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Kumar V, Lakkaboyana SK, Tsouko E, Maina S, Pandey M, Umesh M, Singhal B, Sharma N, Awasthi MK, Andler R, Jayaraj I, Yuzir A. Commercialization potential of agro-based polyhydroxyalkanoates biorefinery: A technical perspective on advances and critical barriers. Int J Biol Macromol 2023; 234:123733. [PMID: 36801274 DOI: 10.1016/j.ijbiomac.2023.123733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/12/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
The exponential increase in the use and careless discard of synthetic plastics has created an alarming concern over the environmental health due to the detrimental effects of petroleum based synthetic polymeric compounds. Piling up of these plastic commodities on various ecological niches and entry of their fragmented parts into soil and water has clearly affected the quality of these ecosystems in the past few decades. Among the many constructive strategies developed to tackle this global issue, use of biopolymers like polyhydroxyalkanoates as sustainable alternatives for synthetic plastics has gained momentum. Despite their excellent material properties and significant biodegradability, polyhydroxyalkanoates still fails to compete with their synthetic counterparts majorly due to the high cost associated with their production and purification thereby limiting their commercialization. Usage of renewable feedstocks as substrates for polyhydroxyalkanoates production has been the thrust area of research to attain the sustainability tag. This review work attempts to provide insights about the recent developments in the production of polyhydroxyalkanoates using renewable feedstock along with various pretreatment methods used for substrate preparation for polyhydroxyalkanoates production. Further, the application of blends based on polyhydroxyalkanoates, and the challenges associated with the waste valorization based polyhydroxyalkanoates production strategy is elaborated in this review work.
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Affiliation(s)
- Vinay Kumar
- Ecotoxicity and Bioconversion Laboratory, Department of Community Medicine, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, Thandalam 602105, India; Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India.
| | - Sivarama Krishna Lakkaboyana
- Department of Chemistry, Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology, Avadi, Chennai 600062, India; Department of Chemical and Environmental Engineering (ChEE), Malaysia-Japan International Institute of Technology (MJIIT)-Universiti Technologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Erminta Tsouko
- Department of Food Science and Nutrition, School of Environment, University of the Aegean, Metropolite Ioakeim 2, 81400, Myrina, Lemnos, Greece
| | - Sofia Maina
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece
| | - Muskan Pandey
- School of Biotechnology, Gautam Buddha University, Greater Noida, U.P., India
| | - Mridul Umesh
- Department of Life Sciences, CHRIST (Deemed to be University), Hosur Road, Bengaluru 560029, Karnataka, India
| | - Barkha Singhal
- School of Biotechnology, Gautam Buddha University, Greater Noida, U.P., India
| | - Neha Sharma
- Metagenomics and Bioprocess Design Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, PR China
| | - Rodrigo Andler
- Escuela de Ingeniería en Biotecnología, Centro de Biotecnología de los Recursos Naturales (Cenbio), Universidad Católica del Maule, Chile
| | - Iyyappan Jayaraj
- Department of Bioengineering, Institute of Biotechnology, Saveetha School of Engineering, SIMATS, Chennai 602105, India
| | - Ali Yuzir
- Department of Chemical and Environmental Engineering (ChEE), Malaysia-Japan International Institute of Technology (MJIIT)-Universiti Technologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
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Prías-Blanco M, Chappell TM, Freed EF, Illa-Berenguer E, Eckert CA, Parrott WA. An Agrobacterium strain auxotrophic for methionine is useful for switchgrass transformation. Transgenic Res 2022; 31:661-676. [PMID: 36239844 PMCID: PMC9747830 DOI: 10.1007/s11248-022-00328-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 09/26/2022] [Indexed: 01/20/2023]
Abstract
Auxotrophic strains of Agrobacterium tumefaciens can contribute to the development of more efficient transformation systems, especially for crops historically considered recalcitrant. Homologous recombination was used to derive methionine auxotrophs of two common A. tumefaciens strains, LBA4404 and EHA105. The EHA105 strains were more efficient for switchgrass transformation, while both the EHA105 and LBA4404 strains worked equally well for the rice control. Event quality, as measured by transgene copy number, was not affected by auxotrophy, but was higher for the LBA4404 strains than the EHA105 strains. Ultimately, the use of auxotrophs reduced bacterial overgrowth during co-cultivation and decreased the need for antibiotics.
