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Sah SK, Fan J, Blanford J, Shanklin J, Xu C. Physiological Functions of Phospholipid:Diacylglycerol Acyltransferases. PLANT & CELL PHYSIOLOGY 2024; 65:863-871. [PMID: 37702708 DOI: 10.1093/pcp/pcad106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/01/2023] [Accepted: 09/08/2023] [Indexed: 09/14/2023]
Abstract
Triacylglycerol (TAG) is among the most energy dense storage forms of reduced carbon in living systems. TAG metabolism plays critical roles in cellular energy balance, lipid homeostasis, cell growth and stress responses. In higher plants, microalgae and fungi, TAG is assembled by acyl-CoA-dependent and acyl-CoA-independent pathways catalyzed by diacylglycerol (DAG) acyltransferase and phospholipid:DAG acyltransferase (PDAT), respectively. This review contains a summary of the current understanding of the physiological functions of PDATs. Emphasis is placed on their role in lipid remodeling and lipid homeostasis in response to abiotic stress or perturbations in lipid metabolism.
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Affiliation(s)
- Saroj Kumar Sah
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jantana Blanford
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | | | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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2
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Zhang WJ, Tang LP, Peng J, Zhai LM, Ma QL, Zhang XS, Su YH. A WRI1-dependent module is essential for the accumulation of auxin and lipid in somatic embryogenesis of Arabidopsis thaliana. THE NEW PHYTOLOGIST 2024; 242:1098-1112. [PMID: 38515249 DOI: 10.1111/nph.19689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/19/2024] [Indexed: 03/23/2024]
Abstract
The potential for totipotency exists in all plant cells; however, the underlying mechanisms remain largely unknown. Earlier findings have revealed that the overexpression of LEAFY COTYLEDON 2 (LEC2) can directly trigger the formation of somatic embryos on the cotyledons of Arabidopsis. Furthermore, cotyledon cells that overexpress LEC2 accumulate significant lipid reserves typically found in seeds. The precise mechanisms and functions governing lipid accumulation in this process remain unexplored. In this study, we demonstrate that WRINKLED1 (WRI1), the key regulator of lipid biosynthesis, is essential for somatic embryo formation, suggesting that WRI1-mediated lipid biosynthesis plays a crucial role in the transition from vegetative to embryonic development. Our findings indicate a direct interaction between WRI1 and LEC2, which enhances the enrichment of LEC2 at downstream target genes and stimulates their induction. Besides, our data suggest that WRI1 forms a complex with LEC1, LEC2, and FUSCA3 (FUS3) to facilitate the accumulation of auxin and lipid for the somatic embryo induction, through strengthening the activation of YUCCA4 (YUC4) and OLEOSIN3 (OLE3) genes. Our results uncover a regulatory module controlled by WRI1, crucial for somatic embryogenesis. These findings provide valuable insights into our understanding of plant cell totipotency.
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Affiliation(s)
- Wen Jie Zhang
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Li Ping Tang
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Jing Peng
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Li Ming Zhai
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Qiu Li Ma
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Xian Sheng Zhang
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
| | - Ying Hua Su
- National Key Laboratory of Wheat Improvement, College of Life Science, Shandong Agricultural University, Tai'an, Shandong, 271018, China
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3
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Shomo ZD, Mahboub S, Vanviratikul H, McCormick M, Tulyananda T, Roston RL, Warakanont J. All members of the Arabidopsis DGAT and PDAT acyltransferase families operate during high and low temperatures. PLANT PHYSIOLOGY 2024; 195:685-697. [PMID: 38386316 DOI: 10.1093/plphys/kiae074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/04/2024] [Accepted: 01/16/2024] [Indexed: 02/23/2024]
Abstract
The accumulation of triacylglycerol (TAG) in vegetative tissues is necessary to adapt to changing temperatures. It has been hypothesized that TAG accumulation is required as a storage location for maladaptive membrane lipids. The TAG acyltransferase family has five members (DIACYLGLYCEROL ACYLTRANSFERSE1/2/3 and PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1/2), and their individual roles during temperature challenges have either been described conflictingly or not at all. Therefore, we used Arabidopsis (Arabidopsis thaliana) loss of function mutants in each acyltransferase to investigate the effects of temperature challenge on TAG accumulation, plasma membrane integrity, and temperature tolerance. All mutants were tested under one high- and two low-temperature regimens, during which we quantified lipids, assessed temperature sensitivity, and measured plasma membrane electrolyte leakage. Our findings revealed reduced effectiveness in TAG production during at least one temperature regimen for all acyltransferase mutants compared to the wild type, resolved conflicting roles of pdat1 and dgat1 by demonstrating their distinct temperature-specific actions, and uncovered that plasma membrane integrity and TAG accumulation do not always coincide, suggesting a multifaceted role of TAG beyond its conventional lipid reservoir function during temperature stress.
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Affiliation(s)
- Zachery D Shomo
- Center for Plant Science Innovation, Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Samira Mahboub
- Center for Plant Science Innovation, Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | | | - Mason McCormick
- Center for Plant Science Innovation, Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Tatpong Tulyananda
- School of Bioinnovation and Bio-Based Product Intelligence, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Rebecca L Roston
- Center for Plant Science Innovation, Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Jaruswan Warakanont
- Department of Botany, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
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4
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Gong W, Chen W, Gao Q, Qian L, Yuan X, Tang S, Hong Y. Glycerol-3-Phosphate Acyltransferase GPAT9 Enhanced Seed Oil Accumulation and Eukaryotic Galactolipid Synthesis in Brassica napus. Int J Mol Sci 2023; 24:16111. [PMID: 38003299 PMCID: PMC10671787 DOI: 10.3390/ijms242216111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/03/2023] [Accepted: 11/04/2023] [Indexed: 11/26/2023] Open
Abstract
Glycerol-3-phosphate acyltransferase GPAT9 catalyzes the first acylation of glycerol-3-phosphate (G3P), a committed step of glycerolipid synthesis in Arabidopsis. The role of GPAT9 in Brassica napus remains to be elucidated. Here, we identified four orthologs of GPAT9 and found that BnaGPAT9 encoded by BnaC01T0014600WE is a predominant isoform and promotes seed oil accumulation and eukaryotic galactolipid synthesis in Brassica napus. BnaGPAT9 is highly expressed in developing seeds and is localized in the endoplasmic reticulum (ER). Ectopic expression of BnaGPAT9 in E. coli and siliques of Brassica napus enhanced phosphatidic acid (PA) production. Overexpression of BnaGPAT9 enhanced seed oil accumulation resulting from increased 18:2-fatty acid. Lipid profiling in developing seeds showed that overexpression of BnaGPAT9 led to decreased phosphatidylcholine (PC) and a corresponding increase in phosphatidylethanolamine (PE), implying that BnaGPAT9 promotes PC flux to storage triacylglycerol (TAG). Furthermore, overexpression of BnaGPAT9 also enhanced eukaryotic galactolipids including monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), with increased 36:6-MGDG and 36:6-DGDG, and decreased 34:6-MGDG in developing seeds. Collectively, these results suggest that ER-localized BnaGPAT9 promotes PA production, thereby enhancing seed oil accumulation and eukaryotic galactolipid biosynthesis in Brassica napus.
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Affiliation(s)
| | | | | | | | | | | | - Yueyun Hong
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China; (W.G.); (W.C.); (Q.G.); (L.Q.); (X.Y.); (S.T.)
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5
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Cao VD, Luo G, Korynta S, Liu H, Liang Y, Shanklin J, Altpeter F. Intron-mediated enhancement of DIACYLGLYCEROL ACYLTRANSFERASE1 expression in energycane promotes a step change for lipid accumulation in vegetative tissues. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:153. [PMID: 37838699 PMCID: PMC10576891 DOI: 10.1186/s13068-023-02393-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 09/09/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Metabolic engineering for hyperaccumulation of lipids in vegetative tissues is a novel strategy for enhancing energy density and biofuel production from biomass crops. Energycane is a prime feedstock for this approach due to its high biomass production and resilience under marginal conditions. DIACYLGLYCEROL ACYLTRANSFERASE (DGAT) catalyzes the last and only committed step in the biosynthesis of triacylglycerol (TAG) and can be a rate-limiting enzyme for the production of TAG. RESULTS In this study, we explored the effect of intron-mediated enhancement (IME) on the expression of DGAT1 and resulting accumulation of TAG and total fatty acid (TFA) in leaf and stem tissues of energycane. To maximize lipid accumulation these evaluations were carried out by co-expressing the lipogenic transcription factor WRINKLED1 (WRI1) and the TAG protect factor oleosin (OLE1). Including an intron in the codon-optimized TmDGAT1 elevated the accumulation of its transcript in leaves by seven times on average based on 5 transgenic lines for each construct. Plants with WRI1 (W), DGAT1 with intron (Di), and OLE1 (O) expression (WDiO) accumulated TAG up to a 3.85% of leaf dry weight (DW), a 192-fold increase compared to non-modified energycane (WT) and a 3.8-fold increase compared to the highest accumulation under the intron-less gene combination (WDO). This corresponded to TFA accumulation of up to 8.4% of leaf dry weight, a 2.8-fold or 6.1-fold increase compared to WDO or WT, respectively. Co-expression of WDiO resulted in stem accumulations of TAG up to 1.14% of DW or TFA up to 2.08% of DW that exceeded WT by 57-fold or 12-fold and WDO more than twofold, respectively. Constitutive expression of these lipogenic "push pull and protect" factors correlated with biomass reduction. CONCLUSIONS Intron-mediated enhancement (IME) of the expression of DGAT resulted in a step change in lipid accumulation of energycane and confirmed that under our experimental conditions it is rate limiting for lipid accumulation. IME should be applied to other lipogenic factors and metabolic engineering strategies. The findings from this study may be valuable in developing a high biomass feedstock for commercial production of lipids and advanced biofuels.
