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Song Y, Wang F, Chen L, Zhang W. Engineering Fatty Acid Biosynthesis in Microalgae: Recent Progress and Perspectives. Mar Drugs 2024; 22:216. [PMID: 38786607 PMCID: PMC11122798 DOI: 10.3390/md22050216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Microalgal lipids hold significant potential for the production of biodiesel and dietary supplements. To enhance their cost-effectiveness and commercial competitiveness, it is imperative to improve microalgal lipid productivity. Metabolic engineering that targets the key enzymes of the fatty acid synthesis pathway, along with transcription factor engineering, are effective strategies for improving lipid productivity in microalgae. This review provides a summary of the advancements made in the past 5 years in engineering the fatty acid biosynthetic pathway in eukaryotic microalgae. Furthermore, this review offers insights into transcriptional regulatory mechanisms and transcription factor engineering aimed at enhancing lipid production in eukaryotic microalgae. Finally, the review discusses the challenges and future perspectives associated with utilizing microalgae for the efficient production of lipids.
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Affiliation(s)
- Yanhui Song
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China; (Y.S.); (L.C.)
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300350, China
| | - Fangzhong Wang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China; (Y.S.); (L.C.)
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300350, China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China; (Y.S.); (L.C.)
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300350, China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China; (Y.S.); (L.C.)
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300350, China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, China
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Bouchnak I, Coulon D, Salis V, D’Andréa S, Bréhélin C. Lipid droplets are versatile organelles involved in plant development and plant response to environmental changes. FRONTIERS IN PLANT SCIENCE 2023; 14:1193905. [PMID: 37426978 PMCID: PMC10327486 DOI: 10.3389/fpls.2023.1193905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/23/2023] [Indexed: 07/11/2023]
Abstract
Since decades plant lipid droplets (LDs) are described as storage organelles accumulated in seeds to provide energy for seedling growth after germination. Indeed, LDs are the site of accumulation for neutral lipids, predominantly triacylglycerols (TAGs), one of the most energy-dense molecules, and sterol esters. Such organelles are present in the whole plant kingdom, from microalgae to perennial trees, and can probably be found in all plant tissues. Several studies over the past decade have revealed that LDs are not merely simple energy storage compartments, but also dynamic structures involved in diverse cellular processes like membrane remodeling, regulation of energy homeostasis and stress responses. In this review, we aim to highlight the functions of LDs in plant development and response to environmental changes. In particular, we tackle the fate and roles of LDs during the plant post-stress recovery phase.
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Affiliation(s)
- Imen Bouchnak
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
| | - Denis Coulon
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
| | - Vincent Salis
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Sabine D’Andréa
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Claire Bréhélin
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
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Li F, Han X, Guan H, Xu MC, Dong YX, Gao XQ. PALD encoding a lipid droplet-associated protein is critical for the accumulation of lipid droplets and pollen longevity in Arabidopsis. THE NEW PHYTOLOGIST 2022; 235:204-219. [PMID: 35348222 DOI: 10.1111/nph.18123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Pollen longevity is critical for plant pollination and hybrid seed production, but few studies have focused on pollen longevity. In this study, we identified an Arabidopsis thaliana gene, Protein associated with lipid droplets (PALD), which is strongly expressed in pollen and critical for the regulation of pollen longevity. PALD was expressed specifically in mature pollen grains and the pollen tube, and its expression was upregulated under dry conditions. PALD encoded a lipid droplet (LD)-associated protein and its N terminus was critical for the LD localization of PALD. The number of LDs and diameter were reduced in pollen grains of the loss-of-function PALD mutants. The viability and germination of the mature pollen grains of the pald mutants were comparable with those of the wild-type, but after the pollen grains were stored under dry conditions, pollen germination and male transmission of the mutant were compromised compared with those of the wild-type. Our study suggests that PALD was required for the maintenance of LD quality in mature pollen grains and regulation of pollen longevity.
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Affiliation(s)
- Fei Li
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Xiao Han
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Huan Guan
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Mei Chen Xu
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Yu Xiu Dong
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Xin-Qi Gao
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
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Yang J, Liu J, Pan Y, Maréchal E, Amato A, Liu M, Gong Y, Li Y, Hu H. PDAT regulates PE as transient carbon sink alternative to triacylglycerol in Nannochloropsis. PLANT PHYSIOLOGY 2022; 189:1345-1362. [PMID: 35385114 PMCID: PMC9237688 DOI: 10.1093/plphys/kiac160] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/14/2022] [Indexed: 05/21/2023]
Abstract
Triacylglycerols (TAGs) are the main storage lipids in photosynthetic organisms under stress. In the oleaginous alga Nannochloropsis oceanica, while multiple acyl CoA:diacylglycerol (DAG) acyltransferases (NoDGATs) are involved in TAG production, the role of the unique phospholipid:DAG acyltransferase (NoPDAT) remains unknown. Here, we performed a functional complementation assay in TAG-deficient yeast (Saccharomyces cerevisiae) and an in vitro assay to probe the acyltransferase activity of NoPDAT. Subcellular localization, overexpression, and knockdown (KD) experiments were also conducted to elucidate the role of NoPDAT in N. oceanica. NoPDAT, residing at the outermost plastid membrane, does not phylogenetically fall into the clades of algae or plants and uses phosphatidylethanolamine (PE) and phosphatidylglycerol with 16:0, 16:1, and 18:1 at position sn-2 as acyl-donors in vivo. NoPDAT KD, not triggering any compensatory mechanism via DGATs, led to an ∼30% decrease of TAG content, accompanied by a vast accumulation of PEs rich in 16:0, 16:1, and 18:1 fatty acids (referred to as "LU-PE") that was positively associated with CO2 availability. We conclude that the NoPDAT pathway is parallel to and independent of the NoDGAT pathway for oil production. LU-PE can serve as an alternative carbon sink for photosynthetically assimilated carbon in N. oceanica when PDAT-mediated TAG biosynthesis is compromised or under stress in the presence of high CO2 levels.