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Affiliation(s)
- Mónica Prías-Blanco
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA
| | - Timothy M Chappell
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA
| | - Emily F Freed
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, CO, USA
| | | | - Carrie A Eckert
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, CO, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Wayne A Parrott
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA.
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA.
- Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA.
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Clifton‐Brown J, Harfouche A, Casler MD, Dylan Jones H, Macalpine WJ, Murphy‐Bokern D, Smart LB, Adler A, Ashman C, Awty‐Carroll D, Bastien C, Bopper S, Botnari V, Brancourt‐Hulmel M, Chen Z, Clark LV, Cosentino S, Dalton S, Davey C, Dolstra O, Donnison I, Flavell R, Greef J, Hanley S, Hastings A, Hertzberg M, Hsu T, Huang LS, Iurato A, Jensen E, Jin X, Jørgensen U, Kiesel A, Kim D, Liu J, McCalmont JP, McMahon BG, Mos M, Robson P, Sacks EJ, Sandu A, Scalici G, Schwarz K, Scordia D, Shafiei R, Shield I, Slavov G, Stanton BJ, Swaminathan K, Taylor G, Torres AF, Trindade LM, Tschaplinski T, Tuskan GA, Yamada T, Yeon Yu C, Zalesny RS, Zong J, Lewandowski I. Breeding progress and preparedness for mass-scale deployment of perennial lignocellulosic biomass crops switchgrass, miscanthus, willow and poplar. GLOBAL CHANGE BIOLOGY. BIOENERGY 2019; 11:118-151. [PMID: 30854028 PMCID: PMC6392185 DOI: 10.1111/gcbb.12566] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/18/2018] [Indexed: 05/07/2023]
Abstract
Genetic improvement through breeding is one of the key approaches to increasing biomass supply. This paper documents the breeding progress to date for four perennial biomass crops (PBCs) that have high output-input energy ratios: namely Panicum virgatum (switchgrass), species of the genera Miscanthus (miscanthus), Salix (willow) and Populus (poplar). For each crop, we report on the size of germplasm collections, the efforts to date to phenotype and genotype, the diversity available for breeding and on the scale of breeding work as indicated by number of attempted crosses. We also report on the development of faster and more precise breeding using molecular breeding techniques. Poplar is the model tree for genetic studies and is furthest ahead in terms of biological knowledge and genetic resources. Linkage maps, transgenesis and genome editing methods are now being used in commercially focused poplar breeding. These are in development in switchgrass, miscanthus and willow generating large genetic and phenotypic data sets requiring concomitant efforts in informatics to create summaries that can be accessed and used by practical breeders. Cultivars of switchgrass and miscanthus can be seed-based synthetic populations, semihybrids or clones. Willow and poplar cultivars are commercially deployed as clones. At local and regional level, the most advanced cultivars in each crop are at technology readiness levels which could be scaled to planting rates of thousands of hectares per year in about 5 years with existing commercial developers. Investment in further development of better cultivars is subject to current market failure and the long breeding cycles. We conclude that sustained public investment in breeding plays a key role in delivering future mass-scale deployment of PBCs.