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Affiliation(s)
- Viet Dang Cao
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA
| | - Guangbin Luo
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA
| | - Shelby Korynta
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA
| | - Hui Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA
| | - Yuanxue Liang
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA.
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, USA.
- Biosciences Department, Brookhaven National Laboratory, Upton, NY, USA.
| | - Fredy Altpeter
- Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA.
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Gainesville, FL, USA.
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Hu W, Ma J, Zhang H, Miu X, Miao X, Deng Y. Integrated lipidomic and transcriptomic analysis reveals diacylglycerol accumulation in olive of Longnan (China). PeerJ 2023; 11:e15724. [PMID: 37583911 PMCID: PMC10424668 DOI: 10.7717/peerj.15724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/18/2023] [Indexed: 08/17/2023] Open
Abstract
Background Olive (Olea europaea L.) oil accumulate more diacylglycerols (DAG) than mostly vegetable oils. Unsaturated fatty acids-enriched DAG consumption enhanced wellness in subjects. However, the mechanism of DAG accumulation is not yet fully understood. Methods In this study, gene network of DAG accumulation and fatty acid composition in the two olive mesocarps ("Chenggu 32" (CG) and "Koroneiki" (QJ)) were investigated by integrating lipidome and transcriptome techniques. Results A total of 1,408 lipid molecules were identified by lipidomic analysis in olive mesocarp, of which DAG (DAG36:3, DAG36:4 and DAG36:5) showed higher content, and triacylglycerols (TAG54:3, TAG54:4) exhibited opposite trend in CG. Specifically, DAG was rich in polyunsaturated fatty acids (especially C18:2) at the sn-2 position, which was inconsistent with TAG at the same positions (Primarily C18:1). Transcriptomic analysis revealed that phospholipase C (NPC, EC 3.1.4.3) were up-regulated relative to QJ, whereas diacylglycerol kinase (ATP) (DGK, EC 2.7.1.107), diacylglycerol acyltransferase (DGAT, EC 2.3.1.20), and phospholipid: diacylglycerol acyltransferase (PDAT, EC 2.3.1.158) were down-regulated. Conclusion We speculated that the non-acyl coenzyme A pathway played a significant role in DAG biosynthesis. Additionally, fatty acyl-ACP thioesterase B (FATB, EC 3.1.2.14), stearoyl [acyl-carrier-protein] 9-desaturase (SAD, EC 1.14.19.2) and omega-6 fatty acid desaturase (FAD2, EC 1.14.19.6) were highly expressed in CG and may be involved in regulating fatty acid composition. Meanwhile, phospholipase A1 (LCAT, EC 3.1.1.32) involved in the acyl editing reaction facilitated PUFA linkage at the sn-2 position of DAG. Our findings provide novel insights to increase the DAG content, improve the fatty acid composition of olive oil, and identify candidate genes for the production of DAG-rich oils.
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Affiliation(s)
- Wei Hu
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, China
| | - Junyi Ma
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, China
| | - Hongjie Zhang
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, China
| | - Xin Miu
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, China
| | - Xin Miao
- College of Life Science, Northwest Normal University, Lanzhou, Gansu, China
| | - Yu Deng
- Institute of Olive, Longnan Academy of Economic Forestry, Wudu, Gansu, China
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7
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Klińska-Bąchor S, Kędzierska S, Demski K, Banaś A. Phospholipid:diacylglycerol acyltransferase1-overexpression stimulates lipid turnover, oil production and fitness in cold-grown plants. BMC PLANT BIOLOGY 2023; 23:370. [PMID: 37491206 PMCID: PMC10369929 DOI: 10.1186/s12870-023-04379-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/12/2023] [Indexed: 07/27/2023]
Abstract
BACKGROUND Extensive population growth and climate change accelerate the search for alternative ways of plant-based biomass, biofuel and feed production. Here, we focus on hitherto unknow, new promising cold-stimulated function of phospholipid:diacylglycerol acyltransferase1 (PDAT1) - an enzyme catalyzing the last step of triacylglycerol (TAG) biosynthesis. RESULT Overexpression of AtPDAT1 boosted seed yield by 160% in Arabidopsis plants exposed to long-term cold compared to standard conditions. Such seeds increased both their weight and acyl-lipids content. This work also elucidates PDAT1's role in leaves, which was previously unclear. Aerial parts of AtPDAT1-overexpressing plants were characterized by accelerated growth at early and vegetative stages of development and by biomass weighing three times more than control. Overexpression of PDAT1 increased the expression of SUGAR-DEPENDENT1 (SDP1) TAG lipase and enhanced lipid remodeling, driving lipid turnover and influencing biomass increment. This effect was especially pronounced in cold conditions, where the elevated synergistic expression of PDAT1 and SDP1 resulted in double biomass increase compared to standard conditions. Elevated phospholipid remodeling also enhanced autophagy flux in AtPDAT1-overexpresing lines subjected to cold, despite the overall diminished autophagy intensity in cold conditions. CONCLUSIONS Our data suggest that PDAT1 promotes greater vitality in cold-exposed plants, stimulates their longevity and boosts oilseed oil production at low temperature.
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Affiliation(s)
- Sylwia Klińska-Bąchor
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, 80-307, Poland.
| | - Sara Kędzierska
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, 80-307, Poland
| | - Kamil Demski
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Lomma, Box 190, 234 22, Sweden
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, 80-307, Poland
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8
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Traver MS, Bartel B. The ubiquitin-protein ligase MIEL1 localizes to peroxisomes to promote seedling oleosin degradation and lipid droplet mobilization. Proc Natl Acad Sci U S A 2023; 120:e2304870120. [PMID: 37410814 PMCID: PMC10629534 DOI: 10.1073/pnas.2304870120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/02/2023] [Indexed: 07/08/2023] Open
Abstract
Lipid droplets are organelles conserved across eukaryotes that store and release neutral lipids to regulate energy homeostasis. In oilseed plants, fats stored in seed lipid droplets provide fixed carbon for seedling growth before photosynthesis begins. As fatty acids released from lipid droplet triacylglycerol are catabolized in peroxisomes, lipid droplet coat proteins are ubiquitinated, extracted, and degraded. In Arabidopsis seeds, the predominant lipid droplet coat protein is OLEOSIN1 (OLE1). To identify genes modulating lipid droplet dynamics, we mutagenized a line expressing mNeonGreen-tagged OLE1 expressed from the OLE1 promoter and isolated mutants with delayed oleosin degradation. From this screen, we identified four miel1 mutant alleles. MIEL1 (MYB30-interacting E3 ligase 1) targets specific MYB transcription factors for degradation during hormone and pathogen responses [D. Marino et al., Nat. Commun. 4, 1476 (2013); H. G. Lee and P. J. Seo, Nat. Commun. 7, 12525 (2016)] but had not been implicated in lipid droplet dynamics. OLE1 transcript levels were unchanged in miel1 mutants, indicating that MIEL1 modulates oleosin levels posttranscriptionally. When overexpressed, fluorescently tagged MIEL1 reduced oleosin levels, causing very large lipid droplets. Unexpectedly, fluorescently tagged MIEL1 localized to peroxisomes. Our data suggest that MIEL1 ubiquitinates peroxisome-proximal seed oleosins, targeting them for degradation during seedling lipid mobilization. The human MIEL1 homolog (PIRH2; p53-induced protein with a RING-H2 domain) targets p53 and other proteins for degradation and promotes tumorigenesis [A. Daks et al., Cells 11, 1515 (2022)]. When expressed in Arabidopsis, human PIRH2 also localized to peroxisomes, hinting at a previously unexplored role for PIRH2 in lipid catabolism and peroxisome biology in mammals.
