1
|
Einhaus A, Baier T, Kruse O. Molecular design of microalgae as sustainable cell factories. Trends Biotechnol 2024; 42:728-738. [PMID: 38092627 DOI: 10.1016/j.tibtech.2023.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 06/09/2024]
Abstract
Microalgae are regarded as sustainable and potent chassis for biotechnology. Their capacity for efficient photosynthesis fuels dynamic growth independent from organic carbon sources and converts atmospheric CO2 directly into various valuable hydrocarbon-based metabolites. However, approaches to gene expression and metabolic regulation have been inferior to those in more established heterotrophs (e.g., prokaryotes or yeast) since the genetic tools and insights in expression regulation have been distinctly less advanced. In recent years, however, these tools and their efficiency have dramatically improved. Various examples have demonstrated new trends in microalgal biotechnology and the potential of microalgae for the transition towards a sustainable bioeconomy.
Collapse
Affiliation(s)
- Alexander Einhaus
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Olaf Kruse
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
| |
Collapse
|
2
|
Bacova R, Kolackova M, Klejdus B, Adam V, Huska D. Epigenetic mechanisms leading to genetic flexibility during abiotic stress responses in microalgae: A review. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
3
|
Navarro FJ, Baulcombe DC. miRNA-Mediated Regulation of Synthetic Gene Circuits in the Green Alga Chlamydomonas reinhardtii. ACS Synth Biol 2019; 8:358-370. [PMID: 30624905 DOI: 10.1021/acssynbio.8b00393] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
MicroRNAs (miRNAs), small RNA molecules of 20-24 nts, have many features that make them useful tools for gene expression regulation-small size, flexible design, target predictability, and action at a late stage of the gene expression pipeline. In addition, their role in fine-tuning gene expression can be harnessed to increase robustness of synthetic gene networks. In this work, we apply a synthetic biology approach to characterize miRNA-mediated gene expression regulation in the unicellular green alga Chlamydomonas reinhardtii. This characterization is then used to build tools based on miRNAs, such as synthetic miRNAs, miRNA-responsive 3'UTRs, miRNA decoys, and self-regulatory loops. These tools will facilitate the engineering of gene expression for new applications and improved traits in this alga.
Collapse
Affiliation(s)
- Francisco J. Navarro
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - David C. Baulcombe
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| |
Collapse
|
4
|
Lou S, Sun T, Li H, Hu Z. Mechanisms of microRNA-mediated gene regulation in unicellular model alga Chlamydomonas reinhardtii. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:244. [PMID: 30202439 PMCID: PMC6129010 DOI: 10.1186/s13068-018-1249-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/31/2018] [Indexed: 05/30/2023]
Abstract
MicroRNAs are a class of endogenous non-coding RNAs that play a vital role in post-transcriptional gene regulation in eukaryotic cells. In plants and animals, miRNAs are implicated in diverse roles ranging from immunity against viral infections, developmental pathways, molecular pathology of cancer and regulation of protein expression. However, the role of miRNAs in the unicellular model green alga Chlamydomonas reinhardtii remains unclear. The mode of action of miRNA-induced gene silencing in C. reinhardtii is very similar to that of higher eukaryotes, in terms of the activation of the RNA-induced silencing complex and mRNA targeting. Certain studies indicate that destabilization of mRNAs and mRNA turnover could be the major possible functions of miRNAs in eukaryotic algae. Here, we summarize recent findings that have advanced our understanding of miRNA regulatory mechanisms in C. reinhardtii.