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Affiliation(s)
- John Clifton‐Brown
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Antoine Harfouche
- Department for Innovation in Biological, Agrofood and Forest systemsUniversity of TusciaViterboItaly
| | | | - Huw Dylan Jones
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | | | | | - Lawrence B. Smart
- Horticulture Section, School of Integrative Plant ScienceCornell UniversityGenevaNew York
| | - Anneli Adler
- SweTree Technologies ABUmeåSweden
- Institute of Crop Production EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Chris Ashman
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Danny Awty‐Carroll
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | | | - Sebastian Bopper
- Department of Seed Science and Technology, Institute of Plant Breeding, Seed Science and Population GeneticsUniversity of HohenheimStuttgartGermany
| | - Vasile Botnari
- Institute of Genetics, Physiology and Plant Protection (IGFPP) of Academy of Sciences of MoldovaChisinauMoldova
| | | | - Zhiyong Chen
- Insitute of MiscanthusHunan Agricultural UniversityHunan ChangshaChina
| | - Lindsay V. Clark
- Department of Crop Sciences & Center for Advanced Bioenergy and Bioproducts Innovation, 279 Edward R Madigan LaboratoryUniversity of IllinoisUrbanaIllinois
| | - Salvatore Cosentino
- Dipartimento di Agricoltura Alimentazione e AmbienteUniversità degli Studi di CataniaCataniaItaly
| | - Sue Dalton
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Chris Davey
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Oene Dolstra
- Plant BreedingWageningen University & ResearchWageningenThe Netherlands
| | - Iain Donnison
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | | | - Joerg Greef
- Julius Kuhn‐Institut (JKI)Bundesforschungsinstitut fur KulturpflanzenBraunschweigGermany
| | | | - Astley Hastings
- Institute of Biological and Environmental ScienceUniversity of AberdeenAberdeenUK
| | | | - Tsai‐Wen Hsu
- Taiwan Endemic Species Research Institute (TESRI)Nantou CountyTaiwan
| | - Lin S. Huang
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Antonella Iurato
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Elaine Jensen
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Xiaoli Jin
- Department of Agronomy & The Key Laboratory of Crop Germplasm Resource of Zhejiang ProvinceZhejiang UniversityHangzhouChina
| | - Uffe Jørgensen
- Department of AgroecologyAarhus University Centre for Circular BioeconomyTjeleDenmark
| | - Andreas Kiesel
- Department of Biobased Products and Energy Crops, Institute of Crop ScienceUniversity of HohenheimStuttgartGermany
| | - Do‐Soon Kim
- Department of Plant Sciences, Research Institute of Agriculture & Life Sciences, CALSSeoul National UniversitySeoulKorea
| | - Jianxiu Liu
- Institute of BotanyJiangsu Province and Chinese Academy of SciencesNanjingChina
| | - Jon P. McCalmont
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Bernard G. McMahon
- Natural Resources Research InstituteUniversity of Minnesota – DuluthDuluthMinnesota
| | | | - Paul Robson
- Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityAberystwythUK
| | - Erik J. Sacks
- Department of Crop Sciences & Center for Advanced Bioenergy and Bioproducts Innovation, 279 Edward R Madigan LaboratoryUniversity of IllinoisUrbanaIllinois
| | - Anatolii Sandu
- Institute of Genetics, Physiology and Plant Protection (IGFPP) of Academy of Sciences of MoldovaChisinauMoldova
| | - Giovanni Scalici
- Dipartimento di Agricoltura Alimentazione e AmbienteUniversità degli Studi di CataniaCataniaItaly
| | - Kai Schwarz
- Julius Kuhn‐Institut (JKI)Bundesforschungsinstitut fur KulturpflanzenBraunschweigGermany
| | - Danilo Scordia
- Dipartimento di Agricoltura Alimentazione e AmbienteUniversità degli Studi di CataniaCataniaItaly
| | - Reza Shafiei
- James Hutton InstituteUniversity of DundeeDundeeUK
| | | | | | | | | | - Gail Taylor
- Biological SciencesUniversity of SouthamptonSouthamptonUK
| | - Andres F. Torres
- Plant BreedingWageningen University & ResearchWageningenThe Netherlands
| | - Luisa M. Trindade
- Plant BreedingWageningen University & ResearchWageningenThe Netherlands
| | - Timothy Tschaplinski
- The Center for Bioenergy InnovationOak Ridge National LaboratoryOak RidgeTennessee
| | - Gerald A. Tuskan
- The Center for Bioenergy InnovationOak Ridge National LaboratoryOak RidgeTennessee
| | - Toshihiko Yamada
- Field Science Centre for the Northern BiosphereHokkaido UniversitySapporoJapan
| | - Chang Yeon Yu
- College of Agriculture and Life Sciences 2Kangwon National UniversityChuncheonSouth Korea
| | | | - Junqin Zong
- Institute of BotanyJiangsu Province and Chinese Academy of SciencesNanjingChina
| | - Iris Lewandowski
- Department of Biobased Products and Energy Crops, Institute of Crop ScienceUniversity of HohenheimStuttgartGermany