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Affiliation(s)
- Melissa S. Traver
- Department of Biosciences, Biochemistry and Cell Biology Program, Rice University, Houston, TX77005
| | - Bonnie Bartel
- Department of Biosciences, Biochemistry and Cell Biology Program, Rice University, Houston, TX77005
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9
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Lewandowska M, Zienkiewicz A, Feussner K, König S, Kunst L, Feussner I. Wound-induced triacylglycerol biosynthesis is jasmonoy-l-isoleucin and abscisic acid independent. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:509-517. [PMID: 36800436 DOI: 10.1111/plb.13513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/14/2023] [Indexed: 05/17/2023]
Abstract
Triacylglycerol (TAG) plays a significant role during plant stress - it maintains lipid homeostasis. Upon wounding plants accumulate TAG, likely as a storage form of fatty acids (FAs) that originate from damaged membranes. This study asked if this process depends on the two phytohormones jasmonoyl-isoleucine (JA-Ile) and abscisic acid (ABA), which are involved in wound signalling. To analyse regulation of wound-induced TAG accumulation, we used mutants deficient in JA-Ile, with reduced ABA and the myb96 mutant, which is deficient in an ABA-dependent transcription factor. The expression of genes involved in TAG biosynthesis, and TAG content after wounding were analysed via LC-MS and GC-FID, plastidial lipid content in all mentioned mutant lines was also determined. The localization of newly synthesized TAG was investigated using lipid droplet staining. TAG accumulation upon wounding was confirmed as well as the fact that the newly synthesized TAG are mostly composed of polyunsaturated fatty acids. Nevertheless, all tested mutant lines were able to accumulate TAG similar to the WT. We observed differences in reduction of plastidial lipids - in WT plants this was higher than in mutant lines. Newly synthesized TAGs were stored in lipid droplets at and around the wounded area. Our results show that TAG accumulation upon wounding is not dependent on JA-Ile or ABA. The newly synthesized TAG species are composed of unsaturated fatty acids of membrane origin, and most likely serves as a transient energy store.
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Affiliation(s)
- M Lewandowska
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
| | - A Zienkiewicz
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
| | - K Feussner
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - S König
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
| | - L Kunst
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - I Feussner
- Department for Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
- Department for Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
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10
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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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11
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Yu L, Shen W, Fan J, Sah SK, Mavraganis I, Wang L, Gao P, Gao J, Zheng Q, Meesapyodsuk D, Yang H, Li Q, Zou J, Xu C. A chloroplast diacylglycerol lipase modulates glycerolipid pathway balance in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023. [PMID: 37006186 DOI: 10.1111/tpj.16228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/20/2023] [Accepted: 03/25/2023] [Indexed: 06/19/2023]
Abstract
Two parallel pathways compartmentalized in the chloroplast and the endoplasmic reticulum contribute to thylakoid lipid synthesis in plants, but how these two pathways are coordinated during thylakoid biogenesis and remodeling remains unknown. We report here the molecular characterization of a homologous ADIPOSE TRIGLYCERIDE LIPASE-LIKE gene, previously referred to as ATGLL. The ATGLL gene is ubiquitously expressed throughout development and rapidly upregulated in response to a wide range of environmental cues. We show that ATGLL is a chloroplast non-regioselective lipase with a hydrolytic activity preferentially towards 16:0 of diacylglycerol (DAG). Comprehensive lipid profiling and radiotracer labeling studies revealed a negative correlation of ATGLL expression and the relative contribution of the chloroplast lipid pathway to thylakoid lipid biosynthesis. Additionally, we show that genetic manipulation of ATGLL expression resulted in changes in triacylglycerol levels in leaves. We propose that ATGLL, through affecting the level of prokaryotic DAG in the chloroplast, plays important roles in balancing the two glycerolipid pathways and in maintaining lipid homeostasis in plants.
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Affiliation(s)
- Linhui Yu
- Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
- State Key Laboratory of Crop Stress Biology for Arid Areas and Institute of Future Agriculture, Northwest A&F University, Yangling, Shanxi, China
| | - Wenyun Shen
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Saroj Kumar Sah
- Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Ioannis Mavraganis
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Liping Wang
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Peng Gao
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Jie Gao
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Qian Zheng
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Dauenpen Meesapyodsuk
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Hui Yang
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Qiang Li
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Jitao Zou
- National Research Council Canada-Aquatic and Crop Resource Development Research Centre, 110 Gymnasium Place, Saskatoon, Saskatchewan, S7N 0W9, Canada
| | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
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12
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Korte P, Unzner A, Damm T, Berger S, Krischke M, Mueller MJ. High triacylglycerol turnover is required for efficient opening of stomata during heat stress in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023. [PMID: 36976526 DOI: 10.1111/tpj.16210] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/04/2023] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
Heat stress triggers the accumulation of triacylglycerols in Arabidopsis leaves, which increases basal thermotolerance. However, how triacylglycerol synthesis is linked to thermotolerance remains unclear and the mechanisms involved remain to be elucidated. It has been shown that triacylglycerol and starch degradation are required to provide energy for stomatal opening induced by blue light at dawn. To investigate whether triacylglycerol turnover is involved in heat-induced stomatal opening during the day, we performed feeding experiments with labeled fatty acids. Heat stress strongly induced both triacylglycerol synthesis and degradation to channel fatty acids destined for peroxisomal ß-oxidation through the triacylglycerol pool. Analysis of mutants defective in triacylglycerol synthesis or peroxisomal fatty acid uptake revealed that triacylglycerol turnover and fatty acid catabolism are required for heat-induced stomatal opening in illuminated leaves. We show that triacylglycerol turnover is continuous (1.2 mol% per min) in illuminated leaves even at 22°C. The ß-oxidation of triacylglycerol-derived fatty acids generates C2 carbon units that are channeled into the tricarboxylic acid pathway in the light. In addition, carbohydrate catabolism is required to provide oxaloacetate as an acceptor for peroxisomal acetyl-CoA and maintain the tricarboxylic acid pathway for energy and amino acid production during the day.
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Affiliation(s)
- Pamela Korte
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Amelie Unzner
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Theresa Damm
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Susanne Berger
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Markus Krischke
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Martin J Mueller
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute of Biosciences, Biocenter, University of Wuerzburg, D-97082, Wuerzburg, Germany
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13
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Sagun JV, Yadav UP, Alonso AP. Progress in understanding and improving oil content and quality in seeds. FRONTIERS IN PLANT SCIENCE 2023; 14:1116894. [PMID: 36778708 PMCID: PMC9909563 DOI: 10.3389/fpls.2023.1116894] [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: 12/05/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
The world's population is projected to increase by two billion by 2050, resulting in food and energy insecurity. Oilseed crops have been identified as key to address these challenges: they produce and store lipids in the seeds as triacylglycerols that can serve as a source of food/feed, renewable fuels, and other industrially-relevant chemicals. Therefore, improving seed oil content and composition has generated immense interest. Research efforts aiming to unravel the regulatory pathways involved in fatty acid synthesis and to identify targets for metabolic engineering have made tremendous progress. This review provides a summary of the current knowledge of oil metabolism and discusses how photochemical activity and unconventional pathways can contribute to high carbon conversion efficiency in seeds. It also highlights the importance of 13C-metabolic flux analysis as a tool to gain insights on the pathways that regulate oil biosynthesis in seeds. Finally, a list of key genes and regulators that have been recently targeted to enhance seed oil production are reviewed and additional possible targets in the metabolic pathways are proposed to achieve desirable oil content and quality.
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14
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Cai Y, Zhai Z, Blanford J, Liu H, Shi H, Schwender J, Xu C, Shanklin J. Purple acid phosphatase2 stimulates a futile cycle of lipid synthesis and degradation, and mitigates the negative growth effects of triacylglycerol accumulation in vegetative tissues. THE NEW PHYTOLOGIST 2022; 236:1128-1139. [PMID: 35851483 DOI: 10.1111/nph.18392] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
Storage lipids (mostly triacylglycerols, TAGs) serve as an important energy and carbon reserve in plants, and hyperaccumulation of TAG in vegetative tissues can have negative effects on plant growth. Purple acid phosphatase2 (PAP2) was previously shown to affect carbon metabolism and boost plant growth. However, the effects of PAP2 on lipid metabolism remain unknown. Here, we demonstrated that PAP2 can stimulate a futile cycle of fatty acid (FA) synthesis and degradation, and mitigate negative growth effects associated with high accumulation of TAG in vegetative tissues. Constitutive expression of PAP2 in Arabidopsis thaliana enhanced both lipid synthesis and degradation in leaves and led to a substantial increase in seed oil yield. Suppressing lipid degradation in a PAP2-overexpressing line by disrupting sugar-dependent1 (SDP1), a predominant TAG lipase, significantly elevated vegetative TAG content and improved plant growth. Diverting FAs from membrane lipids to TAGs in PAP2-overexpressing plants by constitutively expressing phospholipid:diacylglycerol acyltransferase1 (PDAT1) greatly increased TAG content in vegetative tissues without compromising biomass yield. These results highlight the potential of combining PAP2 with TAG-promoting factors to enhance carbon assimilation, FA synthesis and allocation to TAGs for optimized plant growth and storage lipid accumulation in vegetative tissues.