Collapse
Affiliation(s)
- Sulin Lou
- Guangdong Key Laboratory of Plant Epigenetics, Guangdong Engineering Research Center for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Key Laboratory of Optoeletronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoeletronic Engineering, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Ting Sun
- Guangdong Key Laboratory of Plant Epigenetics, Guangdong Engineering Research Center for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Key Laboratory of Optoeletronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoeletronic Engineering, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Hui Li
- Guangdong Key Laboratory of Plant Epigenetics, Guangdong Engineering Research Center for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Zhangli Hu
- Guangdong Key Laboratory of Plant Epigenetics, Guangdong Engineering Research Center for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| |
Collapse
|
5
|
Li H, Liu Y, Wang Y, Chen M, Zhuang X, Wang C, Wang J, Hu Z. Improved photobio-H 2 production regulated by artificial miRNA targeting psbA in green microalga Chlamydomonas reinhardtii. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:36. [PMID: 29449884 PMCID: PMC5808451 DOI: 10.1186/s13068-018-1030-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/23/2018] [Indexed: 06/01/2023]
Abstract
BACKGROUND Sulfur-deprived cultivation of Chlamydomonas reinhardtii, referred as "two-stage culture" transferring the cells from regular algal medium to sulfur-deplete one, has been extensively studied to improve photobio-H2 production in this green microalga. During sulfur-deprivation treatment, the synthesis of a key component of photosystem II complex, D1 protein, was inhibited and improved photobio-H2 production could be established in C. reinhardtii. However, separation of algal cells from a regular liquid culture medium to a sulfur-deprived one is not only a discontinuous process, but also a cost- and time-consuming operation. More applicable and economic alternatives for sustained H2 production by C. reinhardtii are still highly required. RESULTS In the present study, a significant improvement in photobio-H2 production was observed in the transgenic green microalga C. reinhardtii, which employed a newly designed strategy based on a heat-inducible artificial miRNA (amiRNA) expression system targeting D1-encoded gene, psbA. A transgenic algal strain referred as "amiRNA-D1" has been successfully obtained by transforming the expression vector containing a heat-inducible promoter. After heat shock conducted in the same algal cultures, the expression of amiRNA-D1 was detected increased 15-fold accompanied with a 73% decrease of target gene psbA. More interestingly, this transgenic alga accumulated about 60% more H2 content than the wild-type strain CC-849 at the end of 7-day cultivation. CONCLUSIONS The photobio-H2 production in the engineered transgenic alga was significantly improved. Without imposing any nutrient-deprived stress, this novel strategy provided a convenient and efficient way for regulation of photobio-H2 production in green microalga by simply "turn on" the expression of a designed amiRNA.
Collapse
Affiliation(s)
- Hui Li
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Yanmei Liu
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Yuting Wang
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Meirong Chen
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Xiaoshan Zhuang
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Chaogang Wang
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Jiangxin Wang
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Shenzhen Key Laboratory of Marine Bioresource & Eco-environmental Science, Longhua Innovation Institute for Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| |
Collapse
|
6
|
Wang C, Chen X, Li H, Wang J, Hu Z. Artificial miRNA inhibition of phosphoenolpyruvate carboxylase increases fatty acid production in a green microalga Chlamydomonas reinhardtii. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:91. [PMID: 28413446 PMCID: PMC5390379 DOI: 10.1186/s13068-017-0779-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/06/2017] [Indexed: 05/06/2023]
Abstract
BACKGROUND Nutrient limitation, such as nitrogen depletion, is the most widely used method for improving microalgae fatty acid production; however, these harsh conditions also inhibit algal growth significantly and even kill cells at all. To avoid these problems, we used artificial microRNA (amiRNA) technology as a useful tool to manipulate metabolic pathways to increase fatty acid contents effectively in the green microalga Chlamydomonas reinhardtii. We down-regulated the expression of phosphoenolpyruvate carboxylase (PEPC), which catalyzes the formation of oxaloacetate from phosphoenolpyruvate and regulates carbon flux. RESULTS amiRNAs against two CrPEPC genes were designed and transformed into Chlamydomonas cells and amiRNAs were induced by heat shock treatment. The transcription levels of amiRNAs increased 16-28 times, resulting in the remarkable decreases of the expression of CrPEPCs. In the end, inhibiting the expression of the CrPEPC genes dramatically increased the total fatty acid content in the transgenic algae by 28.7-48.6%, which mostly increased the content of C16-C22 fatty acids. Furthermore, the highest content was that of C18:3n3 with an average increase of 35.75%, while C20-C22 fatty acid content significantly increased by 85-160%. CONCLUSIONS Overall our results suggest that heat shock treatment induced the expression of amiRNAs, which can effectively down-regulate the expression of CrPEPCs in C. reinhardtii, resulting in an increase of fatty acid synthesis with the most significant increase occurring for C16 to C22 fatty acids.
