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Antreich SJ, Permann C, Xiao N, Tiloca G, Holzinger A. Zygospore development of Spirogyra (Charophyta) investigated by serial block-face scanning electron microscopy and 3D reconstructions. FRONTIERS IN PLANT SCIENCE 2024; 15:1358974. [PMID: 38559764 PMCID: PMC10978657 DOI: 10.3389/fpls.2024.1358974] [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: 12/20/2023] [Accepted: 02/22/2024] [Indexed: 04/04/2024]
Abstract
Sexual reproduction of Zygnematophyceae by conjugation is a less investigated topic due to the difficulties of the induction of this process and zygospore ripening under laboratory conditions. For this study, we collected field sampled zygospores of Spirogyra mirabilis and three additional Spirogyra strains in Austria and Greece. Serial block-face scanning electron microscopy was performed on high pressure frozen and freeze substituted zygospores and 3D reconstructions were generated, allowing a comprehensive insight into the process of zygospore maturation, involving storage compound and organelle rearrangements. Chloroplasts are drastically changed, while young stages contain both parental chloroplasts, the male chloroplasts are aborted and reorganised as 'secondary vacuoles' which initially contain plastoglobules and remnants of thylakoid membranes. The originally large pyrenoids and the volume of starch granules is significantly reduced during maturation (young: 8 ± 5 µm³, mature: 0.2 ± 0.2 µm³). In contrast, lipid droplets (LDs) increase significantly in number upon zygospore maturation, while simultaneously getting smaller (young: 21 ± 18 µm³, mature: 0.1 ± 0.2 and 0.5 ± 0.9 µm³). Only in S. mirabilis the LD volume increases (34 ± 29 µm³), occupying ~50% of the zygospore volume. Mature zygospores contain barite crystals as confirmed by Raman spectroscopy with a size of 0.02 - 0.05 µm³. The initially thin zygospore cell wall (~0.5 µm endospore, ~0.8 µm exospore) increases in thickness and develops a distinct, electron dense mesospore, which has a reticulate appearance (~1.4 µm) in Spirogyra sp. from Greece. The exo- and endospore show cellulose microfibrils in a helicoidal pattern. In the denser endospore, pitch angles of the microfibril layers were calculated: ~18 ± 3° in S. mirabilis, ~20 ± 3° in Spirogyra sp. from Austria and ~38 ± 8° in Spirogyra sp. from Greece. Overall this study gives new insights into Spirogyra sp. zygospore development, crucial for survival during dry periods and dispersal of this genus.
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Affiliation(s)
- Sebastian J. Antreich
- Department of Bionanosciences, University of Natural Resource and Life Sciences, Vienna, Austria
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | | | - Nannan Xiao
- Department of Bionanosciences, University of Natural Resource and Life Sciences, Vienna, Austria
| | - Giuseppe Tiloca
- Department of Bionanosciences, University of Natural Resource and Life Sciences, Vienna, Austria
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Zou Z, Zhang L, Zhao Y. Integrative Analysis of Oleosin Genes Provides Insights into Lineage-Specific Family Evolution in Brassicales. PLANTS (BASEL, SWITZERLAND) 2024; 13:280. [PMID: 38256833 PMCID: PMC10820149 DOI: 10.3390/plants13020280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/16/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024]
Abstract
Oleosins (OLEs) are a class of small but abundant structural proteins that play essential roles in the formation and stabilization of lipid droplets (LDs) in seeds of oil crops. Despite the proposal of five oleosin clades (i.e., U, SL, SH, T, and M) in angiosperms, their evolution in eudicots has not been well-established. In this study, we employed Brassicales, an economically important order of flowering plants possessing the lineage-specific T clade, as an example to address this issue. Three to 10 members were identified from 10 species representing eight plant families, which include Caricaceae, Moringaceae, Akaniaceae, Capparaceae, and Cleomaceae. Evolutionary and reciprocal best hit-based homologous analyses assigned 98 oleosin genes into six clades (i.e., U, SL, SH, M, N, and T) and nine orthogroups (i.e., U1, U2, SL, SH1, SH2, SH3, M, N, and T). The newly identified N clade represents an ancient group that has already appeared in the basal angiosperm Amborella trichopoda, which are constitutively expressed in the tree fruit crop Carica papaya, including pulp and seeds of the fruit. Moreover, similar to Clade N, the previously defined M clade is actually not Lauraceae-specific but an ancient and widely distributed group that diverged before the radiation of angiosperm. Compared with A. trichopoda, lineage-specific expansion of the family in Brassicales was largely contributed by recent whole-genome duplications (WGDs) as well as the ancient γ event shared by all core eudicots. In contrast to the flower-preferential expression of Clade T, transcript profiling revealed an apparent seed/embryo/endosperm-predominant expression pattern of most oleosin genes in Arabidopsis thaliana and C. papaya. Moreover, the structure and expression divergence of paralogous pairs was frequently observed, and a good example is the lineage-specific gain of an intron. These findings provide insights into lineage-specific family evolution in Brassicales, which facilitates further functional studies in nonmodel plants such as C. papaya.
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Affiliation(s)
- Zhi Zou
- National Key Laboratory for Tropical Crop Breeding, Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Institute of Tropical Biosciences and Biotechnology/Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China;
| | - Li Zhang
- National Key Laboratory for Tropical Crop Breeding, Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Institute of Tropical Biosciences and Biotechnology/Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China;
- Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Yongguo Zhao
- National Key Laboratory for Tropical Crop Breeding, Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Institute of Tropical Biosciences and Biotechnology/Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China;
- College of Biology and Food Engineering, Guangdong University of Petrochemical Technology, Maoming 525011, China
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Permann C, Pichrtová M, Šoljaková T, Herburger K, Jouneau P, Uwizeye C, Falconet D, Marechal E, Holzinger A. 3D-reconstructions of zygospores in Zygnema vaginatum (Charophyta) reveal details of cell wall formation, suggesting adaptations to extreme habitats. PHYSIOLOGIA PLANTARUM 2023; 175:e13988. [PMID: 37616005 PMCID: PMC10953328 DOI: 10.1111/ppl.13988] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 08/25/2023]
Abstract
The streptophyte green algal class Zygnematophyceae is the immediate sister lineage to land plants. Their special form of sexual reproduction via conjugation might have played a key role during terrestrialization. Thus, studying Zygnematophyceae and conjugation is crucial for understanding the conquest of land. Moreover, sexual reproduction features are important for species determination. We present a phylogenetic analysis of a field-sampled Zygnema strain and analyze its conjugation process and zygospore morphology, both at the micro- and nanoscale, including 3D-reconstructions of the zygospore architecture. Vegetative filament size (26.18 ± 1.07 μm) and reproductive features allowed morphological determination of Zygnema vaginatum, which was combined with molecular analyses based on rbcL sequencing. Transmission electron microscopy (TEM) depicted a thin cell wall in young zygospores, while mature cells exhibited a tripartite wall, including a massive and sculptured mesospore. During development, cytological reorganizations were visualized by focused ion beam scanning electron microscopy (FIB-SEM). Pyrenoids were reorganized, and the gyroid cubic central thylakoid membranes, as well as the surrounding starch granules, degraded (starch granule volume: 3.58 ± 2.35 μm3 in young cells; 0.68 ± 0.74 μm3 at an intermediate stage of zygospore maturation). Additionally, lipid droplets (LDs) changed drastically in shape and abundance during zygospore maturation (LD/cell volume: 11.77% in young cells; 8.79% in intermediate cells, 19.45% in old cells). In summary, we provide the first TEM images and 3D-reconstructions of Zygnema zygospores, giving insights into the physiological processes involved in their maturation. These observations help to understand mechanisms that facilitated the transition from water to land in Zygnematophyceae.
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Affiliation(s)
| | - Martina Pichrtová
- Department of Botany, Faculty of ScienceCharles UniversityPragueCzech Republic
| | - Tereza Šoljaková
- Department of Botany, Faculty of ScienceCharles UniversityPragueCzech Republic
| | - Klaus Herburger
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
- Institute of Biological Sciences, University of RostockRostockGermany
| | - Pierre‐Henri Jouneau
- Laboratoire Modélisation et Exploration des MatériauxIRIG, CEA, Univ. Grenoble AlpesGrenobleFrance
| | - Clarisse Uwizeye
- Laboratoire de Physiologie Cellulaire et VégétaleCEA, CNRS, INRAE, Univ. Grenoble AlpesGrenobleFrance
| | - Denis Falconet
- Laboratoire de Physiologie Cellulaire et VégétaleCEA, CNRS, INRAE, Univ. Grenoble AlpesGrenobleFrance
| | - Eric Marechal
- Laboratoire de Physiologie Cellulaire et VégétaleCEA, CNRS, INRAE, Univ. Grenoble AlpesGrenobleFrance
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Zhao Y, Dong Q, Geng Y, Ma C, Shao Q. Dynamic Regulation of Lipid Droplet Biogenesis in Plant Cells and Proteins Involved in the Process. Int J Mol Sci 2023; 24:ijms24087476. [PMID: 37108639 PMCID: PMC10138601 DOI: 10.3390/ijms24087476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Lipid droplets (LDs) are ubiquitous, dynamic organelles found in almost all organisms, including animals, protists, plants and prokaryotes. The cell biology of LDs, especially biogenesis, has attracted increasing attention in recent decades because of their important role in cellular lipid metabolism and other newly identified processes. Emerging evidence suggests that LD biogenesis is a highly coordinated and stepwise process in animals and yeasts, occurring at specific sites of the endoplasmic reticulum (ER) that are defined by both evolutionarily conserved and organism- and cell type-specific LD lipids and proteins. In plants, understanding of the mechanistic details of LD formation is elusive as many questions remain. In some ways LD biogenesis differs between plants and animals. Several homologous proteins involved in the regulation of animal LD formation in plants have been identified. We try to describe how these proteins are synthesized, transported to the ER and specifically targeted to LD, and how these proteins participate in the regulation of LD biogenesis. Here, we review current work on the molecular processes that control LD formation in plant cells and highlight the proteins that govern this process, hoping to provide useful clues for future research.
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Affiliation(s)
- Yiwu Zhao
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
| | - Qingdi Dong
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
| | - Yuhu Geng
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
| | - Changle Ma
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
| | - Qun Shao
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250358, China
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Xu K, Zou W, Peng B, Guo C, Zou X. Lipid Droplets from Plants and Microalgae: Characteristics, Extractions, and Applications. BIOLOGY 2023; 12:biology12040594. [PMID: 37106794 PMCID: PMC10135979 DOI: 10.3390/biology12040594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023]
Abstract
Plant and algal LDs are gaining popularity as a promising non-chemical technology for the production of lipids and oils. In general, these organelles are composed of a neutral lipid core surrounded by a phospholipid monolayer and various surface-associated proteins. Many studies have shown that LDs are involved in numerous biological processes such as lipid trafficking and signaling, membrane remodeling, and intercellular organelle communications. To fully exploit the potential of LDs for scientific research and commercial applications, it is important to develop suitable extraction processes that preserve their properties and functions. However, research on LD extraction strategies is limited. This review first describes recent progress in understanding the characteristics of LDs, and then systematically introduces LD extraction strategies. Finally, the potential functions and applications of LDs in various fields are discussed. Overall, this review provides valuable insights into the properties and functions of LDs, as well as potential approaches for their extraction and utilization. It is hoped that these findings will inspire further research and innovation in the field of LD-based technology.