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High-Efficiency Somatic Embryogenesis from Seedlings of Koelreuteria paniculata Laxm. FORESTS 2018. [DOI: 10.3390/f9120769] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Research Highlights: In the current study, we established a method for plant regeneration via somatic embryogenesis (SE) in Koelreuteria paniculata Laxm. for the first time. Background and Objectives: K. paniculata is an important ornamental and medicinal plant in China. However, the plant has difficulty with asexual reproduction, which imposes a limitation on large-scale propagation. Materials and Methods: Embryogenic calluses were induced from stems of aseptic seedlings on induction media. The effects of different media types and concentrations of N6-benzyladenine (BA), α-naphthaleneacetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D) on callus induction were examined. Embryogenic calluses were then transferred to Driver-Kuniyuki Walnut (DKW) media containing NAA (0.1–0.2 mg L−1) or 2,4-D (0.5–2.0 mg L−1) to develop somatic embryos. Cotyledon embryos were cultured on DKW media containing NAA (0.1–0.2 mg L−1) until maturation, and were then transferred to 1/2 DKW medium supplemented with 1.0 mg L−1 indole-3-butyric acid (IBA) to produce complete plants. The effects of IBA and NAA on rhizogenesis were then examined by clonal culture. Results: The maximum callus induction frequency (80.25%) was obtained on DKW medium supplemented by 0.5 mg L−1 BA, 0.25 mg L−1 NAA, and 1.5 mg L−1 2,4-D. NAA had a more pronounced effect on somatic embryo growth than did 2,4-D, with a maximum SE frequency (54.75%) observed with 0.1 mg L−1 NAA added to DKW medium. For clonal culture, the highest rooting rate (52%) was observed on 1/4 DKW medium containing 1.5 mg L−1 IBA. Histology studies confirmed the presence of embryogenic calluses and somatic embryos in different stages. Conclusions: This protocol provides a novel method for large-scale propagation of K. paniculata, and creates opportunities for genetic engineering in this species.
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Liu W, Mazarei M, Ye R, Peng Y, Shao Y, Baxter HL, Sykes RW, Turner GB, Davis MF, Wang ZY, Dixon RA, Stewart CN. Switchgrass ( Panicum virgatum L.) promoters for green tissue-specific expression of the MYB4 transcription factor for reduced-recalcitrance transgenic switchgrass. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:122. [PMID: 29713381 PMCID: PMC5914048 DOI: 10.1186/s13068-018-1119-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 04/16/2018] [Indexed: 05/09/2023]
Abstract
BACKGROUND Genetic engineering of switchgrass (Panicum virgatum L.) for reduced cell wall recalcitrance and improved biofuel production has been a long pursued goal. Up to now, constitutive promoters have been used to direct the expression of cell wall biosynthesis genes toward attaining that goal. While generally sufficient to gauge a transgene's effects in the heterologous host, constitutive overexpression often leads to undesirable plant phenotypic effects. Green tissue-specific promoters from switchgrass are potentially valuable to directly alter cell wall traits exclusively in harvestable aboveground biomass while not changing root phenotypes. RESULTS We identified and functionally characterized three switchgrass green tissue-specific promoters and assessed marker gene expression patterns and intensity in stably transformed rice (Oryza sativa L.), and then used them to direct the expression of the switchgrass MYB4 (PvMYB4) transcription factor gene in transgenic switchgrass to endow reduced recalcitrance in aboveground biomass. These promoters correspond to photosynthesis-related light-harvesting complex II chlorophyll-a/b binding gene (PvLhcb), phosphoenolpyruvate carboxylase (PvPEPC), and the photosystem II 10 kDa R subunit (PvPsbR). Real-time RT-PCR analysis detected their strong expression in the aboveground tissues including leaf blades, leaf sheaths, internodes, inflorescences, and nodes of switchgrass, which was tightly up-regulated by light. Stable transgenic rice expressing the GUS reporter under the control of each promoter (756-2005 bp in length) further confirmed their strong expression patterns in leaves and stems. With the exception of the serial promoter deletions of PvLhcb, all GUS marker patterns under the control of each 5'-end serial promoter deletion were not different from that conveyed by their respective promoters. All of the shortest promoter fragments (199-275 bp in length) conveyed strong green tissue-specific GUS expression in transgenic rice. PvMYB4 is a master repressor of lignin biosynthesis. The green tissue-specific expression of PvMYB4 via each promoter in transgenic switchgrass led to significant gains in saccharification efficiency, decreased lignin, and decreased S/G lignin ratios. In contrast to constitutive overexpression of PvMYB4, which negatively impacts switchgrass root growth, plant growth was not compromised in green tissue-expressed PvMYB4 switchgrass plants in the current study. CONCLUSIONS Each of the newly described green tissue-specific promoters from switchgrass has utility to change cell wall biosynthesis exclusively in aboveground harvestable biomass without altering root systems. The truncated green tissue promoters are very short and should be useful for targeted expression in a number of monocots to improve shoot traits while restricting gene expression from roots. Green tissue-specific expression of PvMYB4 is an effective strategy for improvement of transgenic feedstocks.