Collapse
Affiliation(s)
- Chaogang Wang
- Guangdong Technology Research Center for Marine Algal Bioengineering, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Xi Chen
- Guangdong Technology Research Center for Marine Algal Bioengineering, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Hui Li
- Guangdong Technology Research Center for Marine Algal Bioengineering, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Jiangxin Wang
- Guangdong Technology Research Center for Marine Algal Bioengineering, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Nanshan District Key Lab for Biopolymers and Safety Evaluation, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Guangdong Key Laboratory of Plant Epigenetics, College of Life Sciences, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| |
Collapse
|
7
|
Burgess SJ, Taha H, Yeoman JA, Iamshanova O, Chan KX, Boehm M, Behrends V, Bundy JG, Bialek W, Murray JW, Nixon PJ. Identification of the Elusive Pyruvate Reductase of Chlamydomonas reinhardtii Chloroplasts. PLANT & CELL PHYSIOLOGY 2016; 57:82-94. [PMID: 26574578 PMCID: PMC4722173 DOI: 10.1093/pcp/pcv167] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/27/2015] [Indexed: 05/19/2023]
Abstract
Under anoxic conditions the green alga Chlamydomonas reinhardtii activates various fermentation pathways leading to the creation of formate, acetate, ethanol and small amounts of other metabolites including d-lactate and hydrogen. Progress has been made in identifying the enzymes involved in these pathways and their subcellular locations; however, the identity of the enzyme involved in reducing pyruvate to d-lactate has remained unclear. Based on sequence comparisons, enzyme activity measurements, X-ray crystallography, biochemical fractionation and analysis of knock-down mutants, we conclude that pyruvate reduction in the chloroplast is catalyzed by a tetrameric NAD(+)-dependent d-lactate dehydrogenase encoded by Cre07.g324550. Its expression during aerobic growth supports a possible function as a 'lactate valve' for the export of lactate to the mitochondrion for oxidation by cytochrome-dependent d-lactate dehydrogenases and by glycolate dehydrogenase. We also present a revised spatial model of fermentation based on our immunochemical detection of the likely pyruvate decarboxylase, PDC3, in the cytoplasm.
Collapse
Affiliation(s)
- Steven J Burgess
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK These authors contributed equally to this work
| | - Hussein Taha
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK These authors contributed equally to this work Present address: Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, BE1410, Brunei Darussalam
| | - Justin A Yeoman
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Oksana Iamshanova
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Kher Xing Chan
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Marko Boehm
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Volker Behrends
- Department of Biomolecular Medicine, Sir Alexander Fleming Building, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Jacob G Bundy
- Department of Biomolecular Medicine, Sir Alexander Fleming Building, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Wojciech Bialek
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - James W Murray
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Peter J Nixon
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| |
Collapse
|
8
|
Yang W, Catalanotti C, Wittkopp TM, Posewitz MC, Grossman AR. Algae after dark: mechanisms to cope with anoxic/hypoxic conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:481-503. [PMID: 25752440 DOI: 10.1111/tpj.12823] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 02/28/2015] [Accepted: 03/03/2015] [Indexed: 06/04/2023]
Abstract
Chlamydomonas reinhardtii is a unicellular, soil-dwelling (and aquatic) green alga that has significant metabolic flexibility for balancing redox equivalents and generating ATP when it experiences hypoxic/anoxic conditions. The diversity of pathways available to ferment sugars is often revealed in mutants in which the activities of specific branches of fermentative metabolism have been eliminated; compensatory pathways that have little activity in parental strains under standard laboratory fermentative conditions are often activated. The ways in which these pathways are regulated and integrated have not been extensively explored. In this review, we primarily discuss the intricacies of dark anoxic metabolism in Chlamydomonas, but also discuss aspects of dark oxic metabolism, the utilization of acetate, and the relatively uncharacterized but critical interactions that link chloroplastic and mitochondrial metabolic networks.
Collapse
Affiliation(s)
- Wenqiang Yang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Claudia Catalanotti
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Tyler M Wittkopp
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Matthew C Posewitz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO, 80401, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| |
Collapse
|
9
|
Yang W, Catalanotti C, D'Adamo S, Wittkopp TM, Ingram-Smith CJ, Mackinder L, Miller TE, Heuberger AL, Peers G, Smith KS, Jonikas MC, Grossman AR, Posewitz MC. Alternative acetate production pathways in Chlamydomonas reinhardtii during dark anoxia and the dominant role of chloroplasts in fermentative acetate production. THE PLANT CELL 2014; 26:4499-518. [PMID: 25381350 PMCID: PMC4277214 DOI: 10.1105/tpc.114.129965] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 07/15/2014] [Accepted: 10/15/2014] [Indexed: 05/18/2023]
Abstract
Chlamydomonas reinhardtii insertion mutants disrupted for genes encoding acetate kinases (EC 2.7.2.1) (ACK1 and ACK2) and a phosphate acetyltransferase (EC 2.3.1.8) (PAT2, but not PAT1) were isolated to characterize fermentative acetate production. ACK1 and PAT2 were localized to chloroplasts, while ACK2 and PAT1 were shown to be in mitochondria. Characterization of the mutants showed that PAT2 and ACK1 activity in chloroplasts plays a dominant role (relative to ACK2 and PAT1 in mitochondria) in producing acetate under dark, anoxic conditions and, surprisingly, also suggested that Chlamydomonas has other pathways that generate acetate in the absence of ACK activity. We identified a number of proteins associated with alternative pathways for acetate production that are encoded on the Chlamydomonas genome. Furthermore, we observed that only modest alterations in the accumulation of fermentative products occurred in the ack1, ack2, and ack1 ack2 mutants, which contrasts with the substantial metabolite alterations described in strains devoid of other key fermentation enzymes.