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Affiliation(s)
| | | | - Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Alberto Amato
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Meijing Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Yangmin Gong
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
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Xu C, Fan J. Links between autophagy and lipid droplet dynamics. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2848-2858. [PMID: 35560198 DOI: 10.1093/jxb/erac003] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/06/2022] [Indexed: 06/15/2023]
Abstract
Autophagy is a catabolic process in which cytoplasmic components are delivered to vacuoles or lysosomes for degradation and nutrient recycling. Autophagy-mediated degradation of membrane lipids provides a source of fatty acids for the synthesis of energy-rich, storage lipid esters such as triacylglycerol (TAG). In eukaryotes, storage lipids are packaged into dynamic subcellular organelles, lipid droplets. In times of energy scarcity, lipid droplets can be degraded via autophagy in a process termed lipophagy to release fatty acids for energy production via fatty acid β-oxidation. On the other hand, emerging evidence suggests that lipid droplets are required for the efficient execution of autophagic processes. Here, we review recent advances in our understanding of metabolic interactions between autophagy and TAG storage, and discuss mechanisms of lipophagy. Free fatty acids are cytotoxic due to their detergent-like properties and their incorporation into lipid intermediates that are toxic at high levels. Thus, we also discuss how cells manage lipotoxic stresses during autophagy-mediated mobilization of fatty acids from lipid droplets and organellar membranes for energy generation.
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Affiliation(s)
- Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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Bai F, Yu L, Shi J, Li-Beisson Y, Liu J. Long-chain acyl-CoA synthetases activate fatty acids for lipid synthesis, remodeling and energy production in Chlamydomonas. THE NEW PHYTOLOGIST 2022; 233:823-837. [PMID: 34665469 DOI: 10.1111/nph.17813] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Long-chain acyl-CoA synthetases (LACSs) play many roles in mammals, yeasts and plants, but knowledge on their functions in microalgae remains fragmented. Here via genetic, biochemical and physiological analyses, we unraveled the function and roles of LACSs in the model microalga Chlamydomonas reinhardtii. In vitro assays on purified recombinant proteins revealed that CrLACS1, CrLACS2 and CrLACS3 all exhibited bona fide LACS activities toward a broad range of free fatty acids. The Chlamydomonas mutants compromised in CrLACS1, CrLACS2 or CrLACS3 did not show any obvious phenotypes in lipid content or growth under nitrogen (N)-replete condition. But under N-deprivation, CrLACS1 or CrLACS2 suppression resulted in c. 50% less oil, yet with a higher amount of chloroplast lipids. By contrast, CrLACS3 suppression impaired oil remobilization and cell growth severely during N-recovery, supporting its role in fatty acid β-oxidation to provide energy and carbon sources for regrowth. Transcriptomics analysis suggested that the observed lipid phenotypes are likely not due to transcriptional reprogramming but rather a shift in metabolic adjustment. Taken together, this study provided solid experimental evidence for essential roles of the three Chlamydomonas LACS enzymes in lipid synthesis, remodeling and catabolism, and highlighted the importance of lipid homeostasis in cell growth under nutrient fluctuations.
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Affiliation(s)
- Fan Bai
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Lihua Yu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Jianan Shi
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Yonghua Li-Beisson
- CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Aix Marseille Université, Saint Paul-Lez-Durance, 13108, France
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
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Interactions between plant lipid-binding proteins and their ligands. Prog Lipid Res 2022; 86:101156. [DOI: 10.1016/j.plipres.2022.101156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 10/05/2021] [Accepted: 01/14/2022] [Indexed: 01/11/2023]
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Kselíková V, Singh A, Bialevich V, Čížková M, Bišová K. Improving microalgae for biotechnology - From genetics to synthetic biology - Moving forward but not there yet. Biotechnol Adv 2021; 58:107885. [PMID: 34906670 DOI: 10.1016/j.biotechadv.2021.107885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/28/2021] [Accepted: 12/07/2021] [Indexed: 12/28/2022]
Abstract
Microalgae are a diverse group of photosynthetic organisms that can be exploited for the production of different compounds, ranging from crude biomass and biofuels to high value-added biochemicals and synthetic proteins. Traditionally, algal biotechnology relies on bioprospecting to identify new highly productive strains and more recently, on forward genetics to further enhance productivity. However, it has become clear that further improvements in algal productivity for biotechnology is impossible without combining traditional tools with the arising molecular genetics toolkit. We review recent advantages in developing high throughput screening methods, preparing genome-wide mutant libraries, and establishing genome editing techniques. We discuss how algae can be improved in terms of photosynthetic efficiency, biofuel and high value-added compound production. Finally, we critically evaluate developments over recent years and explore future potential in the field.