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Affiliation(s)
- Kaiwei Xu
- Institute of Systems Security and Control, College of Computer Science and Technology, Xi'an University of Science and Technology, Xi'an 710054, China
- Shaanxi Provincial Key Laboratory of Land Consolidation, Chang'an University, Xi'an 710074, China
| | - Wen Zou
- State Owned SIDA Machinery Manufacturing, Xianyang 712201, China
| | - Biao Peng
- Shaanxi Provincial Key Laboratory of Land Consolidation, Chang'an University, Xi'an 710074, China
- Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Natural Resources, Xi'an 710021, China
| | - Chao Guo
- Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Natural Resources, Xi'an 710021, China
| | - Xiaotong Zou
- Faculty of Printing, Packaging Engineering and Digital Media Technology, Xi'an University of Technology, Xi'an 710048, China
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Huang MD, Wu CW, Chou HY, Cheng SY, Chang HY. The revealing of a novel lipid transfer protein lineage in green algae. BMC PLANT BIOLOGY 2023; 23:21. [PMID: 36627558 PMCID: PMC9832785 DOI: 10.1186/s12870-023-04040-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Non-specific lipid transfer proteins (nsLTPs) are a group of small and basic proteins that can bind and transfer various lipid molecules to the apoplastic space. A typical nsLTP carries a conserved architecture termed eight-cysteine motif (8CM), a scaffold of loop-linked helices folding into a hydrophobic cavity for lipids binding. Encoded by a multigene family, nsLTPs are widely distributed in terrestrial plants from bryophytes to angiosperms with dozens of gene members in a single species. Although the nsLTPs in the most primitive plants such as Marchantia already reach 14 members and are divergent enough to form separate groups, so far none have been identified in any species of green algae. RESULTS By using a refined searching strategy, we identified putative nsLTP genes in more than ten species of green algae as one or two genes per haploid genome but not in red and brown algae. The analyses show that the algal nsLTPs carry unique characteristics, including the extended 8CM spacing, larger molecular mass, lower pI value and multiple introns in a gene, which suggests that they could be a novel nsLTP lineage. Moreover, the results of further investigation on the two Chlamydomonas nsLTPs using transcript and protein assays demonstrated their late zygotic stage expression patterns and the canonical nsLTP properties were also verified, such as the fatty acids binding and proteinase resistance activities. CONCLUSIONS In conclusion, a novel nsLTP lineage is identified in green algae, which carries some unique sequences and molecular features that are distinguishable from those in land plants. Combined with the results of further examinations of the Chlamydomonas nsLTPs in vitro, possible roles of the algal nsLTPs are also suggested. This study not only reveals the existence of the nsLTPs in green algae but also contributes to facilitating future studies on this enigmatic protein family.
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Affiliation(s)
- Ming-Der Huang
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424.
| | - Chin-Wei Wu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424
| | - Hong-Yun Chou
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424
| | - Sou-Yu Cheng
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424
| | - Hsin-Yang Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan, 80424.
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, 11221.
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7
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Regulation of Heat Stress in Physcomitrium (Physcomitrella) patens Provides Novel Insight into the Functions of Plant RNase H1s. Int J Mol Sci 2022; 23:ijms23169270. [PMID: 36012542 PMCID: PMC9409398 DOI: 10.3390/ijms23169270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/02/2022] [Accepted: 08/13/2022] [Indexed: 11/17/2022] Open
Abstract
RNase H1s are associated with growth and development in both plants and animals, while the roles of RNase H1s in bryophytes have been rarely reported. Our previous data found that PpRNH1A, a member of the RNase H1 family, could regulate the development of Physcomitrium (Physcomitrella) patens by regulating the auxin. In this study, we further investigated the biological functions of PpRNH1A and found PpRNH1A may participate in response to heat stress by affecting the numbers and the mobilization of lipid droplets and regulating the expression of heat-related genes. The expression level of PpRNH1A was induced by heat stress (HS), and we found that the PpRNH1A overexpression plants (A-OE) were more sensitive to HS. At the same time, A-OE plants have a higher number of lipid droplets but with less mobility in cells. Consistent with the HS sensitivity phenotype in A-OE plants, transcriptomic analysis results indicated that PpRNH1A is involved in the regulation of expression of heat-related genes such as DNAJ and DNAJC. Taken together, these results provide novel insight into the functions of RNase H1s.
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Şen A, Acevedo-Fani A, Dave A, Ye A, Husny J, Singh H. Plant oil bodies and their membrane components: new natural materials for food applications. Crit Rev Food Sci Nutr 2022; 64:256-279. [PMID: 35917117 DOI: 10.1080/10408398.2022.2105808] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Plants store triacylglycerols in the form of oil bodies (OBs) as an energy source for germination and subsequent seedling growth. The interfacial biomaterials from these OBs are called OB membrane materials (OBMMs) and have several applications in foods, e.g., as emulsifiers. OBMMs are preferred, compared with their synthetic counterparts, in food applications as emulsifiers because they are natural, i.e., suitable for clean label, and may stabilize bioactive components during storage. This review focuses mainly on the extraction technologies for plant OBMMs, the functionality of these materials, and the interaction of OB membranes with other food components. Different sources of OBs are evaluated and the challenges during the extraction and use of these OBMMs for food applications are addressed.
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Affiliation(s)
- Aylin Şen
- Riddet Institute, Massey University, Palmerston North, New Zealand
| | | | - Anant Dave
- Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Aiqian Ye
- Riddet Institute, Massey University, Palmerston North, New Zealand
| | | | - Harjinder Singh
- Riddet Institute, Massey University, Palmerston North, New Zealand
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Kanazawa T, Nishihama R, Ueda T. Normal oil body formation in Marchantia polymorpha requires functional coat protein complex I proteins. FRONTIERS IN PLANT SCIENCE 2022; 13:979066. [PMID: 36046592 PMCID: PMC9420845 DOI: 10.3389/fpls.2022.979066] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 07/25/2022] [Indexed: 05/13/2023]
Abstract
Eukaryotic cells possess endomembrane organelles equipped with specific sets of proteins, lipids, and polysaccharides that are fundamental for realizing each organelle's specific function and shape. A tightly regulated membrane trafficking system mediates the transportation and localization of these substances. Generally, the secretory/exocytic pathway is responsible for transporting cargo to the plasma membrane and/or the extracellular space. However, in the case of oil body cells in the liverwort Marchantia polymorpha, the oil body, a liverwort-unique organelle, is thought to be formed by secretory vesicle fusion through redirection of the secretory pathway inside the cell. Although their formation mechanism remains largely unclear, oil bodies exhibit a complex and bumpy surface structure. In this study, we isolated a mutant with spherical oil bodies through visual screening of mutants with abnormally shaped oil bodies. This mutant harbored a mutation in a coat protein complex I (COPI) subunit MpSEC28, and a similar effect on oil body morphology was also detected in knockdown mutants of other COPI subunits. Fluorescently tagged MpSEC28 was localized to the periphery of the Golgi apparatus together with other subunits, suggesting that it is involved in retrograde transport from and/or in the Golgi apparatus as a component of the COPI coat. The Mpsec28 mutants also exhibited weakened stiffness of the thalli, suggesting impaired cell-cell adhesion and cell wall integrity. These findings suggest that the mechanism of cell wall biosynthesis is also involved in shaping the oil body in M. polymorpha, supporting the redirection of the secretory pathway inward the cell during oil body formation.
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Affiliation(s)
- Takehiko Kanazawa
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Aichi, Japan
- The Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Ryuichi Nishihama
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Japan
| | - Takashi Ueda
- Division of Cellular Dynamics, National Institute for Basic Biology, Okazaki, Aichi, Japan
- The Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
- *Correspondence: Takashi Ueda,
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Bosch M, Sweet MJ, Parton RG, Pol A. Lipid droplets and the host-pathogen dynamic: FATal attraction? J Cell Biol 2021; 220:e202104005. [PMID: 34165498 PMCID: PMC8240858 DOI: 10.1083/jcb.202104005] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 02/06/2023] Open
Abstract
In the ongoing conflict between eukaryotic cells and pathogens, lipid droplets (LDs) emerge as a choke point in the battle for nutrients. While many pathogens seek the lipids stored in LDs to fuel an expensive lifestyle, innate immunity rewires lipid metabolism and weaponizes LDs to defend cells and animals. Viruses, bacteria, and parasites directly and remotely manipulate LDs to obtain substrates for metabolic energy, replication compartments, assembly platforms, membrane blocks, and tools for host colonization and/or evasion such as anti-inflammatory mediators, lipoviroparticles, and even exosomes. Host LDs counterattack such advances by synthesizing bioactive lipids and toxic nucleotides, organizing immune signaling platforms, and recruiting a plethora of antimicrobial proteins to provide a front-line defense against the invader. Here, we review the current state of this conflict. We will discuss why, when, and how LDs efficiently coordinate and precisely execute a plethora of immune defenses. In the age of antimicrobial resistance and viral pandemics, understanding innate immune strategies developed by eukaryotic cells to fight and defeat dangerous microorganisms may inform future anti-infective strategies.
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Affiliation(s)
- Marta Bosch
- Lipid Trafficking and Disease Group, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
- Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Matthew J. Sweet
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
- Centre for Inflammation and Disease Research, Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Australia
| | - Robert G. Parton
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
- Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Australia
| | - Albert Pol
- Lipid Trafficking and Disease Group, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
- Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
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Zhang Y, Ye Y, Bai F, Liu J. The oleaginous astaxanthin-producing alga Chromochloris zofingiensis: potential from production to an emerging model for studying lipid metabolism and carotenogenesis. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:119. [PMID: 33992124 PMCID: PMC8126118 DOI: 10.1186/s13068-021-01969-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/07/2021] [Indexed: 05/05/2023]
Abstract
The algal lipids-based biodiesel, albeit having advantages over plant oils, still remains high in the production cost. Co-production of value-added products with lipids has the potential to add benefits and is thus believed to be a promising strategy to improve the production economics of algal biodiesel. Chromochloris zofingiensis, a unicellular green alga, has been considered as a promising feedstock for biodiesel production because of its robust growth and ability of accumulating high levels of triacylglycerol under multiple trophic conditions. This alga is also able to synthesize high-value keto-carotenoids and has been cited as a candidate producer of astaxanthin, the strongest antioxidant found in nature. The concurrent accumulation of triacylglycerol and astaxanthin enables C. zofingiensis an ideal cell factory for integrated production of the two compounds and has potential to improve algae-based production economics. Furthermore, with the advent of chromosome-level whole genome sequence and genetic tools, C. zofingiensis becomes an emerging model for studying lipid metabolism and carotenogenesis. In this review, we summarize recent progress on the production of triacylglycerol and astaxanthin by C. zofingiensis. We also update our understanding in the distinctive molecular mechanisms underlying lipid metabolism and carotenogenesis, with an emphasis on triacylglycerol and astaxanthin biosynthesis and crosstalk between the two pathways. Furthermore, strategies for trait improvements are discussed regarding triacylglycerol and astaxanthin synthesis in C. zofingiensis.
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Affiliation(s)
- Yu Zhang
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Ying Ye
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Fan Bai
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China.
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Sánchez-Albarrán F, Suárez-Rodríguez LM, Ruíz-Herrera LF, López-Meza JE, López-Gómez R. Two Oleosins Expressed in the Mesocarp of Native Mexican Avocado, Key Genes in the Oil Content. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2021; 76:20-25. [PMID: 33184746 DOI: 10.1007/s11130-020-00868-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
Intracellular lipid droplets (LD) provide the oil storage mechanism of plants. They are found within seeds as individual structures, even under conditions of cold stress and dehydration, due to the protein that covers them. This protein, called oleosin, is found exclusively in plants and has been widely studied in seeds. Avocado fruits (Persea americana Mill.) are rich in oil, which is stored in the mesocarp, not in the seeds. The presence of oleosin in the mesocarp tissue of avocadoes has been reported, but its physiological role is still unknown. In this study, we identify two genes that code for oleosin in the mesocarp of the native Mexican avocado. These sequences are very different from those of seed oleosins. Both genes are expressed during fruit ripening, while one, PaOle1, has the highest expression in the green fruit stage. The protein of PaOle1 is stable during the fruit ripening process and covers all the mesocarp LDs. The expression of PaOle1 gene and protein is organ specific to avocado mesocarp. Among avocadoes varieties oleosin abundance is directly related to oil content.