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Affiliation(s)
- Yingqi Cai
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Zhiyang Zhai
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jantana Blanford
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Hui Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Hai Shi
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jorg Schwender
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
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15
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Luo G, Cao VD, Kannan B, Liu H, Shanklin J, Altpeter F. Metabolic engineering of energycane to hyperaccumulate lipids in vegetative biomass. BMC Biotechnol 2022; 22:24. [PMID: 36042455 PMCID: PMC9425976 DOI: 10.1186/s12896-022-00753-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022] Open
Abstract
Background The metabolic engineering of high-biomass crops for lipid production in their vegetative biomass has recently been proposed as a strategy to elevate energy density and lipid yields for biodiesel production. Energycane and sugarcane are highly polyploid, interspecific hybrids between Saccharum officinarum and Saccharum spontaneum that differ in the amount of ancestral contribution to their genomes. This results in greater biomass yield and persistence in energycane, which makes it the preferred target crop for biofuel production. Results Here, we report on the hyperaccumulation of triacylglycerol (TAG) in energycane following the overexpression of the lipogenic factors Diacylglycerol acyltransferase1-2 (DGAT1-2) and Oleosin1 (OLE1) in combination with RNAi suppression of SUGAR-DEPENDENT1 (SDP1) and Trigalactosyl diacylglycerol1 (TGD1). TAG accumulated up to 1.52% of leaf dry weight (DW,) a rate that was 30-fold that of non-modified energycane, in addition to almost doubling the total fatty acid content in leaves to 4.42% of its DW. Pearson’s correlation analysis showed that the accumulation of TAG had the highest correlation with the expression level of ZmDGAT1-2, followed by the level of RNAi suppression for SDP1. Conclusions This is the first report on the metabolic engineering of energycane and demonstrates that this resilient, high-biomass crop is an excellent target for the further optimization of the production of lipids from vegetative tissues. Supplementary Information The online version contains supplementary material available at 10.1186/s12896-022-00753-7.
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Affiliation(s)
- Guangbin Luo
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
| | - Viet Dang Cao
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
| | - Baskaran Kannan
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA
| | - Hui Liu
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA.
| | - Fredy Altpeter
- Plant Molecular and Cellular Biology Program, Agronomy Department, Genetics Institute, University of Florida, IFAS, Gainesville, FL, USA.
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16
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An increase in the membrane lipids recycling by PDAT overexpression stimulates the accumulation of triacylglycerol in Nannochloropsis gaditana. J Biotechnol 2022; 357:28-37. [PMID: 35931238 DOI: 10.1016/j.jbiotec.2022.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/18/2022] [Accepted: 07/30/2022] [Indexed: 11/23/2022]
Abstract
Oleaginous microalgae represent potential feedstocks for the sustainable production of lipids thanks to their ability to accumulate triacylglycerols (TAGs). TAG accumulation in several algal species is strongly induced under specific conditions such as nutrient deprivation and high light which, however, also negatively impact growth. Genetic modification of lipogenic pathways can potentially enhance TAG accumulation without negatively affecting growth, avoiding the trade-off between biomass and lipids productivity. In this study, the phospholipid: diacylglycerol acyltransferase (PDAT), an enzyme involved in membrane lipid recycling, was overexpressed in the seawater alga Nannochloropsis gaditana. PDAT overexpression induced increased TAG content in actively growing algae cultures while no effects were observed in conditions naturally stimulating strong lipid accumulation such as high light and nitrogen starvation. The increase of TAG content was confirmed also in a strain cultivated in industrially relevant conditions even though PDAT overexpression, if too strong, the gene overexpression becomes detrimental for growth in the longer term. Results overall suggest that genetic modulation of the PDAT gene represents a promising strategy to increase microalgae lipids content by minimizing negative effects on biomass productivity.
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17
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Lee Y, Park R, Miller SM, Li Y. Genetic compensation of triacylglycerol biosynthesis in the green microalga Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1069-1080. [PMID: 35727866 PMCID: PMC9545326 DOI: 10.1111/tpj.15874] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 06/10/2022] [Accepted: 06/16/2022] [Indexed: 06/14/2023]
Abstract
Genetic compensation has been proposed to explain phenotypic differences between gene knockouts and knockdowns in several metazoan and plant model systems. With the rapid development of reverse genetic tools such as CRISPR/Cas9 and RNAi in microalgae, it is increasingly important to assess whether genetic compensation affects the phenotype of engineered algal mutants. While exploring triacylglycerol (TAG) biosynthesis pathways in the model alga Chlamydomonas reinhardtii, it was discovered that knockout of certain genes catalyzing rate-limiting steps of TAG biosynthesis, type-2 diacylglycerol acyltransferase genes (DGTTs), triggered genetic compensation under abiotic stress conditions. Genetic compensation of a DGTT1 null mutation by a related PDAT gene was observed regardless of the strain background or mutagenesis approach, for example, CRISPR/Cas 9 or insertional mutagenesis. However, no compensation was found in the PDAT knockout mutant. The effect of PDAT knockout was evaluated in a Δvtc1 mutant, in which PDAT was upregulated under stress, resulting in a 90% increase in TAG content. Knockout of PDAT in the Δvtc1 background induced a 12.8-fold upregulation of DGTT1 and a 272.3% increase in TAG content in Δvtc1/pdat1 cells, while remaining viable. These data suggest that genetic compensation contributes to the genetic robustness of microalgal TAG biosynthetic pathways, maintaining lipid and redox homeostasis in the knockout mutants under abiotic stress. This work demonstrates examples of genetic compensation in microalgae, implies the physiological relevance of genetic compensation in TAG biosynthesis under stress, and provides guidance for future genetic engineering and mutant characterization efforts.
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Affiliation(s)
- Yi‐Ying Lee
- Institute of Marine and Environmental TechnologyUniversity of Maryland Center for Environmental ScienceBaltimoreMD21202USA
| | - Rudolph Park
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMD21250USA
| | - Stephen M. Miller
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMD21250USA
| | - Yantao Li
- Institute of Marine and Environmental TechnologyUniversity of Maryland Center for Environmental ScienceBaltimoreMD21202USA
- Department of Marine BiotechnologyUniversity of Maryland, Baltimore CountyBaltimoreMD21202USA
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18
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Kang L, Wu Y, Zhang J, An Q, Zhou C, Li D, Pan C. Nano-selenium enhances the antioxidant capacity, organic acids and cucurbitacin B in melon (Cucumis melo L.) plants. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 241:113777. [PMID: 35738099 DOI: 10.1016/j.ecoenv.2022.113777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Pesticides are widely used in melon production causing safety issues around the consumption of melon and increasing pathogen and insect tolerance to pesticides. This study investigated whether a nano-selenium (Nano-Se) spray treatment can improve resistance to biological stress in melon plants, reducing the need for pesticides, and how this mechanism is activated. To achieve this, we examine the ultrastructure and physio-biochemical responses of two melon cultivars after foliar spraying with Nano-Se. Nano-Se treatment reduced plastoglobulins in leaf mesophyll cells, thylakoid films were left intact, and compound starch granules increased. Nano-Se treatment also increased root mitochondria and left nucleoli intact. Nano-Se treatment enhanced ascorbate peroxidase, peroxidase, phenylalanine ammonia lyase, β-1,3-glucanase, chitinase activities and their mRNA levels in treated melon plants compared to control plants (without Nano-Se treatments). Exogenous application of Nano-Se improved fructose, glucose, galactitol, stachyose, lactic acid, tartaric acid, fumaric acid, malic acid and succinic acid in treated plants compared to control plants. In addition, Nano-Se treatment enhanced cucurbitacin B and up-regulated eight cucurbitacin B synthesis-related genes. We conclude that Nano-Se treatment of melon plants triggered antioxidant capacity, photosynthesis, organic acids, and up-regulated cucurbitacin B synthesis-related genes, which plays a comprehensive role in stress resistance in melon plants.
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Affiliation(s)
- Lu Kang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China; Institute of Agricultural Quality Standards and Testing Technology, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - Yangliu Wu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Jingbang Zhang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Quanshun An
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Chunran Zhou
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Dong Li
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Canping Pan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China.