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Affiliation(s)
- Wusheng Liu
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- Department of Horticultural Science, North Carolina State University, Raleigh, NC USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Rongjian Ye
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
| | - Yanhui Peng
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
| | - Yuanhua Shao
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
| | - Holly L. Baxter
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Robert W. Sykes
- National Renewable Energy Laboratory, Golden, CO USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Geoffrey B. Turner
- National Renewable Energy Laboratory, Golden, CO USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Mark F. Davis
- National Renewable Energy Laboratory, Golden, CO USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Zeng-Yu Wang
- Noble Research Institute, Ardmore, OK USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - Richard A. Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, TX USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, TN USA
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Xu W, Liu W, Ye R, Mazarei M, Huang D, Zhang X, Stewart CN. A profilin gene promoter from switchgrass (Panicum virgatum L.) directs strong and specific transgene expression to vascular bundles in rice. PLANT CELL REPORTS 2018; 37:587-597. [PMID: 29340787 DOI: 10.1007/s00299-018-2253-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/05/2018] [Indexed: 05/25/2023]
Abstract
A switchgrass vascular tissue-specific promoter (PvPfn2) and its 5'-end serial deletions drive high levels of vascular bundle transgene expression in transgenic rice. Constitutive promoters are widely used for crop genetic engineering, which can result in multiple off-target effects, including suboptimal growth and epigenetic gene silencing. These problems can be potentially avoided using tissue-specific promoters for targeted transgene expression. One particularly urgent need for targeted cell wall modification in bioenergy crops, such as switchgrass (Panicum virgatum L.), is the development of vasculature-active promoters to express cell wall-affective genes only in the specific tissues, i.e., xylem and phloem. From a switchgrass expression atlas we identified promoter sequence upstream of a vasculature-specific switchgrass profilin gene (PvPfn2), especially in roots, nodes and inflorescences. When the putative full-length (1715 bp) and 5'-end serial deletions of the PvPfn2 promoter (shortest was 413 bp) were used to drive the GUS reporter expression in stably transformed rice (Oryza sativa L.), strong vasculature-specificity was observed in various tissues including leaves, leaf sheaths, stems, and flowers. The promoters were active in both phloem and xylem. It is interesting to note that the promoter was active in many more tissues in the heterologous rice system than in switchgrass. Surprisingly, all four 5'-end promoter deletions, including the shortest fragment, had the same expression patterns as the full-length promoter and with no attenuation in GUS expression in rice. These results indicated that the PvPfn2 promoter variants are new tools to direct transgene expression specifically to vascular tissues in monocots. Of special interest is the very compact version of the promoter, which could be of use for vasculature-specific genetic engineering in monocots.
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Affiliation(s)
- Wenzhi Xu
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
- Department of Grassland Science, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Wusheng Liu
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
- Department of Horticultural Science, North Carolina State University, Raleigh, NC, USA
| | - Rongjian Ye
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Debao Huang
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA
| | - Xinquan Zhang
- Department of Grassland Science, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, USA.