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Affiliation(s)
- Veronika Kselíková
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Anjali Singh
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Vitali Bialevich
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Mária Čížková
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Kateřina Bišová
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic.
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Genetic engineering of microalgae for enhanced lipid production. Biotechnol Adv 2021; 52:107836. [PMID: 34534633 DOI: 10.1016/j.biotechadv.2021.107836] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 12/24/2022]
Abstract
Microalgae have the potential to become microbial cell factories for lipid production. Their ability to convert sunlight and CO2 into valuable lipid compounds has attracted interest from cosmetic, biofuel, food and feed industries. In order to make microalgae-derived products cost-effective and commercially competitive, enhanced growth rates and lipid productivities are needed, which require optimization of cultivation systems and strain improvement. Advances in genetic tool development and omics technologies have increased our understanding of lipid metabolism, which has opened up possibilities for targeted metabolic engineering. In this review we provide a comprehensive overview on the developments made to genetically engineer microalgal strains over the last 30 years. We focus on the strategies that lead to an increased lipid content and altered fatty acid profile. These include the genetic engineering of the fatty acid synthesis pathway, Kennedy pathway, polyunsaturated fatty acid and triacylglycerol metabolisms and fatty acid catabolism. Moreover, genetic engineering of specific transcription factors, NADPH generation and central carbon metabolism, which lead to increase of lipid accumulation are also reviewed.
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Assessment on the oil accumulation by knockdown of triacylglycerol lipase in the oleaginous diatom Fistulifera solaris. Sci Rep 2021; 11:20905. [PMID: 34686744 PMCID: PMC8536745 DOI: 10.1038/s41598-021-00453-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/06/2021] [Indexed: 11/08/2022] Open
Abstract
Microalgae are promising producers of biofuel due to higher accumulation of triacylglycerol (TAG). However, further improvement of the lipid metabolism is critical for feasible application of microalgae in industrial production of biofuel. Suppression of lipid degradation pathways is a promising way to remarkably increase the lipid production in model diatoms. In this study, we established an antisense-based knockdown (KD) technique in the marine oleaginous diatom, Fistulifera solaris. This species has a capability to accumulate high content of lipids. Tgl1 KD showed positive impact on cell growth and lipid accumulation in conventional culture in f/2 medium, resulting in higher oil contents compared to wild type strain. However, these impacts of Tgl1 KD were slight when the cells were subjected to the two-stage growth system. The Tgl1 KD resulted in slight change of fatty acid composition; increasing in C14:0, C16:0 and C16:1, and decreasing in C20:5. This study indicates that, although Tgl1 played a certain role in lipid degradation in F. solaris, suppression of only a single type of TAG lipase was not significantly effective to improve the lipid production. Comprehensive understanding of the lipid catabolism in this microalga is essential to further improve the lipid production.
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Li-Beisson Y, Kong F, Wang P, Lee Y, Kang BH. The disassembly of lipid droplets in Chlamydomonas. THE NEW PHYTOLOGIST 2021; 231:1359-1364. [PMID: 34028037 DOI: 10.1111/nph.17505] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Lipid droplets (LDs) are ubiquitous and specialized organelles in eukaryotic cells. Consisting of a triacylglycerol core surrounded by a monolayer of membrane lipids, LDs are decorated with proteins and have myriad functions, from carbon/energy storage to membrane lipid remodeling and signal transduction. The biogenesis and turnover of LDs are therefore tightly coordinated with cellular metabolic needs in a fluctuating environment. Lipid droplet turnover requires remodeling of the protein coat, lipolysis, autophagy and fatty acid β-oxidation. Several key components of these processes have been identified in Chlamydomonas (Chlamydomonas reinhardtii), including the major lipid droplet protein, a CXC-domain containing regulatory protein, the phosphatidylethanolamine-binding DTH1 (DELAYED IN TAG HYDROLYSIS1), two lipases and two enzymes involved in fatty acid β-oxidation. Here, we review LD turnover and discuss its physiological significance in Chlamydomonas, a major model green microalga in research on algal oil.
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Affiliation(s)
- Yonghua Li-Beisson
- CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Aix-Marseille Univ, Saint Paul-Lez-Durance, 13108, France
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian, 116024, China
| | - Pengfei Wang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Youngsook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Byung-Ho Kang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
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