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19
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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20
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Yang J, Liu J, Pan Y, Maréchal E, Amato A, Liu M, Gong Y, Li Y, Hu H. PDAT regulates PE as transient carbon sink alternative to triacylglycerol in Nannochloropsis. PLANT PHYSIOLOGY 2022; 189:1345-1362. [PMID: 35385114 PMCID: PMC9237688 DOI: 10.1093/plphys/kiac160] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/14/2022] [Indexed: 05/21/2023]
Abstract
Triacylglycerols (TAGs) are the main storage lipids in photosynthetic organisms under stress. In the oleaginous alga Nannochloropsis oceanica, while multiple acyl CoA:diacylglycerol (DAG) acyltransferases (NoDGATs) are involved in TAG production, the role of the unique phospholipid:DAG acyltransferase (NoPDAT) remains unknown. Here, we performed a functional complementation assay in TAG-deficient yeast (Saccharomyces cerevisiae) and an in vitro assay to probe the acyltransferase activity of NoPDAT. Subcellular localization, overexpression, and knockdown (KD) experiments were also conducted to elucidate the role of NoPDAT in N. oceanica. NoPDAT, residing at the outermost plastid membrane, does not phylogenetically fall into the clades of algae or plants and uses phosphatidylethanolamine (PE) and phosphatidylglycerol with 16:0, 16:1, and 18:1 at position sn-2 as acyl-donors in vivo. NoPDAT KD, not triggering any compensatory mechanism via DGATs, led to an ∼30% decrease of TAG content, accompanied by a vast accumulation of PEs rich in 16:0, 16:1, and 18:1 fatty acids (referred to as "LU-PE") that was positively associated with CO2 availability. We conclude that the NoPDAT pathway is parallel to and independent of the NoDGAT pathway for oil production. LU-PE can serve as an alternative carbon sink for photosynthetically assimilated carbon in N. oceanica when PDAT-mediated TAG biosynthesis is compromised or under stress in the presence of high CO2 levels.
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Affiliation(s)
| | | | - Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Alberto Amato
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Meijing Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Yangmin Gong
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
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21
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Xu C, Fan J. Links between autophagy and lipid droplet dynamics. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2848-2858. [PMID: 35560198 DOI: 10.1093/jxb/erac003] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/06/2022] [Indexed: 06/15/2023]
Abstract
Autophagy is a catabolic process in which cytoplasmic components are delivered to vacuoles or lysosomes for degradation and nutrient recycling. Autophagy-mediated degradation of membrane lipids provides a source of fatty acids for the synthesis of energy-rich, storage lipid esters such as triacylglycerol (TAG). In eukaryotes, storage lipids are packaged into dynamic subcellular organelles, lipid droplets. In times of energy scarcity, lipid droplets can be degraded via autophagy in a process termed lipophagy to release fatty acids for energy production via fatty acid β-oxidation. On the other hand, emerging evidence suggests that lipid droplets are required for the efficient execution of autophagic processes. Here, we review recent advances in our understanding of metabolic interactions between autophagy and TAG storage, and discuss mechanisms of lipophagy. Free fatty acids are cytotoxic due to their detergent-like properties and their incorporation into lipid intermediates that are toxic at high levels. Thus, we also discuss how cells manage lipotoxic stresses during autophagy-mediated mobilization of fatty acids from lipid droplets and organellar membranes for energy generation.
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Affiliation(s)
- Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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22
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Yang Z, Liu X, Wang K, Li Z, Jia Q, Zhao C, Zhang M. ABA-INSENSITIVE 3 with or without FUSCA3 highly up-regulates lipid droplet proteins and activates oil accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2077-2092. [PMID: 34849730 DOI: 10.1093/jxb/erab524] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 11/26/2021] [Indexed: 05/25/2023]
Abstract
ABA-INSENSITIVE 3 (ABI3) has long been known for activation of storage protein accumulation. A role of ABI3 on oil accumulation was previously suggested based on a decrease of oil content in seeds of abi3 mutant. However, this conclusion could not exclude possibilities of indirect or pleiotropic effects, such as through mutual regulatory interactions with FUSCA3 (FUS3), an activator of oil accumulation. To identify that ABI3 functions independent of the effects of related seed transcription factors, we expressed ABI3 under the control of an inducible promoter in tobacco BY2 cells and Arabidopsis rosette leaves. Inducible expression of ABI3 activated oil accumulation in these non-seed cells, demonstrating a general role of ABI3 in regulation of oil biosynthesis. Further expressing ABI3 in rosette leaves of fus3 knockout mutant still caused up to 3-fold greater triacylglycerol accumulation, indicating ABI3 can activate lipid accumulation independently of FUS3. Transcriptome analysis revealed that LIPID DROPLET PROTEIN (LDP) genes, including OLEOSINs and CALEOSINs, were up-regulated up to 1000-fold by ABI3 in the absence of FUS3, while the expression of WRINKLED1 was doubled. Taken together, our results provide genetic evidence that ABI3 activates oil accumulation with or without FUS3, most likely through up-regulating LDPs and WRINKLED1.
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Affiliation(s)
- Zheng Yang
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiangling Liu
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
| | - Kai Wang
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhuowei Li
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
| | - Qingli Jia
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
| | - Cuizhu Zhao
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
| | - Meng Zhang
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China
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Overexpression of phospholipid: diacylglycerol acyltransferase in Brassica napus results in changes in lipid metabolism and oil accumulation. Biochem J 2022; 479:805-823. [PMID: 35298586 PMCID: PMC9022997 DOI: 10.1042/bcj20220003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/05/2022] [Accepted: 03/17/2022] [Indexed: 11/17/2022]
Abstract
The regulation of lipid metabolism in oil seeds is still not fully understood and increasing our knowledge in this regard is of great economic, as well as intellectual, importance. Oilseed rape (Brassica napus) is a major global oil crop where increases in triacylglycerol (TAG) accumulation have been achieved by overexpression of relevant biosynthetic enzymes. In this study, we expressed Arabidopsis phospholipid: diacylglycerol acyltransferase (PDAT1), one of the two major TAG-forming plant enzymes in B. napus DH12075 to evaluate its effect on lipid metabolism in developing seeds and to estimate its flux control coefficient. Despite several-fold increase in PDAT activity, seeds of three independently generated PDAT transgenic events showed a small but consistent decrease in seed oil content and had altered fatty acid composition of phosphoglycerides and TAG, towards less unsaturation. Mass spectrometry imaging of seed sections confirmed the shift in lipid compositions and indicated that PDAT overexpression altered the distinct heterogeneous distributions of phosphatidylcholine (PC) molecular species. Similar, but less pronounced, changes in TAG molecular species distributions were observed. Our data indicate that PDAT exerts a small, negative, flux control on TAG biosynthesis and could have under-appreciated effects in fine-tuning of B. napus seed lipid composition in a tissue-specific manner. This has important implications for efforts to increase oil accumulation in similar crops.
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Green Chemistry Production of Codlemone, the Sex Pheromone of the Codling Moth (Cydia pomonella), by Metabolic Engineering of the Oilseed Crop Camelina (Camelina sativa). J Chem Ecol 2021; 47:950-967. [PMID: 34762210 PMCID: PMC8642345 DOI: 10.1007/s10886-021-01316-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/10/2021] [Accepted: 09/14/2021] [Indexed: 11/18/2022]
Abstract
Synthetic pheromones have been used for pest control over several decades. The conventional synthesis of di-unsaturated pheromone compounds is usually complex and costly. Camelina (Camelina sativa) has emerged as an ideal, non-food biotech oilseed platform for production of oils with modified fatty acid compositions. We used Camelina as a plant factory to produce mono- and di-unsaturated C12 chain length moth sex pheromone precursors, (E)-9-dodecenoic acid and (E,E)-8,10-dodecadienoic acid, by introducing a fatty acyl-ACP thioesterase FatB gene UcTE from California bay laurel (Umbellularia californica) and a bifunctional ∆9 desaturase gene Cpo_CPRQ from the codling moth, Cydia pomonella. Different transgene combinations were investigated for increasing pheromone precursor yield. The most productive Camelina line was engineered with a vector that contained one copy of UcTE and the viral suppressor protein encoding P19 transgenes and three copies of Cpo_CPRQ transgene. The T2 generation of this line produced 9.4% of (E)-9-dodecenoic acid and 5.5% of (E,E)-8,10-dodecadienoic acid of the total fatty acids, and seeds were selected to advance top-performing lines to homozygosity. In the T4 generation, production levels of (E)-9-dodecenoic acid and (E,E)-8,10-dodecadienoic acid remained stable. The diene acid together with other seed fatty acids were converted into corresponding alcohols, and the bioactivity of the plant-derived codlemone was confirmed by GC-EAD and a flight tunnel assay. Trapping in orchards and home gardens confirmed significant and specific attraction of C. pomonella males to the plant-derived codlemone.