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Affiliation(s)
- Fernando Sánchez-Albarrán
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Luis María Suárez-Rodríguez
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - León Francisco Ruíz-Herrera
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Joel Edmundo López-Meza
- Centro Multidisciplinario de Estudios en Biotecnología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Rodolfo López-Gómez
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico.
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de Vries J, Ischebeck T. Ties between Stress and Lipid Droplets Pre-date Seeds. TRENDS IN PLANT SCIENCE 2020; 25:1203-1214. [PMID: 32921563 DOI: 10.1016/j.tplants.2020.07.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 05/12/2023]
Abstract
Seeds were a key evolutionary innovation. These durable structures provide a concerted solution to two challenges on land: dispersal and stress. Lipid droplets (LDs) that act as nutrient storage reservoirs are one of the main cell-biological reasons for seed endurance. Although LDs are key structures in spermatophytes and are especially abundant in seeds, they are found across plants and algae, and increase during stress. Further, the proteins that underpin their form and function often have deep homologs. We propose an evolutionary scenario in which (i) the generation of LDs arose as a mechanism to mediate general drought and desiccation resilience, and (ii) the required protein framework was co-opted by spermatophytes for a seed-specific program.
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Affiliation(s)
- Jan de Vries
- University of Goettingen, Institute for Microbiology and Genetics, Department of Applied Bioinformatics, Goldschmidtstrasse 1, 37077 Goettingen, Germany; University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), 37077 Goettingen, Germany; University of Goettingen, Campus Institute Data Science (CIDAS), Goldschmidtstrasse 1, 37077 Goettingen, Germany.
| | - Till Ischebeck
- University of Goettingen, Goettingen Center for Molecular Biosciences (GZMB), 37077 Goettingen, Germany; University of Goettingen, Albrecht-von-Haller-Institute for Plant Sciences, Department of Plant Biochemistry, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany.
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14
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Lundquist PK, Shivaiah KK, Espinoza-Corral R. Lipid droplets throughout the evolutionary tree. Prog Lipid Res 2020; 78:101029. [PMID: 32348789 DOI: 10.1016/j.plipres.2020.101029] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 04/11/2020] [Accepted: 04/18/2020] [Indexed: 12/11/2022]
Abstract
Intracellular lipid droplets are utilized for lipid storage and metabolism in organisms as evolutionarily diverse as animals, fungi, plants, bacteria, and archaea. These lipid droplets demonstrate great diversity in biological functions and protein and lipid compositions, yet fundamentally share common molecular and ultrastructural characteristics. Lipid droplet research has been largely fragmented across the diversity of lipid droplet classes and sub-classes. However, we suggest that there is great potential benefit to the lipid community in better integrating the lipid droplet research fields. To facilitate such integration, we survey the protein and lipid compositions, functional roles, and mechanisms of biogenesis across the breadth of lipid droplets studied throughout the natural world. We depict the big picture of lipid droplet biology, emphasizing shared characteristics and unique differences seen between different classes. In presenting the known diversity of lipid droplets side-by-side it becomes necessary to offer for the first time a consistent system of categorization and nomenclature. We propose a division into three primary classes that reflect their sub-cellular location: i) cytoplasmic lipid droplets (CYTO-LDs), that are present in the eukaryotic cytoplasm, ii) prokaryotic lipid droplets (PRO-LDs), that exist in the prokaryotic cytoplasm, and iii) plastid lipid droplets (PL-LDs), that are found in plant plastids, organelles of photosynthetic eukaryotes. Within each class there is a remarkable array of sub-classes displaying various sizes, shapes and compositions. A more integrated lipid droplet research field will provide opportunities to better build on discoveries and accelerate the pace of research in ways that have not been possible.
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Affiliation(s)
- Peter K Lundquist
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA.
| | - Kiran-Kumar Shivaiah
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
| | - Roberto Espinoza-Corral
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
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15
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Ischebeck T, Krawczyk HE, Mullen RT, Dyer JM, Chapman KD. Lipid droplets in plants and algae: Distribution, formation, turnover and function. Semin Cell Dev Biol 2020; 108:82-93. [PMID: 32147380 DOI: 10.1016/j.semcdb.2020.02.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/28/2020] [Accepted: 02/29/2020] [Indexed: 01/02/2023]
Abstract
Plant oils represent an energy-rich and carbon-dense group of hydrophobic compounds. These oils are not only of economic interest, but also play important, fundamental roles in plant and algal growth and development. The subcellular storage compartments of plant lipids, referred to as lipid droplets (LDs), have long been considered relatively inert oil vessels. However, research in the last decade has revealed that LDs play far more dynamic roles in plant biology than previously appreciated, including transient neutral lipid storage, membrane remodeling, lipid signaling, and stress responses. Here we discuss recent developments in the understanding of LD formation, turnover and function in land plants and algae.
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Affiliation(s)
- Till Ischebeck
- University of Göttingen, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, 37077, Göttingen, Germany.
| | - Hannah E Krawczyk
- University of Göttingen, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, 37077, Göttingen, Germany
| | - Robert T Mullen
- University of Guelph, Department of Molecular Cell Biology, Guelph, Ontario, N1G 2W1, Canada
| | - John M Dyer
- United States Department of Agriculture, Agriculture Research Service, US Arid-Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Kent D Chapman
- University of North Texas, BioDiscovery Institute, Department of Biological Sciences, Denton, TX, 76203, USA
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16
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Cecchin M, Marcolungo L, Rossato M, Girolomoni L, Cosentino E, Cuine S, Li‐Beisson Y, Delledonne M, Ballottari M. Chlorella vulgaris genome assembly and annotation reveals the molecular basis for metabolic acclimation to high light conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:1289-1305. [PMID: 31437318 PMCID: PMC6972661 DOI: 10.1111/tpj.14508] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 05/05/2023]
Abstract
Chlorella vulgaris is a fast-growing fresh-water microalga cultivated on the industrial scale for applications ranging from food to biofuel production. To advance our understanding of its biology and to establish genetics tools for biotechnological manipulation, we sequenced the nuclear and organelle genomes of Chlorella vulgaris 211/11P by combining next generation sequencing and optical mapping of isolated DNA molecules. This hybrid approach allowed us to assemble the nuclear genome in 14 pseudo-molecules with an N50 of 2.8 Mb and 98.9% of scaffolded genome. The integration of RNA-seq data obtained at two different irradiances of growth (high light, HL versus low light, LL) enabled us to identify 10 724 nuclear genes, coding for 11 082 transcripts. Moreover, 121 and 48 genes, respectively, were found in the chloroplast and mitochondrial genome. Functional annotation and expression analysis of nuclear, chloroplast and mitochondrial genome sequences revealed particular features of Chlorella vulgaris. Evidence of horizontal gene transfers from chloroplast to mitochondrial genome was observed. Furthermore, comparative transcriptomic analyses of LL versus HL provided insights into the molecular basis for metabolic rearrangement under HL versus LL conditions leading to enhanced de novo fatty acid biosynthesis and triacylglycerol accumulation. The occurrence of a cytosolic fatty acid biosynthetic pathway could be predicted and its upregulation upon HL exposure was observed, consistent with the increased lipid amount under HL conditions. These data provide a rich genetic resource for future genome editing studies, and potential targets for biotechnological manipulation of Chlorella vulgaris or other microalgae species to improve biomass and lipid productivity.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Luca Marcolungo
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Marzia Rossato
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Laura Girolomoni
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Emanuela Cosentino
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Stephan Cuine
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Yonghua Li‐Beisson
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Massimo Delledonne
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Matteo Ballottari
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
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17
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Wang X, Wei H, Mao X, Liu J. Proteomics Analysis of Lipid Droplets from the Oleaginous Alga Chromochloris zofingiensis Reveals Novel Proteins for Lipid Metabolism. GENOMICS PROTEOMICS & BIOINFORMATICS 2019; 17:260-272. [PMID: 31494267 PMCID: PMC6818385 DOI: 10.1016/j.gpb.2019.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/13/2018] [Accepted: 01/04/2019] [Indexed: 11/30/2022]
Abstract
Chromochloris zofingiensis represents an industrially relevant and unique green alga, given its capability of synthesizing triacylglycerol (TAG) and astaxanthin simultaneously for storage in lipid droplets (LDs). To further decipher lipid metabolism, the nitrogen deprivation (ND)-induced LDs from C. zofingiensis were isolated, purified, and subjected to proteomic analysis. Intriguingly, many C. zofingiensis LD proteins had no orthologs present in LD proteome of the model alga Chlamydomonas reinhardtii. Seven novel LD proteins (i.e., two functionally unknown proteins, two caleosins, two lipases, and one l-gulonolactone oxidase) and the major LD protein (MLDP), which were all transcriptionally up-regulated by ND, were selected for further investigation. Heterologous expression in yeast demonstrated that all tested LD proteins were localized to LDs and all except the two functionally unknown proteins enabled yeast to produce more TAG. MLDP could restore the phenotype of mldp mutant strain and enhance TAG synthesis in wild-type strain of C. reinhardtii. Although MLDP and caleosins had a comparable abundance in LDs, they responded distinctly to ND at the transcriptional level. The two lipases, instead of functioning as TAG lipases, likely recycled polar lipids to support TAG synthesis. For the first time, we reported that l-gulonolactone oxidase was abundant in LDs and facilitated TAG accumulation. Moreover, we also proposed a novel working model for C. zofingiensis LDs. Taken together, our work unravels the unique characteristics of C. zofingiensis LDs and provides insights into algal LD biogenesis and TAG synthesis, which would facilitate genetic engineering of this alga for TAG improvement.
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Affiliation(s)
- Xiaofei Wang
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Hehong Wei
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Xuemei Mao
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing 100871, China.
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18
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Chen K, Yin Y, Liu S, Guo Z, Zhang K, Liang Y, Zhang L, Zhao W, Chao H, Li M. Genome-wide identification and functional analysis of oleosin genes in Brassica napus L. BMC PLANT BIOLOGY 2019; 19:294. [PMID: 31272381 PMCID: PMC6610931 DOI: 10.1186/s12870-019-1891-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/18/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Rapeseed is the third largest oil seed crop in the world. The seeds of this plant store lipids in oil bodies, and oleosin is the most important structural protein in oil bodies. However, the function of oleosin in oil crops has received little attention. RESULTS In the present study, 48 oleosin sequences from the Brassica napus genome were identified and divided into four lineages (T, U, SH, SL). Synteny analysis revealed that most of the oleosin genes were conserved, and all of these genes experienced purifying selection during evolution. Three and four important oleosin genes from Arabidopsis and B. napus, respectively, were cloned and analyzed for function in Arabidopsis. Overexpression of these oleosin genes in Arabidopsis increased the seed oil content slightly, except for BnaOLE3. Further analysis revealed that the average oil body size of the transgenic seeds was slightly larger than that of the wild type (WT), except for BnaOLE1. The fatty acid profiles showed that the linoleic acid content (13.3% at most) increased and the peanut acid content (11% at most) decreased in the transgenic lines. In addition, the seed size and thousand-seed weight (TSW) also increased in the transgenic lines, which could lead to increased total lipid production. CONCLUSION We identified oleosin genes in the B. napus genome, and overexpression of oleosin in Arabidopsis seeds increased the seed weight and linoleic acid content (13.3% at most).
