops has the potential to provide a sustainable supply of bioplastics and energy from a single plant feedstock. One of the major challenges in engineering C4 plants for the production of poly[(R)-3-hydroxybutyrate] (PHB) is the significantly lower level of polymer produced in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells, thereby limiting the full PHB yield-potential of the plant. In this study, we provide evidence that the access to substrate for PHB synthesis may limit polymer production in M chloroplasts. Production of PHB in M cells of sugarcane is significantly increased by replacing β-ketothiolase, the first enzyme in the bacterial PHA pathway, with acetoacetyl-CoA synthase. This novel pathway enabled the production of PHB reaching an average of 6.3% of the dry weight of total leaf biomass, with levels ranging from 3.6 to 11.8% of the dry weight (DW) of individual leaves. These yields are more than twice the level reported in PHB-producing sugarcane containing the β-ketothiolase and illustrate the importance of producing polymer in mesophyll plastids to maximize yield. The molecular weight of the polymer produced was greater than 2 × 10(6) Da. These results are a major step forward in engineering a high biomass C4 grass for the commercial production of PHB.
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Affiliation(s)
- Richard B McQualter
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | - Lars A Petrasovits
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | - Leigh K Gebbie
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | | | - Deborah M Blackman
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | - Panagiotis Chrysanthopoulos
- Metabolomics Australia Queensland Node, Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | - Mark P Hodson
- Central Analytical Research Facility, Queensland University of Technology, Brisbane, Qld, Australia
| | - Manuel R Plan
- Central Analytical Research Facility, Queensland University of Technology, Brisbane, Qld, Australia
| | - James D Riches
- Metabolomics Australia Queensland Node, Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | | | - Stevens M Brumbley
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
| | - Lars K Nielsen
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane, Qld, Australia
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Snell KD, Singh V, Brumbley SM. Production of novel biopolymers in plants: recent technological advances and future prospects. Curr Opin Biotechnol 2015; 32:68-75. [DOI: 10.1016/j.copbio.2014.11.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 11/06/2014] [Indexed: 12/27/2022]
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Tilbrook K, Poirier Y, Gebbie L, Schenk PM, McQualter RB, Brumbley SM. Reduced peroxisomal citrate synthase activity increases substrate availability for polyhydroxyalkanoate biosynthesis in plant peroxisomes. PLANT BIOTECHNOLOGY JOURNAL 2014; 12:1044-1052. [PMID: 24944109 DOI: 10.1111/pbi.12211] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/25/2014] [Accepted: 05/01/2014] [Indexed: 06/03/2023]
Abstract
Polyhydroxyalkanoates (PHAs) are bacterial carbon storage polymers used as renewable, biodegradable plastics. PHA production in plants may be a way to reduce industrial PHA production costs. We recently demonstrated a promising level of peroxisomal PHA production in the high biomass crop species sugarcane. However, further production strategies are needed to boost PHA accumulation closer to commercial targets. Through exogenous fatty acid feeding of Arabidopsis thaliana plants that contain peroxisome-targeted PhaA, PhaB and PhaC enzymes from Cupriavidus necator, we show here that the availability of substrates derived from the β-oxidation cycle limits peroxisomal polyhydroxybutyrate (PHB) biosynthesis. Knockdown of peroxisomal citrate synthase activity using artificial microRNA increased PHB production levels approximately threefold. This work demonstrates that reduction of peroxisomal citrate synthase activity may be a valid metabolic engineering strategy for increasing PHA production in other plant species.
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Affiliation(s)
- Kimberley Tilbrook
- School of Biological Science, The University of Queensland, Brisbane, Qld, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Qld, Australia; The Cooperative Research Centre for Sugar Industry Innovation through Biotechnology, The University of Queensland, Brisbane, Qld, Australia
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McQualter RB, Somleva MN, Gebbie LK, Li X, Petrasovits LA, Snell KD, Nielsen LK, Brumbley SM. Factors affecting polyhydroxybutyrate accumulation in mesophyll cells of sugarcane and switchgrass. BMC Biotechnol 2014; 14:83. [PMID: 25209261 PMCID: PMC4165624 DOI: 10.1186/1472-6750-14-83] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/29/2014] [Indexed: 12/04/2022] Open
Abstract
Background Polyhydroxyalkanoates are linear biodegradable polyesters produced by bacteria as a carbon store and used to produce a range of bioplastics. Widespread polyhydroxyalkanoate production in C4 crops would decrease petroleum dependency by producing a renewable supply of biodegradable plastics along with residual biomass that could be converted into biofuels or energy. Increasing yields to commercial levels in biomass crops however remains a challenge. Previously, lower accumulation levels of the short side chain polyhydroxyalkanoate, polyhydroxybutyrate (PHB), were observed in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells in transgenic maize (Zea mays), sugarcane (Saccharum sp.), and switchgrass (Panicum virgatum L.) leading to a significant decrease in the theoretical yield potential. Here we explore various factors which might affect polymer accumulation in mesophyll cells, including targeting of the PHB pathway enzymes to the mesophyll plastid and their access to substrate. Results The small subunit of Rubisco from pea effectively targeted the PHB biosynthesis enzymes to both M and BS chloroplasts of sugarcane and switchgrass. PHB enzyme activity was retained following targeting to M plastids and was equivalent to that found in the BS plastids. Leaf total fatty acid content was not affected by PHB production. However, when fatty acid synthesis was chemically inhibited, polymer accumulated in M cells. Conclusions In this study, we provide evidence that access to substrate and neither poor targeting nor insufficient activity of the PHB biosynthetic enzymes may be the limiting factor for polymer production in mesophyll chloroplasts of C4 plants.
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Affiliation(s)
| | | | | | | | | | | | | | - Stevens M Brumbley
- Australian Institute for Bioengineering and Nanotechnology, the University of Queensland, Brisbane QLD 4072, Australia.
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