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Cheng K, Pan YF, Liu LM, Zhang HQ, Zhang YM. Integrated Transcriptomic and Bioinformatics Analyses Reveal the Molecular Mechanisms for the Differences in Seed Oil and Starch Content Between Glycine max and Cicer arietinum. FRONTIERS IN PLANT SCIENCE 2021; 12:743680. [PMID: 34764968 PMCID: PMC8576049 DOI: 10.3389/fpls.2021.743680] [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: 07/19/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
The seed oil and starch content of soybean are significantly different from that of chickpea. However, there are limited studies on its molecular mechanisms. To address this issue, we conducted integrated transcriptomic and bioinformatics analyses for species-specific genes and acyl-lipid-, starch-, and carbon metabolism-related genes. Among seven expressional patterns of soybean-specific genes, four were highly expressed at the middle- and late oil accumulation stages; these genes significantly enriched fatty acid synthesis and carbon metabolism, and along with common acetyl CoA carboxylase (ACCase) highly expressed at soybean middle seed development stage, common starch-degrading enzyme beta-amylase-5 (BAM5) was highly expressed at soybean early seed development stage and oil synthesis-related genes ACCase, KAS, KAR, ACP, and long-chain acyl-CoA synthetase (LACS) were co-expressed with WRI1, which may result in high seed oil content and low seed starch content in soybean. The common ADP-glucose pyrophosphorylase (AGPase) was highly expressed at chickpea middle seed development stage, along with more starch biosynthesis genes co-expressed with four-transcription-factor homologous genes in chickpea than in soybean, and the common WRI1 was not co-expressed with oil synthesis genes in chickpea, which may result in high seed starch content and low seed oil content in chickpea. The above results may be used to improve chickpea seed oil content in two ways. One is to edit CaWRI1 to co-express with oil synthesis-related genes, which may increase carbon metabolites flowing to oil synthesis, and another is to increase the expression levels of miRNA159 and miRNA319 to inhibit the expression of MYB33, which may downregulate starch synthesis-related genes, making more carbon metabolites flow into oil synthesis. Our study will provide a basis for future breeding efforts to increase the oil content of chickpea seeds.
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Tracing Key Molecular Regulators of Lipid Biosynthesis in Tuber Development of Cyperus esculentus Using Transcriptomics and Lipidomics Profiling. Genes (Basel) 2021; 12:genes12101492. [PMID: 34680888 PMCID: PMC8535953 DOI: 10.3390/genes12101492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 11/17/2022] Open
Abstract
Cyperus esculentus is widely representing one of the important oil crops around the world, which provides valuable resources of edible tubers called tiger nut. The chemical composition and high ability to produce fats emphasize the role of tiger nut in promoting oil crop productivity. However, the underlying molecular mechanism of the production and accumulation of lipids in tiger nut development still remains unclear. Here, we conducted comprehensive transcriptomics and lipidomics analyses at different developmental stages of tuber in Cyperus esculentus. Lipidomic analyses confirmed that the accumulation of lipids including glycolipids, phospholipids, and glycerides were significantly enriched during tuber development from early to mature stage. The proportion of phosphatidylcholines (PC) declined during all stages and phosphatidyl ethanolamine (PE) was significantly declined in early and middle stages. These findings implied that PC is actively involved in triacylglycerol (TAG) biosynthesis during the tubers development, whereas PE may participate in TAG metabolism during early and middle stages. Comparative transcriptomics analyses indicated several genomic and metabolic pathways associated with lipid metabolism during tuber development in tiger nut. The Pearson correlation analysis showed that TAG synthesis in different developmental stages was attributed to 37 candidate transcripts including CePAH1. The up-regulation of diacylglycerol (DAG) and oil content in yeast, resulted from the inducible expression of exogenous CePAH1 confirmed the central role of this candidate gene in lipid metabolism. Our results demonstrated the foundation of an integrative metabolic model for understanding the molecular mechanism of tuber development in tiger nut, in which lipid biosynthesis plays a central role.
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Sterols are required for the coordinated assembly of lipid droplets in developing seeds. Nat Commun 2021; 12:5598. [PMID: 34552075 PMCID: PMC8458542 DOI: 10.1038/s41467-021-25908-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 09/09/2021] [Indexed: 12/23/2022] Open
Abstract
Lipid droplets (LDs) are intracellular organelles critical for energy storage and lipid metabolism. They are typically composed of an oil core coated by a monolayer of phospholipids and proteins such as oleosins. The mechanistic details of LD biogenesis remain poorly defined. However, emerging evidence suggest that their formation is a spatiotemporally regulated process, occurring at specific sites of the endoplasmic reticulum defined by a specific set of lipids and proteins. Here, we show that sterols are required for formation of oleosin-coated LDs in Arabidopsis. Analysis of sterol pathway mutants revealed that deficiency in several ∆5-sterols accounts for the phenotype. Importantly, mutants deficient in these sterols also display reduced LD number, increased LD size and reduced oil content in seeds. Collectively, our data reveal a role of sterols in coordinating the synthesis of oil and oleosins and their assembly into LDs, highlighting the importance of membrane lipids in regulating LD biogenesis. Lipid droplet biogenesis originates at the endoplasmic reticulum and is defined by a specific set of lipids and proteins. Here, the authors show that sterols play an important role in coordinating oil and oleosin biosynthesis for the formation of lipid droplets in plant leaves and seeds.
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Yu L, Zhou C, Fan J, Shanklin J, Xu C. Mechanisms and functions of membrane lipid remodeling in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:37-53. [PMID: 33853198 DOI: 10.1111/tpj.15273] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 05/20/2023]
Abstract
Lipid remodeling, defined herein as post-synthetic structural modifications of membrane lipids, play crucial roles in regulating the physicochemical properties of cellular membranes and hence their many functions. Processes affected by lipid remodeling include lipid metabolism, membrane repair, cellular homeostasis, fatty acid trafficking, cellular signaling and stress tolerance. Glycerolipids are the major structural components of cellular membranes and their composition can be adjusted by modifying their head groups, their acyl chain lengths and the number and position of double bonds. This review summarizes recent advances in our understanding of mechanisms of membrane lipid remodeling with emphasis on the lipases and acyltransferases involved in the modification of phosphatidylcholine and monogalactosyldiacylglycerol, the major membrane lipids of extraplastidic and photosynthetic membranes, respectively. We also discuss the role of triacylglycerol metabolism in membrane acyl chain remodeling. Finally, we discuss emerging data concerning the functional roles of glycerolipid remodeling in plant stress responses. Illustrating the molecular basis of lipid remodeling may lead to novel strategies for crop improvement and other biotechnological applications such as bioenergy production.
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Affiliation(s)
- Linhui Yu
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Chao Zhou
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
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29
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Chen H, Wang Q. Regulatory mechanisms of lipid biosynthesis in microalgae. Biol Rev Camb Philos Soc 2021; 96:2373-2391. [PMID: 34101323 DOI: 10.1111/brv.12759] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 02/01/2023]
Abstract
Microalgal lipids are highly promising feedstocks for biofuel production. Microalgal lipids, especially triacylglycerol, and practical applications of these compounds have received increasing attention in recent years. For the commercial use of microalgal lipids to be feasible, many fundamental biological questions must be addressed based on detailed studies of algal biology, including how lipid biosynthesis occurs and is regulated. Here, we review the current understanding of microalgal lipid biosynthesis, with a focus on the underlying regulatory mechanisms. We also present possible solutions for overcoming various obstacles to understanding the basic biology of microalgal lipid biosynthesis and the practical application of microalgae-based lipids. This review will provide a theoretical reference for both algal researchers and decision makers regarding the future directions of microalgal research, particularly pertaining to microalgal-based lipid biosynthesis.
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Affiliation(s)
- Hui Chen
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China
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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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31
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Barros JAS, Magen S, Lapidot-Cohen T, Rosental L, Brotman Y, Araújo WL, Avin-Wittenberg T. Autophagy is required for lipid homeostasis during dark-induced senescence. PLANT PHYSIOLOGY 2021; 185:1542-1558. [PMID: 33793926 PMCID: PMC8133563 DOI: 10.1093/plphys/kiaa120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/14/2020] [Indexed: 05/31/2023]
Abstract
Autophagy is an evolutionarily conserved mechanism that mediates the degradation of cytoplasmic components in eukaryotic cells. In plants, autophagy has been extensively associated with the recycling of proteins during carbon-starvation conditions. Even though lipids constitute a significant energy reserve, our understanding of the function of autophagy in the management of cell lipid reserves and components remains fragmented. To further investigate the significance of autophagy in lipid metabolism, we performed an extensive lipidomic characterization of Arabidopsis (Arabidopsis thaliana) autophagy mutants (atg) subjected to dark-induced senescence conditions. Our results revealed an altered lipid profile in atg mutants, suggesting that autophagy affects the homeostasis of multiple lipid components under dark-induced senescence. The acute degradation of chloroplast lipids coupled with the differential accumulation of triacylglycerols (TAGs) and plastoglobuli indicates an alternative metabolic reprogramming toward lipid storage in atg mutants. The imbalance of lipid metabolism compromises the production of cytosolic lipid droplets and the regulation of peroxisomal lipid oxidation pathways in atg mutants.