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Affiliation(s)
- Kang Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Yongtai Yin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Si Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Zhenyi Guo
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Kai Zhang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Yu Liang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Lina Zhang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Weiguo Zhao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Hongbo Chao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Maoteng Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang, China
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19
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Ozias‐Akins P, Breiteneder H. The functional biology of peanut allergens and possible links to their allergenicity. Allergy 2019; 74:888-898. [PMID: 30636003 PMCID: PMC6563476 DOI: 10.1111/all.13719] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/17/2018] [Accepted: 01/06/2019] [Indexed: 12/24/2022]
Abstract
Peanut is one of the most common food triggers of fatal anaphylaxis worldwide although peanut allergy affects only 1%-2% of the general population. Peanuts are the source of highly potent allergenic proteins. It is emerging that the allergenicity of certain proteins is linked to their biological function. Peanut is an unusual crop in that it flowers aboveground but produces its seed-containing pods underground. This so-called geocarpic fruiting habit exposes pods and seeds during their development to soilborne pathogens and pests. Pest damage can also open routes of entry for opportunistic fungi such as Aspergillus. Although seed proteins have primary functions in nutrient reservoirs, lipid storage bodies, or the cytoskeleton, they have also evolved to act as part of the plant's defense system to enhance fitness and survival of the species. When interacting with pathogens or pests, these proteins modify and damage cells' membranes, interact with immune receptors, and modulate signaling pathways. Moreover, following exposure, the immune system of predisposed individuals reacts to these proteins with the production of specific IgE. This review explores the evolutionary biology of peanut and its seed proteins and highlights possible links between the proteins' biological function and their allergenicity.
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Affiliation(s)
- Peggy Ozias‐Akins
- Genetic & Genomics and Department of Horticulture Institute of Plant Breeding University of Georgia Tifton Georgia
| | - Heimo Breiteneder
- Institute of Pathophysiology and Allergy Research Medical University of Vienna Vienna Austria
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20
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Devadasu E, Chinthapalli DK, Chouhan N, Madireddi SK, Rasineni GK, Sripadi P, Subramanyam R. Changes in the photosynthetic apparatus and lipid droplet formation in Chlamydomonas reinhardtii under iron deficiency. PHOTOSYNTHESIS RESEARCH 2019; 139:253-266. [PMID: 30218258 DOI: 10.1007/s11120-018-0580-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 08/28/2018] [Indexed: 05/19/2023]
Abstract
The unicellular photosynthetic alga Chlamydomonas reinhardtii was propagated in iron deficiency medium and patterns of growth, photosynthetic efficiency, lipid accumulation, as well as the expression of lipid biosynthetic and photosynthesis-related proteins were analysed and compared with iron-sufficient growth conditions. As expected, the photosynthetic rate was reduced (maximally after 4 days of growth) as a result of increased non-photochemical quenching (NPQ). Surprisingly, the stress-response protein LHCSR3 was expressed in conditions of iron deficiency that cause NPQ induction. In addition, the protein contents of both the PSI and PSII reaction centres were gradually reduced during growth in iron deficiency medium. Interestingly, the two generations of Fe deficiency cells could be able to recover the photosynthesis but the second generation cells recovered much slower as these cells were severely in shock. Analysis by flow cytometry with fluorescence-activated cell sorting and thin layer chromatography showed that iron deficiency also induced the accumulation of triacylglycerides (TAG), which resulted in the formation of lipid droplets. This was most significant between 48 and 72 h of growth. Dramatic increases in DGAT2A and PDAT1 levels were caused by iron starvation, which indicated that the biosynthesis of TAG had been increased. Analysis using gas chromatography mass spectrometry showed that levels of 16:0, 18:0, 18:2 and 18:3Δ9,12,15 fatty acids were significantly elevated. The results of this study highlight the genes/enzymes of Chlamydomonas that affect lipid synthesis through their influence on photosynthesis, and these represent potential targets of metabolic engineering to develop strains for biofuel production.
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Affiliation(s)
- Elsinraju Devadasu
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Dinesh Kumar Chinthapalli
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
- Analytical Chemistry and Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500 007, India
| | - Nisha Chouhan
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Sai Kiran Madireddi
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Girish Kumar Rasineni
- Center for Excellence in Medical Services Pvt. Ltd., Kineta Towers, Road No. 3, Banjara Hills, Hyderabad, Telangana, 500034, India
| | - Prabhakar Sripadi
- Analytical Chemistry and Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, Telangana, 500 007, India
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India.
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21
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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22
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Huang S, Jiang L, Zhuang X. Possible Roles of Membrane Trafficking Components for Lipid Droplet Dynamics in Higher Plants and Green Algae. FRONTIERS IN PLANT SCIENCE 2019; 10:207. [PMID: 30858860 PMCID: PMC6397863 DOI: 10.3389/fpls.2019.00207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/07/2019] [Indexed: 05/04/2023]
Abstract
Lipid droplets are ubiquitous dynamic organelles that contain neutral lipids surrounded by a phospholipid monolayer. They can store and supply lipids for energy metabolism and membrane synthesis. In addition, protein transport and lipid exchange often occur between LDs and various organelles to control lipid homeostasis in response to multiple stress responses and cellular signaling. In recent years, multiple membrane trafficking proteins have been identified through LD proteomics and genetic analyses. These membrane trafficking machineries are emerging as critical regulators to function in different LD-organelle interactions, e.g., for LD dynamics, biogenesis and turnover. In this review, we will summarize recent advances in regard to LD-related membrane trafficking proteins and discuss future investigations in higher plants and green algae.
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Affiliation(s)
- Shuxian Huang
- Centre for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Liwen Jiang
- Centre for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
- The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Xiaohong Zhuang
- Centre for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
- *Correspondence: Xiaohong Zhuang,
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23
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Zhang C, Liu P. The New Face of the Lipid Droplet: Lipid Droplet Proteins. Proteomics 2018; 19:e1700223. [DOI: 10.1002/pmic.201700223] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/13/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Congyan Zhang
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Pingsheng Liu
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100049 China
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Arora N, Pienkos PT, Pruthi V, Poluri KM, Guarnieri MT. Leveraging algal omics to reveal potential targets for augmenting TAG accumulation. Biotechnol Adv 2018; 36:1274-1292. [PMID: 29678388 DOI: 10.1016/j.biotechadv.2018.04.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 04/11/2018] [Accepted: 04/15/2018] [Indexed: 02/08/2023]
Abstract
Ongoing global efforts to commercialize microalgal biofuels have expedited the use of multi-omics techniques to gain insights into lipid biosynthetic pathways. Functional genomics analyses have recently been employed to complement existing sequence-level omics studies, shedding light on the dynamics of lipid synthesis and its interplay with other cellular metabolic pathways, thus revealing possible targets for metabolic engineering. Here, we review the current status of algal omics studies to reveal potential targets to augment TAG accumulation in various microalgae. This review specifically aims to examine and catalog systems level data related to stress-induced TAG accumulation in oleaginous microalgae and inform future metabolic engineering strategies to develop strains with enhanced bioproductivity, which could pave a path for sustainable green energy.
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Affiliation(s)
- Neha Arora
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Philip T Pienkos
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Vikas Pruthi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Michael T Guarnieri
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
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Maeda Y, Nojima D, Yoshino T, Tanaka T. Structure and properties of oil bodies in diatoms. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0408. [PMID: 28717018 DOI: 10.1098/rstb.2016.0408] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2017] [Indexed: 01/23/2023] Open
Abstract
Diatoms accumulate triacylglycerols in spherical organelles called oil bodies when exposed to nutrient deprivation conditions. Oil body biology in diatoms has attracted significant attention due to the complexity of the intracellular organelles and the unique combination of genes generated by the evolutionary history of secondary endosymbiosis. The demand for biofuel production has further increased the interest in and importance of a better understanding of oil body biology in diatoms, because it could provide targets for genetic engineering to further enhance their promising lipid accumulation. This review describes recent progress in studies of the structure and properties of diatom oil bodies. Firstly, the general features of diatom oil bodies are described, in particular, their number, size and morphology, as well as the quantity and quality of lipids they contain. Subsequently, the diatom oil body-associated proteins, which were recently discovered through oil body proteomics, are introduced. Then, the metabolic pathways responsible for the biogenesis and degradation of diatom oil bodies are summarized. During biogenesis and degradation, oil bodies interact with other organelles, including chloroplasts, the endoplasmic reticulum and mitochondria, suggesting their dynamic nature in response to environmental changes. Finally, the functions of oil bodies in diatoms are discussed.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- Yoshiaki Maeda
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Daisuke Nojima
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Tomoko Yoshino
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Tsuyoshi Tanaka
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
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26
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Huang AHC. Plant Lipid Droplets and Their Associated Proteins: Potential for Rapid Advances. PLANT PHYSIOLOGY 2018; 176:1894-1918. [PMID: 29269574 PMCID: PMC5841732 DOI: 10.1104/pp.17.01677] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 12/10/2017] [Indexed: 05/19/2023]
Abstract
Cytoplasmic lipid droplets (LDs) of neutral lipids (triacylglycerols [TAGs], sterylesters, etc.) are reserves of high-energy metabolites and other constituents for future needs. They are present in diverse cells of eukaryotes and prokaryotes. An LD has a core of neutral lipids enclosed with a monolayer of phospholipids and proteins, which play structural and/or metabolic roles. During the past 3 decades, studies of LDs in diverse organisms have blossomed after they were found to be involved in prevalent human diseases and industrial uses. LDs in plant seeds were studied before those in mammals and microbes, and the latter studies have since moved forward. Plant LDs carry a hallmark protein called oleosin, which has a long hydrophobic hairpin penetrating the TAG core and stabilizing the LD. The oleosin gene first appeared in green algae and has evolved in enhancing promoter strength, tandem repeats, and/or expression specificity, leading to the appearance of new LD organelles, such as tapetosomes in Brassicaceae. The synthesis of LDs occurs with TAG-synthesizing enzymes on the endoplasmic reticulum (ER), and nascent TAGs are sequestered in the acyl moiety region between the bilayers of phospholipids, which results in ER-LD swelling. Oleosin is synthesized on the cytosol side of the ER and extracts the LD from the ER-LD to cytosol. This extraction of LD to the cytosol is controlled solely by the innate properties of oleosin, and modified oleosin can redirect the LD to the ER lumen and then vacuoles. The breakdown of LDs requires lipase associating with core retromer and binding to peroxisomes, which then send the enzyme to LDs via tubular extensions. Two groups of LD-associated proteins, caleosin/dioxygenase/steroleosin and LD/oil body-associated proteins, participate in cellular stress defenses via enzymic activities and binding, respectively. The surface of LDs in all plant cells may be an inert refuge for these and other proteins, which exert functions on diverse cell components. Oleosin-LDs have been explored for commercial applications; successes in their uses will rely on overcoming conceptual and technical difficulties.
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Affiliation(s)
- Anthony H C Huang
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, California 92521
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Song Y, Wang XD, Rose RJ. Oil body biogenesis and biotechnology in legume seeds. PLANT CELL REPORTS 2017; 36:1519-1532. [PMID: 28866824 PMCID: PMC5602053 DOI: 10.1007/s00299-017-2201-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/23/2017] [Indexed: 05/08/2023]
Abstract
The seeds of many legume species including soybean, Pongamia pinnata and the model legume Medicago truncatula store considerable oil, apart from protein, in their cotyledons. However, as a group, legume storage strategies are quite variable and provide opportunities for better understanding of carbon partitioning into different storage products. Legumes with their ability to fix nitrogen can also increase the sustainability of agricultural systems. This review integrates the cell biology, biochemistry and molecular biology of oil body biogenesis before considering biotechnology strategies to enhance oil body biosynthesis. Cellular aspects of packaging triacylglycerol (TAG) into oil bodies are emphasized. Enhancing seed oil content has successfully focused on the up-regulation of the TAG biosynthesis pathways using overexpression of enzymes such as diacylglycerol acyltransferase1 and transcription factors such as WRINKLE1 and LEAFY COTYLEDON1. While these strategies are central, decreasing carbon flow into other storage products and maximizing the packaging of oil bodies into the cytoplasm are other strategies that need further examination. Overall there is much potential for integrating carbon partitioning, up-regulation of fatty acid and TAG synthesis and oil body packaging, for enhancing oil levels. In addition to the potential for integrated strategies to improving oil yields, the capacity to modify fatty acid composition and use of oil bodies as platforms for the production of recombinant proteins in seed of transgenic legumes provide other opportunities for legume biotechnology.