Collapse
Affiliation(s)
- Wenqiang Yang
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Claudia Catalanotti
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Sarah D'Adamo
- Colorado School of Mines, Department of Chemistry and Geochemistry, Golden, Colorado 80401
| | - Tyler M Wittkopp
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305 Stanford University, Department of Biology, Stanford, California 94305
| | - Cheryl J Ingram-Smith
- Clemson University, Department of Genetics and Biochemistry, Clemson, South Carolina 29634
| | - Luke Mackinder
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Tarryn E Miller
- Colorado School of Mines, Department of Chemistry and Geochemistry, Golden, Colorado 80401
| | - Adam L Heuberger
- Colorado State University, Proteomics and Metabolomics Facility, Fort Collins, Colorado 80523
| | - Graham Peers
- Colorado State University, Department of Biology, Fort Collins, Colorado 80523
| | - Kerry S Smith
- Clemson University, Department of Genetics and Biochemistry, Clemson, South Carolina 29634
| | - Martin C Jonikas
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Arthur R Grossman
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305
| | - Matthew C Posewitz
- Colorado School of Mines, Department of Chemistry and Geochemistry, Golden, Colorado 80401
| |
Collapse
|
10
|
Hu J, Deng X, Shao N, Wang G, Huang K. Rapid construction and screening of artificial microRNA systems in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:1052-64. [PMID: 24974733 DOI: 10.1111/tpj.12606] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 05/09/2023]
Abstract
The unicellular green algae Chlamydomonas reinhardtii is a classic model for the study of flagella/cilia and photosynthesis, and it has recently been exploited for producing biopharmaceuticals and biofuel. Due to the low frequency of homologous recombination, reverse genetic manipulation in Chlamydomonas relies mainly on miRNA- and siRNA-based knockdown methods. However, the difficulty in constructing artificial miRNA vectors, laborious screening of knockdown transformants, and undesired epigenetic silencing of exogenous miRNA constructs limit their application. We have established a one-step procedure to construct an artificial miRNA precursor by annealing eight oligonucleotides of approximately 40 nucleotides. In the final construct, the Gaussia princeps luciferase gene (G-Luc) is positioned between the promoter and the artificial miRNA precursor so that knockdown strains may quickly be screened by visualizing luciferase luminescence using a photon-counting camera. Furthermore, the luciferase activity of transformants correlates with the knockdown level of two test target proteins: the chloroplast protein VIPP1 (vesicle inducing protein in plastids 1) and the flagellar protein CDPK3 (calcium-dependent protein kinase 3). Adding an intron from RBCS2 (ribulose bisphosphate carboxylase/oxygenase small subunit 2) to the miRNA construct enhanced both the luciferase activity and the miRNA knockdown efficiency. A second miRNA vector incorporated the promoter of the nitrate reductase gene to allow inducible expression of the artificial miRNA. These vectors will facilitate application of the artificial miRNA and provide tools for studying the mechanism of epigenetics in Chlamydomonas, and may also be adapted for use in other model organisms.
Collapse
Affiliation(s)
- Jinlu Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China; University of the Chinese Academy of Sciences, Beijing, 100039, China
| | | | | | | | | |
Collapse
|
11
|
Tiwari M, Sharma D, Trivedi PK. Artificial microRNA mediated gene silencing in plants: progress and perspectives. PLANT MOLECULAR BIOLOGY 2014; 86:1-18. [PMID: 25022825 DOI: 10.1007/s11103-014-0224-7] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 07/05/2014] [Indexed: 05/24/2023]
Abstract
Homology based gene silencing has emerged as a convenient approach for repressing expression of genes in order to study their functions. For this purpose, several antisense or small interfering RNA based gene silencing techniques have been frequently employed in plant research. Artificial microRNAs (amiRNAs) mediated gene silencing represents one of such techniques which can utilize as a potential tool in functional genomics. Similar to microRNAs, amiRNAs are single-stranded, approximately 21 nt long, and designed by replacing the mature miRNA sequences of duplex within pre-miRNAs. These amiRNAs are processed via small RNA biogenesis and silencing machinery and deregulate target expression. Holding to various refinements, amiRNA technology offers several advantages over other gene silencing methods. This is a powerful and robust tool, and could be applied to unravel new insight of metabolic pathways and gene functions across the various disciplines as well as in translating observations for improving favourable traits in plants. This review highlights general background of small RNAs, improvements made in RNAi based gene silencing, implications of amiRNA in gene silencing, and describes future themes for improving value of this technology in plant science.
Collapse
Affiliation(s)
- Manish Tiwari
- Council of Scientific and Industrial Research-National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India
| | | | | |
Collapse
|