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Lin CY, Donohoe BS, Ahuja N, Garrity DM, Qu R, Tucker MP, Himmel ME, Wei H. Evaluation of parameters affecting switchgrass tissue culture: toward a consolidated procedure for Agrobacterium-mediated transformation of switchgrass ( Panicum virgatum). PLANT METHODS 2017; 13:113. [PMID: 29270209 PMCID: PMC5735814 DOI: 10.1186/s13007-017-0263-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/06/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Switchgrass (Panicum virgatum), a robust perennial C4-type grass, has been evaluated and designated as a model bioenergy crop by the U.S. DOE and USDA. Conventional breeding of switchgrass biomass is difficult because it displays self-incompatible hindrance. Therefore, direct genetic modifications of switchgrass have been considered the more effective approach to tailor switchgrass with traits of interest. Successful transformations have demonstrated increased biomass yields, reduction in the recalcitrance of cell walls and enhanced saccharification efficiency. Several tissue culture protocols have been previously described to produce transgenic switchgrass lines using different nutrient-based media, co-cultivation approaches, and antibiotic strengths for selection. RESULTS After evaluating the published protocols, we consolidated these approaches and optimized the process to develop a more efficient protocol for producing transgenic switchgrass. First, seed sterilization was optimized, which led to a 20% increase in yield of induced calluses. Second, we have selected a N6 macronutrient/B5 micronutrient (NB)-based medium for callus induction from mature seeds of the Alamo cultivar, and chose a Murashige and Skoog-based medium to regenerate both Type I and Type II calluses. Third, Agrobacterium-mediated transformation was adopted that resulted in 50-100% positive regenerated transformants after three rounds (2 weeks/round) of selection with antibiotic. Genomic DNA PCR, RT-PCR, Southern blot, visualization of the red fluorescent protein and histochemical β-glucuronidase (GUS) staining were conducted to confirm the positive switchgrass transformants. The optimized methods developed here provide an improved strategy to promote the production and selection of callus and generation of transgenic switchgrass lines. CONCLUSION The process for switchgrass transformation has been evaluated and consolidated to devise an improved approach for transgenic switchgrass production. With the optimization of seed sterilization, callus induction, and regeneration steps, a reliable and effective protocol is established to facilitate switchgrass engineering.
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Affiliation(s)
- Chien-Yuan Lin
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Neha Ahuja
- Department of Biology, Colorado State University, Fort Collins, CO 80523 USA
| | - Deborah M. Garrity
- Department of Biology, Colorado State University, Fort Collins, CO 80523 USA
| | - Rongda Qu
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695-7287 USA
| | - Melvin P. Tucker
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
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Burris KP, Dlugosz EM, Collins AG, Stewart CN, Lenaghan SC. Development of a rapid, low-cost protoplast transfection system for switchgrass (Panicum virgatum L.). PLANT CELL REPORTS 2016; 35:693-704. [PMID: 26685665 PMCID: PMC4757626 DOI: 10.1007/s00299-015-1913-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/19/2015] [Accepted: 11/26/2015] [Indexed: 05/03/2023]
Abstract
A switchgrass protoplast system was developed, achieving a cost reduction of ~1000-fold, a threefold increase in transformation efficiency, and a fourfold reduction in required DNA quantity compared to previous methods. In recent years, there has been a resurgence in the use of protoplast systems for rapid screening of gene silencing and genome-editing targets for siRNA, miRNA, and CRISPR technologies. In the case of switchgrass (Panicum virgatum L.), to achieve economic feasibility for biofuel production, it is necessary to develop plants with decreased cell wall recalcitrance to reduce processing costs. To achieve this goal, transgenic plants have been generated with altered cell wall chemistry; however, with limited success owing to the complexity of cell walls. Because of the considerable cost, time, and effort required to screen transgenic plants, a protoplast system that can provide data at an early stage has potential to eliminate low performing candidate genes/targets prior to the creation of transgenic plants. Despite the advantages of protoplast systems, protoplast isolation in switchgrass has proven costly, requiring expensive lab-grade enzymes and high DNA quantities. In this paper, we describe a low-cost protoplast isolation system using a mesophyll culture approach and a cell suspension culture. Results from this work show a cost reduction of ~1000-fold compared to previous methods of protoplast isolation in switchgrass, with a cost of $0.003 (USD) per reaction for mesophyll protoplasts and $0.018 for axenic cell culture-derived protoplasts. Further, the efficiency of protoplast transformation was optimized threefold over previous methods, despite a fourfold reduction in DNA quantity. The methods developed in this work remove the cost barrier previously limiting high-throughput screening of genome-editing and gene silencing targets in switchgrass, paving the way for more efficient development of transgenic plants.
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Affiliation(s)
- Kellie P Burris
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Elizabeth M Dlugosz
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - A Grace Collins
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - C Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Scott C Lenaghan
- Center for Renewable Carbon, University of Tennessee, Knoxville, TN, 37996, USA.
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
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