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Affiliation(s)
- Youhong Song
- School of Agronomy, Anhui Agricultural University, Hefei, 230036, People's Republic of China
| | - Xin-Ding Wang
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Ray J Rose
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia.
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Zulu NN, Popko J, Zienkiewicz K, Tarazona P, Herrfurth C, Feussner I. Heterologous co-expression of a yeast diacylglycerol acyltransferase ( ScDGA1) and a plant oleosin ( AtOLEO3) as an efficient tool for enhancing triacylglycerol accumulation in the marine diatom Phaeodactylum tricornutum. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:187. [PMID: 28725267 PMCID: PMC5514505 DOI: 10.1186/s13068-017-0874-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/11/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Microalgae are promising alternate and renewable sources for producing valuable products such as biofuel and essential fatty acids. Although this is the case, there are still challenges impeding on the effective commercial production of microalgal products. For instance, their product yield is still too low. Therefore, this study was oriented towards enhancing triacylglycerol (TAG) accumulation in the diatom Phaeodactylum tricornutum (strain Pt4). To achieve this, a type 2 acyl-CoA:diacylglycerol acyltransferase from yeast (ScDGA1) and the lipid droplet (LD) stabilizing oleosin protein 3 from Arabidopsis thaliana (AtOLEO3) were expressed in Pt4. RESULTS The individual expression of ScDGA1 and AtOLEO3 in Pt4 resulted in a 2.3- and 1.4-fold increase in TAG levels, respectively, in comparison to the wild type. The co-expression of both, ScDGA1 and AtOLEO3, was accompanied by a 3.6-fold increase in TAG content. On the cellular level, the lines co-expressing ScDGA1 and AtOLEO3 showed the presence of the larger and increased numbers of lipid droplets when compared to transformants expressing single genes and an empty vector. Under nitrogen stress, TAG productivity was further increased twofold in comparison to nitrogen-replete conditions. While TAG accumulation was enhanced in the analyzed transformants, the fatty acid composition remained unchanged neither in the total lipid nor in the TAG profile. CONCLUSIONS The co-expression of two genes was shown to be a more effective strategy for enhancing TAG accumulation in P. tricornutum strain Pt4 than a single gene strategy. For the first time in a diatom, a LD protein from a vascular plant, oleosin, was shown to have an impact on TAG accumulation and on LD organization.
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Affiliation(s)
- Nodumo Nokulunga Zulu
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
- Novagreen Projektmanagement GmbH, 49377 Vechta, Germany
| | - Jennifer Popko
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Krzysztof Zienkiewicz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Pablo Tarazona
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Cornelia Herrfurth
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077 Goettingen, Germany
- Department of Plant Biochemistry, International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, 37077 Goettingen, Germany
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Pyc M, Cai Y, Greer MS, Yurchenko O, Chapman KD, Dyer JM, Mullen RT. Turning Over a New Leaf in Lipid Droplet Biology. TRENDS IN PLANT SCIENCE 2017; 22:596-609. [PMID: 28454678 DOI: 10.1016/j.tplants.2017.03.012] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 03/22/2017] [Accepted: 03/24/2017] [Indexed: 05/08/2023]
Abstract
Lipid droplets (LDs) in plants have long been viewed as storage depots for neutral lipids that serve as sources of carbon, energy, and lipids for membrane biosynthesis. While much of our knowledge of LD function in plants comes from studies of oilseeds, a recent surge in research on LDs in non-seed cell types has led to an array of new discoveries. It is now clear that both evolutionarily conserved and kingdom-specific mechanisms underlie the biogenesis of LDs in eukaryotes, and proteomics and homology-based approaches have identified new protein players. This review highlights some of these recent discoveries and other new areas of plant LD research, including their role in stress responses and as targets of metabolic engineering strategies aimed at increasing oil content in bioenergy crops.
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Affiliation(s)
- Michal Pyc
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Yingqi Cai
- Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX 76203, USA
| | - Michael S Greer
- Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX 76203, USA
| | - Olga Yurchenko
- US Department of Agriculture, Agricultural Research Service, US Arid-Land Agricultural Research Center, Maricopa, AZ 85138, USA
| | - Kent D Chapman
- Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX 76203, USA
| | - John M Dyer
- US Department of Agriculture, Agricultural Research Service, US Arid-Land Agricultural Research Center, Maricopa, AZ 85138, USA.
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
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30
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Wang QL, Li Cui C, Jiang LZ, Liu Y, Liang XT, Hou JC. Oil Bodies Extracted from High-Fat and Low-Fat Soybeans: Stability and Composition During Storage. J Food Sci 2017; 82:1319-1325. [PMID: 28471049 DOI: 10.1111/1750-3841.13715] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 03/15/2017] [Accepted: 03/24/2017] [Indexed: 11/27/2022]
Abstract
Soybeans contain oil bodies (OBs) that encapsulate triacylglycerols (TAGs) with a phospholipid monolayer carrying scattered proteins. In nature, soybean OBs can form natural emulsions in aqueous media and may serve as natural, minimally processed, stable, and pre-emulsified oil for addition into appropriate food systems. In this study, OBs were obtained by aqueous extraction from the mature seeds of 2 soybean crop cultivars, high-fat soybean and low-fat soybeans. The compositions of the extracted OBs were analyzed during storage at room temperature up to 14 d (pH = 7). The oxidative stability of these OBs, stored at 60 °C, was evaluated by measuring the presence of primary (lipid hydroperoxides) and secondary lipid oxidation products (malondialdehyde) by determining the standard peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) value. During storage, the contents of unsaturated fatty acids, phospholipids, and tocopherols declined in both OBs, while their mean particle diameters (d32 ) and ζ-potentials increased. The changes in PV and TBARS values exhibited a similar trend for both OBs, but the OBs from low-fat soybeans had significantly lower PV and higher TBARS values than the OBs from high-fat soybean cultivars (P < 0.05). Overall, the OBs from both soybean cultivars had good stability during storage.
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Affiliation(s)
- Qiu Ling Wang
- College of Food Science, Northeast Agricultural Univ, Harbin, 150030, China
| | - Chun Li Cui
- College of Food Science, Northeast Agricultural Univ, Harbin, 150030, China
| | - Lian Zhou Jiang
- College of Food Science, Northeast Agricultural Univ, Harbin, 150030, China
| | - Yue Liu
- College of Food Science, Northeast Agricultural Univ, Harbin, 150030, China
| | - Xin Ting Liang
- College of Food Science, Northeast Agricultural Univ, Harbin, 150030, China
| | - Jun Cai Hou
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural Univ, No. 59 Mucai St., Xiangfang Dist, 150030, Harbin, China
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31
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Nobusawa T, Hori K, Mori H, Kurokawa K, Ohta H. Differently localized lysophosphatidic acid acyltransferases crucial for triacylglycerol biosynthesis in the oleaginous alga Nannochloropsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:547-559. [PMID: 28218992 DOI: 10.1111/tpj.13512] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 05/04/2023]
Abstract
The production of renewable bioenergy will be necessary to meet rising global fossil fuel demands. Members of the marine microalgae genus Nannochloropsis produce large quantities of oils (triacylglycerols; TAGs), and this genus is regarded as one of the most promising for biodiesel production. Recent genome sequencing and transcriptomic studies on Nannochloropsis have provided a foundation for understanding its oleaginous trait, but the mechanism underlying oil accumulation remains to be clarified. Here we report Nannochloropsis knock-out strains of four extraplastidic lysophosphatidic acid acyltransferases (LPAT1-LPAT4) that catalyze a major de novo biosynthetic step of TAGs and membrane lipids. We found that the four LPATs are differently involved in lipid metabolic flow in Nannochloropsis. Double knock-outs among the LPATs revealed the pivotal LPATs for TAG biosynthesis, and localization analysis indicated that the stramenopile-specific LPATs (LPAT3 and LPAT4) associated with TAG synthesis reside at the perimeter of lipid droplets. No homologous region has been found with other lipid droplet-associated proteins, however. Lipid droplets are an organelle found in nearly all organisms, and recently they were shown to play important roles in cellular metabolism and signaling. Our results provide direct evidence for the importance of the perimeter of lipid droplet in TAG synthesis in addition to its known role in maintaining TAG stability, and these findings suggest that the oleaginous trait of Nannochloropsis is enabled by the acquisition of LPATs at the perimeter of lipid droplets.
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Affiliation(s)
- Takashi Nobusawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
- CREST, JST, Yokohama, Japan
| | - Koichi Hori
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
- CREST, JST, Yokohama, Japan
| | - Hiroshi Mori
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
- CREST, JST, Yokohama, Japan
| | - Ken Kurokawa
- CREST, JST, Yokohama, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Center for Information Biology, National Institute of Genetics, Yata 1111, Mishima, 411-8540, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
- CREST, JST, Yokohama, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama, Japan
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32
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Wei L, Huang X. Long-duration effect of multi-factor stresses on the cellular biochemistry, oil-yielding performance and morphology of Nannochloropsis oculata. PLoS One 2017; 12:e0174646. [PMID: 28346505 PMCID: PMC5367823 DOI: 10.1371/journal.pone.0174646] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/13/2017] [Indexed: 12/03/2022] Open
Abstract
Microalga Nannochloropsis oculata is a promising alternative feedstock for biodiesel. Elevating its oil-yielding capacity is conducive to cost-saving biodiesel production. However, the regulatory processes of multi-factor collaborative stresses (MFCS) on the oil-yielding performance of N. oculata are unclear. The duration effects of MFCS (high irradiation, nitrogen deficiency and elevated iron supplementation) on N. oculata were investigated in an 18-d batch culture. Despite the reduction in cell division, the biomass concentration increased, resulting from the large accumulation of the carbon/energy-reservoir. However, different storage forms were found in different cellular storage compounds, and both the protein content and pigment composition swiftly and drastically changed. The analysis of four biodiesel properties using pertinent empirical equations indicated their progressive effective improvement in lipid classes and fatty acid composition. The variation curve of neutral lipid productivity was monitored with fluorescent Nile red and was closely correlated to the results from conventional methods. In addition, a series of changes in the organelles (e.g., chloroplast, lipid body and vacuole) and cell shape, dependent on the stress duration, were observed by TEM and LSCM. These changes presumably played an important role in the acclimation of N. oculata to MFCS and accordingly improved its oil-yielding performance.
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Affiliation(s)
- Likun Wei
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Xuxiong Huang
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Centre of Aquaculture, Shanghai, China
- Shanghai University Knowledge Service Platform, Shanghai Ocean University Aquatic Animal Breeding Centre (ZF1206), Shanghai, China
- * E-mail:
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33
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Zulu NN, Popko J, Zienkiewicz K, Tarazona P, Herrfurth C, Feussner I. Heterologous co-expression of a yeast diacylglycerol acyltransferase ( ScDGA1) and a plant oleosin ( AtOLEO3) as an efficient tool for enhancing triacylglycerol accumulation in the marine diatom Phaeodactylum tricornutum. BIOTECHNOLOGY FOR BIOFUELS 2017. [PMID: 28725267 DOI: 10.1186/s13068-017-0874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND Microalgae are promising alternate and renewable sources for producing valuable products such as biofuel and essential fatty acids. Although this is the case, there are still challenges impeding on the effective commercial production of microalgal products. For instance, their product yield is still too low. Therefore, this study was oriented towards enhancing triacylglycerol (TAG) accumulation in the diatom Phaeodactylum tricornutum (strain Pt4). To achieve this, a type 2 acyl-CoA:diacylglycerol acyltransferase from yeast (ScDGA1) and the lipid droplet (LD) stabilizing oleosin protein 3 from Arabidopsis thaliana (AtOLEO3) were expressed in Pt4. RESULTS The individual expression of ScDGA1 and AtOLEO3 in Pt4 resulted in a 2.3- and 1.4-fold increase in TAG levels, respectively, in comparison to the wild type. The co-expression of both, ScDGA1 and AtOLEO3, was accompanied by a 3.6-fold increase in TAG content. On the cellular level, the lines co-expressing ScDGA1 and AtOLEO3 showed the presence of the larger and increased numbers of lipid droplets when compared to transformants expressing single genes and an empty vector. Under nitrogen stress, TAG productivity was further increased twofold in comparison to nitrogen-replete conditions. While TAG accumulation was enhanced in the analyzed transformants, the fatty acid composition remained unchanged neither in the total lipid nor in the TAG profile. CONCLUSIONS The co-expression of two genes was shown to be a more effective strategy for enhancing TAG accumulation in P. tricornutum strain Pt4 than a single gene strategy. For the first time in a diatom, a LD protein from a vascular plant, oleosin, was shown to have an impact on TAG accumulation and on LD organization.