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Affiliation(s)
- Jessica A S Barros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, Brazil
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram 9190401, Israel
| | - Sahar Magen
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram 9190401, Israel
| | - Taly Lapidot-Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, 8410501 Beer-Sheva, Israel
| | - Leah Rosental
- Department of Life Sciences, Ben-Gurion University of the Negev, 8410501 Beer-Sheva, Israel
| | - Yariv Brotman
- Department of Life Sciences, Ben-Gurion University of the Negev, 8410501 Beer-Sheva, Israel
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, Brazil
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram 9190401, Israel
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Singh R, Arora A, Singh V. Biodiesel from oil produced in vegetative tissues of biomass - A review. BIORESOURCE TECHNOLOGY 2021; 326:124772. [PMID: 33551280 DOI: 10.1016/j.biortech.2021.124772] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
Biodiesel is a green, renewable alternative to petroleum-derived diesel. However, using vegetable oil for biodiesel production significantly challenges the food security. Progress in metabolic engineering, understanding of lipid biosynthesis and storage have enabled engineering of vegetative tissues of plants such as sugarcane, sorghum, and tobacco for lipid production. Such sources could be cultivated on land resources, which are currently not suitable for row crops. Besides achieving significant lipid accumulation, it is imperative to maintain the fatty acid and lipid profile ideal for biodiesel production and engine performance. In this study, genetic modifications used to induce lipid accumulation in transgenic crops and the proposed strategies for efficient recovery of oil from these crops have been presented. This paper highlights that lipids sourced from vegetative biomass in their native form would pose significant challenges in biodiesel production. Therefore, different strategies have been presented for improving feedstock quality to achieve high-quality biodiesel production.
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Affiliation(s)
- Ramkrishna Singh
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, 1304 W. Pennsylvania Avenue, Urbana, IL 61801, USA; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Amit Arora
- Indian Institute of Technology Bombay, Powai, Mumbai 400076, India; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Vijay Singh
- Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, 1304 W. Pennsylvania Avenue, Urbana, IL 61801, USA; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Zhai Z, Liu H, Shanklin J. Ectopic Expression of OLEOSIN 1 and Inactivation of GBSS1 Have a Synergistic Effect on Oil Accumulation in Plant Leaves. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10030513. [PMID: 33803467 PMCID: PMC8000217 DOI: 10.3390/plants10030513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/03/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
During the transformation of wild-type (WT) Arabidopsis thaliana, a T-DNA containing OLEOSIN-GFP (OLE1-GFP) was inserted by happenstance within the GBSS1 gene, resulting in significant reduction in amylose and increase in leaf oil content in the transgenic line (OG). The synergistic effect on oil accumulation of combining gbss1 with the expression of OLE1-GFP was confirmed by transforming an independent gbss1 mutant (GABI_914G01) with OLE1-GFP. The resulting OLE1-GFP/gbss1 transgenic lines showed higher leaf oil content than the individual OLE1-GFP/WT or single gbss1 mutant lines. Further stacking of the lipogenic factors WRINKLED1, Diacylglycerol O-Acyltransferase (DGAT1), and Cys-OLEOSIN1 (an engineered sesame OLEOSIN1) in OG significantly elevated its oil content in mature leaves to 2.3% of dry weight, which is 15 times higher than that in WT Arabidopsis. Inducible expression of the same lipogenic factors was shown to be an effective strategy for triacylglycerol (TAG) accumulation without incurring growth, development, and yield penalties.
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Affiliation(s)
- Zhiyang Zhai
- Correspondence: (Z.Z.); (J.S.); Tel.: +1-631-344-5360 (Z.Z.); +1-631-344-3414 (J.S.)
| | | | - John Shanklin
- Correspondence: (Z.Z.); (J.S.); Tel.: +1-631-344-5360 (Z.Z.); +1-631-344-3414 (J.S.)
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34
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Cooney LJ, Beechey-Gradwell Z, Winichayakul S, Richardson KA, Crowther T, Anderson P, Scott RW, Bryan G, Roberts NJ. Changes in Leaf-Level Nitrogen Partitioning and Mesophyll Conductance Deliver Increased Photosynthesis for Lolium perenne Leaves Engineered to Accumulate Lipid Carbon Sinks. FRONTIERS IN PLANT SCIENCE 2021; 12:641822. [PMID: 33897730 PMCID: PMC8063613 DOI: 10.3389/fpls.2021.641822] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Diacylglycerol acyl-transferase (DGAT) and cysteine oleosin (CO) expression confers a novel carbon sink (of encapsulated lipid droplets) in leaves of Lolium perenne and has been shown to increase photosynthesis and biomass. However, the physiological mechanism by which DGAT + CO increases photosynthesis remains unresolved. To evaluate the relationship between sink strength and photosynthesis, we examined fatty acids (FA), water-soluble carbohydrates (WSC), gas exchange parameters and leaf nitrogen for multiple DGAT + CO lines varying in transgene accumulation. To identify the physiological traits which deliver increased photosynthesis, we assessed two important determinants of photosynthetic efficiency, CO2 conductance from atmosphere to chloroplast, and nitrogen partitioning between different photosynthetic and non-photosynthetic pools. We found that DGAT + CO accumulation increased FA at the expense of WSC in leaves of L. perenne and for those lines with a significant reduction in WSC, we also observed an increase in photosynthesis and photosynthetic nitrogen use efficiency. DGAT + CO L. perenne displayed no change in rubisco content or Vcmax but did exhibit a significant increase in specific leaf area (SLA), stomatal and mesophyll conductance, and leaf nitrogen allocated to photosynthetic electron transport. Collectively, we showed that increased carbon demand via DGAT+CO lipid sink accumulation can induce leaf-level changes in L. perenne which deliver increased rates of photosynthesis and growth. Carbon sinks engineered within photosynthetic cells provide a promising new strategy for increasing photosynthesis and crop productivity.
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35
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Yu L, Fan J, Zhou C, Xu C. Chloroplast lipid biosynthesis is fine-tuned to thylakoid membrane remodeling during light acclimation. PLANT PHYSIOLOGY 2021; 185:94-107. [PMID: 33631801 PMCID: PMC8133659 DOI: 10.1093/plphys/kiaa013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/21/2020] [Indexed: 05/29/2023]
Abstract
Reprogramming metabolism, in addition to modifying the structure and function of the photosynthetic machinery, is crucial for plant acclimation to changing light conditions. One of the key acclimatory responses involves reorganization of the photosynthetic membrane system including changes in thylakoid stacking. Glycerolipids are the main structural component of thylakoids and their synthesis involves two main pathways localized in the plastid and the endoplasmic reticulum (ER); however, the role of lipid metabolism in light acclimation remains poorly understood. We found that fatty acid synthesis, membrane lipid content, the plastid lipid biosynthetic pathway activity, and the degree of thylakoid stacking were significantly higher in plants grown under low light compared with plants grown under normal light. Plants grown under high light, on the other hand, showed a lower rate of fatty acid synthesis, a higher fatty acid flux through the ER pathway, higher triacylglycerol content, and thylakoid membrane unstacking. We additionally demonstrated that changes in rates of fatty acid synthesis under different growth light conditions are due to post-translational regulation of the plastidic acetyl-CoA carboxylase activity. Furthermore, Arabidopsis mutants defective in one of the two glycerolipid biosynthetic pathways displayed altered growth patterns and a severely reduced ability to remodel thylakoid architecture, particularly under high light. Overall, this study reveals how plants fine-tune fatty acid and glycerolipid biosynthesis to cellular metabolic needs in response to long-term changes in light conditions, highlighting the importance of lipid metabolism in light acclimation.