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Affiliation(s)
- Nodumo Nokulunga Zulu
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
- Novagreen Projektmanagement GmbH, 49377 Vechta, Germany
| | - Jennifer Popko
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Krzysztof Zienkiewicz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Pablo Tarazona
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Cornelia Herrfurth
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37077 Goettingen, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077 Goettingen, Germany
- Department of Plant Biochemistry, International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, 37077 Goettingen, Germany
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Zhi Y, Taylor MC, Campbell PM, Warden AC, Shrestha P, El Tahchy A, Rolland V, Vanhercke T, Petrie JR, White RG, Chen W, Singh SP, Liu Q. Comparative Lipidomics and Proteomics of Lipid Droplets in the Mesocarp and Seed Tissues of Chinese Tallow ( Triadica sebifera). FRONTIERS IN PLANT SCIENCE 2017; 8:1339. [PMID: 28824675 PMCID: PMC5541829 DOI: 10.3389/fpls.2017.01339] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/18/2017] [Indexed: 05/04/2023]
Abstract
Lipid droplets (LDs) are composed of a monolayer of phospholipids (PLs), surrounding a core of non-polar lipids that consist mostly of triacylglycerols (TAGs) and to a lesser extent diacylglycerols. In this study, lipidome analysis illustrated striking differences in non-polar lipids and PL species between LDs derived from Triadica sebifera seed kernels and mesocarp. In mesocarp LDs, the most abundant species of TAG contained one C18:1 and two C16:0 and fatty acids, while TAGs containing three C18 fatty acids with higher level of unsaturation were dominant in the seed kernel LDs. This reflects the distinct differences in fatty acid composition of mesocarp (palmitate-rich) and seed-derived oil (α-linoleneate-rich) in T. sebifera. Major PLs in seed LDs were found to be rich in polyunsaturated fatty acids, in contrast to those with relatively shorter carbon chain and lower level of unsaturation in mesocarp LDs. The LD proteome analysis in T. sebifera identified 207 proteins from mesocarp, and 54 proteins from seed kernel, which belong to various functional classes including lipid metabolism, transcription and translation, trafficking and transport, cytoskeleton, chaperones, and signal transduction. Oleosin and lipid droplets associated proteins (LDAP) were found to be the predominant proteins associated with LDs in seed and mesocarp tissues, respectively. We also show that LDs appear to be in close proximity to a number of organelles including the endoplasmic reticulum, mitochondria, peroxisomes, and Golgi apparatus. This comparative study between seed and mesocarp LDs may shed some light on the structure of plant LDs and improve our understanding of their functionality and cellular metabolic networks in oleaginous plant tissues.
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Affiliation(s)
- Yao Zhi
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
- CSIRO Agriculture and FoodCanberra, ACT, Australia
| | | | | | | | | | | | | | | | | | | | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
- *Correspondence: Wenli Chen
| | | | - Qing Liu
- CSIRO Agriculture and FoodCanberra, ACT, Australia
- Qing Liu
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Shemesh Z, Leu S, Khozin-Goldberg I, Didi-Cohen S, Zarka A, Boussiba S. Inducible expression of Haematococcus oil globule protein in the diatom Phaeodactylum tricornutum : Association with lipid droplets and enhancement of TAG accumulation under nitrogen starvation. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.07.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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36
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Goncalves EC, Wilkie AC, Kirst M, Rathinasabapathi B. Metabolic regulation of triacylglycerol accumulation in the green algae: identification of potential targets for engineering to improve oil yield. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:1649-60. [PMID: 26801206 PMCID: PMC5066758 DOI: 10.1111/pbi.12523] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/13/2015] [Accepted: 11/25/2015] [Indexed: 05/03/2023]
Abstract
The great need for more sustainable alternatives to fossil fuels has increased our research interests in algal biofuels. Microalgal cells, characterized by high photosynthetic efficiency and rapid cell division, are an excellent source of neutral lipids as potential fuel stocks. Various stress factors, especially nutrient-starvation conditions, induce an increased formation of lipid bodies filled with triacylglycerol in these cells. Here we review our knowledge base on glycerolipid synthesis in the green algae with an emphasis on recent studies on carbon flux, redistribution of lipids under nutrient-limiting conditions and its regulation. We discuss the contributions and limitations of classical and novel approaches used to elucidate the algal triacylglycerol biosynthetic pathway and its regulatory network in green algae. Also discussed are gaps in knowledge and suggestions for much needed research both on the biology of triacylglycerol accumulation and possible avenues to engineer improved algal strains.
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Affiliation(s)
- Elton C Goncalves
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Ann C Wilkie
- Soil and Water Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Matias Kirst
- School of Forestry, University of Florida, Gainesville, FL, USA
| | - Bala Rathinasabapathi
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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Huang MD, Huang AHC. Bioinformatics Reveal Five Lineages of Oleosins and the Mechanism of Lineage Evolution Related to Structure/Function from Green Algae to Seed Plants. PLANT PHYSIOLOGY 2015; 169:453-70. [PMID: 26232488 PMCID: PMC4577406 DOI: 10.1104/pp.15.00634] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/28/2015] [Indexed: 05/20/2023]
Abstract
Plant cells contain subcellular lipid droplets with a triacylglycerol matrix enclosed by a layer of phospholipids and the small structural protein oleosin. Oleosins possess a conserved central hydrophobic hairpin of approximately 72 residues penetrating into the lipid droplet matrix and amphipathic amino- and carboxyl (C)-terminal peptides lying on the phospholipid surface. Bioinformatics of 1,000 oleosins of green algae and all plants emphasizing biological implications reveal five oleosin lineages: primitive (in green algae, mosses, and ferns), universal (U; all land plants), and three in specific organs or phylogenetic groups, termed seed low-molecular-weight (SL; seed plants), seed high-molecular-weight (SH; angiosperms), and tapetum (T; Brassicaceae) oleosins. Transition from one lineage to the next is depicted from lineage intermediates at junctions of phylogeny and organ distributions. Within a species, each lineage, except the T oleosin lineage, has one to four genes per haploid genome, only approximately two of which are active. Primitive oleosins already possess all the general characteristics of oleosins. U oleosins have C-terminal sequences as highly conserved as the hairpin sequences; thus, U oleosins including their C-terminal peptide exert indispensable, unknown functions. SL and SH oleosin transcripts in seeds are in an approximately 1:1 ratio, which suggests the occurrence of SL-SH oleosin dimers/multimers. T oleosins in Brassicaceae are encoded by rapidly evolved multitandem genes for alkane storage and transfer. Overall, oleosins have evolved to retain conserved hairpin structures but diversified for unique structures and functions in specific cells and plant families. Also, our studies reveal oleosin in avocado (Persea americana) mesocarp and no acyltransferase/lipase motifs in most oleosins.
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Affiliation(s)
- Ming-Der Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan 11529 (M.-D.H.); andCenter for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92521 (A.H.C.H.)
| | - Anthony H C Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan 11529 (M.-D.H.); andCenter for Plant Cell Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92521 (A.H.C.H.)
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Kilaru A, Cao X, Dabbs PB, Sung HJ, Rahman MM, Thrower N, Zynda G, Podicheti R, Ibarra-Laclette E, Herrera-Estrella L, Mockaitis K, Ohlrogge JB. Oil biosynthesis in a basal angiosperm: transcriptome analysis of Persea Americana mesocarp. BMC PLANT BIOLOGY 2015. [PMID: 26276496 DOI: 10.1186/s12870-015-0586-582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND The mechanism by which plants synthesize and store high amounts of triacylglycerols (TAG) in tissues other than seeds is not well understood. The comprehension of controls for carbon partitioning and oil accumulation in nonseed tissues is essential to generate oil-rich biomass in perennial bioenergy crops. Persea americana (avocado), a basal angiosperm with unique features that are ancestral to most flowering plants, stores ~ 70 % TAG per dry weight in its mesocarp, a nonseed tissue. Transcriptome analyses of select pathways, from generation of pyruvate and leading up to TAG accumulation, in mesocarp tissues of avocado was conducted and compared with that of oil-rich monocot (oil palm) and dicot (rapeseed and castor) tissues to identify tissue- and species-specific regulation and biosynthesis of TAG in plants. RESULTS RNA-Seq analyses of select lipid metabolic pathways of avocado mesocarp revealed patterns similar to that of other oil-rich species. However, only some predominant orthologs of the fatty acid biosynthetic pathway genes in this basal angiosperm were similar to those of monocots and dicots. The accumulation of TAG, rich in oleic acid, was associated with higher transcript levels for a putative stearoyl-ACP desaturase and endoplasmic reticulum (ER)-associated acyl-CoA synthetases, during fruit development. Gene expression levels for enzymes involved in terminal steps to TAG biosynthesis in the ER further indicated that both acyl-CoA-dependent and -independent mechanisms might play a role in TAG assembly, depending on the developmental stage of the fruit. Furthermore, in addition to the expression of an ortholog of WRINKLED1 (WRI1), a regulator of fatty acid biosynthesis, high transcript levels for WRI2-like and WRI3-like suggest a role for additional transcription factors in nonseed oil accumulation. Plastid pyruvate necessary for fatty acid synthesis is likely driven by the upregulation of genes involved in glycolysis and transport of its intermediates. Together, a comparative transcriptome analyses for storage oil biosynthesis in diverse plants and tissues suggested that several distinct and conserved features in this basal angiosperm species might contribute towards its rich TAG content. CONCLUSIONS Our work represents a comprehensive transcriptome resource for a basal angiosperm species and provides insight into their lipid metabolism in mesocarp tissues. Furthermore, comparison of the transcriptome of oil-rich mesocarp of avocado, with oil-rich seed and nonseed tissues of monocot and dicot species, revealed lipid gene orthologs that are highly conserved during evolution. The orthologs that are distinctively expressed in oil-rich mesocarp tissues of this basal angiosperm, such as WRI2, ER-associated acyl-CoA synthetases, and lipid-droplet associated proteins were also identified. This study provides a foundation for future investigations to increase oil-content and has implications for metabolic engineering to enhance storage oil content in nonseed tissues of diverse species.
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Affiliation(s)
- Aruna Kilaru
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
| | - Xia Cao
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
- Bayer CropSciences, Morrisville, NC, 27560, USA.
| | - Parker B Dabbs
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
| | - Ha-Jung Sung
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
| | - Md Mahbubur Rahman
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
| | - Nicholas Thrower
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
| | - Greg Zynda
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47408, USA.
| | - Ram Podicheti
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47408, USA.
| | - Enrique Ibarra-Laclette
- Laboratorio Nacional de Genómica para la Biodiversidad-Langebio/Unidad de Genómica Avanzada UGA, Centro de Investigación y Estudios Avanzados del IPN, 36500, Irapuato, Guanajuato, Mexico.
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C., 91070, Xalapa, Veracruz, Mexico.
| | - Luis Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad-Langebio/Unidad de Genómica Avanzada UGA, Centro de Investigación y Estudios Avanzados del IPN, 36500, Irapuato, Guanajuato, Mexico.
| | | | - John B Ohlrogge
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA.
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39
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Kilaru A, Cao X, Dabbs PB, Sung HJ, Rahman MM, Thrower N, Zynda G, Podicheti R, Ibarra-Laclette E, Herrera-Estrella L, Mockaitis K, Ohlrogge JB. Oil biosynthesis in a basal angiosperm: transcriptome analysis of Persea Americana mesocarp. BMC PLANT BIOLOGY 2015; 15:203. [PMID: 26276496 PMCID: PMC4537532 DOI: 10.1186/s12870-015-0586-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/29/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND The mechanism by which plants synthesize and store high amounts of triacylglycerols (TAG) in tissues other than seeds is not well understood. The comprehension of controls for carbon partitioning and oil accumulation in nonseed tissues is essential to generate oil-rich biomass in perennial bioenergy crops. Persea americana (avocado), a basal angiosperm with unique features that are ancestral to most flowering plants, stores ~ 70 % TAG per dry weight in its mesocarp, a nonseed tissue. Transcriptome analyses of select pathways, from generation of pyruvate and leading up to TAG accumulation, in mesocarp tissues of avocado was conducted and compared with that of oil-rich monocot (oil palm) and dicot (rapeseed and castor) tissues to identify tissue- and species-specific regulation and biosynthesis of TAG in plants. RESULTS RNA-Seq analyses of select lipid metabolic pathways of avocado mesocarp revealed patterns similar to that of other oil-rich species. However, only some predominant orthologs of the fatty acid biosynthetic pathway genes in this basal angiosperm were similar to those of monocots and dicots. The accumulation of TAG, rich in oleic acid, was associated with higher transcript levels for a putative stearoyl-ACP desaturase and endoplasmic reticulum (ER)-associated acyl-CoA synthetases, during fruit development. Gene expression levels for enzymes involved in terminal steps to TAG biosynthesis in the ER further indicated that both acyl-CoA-dependent and -independent mechanisms might play a role in TAG assembly, depending on the developmental stage of the fruit. Furthermore, in addition to the expression of an ortholog of WRINKLED1 (WRI1), a regulator of fatty acid biosynthesis, high transcript levels for WRI2-like and WRI3-like suggest a role for additional transcription factors in nonseed oil accumulation. Plastid pyruvate necessary for fatty acid synthesis is likely driven by the upregulation of genes involved in glycolysis and transport of its intermediates. Together, a comparative transcriptome analyses for storage oil biosynthesis in diverse plants and tissues suggested that several distinct and conserved features in this basal angiosperm species might contribute towards its rich TAG content. CONCLUSIONS Our work represents a comprehensive transcriptome resource for a basal angiosperm species and provides insight into their lipid metabolism in mesocarp tissues. Furthermore, comparison of the transcriptome of oil-rich mesocarp of avocado, with oil-rich seed and nonseed tissues of monocot and dicot species, revealed lipid gene orthologs that are highly conserved during evolution. The orthologs that are distinctively expressed in oil-rich mesocarp tissues of this basal angiosperm, such as WRI2, ER-associated acyl-CoA synthetases, and lipid-droplet associated proteins were also identified. This study provides a foundation for future investigations to increase oil-content and has implications for metabolic engineering to enhance storage oil content in nonseed tissues of diverse species.
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Affiliation(s)
- Aruna Kilaru
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
| | - Xia Cao
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
- Bayer CropSciences, Morrisville, NC, 27560, USA.
| | - Parker B Dabbs
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
| | - Ha-Jung Sung
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
| | - Md Mahbubur Rahman
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN, 37614, USA.
| | - Nicholas Thrower
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
| | - Greg Zynda
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47408, USA.
| | - Ram Podicheti
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47408, USA.
| | - Enrique Ibarra-Laclette
- Laboratorio Nacional de Genómica para la Biodiversidad-Langebio/Unidad de Genómica Avanzada UGA, Centro de Investigación y Estudios Avanzados del IPN, 36500, Irapuato, Guanajuato, Mexico.
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C., 91070, Xalapa, Veracruz, Mexico.
| | - Luis Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad-Langebio/Unidad de Genómica Avanzada UGA, Centro de Investigación y Estudios Avanzados del IPN, 36500, Irapuato, Guanajuato, Mexico.
| | | | - John B Ohlrogge
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA.
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40
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Tsai CH, Zienkiewicz K, Amstutz CL, Brink BG, Warakanont J, Roston R, Benning C. Dynamics of protein and polar lipid recruitment during lipid droplet assembly in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:650-60. [PMID: 26096381 DOI: 10.1111/tpj.12917] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/14/2015] [Accepted: 06/16/2015] [Indexed: 05/03/2023]
Abstract
In plants, neutral lipids are frequently synthesized and stored in seed tissues, where the assembly of lipid droplets (LDs) coincides with the accumulation of triacylglycerols (TAGs). In addition, photosynthetic, vegetative cells can form cytosolic LDs and much less information is known about the makeup and biogenesis of these LDs. Here we focus on Chlamydomonas reinhardtii as a reference model for LDs in a photosynthetic cell, because in this unicellular green alga LD dynamics can be readily manipulated by nitrogen availability. Nitrogen deprivation leads to cellular quiescence during which cell divisions cease and TAGs accumulate. The major lipid droplet protein (MLDP) forms a proteinaceous coat surrounding mature LDs. Reducing the amount of MLDP affects LD size and number, TAG breakdown and timely progression out of cellular quiescence following nitrogen resupply. Depending on nitrogen availability, MLDP recruits different proteins to LDs, tubulins in particular. Conversely, depolymerization of microtubules drastically alters the association of MLDP with LDs. LDs also contain select chloroplast envelope membrane proteins hinting at an origin of LDs, at least in part, from chloroplast membranes. Moreover, LD surface lipids are rich in de novo synthesized fatty acids, and are mainly composed of galactolipids which are typical components of chloroplast membranes. The composition of the LD membrane is altered in the absence of MLDP. Collectively, our results suggest a mechanism for LD formation in C. reinhardtii involving chloroplast envelope membranes by which specific proteins are recruited to LDs and a specialized polar lipid monolayer surrounding the LD is formed.
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Affiliation(s)
- Chia-Hong Tsai
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Krzysztof Zienkiewicz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073, Göttingen, Germany
| | - Cynthia L Amstutz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Benedikt G Brink
- Department of Biology and Center for Biotechnology, Bielefeld University, 33615, Bielefeld, Germany
| | - Jaruswan Warakanont
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Rebecca Roston
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
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41
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D'Andrea S. Lipid droplet mobilization: The different ways to loosen the purse strings. Biochimie 2015; 120:17-27. [PMID: 26187474 DOI: 10.1016/j.biochi.2015.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/11/2015] [Indexed: 01/25/2023]
Abstract
Cytosolic lipid droplets are dynamic lipid-storage organelles that play a crucial role as reservoirs of metabolic energy and membrane precursors. These organelles are present in virtually all cell types, from unicellular to pluricellular organisms. Despite similar structural organization, lipid droplets are heterogeneous in morphology, distribution and composition. The protein repertoire associated to lipid droplet controls the organelle dynamics. Distinct structural lipid droplet proteins are associated to specific lipolytic pathways. The role of these structural lipid droplet-associated proteins in the control of lipid droplet degradation and lipid store mobilization is discussed. The control of the strictly-regulated lipolysis in lipid-storing tissues is compared between mammals and plants. Differences in the cellular regulation of lipolysis between lipid-storing tissues and other cell types are also discussed.
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Affiliation(s)
- Sabine D'Andrea
- INRA, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France; AgroParisTech, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France.
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42
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Li-Beisson Y, Beisson F, Riekhof W. Metabolism of acyl-lipids in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:504-522. [PMID: 25660108 DOI: 10.1111/tpj.12787] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 01/24/2015] [Accepted: 02/02/2015] [Indexed: 05/03/2023]
Abstract
Microalgae are emerging platforms for production of a suite of compounds targeting several markets, including food, nutraceuticals, green chemicals, and biofuels. Many of these products, such as biodiesel or polyunsaturated fatty acids (PUFAs), derive from lipid metabolism. A general picture of lipid metabolism in microalgae has been deduced from well characterized pathways of fungi and land plants, but recent advances in molecular and genetic analyses of microalgae have uncovered unique features, pointing out the necessity to study lipid metabolism in microalgae themselves. In the past 10 years, in addition to its traditional role as a model for photosynthetic and flagellar motility processes, Chlamydomonas reinhardtii has emerged as a model organism to study lipid metabolism in green microalgae. Here, after summarizing data on total fatty acid composition, distribution of acyl-lipid classes, and major acyl-lipid molecular species found in C. reinhardtii, we review the current knowledge on the known or putative steps for fatty acid synthesis, glycerolipid desaturation and assembly, membrane lipid turnover, and oil remobilization. A list of characterized or putative enzymes for the major steps of acyl-lipid metabolism in C. reinhardtii is included, and subcellular localizations and phenotypes of associated mutants are discussed. Biogenesis and composition of Chlamydomonas lipid droplets and the potential importance of lipolytic processes in increasing cellular oil content are also highlighted.
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Affiliation(s)
- Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique (CNRS), 13108, Saint-Paul-lez-Durance, France
- Aix-Marseille Université, UMR 7265, 13284, Marseille, France
| | - Fred Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique (CNRS), 13108, Saint-Paul-lez-Durance, France
- Aix-Marseille Université, UMR 7265, 13284, Marseille, France
| | - Wayne Riekhof
- School of Biological Sciences and Center for Biological Chemistry, University of Nebraska - Lincoln, Lincoln, NE, 68588, USA
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43
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Goold H, Beisson F, Peltier G, Li-Beisson Y. Microalgal lipid droplets: composition, diversity, biogenesis and functions. PLANT CELL REPORTS 2015; 34:545-55. [PMID: 25433857 DOI: 10.1007/s00299-014-1711-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/12/2014] [Accepted: 11/19/2014] [Indexed: 05/03/2023]
Abstract
Lipid droplet is the major site of neutral lipid storage in eukaryotic cells, and increasing evidence show its involvement in numerous cellular processes such as lipid homeostasis, signaling, trafficking and inter-organelle communications. Although the biogenesis, structure, and functions of lipid droplets have been well documented for seeds of vascular plants, mammalian adipose tissues, insects and yeasts, relative little is known about lipid droplets in microalgae. Over the past 5 years, the growing interest of microalgae as a platform for biofuel, green chemicals or value-added polyunsaturated fatty acid production has brought algal lipid droplets into spotlight. Studies conducted on the green microalga Chlamydomonas reinhardtii and other model microalgae such as Haematococcus and Nannochloropsis species have led to the identification of proteins associated with lipid droplets, which include putative structural proteins different from plant oleosins and animal perilipins, as well as candidate proteins for lipid biosynthesis, mobilization, trafficking and homeostasis. Biochemical and microscopy studies have also started to shed light on the role of chloroplasts in the biogenesis of lipid droplets in Chlamydomonas.
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Affiliation(s)
- Hugh Goold
- CEA, IBEB, Lab Bioenerget Biotechnol Bacteries and Microalgues, Saint-Paul-lez-Durance, 13108, France
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44
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Charuchinda P, Waditee-Sirisattha R, Kageyama H, Yamada D, Sirisattha S, Tanaka Y, Mahakhant A, Takabe T. Caleosin from Chlorella vulgaris TISTR 8580 is salt-induced and heme-containing protein. Biosci Biotechnol Biochem 2015; 79:1119-24. [PMID: 25703935 DOI: 10.1080/09168451.2015.1010480] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Physiological and functional properties of lipid droplet-associated proteins in algae remain scarce. We report here the caleosin gene from Chlorella vulgaris encodes a protein of 279 amino acid residues. Amino acid sequence alignment showed high similarity to the putative caleosins from fungi, but less to plant caleosins. When the C. vulgaris TISTR 8580 cells were treated with salt stress (0.3 M NaCl), the level of triacylglycerol increased significantly. The mRNA contents for caleosin in Chlorella cells significantly increased under salt stress condition. Caleosin gene was expressed in E. coli. Crude extract of E. coli cells exhibited the cumene hydroperoxide-dependent oxidation of aniline. Absorption spectroscopy showed a peak around 415 nm which was decreased upon addition of cumene hydroperoxide. Native polyacrylamide gel electrophoresis suggests caleosin existed as the oligomer. These data indicate that a fresh water C. vulgaris TISTR 8580 contains a salt-induced heme-protein caleosin.
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Affiliation(s)
- Pairpilin Charuchinda
- a Graduate School of Environmental and Human Sciences , Meijo University , Nagoya , Japan
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45
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Davidi L, Levin Y, Ben-Dor S, Pick U. Proteome analysis of cytoplasmatic and plastidic β-carotene lipid droplets in Dunaliella bardawil. PLANT PHYSIOLOGY 2015; 167:60-79. [PMID: 25404729 PMCID: PMC4281002 DOI: 10.1104/pp.114.248450] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The halotolerant green alga Dunaliella bardawil is unique in that it accumulates under stress two types of lipid droplets: cytoplasmatic lipid droplets (CLD) and β-carotene-rich (βC) plastoglobuli. Recently, we isolated and analyzed the lipid and pigment compositions of these lipid droplets. Here, we describe their proteome analysis. A contamination filter and an enrichment filter were utilized to define core proteins. A proteome database of Dunaliella salina/D. bardawil was constructed to aid the identification of lipid droplet proteins. A total of 124 and 42 core proteins were identified in βC-plastoglobuli and CLD, respectively, with only eight common proteins. Dunaliella spp. CLD resemble cytoplasmic droplets from Chlamydomonas reinhardtii and contain major lipid droplet-associated protein and enzymes involved in lipid and sterol metabolism. The βC-plastoglobuli proteome resembles the C. reinhardtii eyespot and Arabidopsis (Arabidopsis thaliana) plastoglobule proteomes and contains carotene-globule-associated protein, plastid-lipid-associated protein-fibrillins, SOUL heme-binding proteins, phytyl ester synthases, β-carotene biosynthesis enzymes, and proteins involved in membrane remodeling/lipid droplet biogenesis: VESICLE-INDUCING PLASTID PROTEIN1, synaptotagmin, and the eyespot assembly proteins EYE3 and SOUL3. Based on these and previous results, we propose models for the biogenesis of βC-plastoglobuli and the biosynthesis of β-carotene within βC-plastoglobuli and hypothesize that βC-plastoglobuli evolved from eyespot lipid droplets.
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Affiliation(s)
- Lital Davidi
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yishai Levin
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
| | - Shifra Ben-Dor
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
| | - Uri Pick
- Department of Biological Chemistry (L.D., U.P.), Nancy and Stephen Grand Israel National Center for Personalized Medicine (Y.L.), and Biological Services Unit (S.B.-D.), Weizmann Institute of Science, Rehovot 76100, Israel
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Liu Y, Zhang C, Shen X, Zhang X, Cichello S, Guan H, Liu P. Microorganism lipid droplets and biofuel development. BMB Rep 2014; 46:575-81. [PMID: 24355300 PMCID: PMC4133864 DOI: 10.5483/bmbrep.2013.46.12.271] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Indexed: 01/28/2023] Open
Abstract
Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from CO2 via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech ‘factories’ to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development. [BMB Reports 2013; 46(12): 575-581]
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Affiliation(s)
| | | | | | | | | | - Hongbin Guan
- Marine College, Shandong University at Weihai, 180 Wenhua Xilu, Weihai, Shandong 264209, China
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese, Academy of Sciences, Beijing 100101, China
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Abstract
Oleosins form a steric barrier surface on lipid droplets in cytoplasm, preventing them from contacting and coalescing with adjacent droplets. Oleosin genes have been detected in numerous plant species. However, the presence of oleosin genes in the most basally diverging lineage of land plants, liverworts, has not been reported previously. Thus we explored whether liverworts have an oleosin gene. In Marchantia polymorpha L., a thalloid liverwort, one predicted sequence was found that could encode oleosin, possessing the hallmark of oleosin, a proline knot (-PX5SPX3P-) motif. The phylogeny of the oleosin gene family in land plants was reconstructed based on both nucleotide and amino acid sequences of oleosins, from 31 representative species covering almost all the main lineages of land plants. Based on our phylogenetic trees, oleosin genes were classified into three groups: M-oleosins (defined here as a novel group distinct from the two previously known groups), low molecular weight isoform (L-oleosin), and high molecular weight isoform (H-oleosin), according to their amino-acid organization, phylogenetic relationships, expression tissues, and immunological characteristics. In liverworts, mosses, lycophytes, and gymnosperms, only M-oleosins have been described. In angiosperms, however, while this isoform remains and is highly expressed in the gametophyte pollen tube, two other isoforms also occur, L-oleosins and H-oleosins. Phylogenetic analyses suggest that the M-oleosin isoform is the precursor to the ancestor of L-oleosins and H-oleosins. The later two isoforms evolved by successive gene duplications in ancestral angiosperms. At the genomic level, most oleosins possess no introns. If introns are present, in both the L-isoform and the M-isoform a single intron inserts behind the central region, while in the H-isoform, a single intron is located at the 5'-terminus. This study fills a major gap in understanding functional gene evolution of oleosin in land plants, shedding new light on evolutionary transitions of lipid storage strategies.
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Affiliation(s)
- Yuan Fang
- School of Life Science, East China Normal University, Shanghai, China
- University and Jepson Herbaria, and Department of Integrative Biology, University of California, Berkeley, California, United State of America
| | - Rui-Liang Zhu
- School of Life Science, East China Normal University, Shanghai, China
| | - Brent D. Mishler
- University and Jepson Herbaria, and Department of Integrative Biology, University of California, Berkeley, California, United State of America
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Davidi L, Shimoni E, Khozin-Goldberg I, Zamir A, Pick U. Origin of β-carotene-rich plastoglobuli in Dunaliella bardawil. PLANT PHYSIOLOGY 2014; 164:2139-56. [PMID: 24567188 PMCID: PMC3982768 DOI: 10.1104/pp.113.235119] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 02/20/2014] [Indexed: 05/17/2023]
Abstract
The halotolerant microalgae Dunaliella bardawil accumulates under nitrogen deprivation two types of lipid droplets: plastoglobuli rich in β-carotene (βC-plastoglobuli) and cytoplasmatic lipid droplets (CLDs). We describe the isolation, composition, and origin of these lipid droplets. Plastoglobuli contain β-carotene, phytoene, and galactolipids missing in CLDs. The two preparations contain different lipid-associated proteins: major lipid droplet protein in CLD and the Prorich carotene globule protein in βC-plastoglobuli. The compositions of triglyceride (TAG) molecular species, total fatty acids, and sn-1+3 and sn-2 positions in the two lipid pools are similar, except for a small increase in palmitic acid in plastoglobuli, suggesting a common origin. The formation of CLD TAG precedes that of βC-plastoglobuli, reaching a maximum after 48 h of nitrogen deprivation and then decreasing. Palmitic acid incorporation kinetics indicated that, at early stages of nitrogen deprivation, CLD TAG is synthesized mostly from newly formed fatty acids, whereas in βC-plastoglobuli, a large part of TAG is produced from fatty acids of preformed membrane lipids. Electron microscopic analyses revealed that CLDs adhere to chloroplast envelope membranes concomitant with appearance of small βC-plastoglobuli within the chloroplast. Based on these results, we propose that CLDs in D. bardawil are produced in the endoplasmatic reticulum, whereas βC-plastoglobuli are made, in part, from hydrolysis of chloroplast membrane lipids and in part, by a continual transfer of TAG or fatty acids derived from CLD.
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López-Ribera I, La Paz JL, Repiso C, García N, Miquel M, Hernández ML, Martínez-Rivas JM, Vicient CM. The evolutionary conserved oil body associated protein OBAP1 participates in the regulation of oil body size. PLANT PHYSIOLOGY 2014; 164:1237-49. [PMID: 24406791 PMCID: PMC3938616 DOI: 10.1104/pp.113.233221] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 01/06/2014] [Indexed: 05/23/2023]
Abstract
A transcriptomic approach has been used to identify genes predominantly expressed in maize (Zea mays) scutellum during maturation. One of the identified genes is oil body associated protein1 (obap1), which is transcribed during seed maturation predominantly in the scutellum, and its expression decreases rapidly after germination. Proteins similar to OBAP1 are present in all plants, including primitive plants and mosses, and in some fungi and bacteria. In plants, obap genes are divided in two subfamilies. Arabidopsis (Arabidopsis thaliana) genome contains five genes coding for OBAP proteins. Arabidopsis OBAP1a protein is accumulated during seed maturation and disappears after germination. Agroinfiltration of tobacco (Nicotiana benthamiana) epidermal leaf cells with fusions of OBAP1 to yellow fluorescent protein and immunogold labeling of embryo transmission electron microscopy sections showed that OBAP1 protein is mainly localized in the surface of the oil bodies. OBAP1 protein was detected in the oil body cellular fraction of Arabidopsis embryos. Deletion analyses demonstrate that the most hydrophilic part of the protein is responsible for the oil body localization, which suggests an indirect interaction of OBAP1 with other proteins in the oil body surface. An Arabidopsis mutant with a transfer DNA inserted in the second exon of the obap1a gene and an RNA interference line against the same gene showed a decrease in the germination rate, a decrease in seed oil content, and changes in fatty acid composition, and their embryos have few, big, and irregular oil bodies compared with the wild type. Taken together, our findings suggest that OBAP1 protein is involved in the stability of oil bodies.
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The path to triacylglyceride obesity in the sta6 strain of Chlamydomonas reinhardtii. EUKARYOTIC CELL 2014; 13:591-613. [PMID: 24585881 DOI: 10.1128/ec.00013-14] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
When the sta6 (starch-null) strain of the green microalga Chlamydomonas reinhardtii is nitrogen starved in acetate and then "boosted" after 2 days with additional acetate, the cells become "obese" after 8 days, with triacylglyceride (TAG)-filled lipid bodies filling their cytoplasm and chloroplasts. To assess the transcriptional correlates of this response, the sta6 strain and the starch-forming cw15 strain were subjected to RNA-Seq analysis during the 2 days prior and 2 days after the boost, and the data were compared with published reports using other strains and growth conditions. During the 2 h after the boost, ∼425 genes are upregulated ≥2-fold and ∼875 genes are downregulated ≥2-fold in each strain. Expression of a small subset of "sensitive" genes, encoding enzymes involved in the glyoxylate and Calvin-Benson cycles, gluconeogenesis, and the pentose phosphate pathway, is responsive to culture conditions and genetic background as well as to boosting. Four genes-encoding a diacylglycerol acyltransferase (DGTT2), a glycerol-3-P dehydrogenase (GPD3), and two candidate lipases (Cre03.g155250 and Cre17.g735600)-are selectively upregulated in the sta6 strain. Although the bulk rate of acetate depletion from the medium is not boost enhanced, three candidate acetate permease-encoding genes in the GPR1/FUN34/YaaH superfamily are boost upregulated, and 13 of the "sensitive" genes are strongly responsive to the cell's acetate status. A cohort of 64 autophagy-related genes is downregulated by the boost. Our results indicate that the boost serves both to avert an autophagy program and to prolong the operation of key pathways that shuttle carbon from acetate into storage lipid, the combined outcome being enhanced TAG accumulation, notably in the sta6 strain.
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