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Affiliation(s)
- Linhui Yu
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Chao Zhou
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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36
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Chen GQ, Kim WN, Johnson K, Park ME, Lee KR, Kim HU. Transcriptome Analysis and Identification of Lipid Genes in Physaria lindheimeri, a Genetic Resource for Hydroxy Fatty Acids in Seed Oil. Int J Mol Sci 2021; 22:ijms22020514. [PMID: 33419225 PMCID: PMC7825617 DOI: 10.3390/ijms22020514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
Hydroxy fatty acids (HFAs) have numerous industrial applications but are absent in most vegetable oils. Physaria lindheimeri accumulating 85% HFA in its seed oil makes it a valuable resource for engineering oilseed crops for HFA production. To discover lipid genes involved in HFA synthesis in P. lindheimeri, transcripts from developing seeds at various stages, as well as leaf and flower buds, were sequenced. Ninety-seven percent clean reads from 552,614,582 raw reads were assembled to 129,633 contigs (or transcripts) which represented 85,948 unique genes. Gene Ontology analysis indicated that 60% of the contigs matched proteins involved in biological process, cellular component or molecular function, while the remaining matched unknown proteins. We identified 42 P. lindheimeri genes involved in fatty acid and seed oil biosynthesis, and 39 of them shared 78-100% nucleotide identity with Arabidopsis orthologs. We manually annotated 16 key genes and 14 of them contained full-length protein sequences, indicating high coverage of clean reads to the assembled contigs. A detailed profiling of the 16 genes revealed various spatial and temporal expression patterns. The further comparison of their protein sequences uncovered amino acids conserved among HFA-producing species, but these varied among non-HFA-producing species. Our findings provide essential information for basic and applied research on HFA biosynthesis.
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Affiliation(s)
- Grace Q. Chen
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA 94710, USA;
- Correspondence: (G.Q.C.); (H.U.K.)
| | - Won Nyeong Kim
- Department of Bioindustry and Bioresource Engineering, Sejong University, Seoul 05006, Korea;
| | - Kumiko Johnson
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA 94710, USA;
| | - Mid-Eum Park
- Department of Molecular Biology, Graduate School, Sejong University, Seoul 05006, Korea;
| | - Kyeong-Ryeol Lee
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju 54974, Korea;
| | - Hyun Uk Kim
- Department of Bioindustry and Bioresource Engineering, Sejong University, Seoul 05006, Korea;
- Department of Molecular Biology, Graduate School, Sejong University, Seoul 05006, Korea;
- Correspondence: (G.Q.C.); (H.U.K.)
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Hernández ML, Moretti S, Sicardo MD, García Ú, Pérez A, Sebastiani L, Martínez-Rivas JM. Distinct Physiological Roles of Three Phospholipid:Diacylglycerol Acyltransferase Genes in Olive Fruit with Respect to Oil Accumulation and the Response to Abiotic Stress. FRONTIERS IN PLANT SCIENCE 2021; 12:751959. [PMID: 34868139 PMCID: PMC8632719 DOI: 10.3389/fpls.2021.751959] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/21/2021] [Indexed: 05/13/2023]
Abstract
Three different cDNA sequences, designated OepPDAT1-1, OepPDAT1-2, and OepPDAT2, encoding three phospholipid:diacylglycerol acyltransferases (PDAT) have been isolated from olive (Olea europaea cv. Picual). Sequence analysis showed the distinctive features typical of the PDAT family and together with phylogenetic analysis indicated that they encode PDAT. Gene expression analysis in different olive tissues showed that transcript levels of these three PDAT genes are spatially and temporally regulated and suggested that, in addition to acyl-CoA:diacylglycerol acyltransferase, OePDAT1-1 may contribute to the biosynthesis of triacylglycerols in the seed, whereas OePDAT1-2 could be involved in the triacylglycerols content in the mesocarp and, therefore, in the olive oil. The relative contribution of PDAT and acyl-CoA:diacylglycerol acyltransferase enzymes to the triacylglycerols content in olive appears to be tissue-dependent. Furthermore, water regime, temperature, light, and wounding regulate PDAT genes at transcriptional level in the olive fruit mesocarp, indicating that PDAT could be involved in the response to abiotic stresses. Altogether, this study represents an advance in our knowledge on the regulation of oil accumulation in oil fruit.
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Affiliation(s)
- M. Luisa Hernández
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Samuele Moretti
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
| | - M. Dolores Sicardo
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Úrsula García
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Ana Pérez
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
| | - Luca Sebastiani
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy
| | - José M. Martínez-Rivas
- Department of Biochemistry and Molecular Biology of Plant Products, Instituto de la Grasa (IG-CSIC), Campus Universidad Pablo de Olavide, Seville, Spain
- *Correspondence: José M. Martínez-Rivas,
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Demski K, Łosiewska A, Jasieniecka-Gazarkiewicz K, Klińska S, Banaś A. Phospholipid:Diacylglycerol Acyltransferase1 Overexpression Delays Senescence and Enhances Post-heat and Cold Exposure Fitness. FRONTIERS IN PLANT SCIENCE 2020; 11:611897. [PMID: 33381143 PMCID: PMC7767865 DOI: 10.3389/fpls.2020.611897] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/26/2020] [Indexed: 05/27/2023]
Abstract
In an alternative pathway to acyl-CoA: diacylglycerol acyltransferase (DGAT)-mediated triacylglycerol (TAG) synthesis from diacylglycerol, phospholipid:diacylglycerol acyltransferase (PDAT) utilizes not acyl-CoA but an acyl group from sn-2 position of a phospholipid, to form TAG. The enzyme's activity in vitro matches DGAT's in a number of plant species, however its main function in plants (especially in vegetative tissue) is debatable. In the presented study, we cultivated PDAT1-overexpressing, pdat1 knockout and wild-type lines of Arabidopsis thaliana through their whole lifecycle. PDAT1 overexpression prolonged Arabidopsis lifespan in comparison to wild-type plants, whereas knocking out pdat1 accelerated the plant's senescence. After subjecting the 3-week old seedlings of the studied lines (grown in vitro) to 2-h heat stress (40°C) and then growing them for one more week in standard conditions, the difference in weight between wild-type and PDAT1-overexpressing lines increased in comparison to the difference between plants grown only in optimal conditions. In another experiment all lines exposed to 2-week cold stress experienced loss of pigment, except for PDAT1-overexpressing lines, which green rosettes additionally weighed 4 times more than wild-type. Our results indicate that plants depleted of PDAT1 are more susceptible to cold exposure, while PDAT1 overexpression grants plants a certain heat and cold resilience. Since it was shown, that lysophospholipids may be intertwined with stress response, we decided to also conduct in vitro assays of acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) and acylCoA:lysophosphatidylethanolamine acyltransferase (LPEAT) activity in microsomal fractions from the PDAT1-overexpressing Arabidopsis lines in standard conditions. The results show significant increase in LPEAT and LPCAT activity in comparison to wild-type plants. PDAT1-overexpressing lines' rosettes also present twice as high expression of LPCAT2 in comparison to control. The presented study shows how much heightened expression of PDAT1 augments plant condition after stress and extends its lifespan.
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Barros JAS, Siqueira JAB, Cavalcanti JHF, Araújo WL, Avin-Wittenberg T. Multifaceted Roles of Plant Autophagy in Lipid and Energy Metabolism. TRENDS IN PLANT SCIENCE 2020; 25:1141-1153. [PMID: 32565020 DOI: 10.1016/j.tplants.2020.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
Together with sugars and proteins, lipids constitute the main carbon reserves in plants. Lipids are selectively recycled and catabolized for energy production during development and in response to environmental stresses. Autophagy is a major catabolic pathway, operating in the recycling of cellular components in eukaryotes. Although the autophagic degradation of lipids has been mainly characterized in mammals and yeast, growing evidence has highlighted the role of autophagy in several aspects of lipid metabolism in plants. Here, we summarize recent findings focusing on autophagy functions in lipid droplet (LD) metabolism. We further provide novel insights regarding the relevance of autophagy in the maintenance and clearance of mitochondria and peroxisomes and its consequences for proper lipid usage and energy homeostasis in plants.
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Affiliation(s)
- Jessica A S Barros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil; Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - João A B Siqueira
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil
| | - João H F Cavalcanti
- Instituto de Educação, Agricultura e Ambiente, Universidade Federal do Amazonas, Humaitá, Amazonas, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
| | - Tamar Avin-Wittenberg
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel.
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Xu C, Fan J, Shanklin J. Metabolic and functional connections between cytoplasmic and chloroplast triacylglycerol storage. Prog Lipid Res 2020; 80:101069. [DOI: 10.1016/j.plipres.2020.101069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/23/2020] [Accepted: 10/24/2020] [Indexed: 12/14/2022]
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Spangenberg JE, Schweizer M, Zufferey V. Shifts in carbon and nitrogen stable isotope composition and epicuticular lipids in leaves reflect early water-stress in vineyards. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 739:140343. [PMID: 32758968 DOI: 10.1016/j.scitotenv.2020.140343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
Changes in leaf carbon and nitrogen isotope composition (δ13C and δ15N values) and the accumulation of epicuticular lipids have been associated with plant responses to water stress. We investigated their potential use as indicators of early plant water deficit in two grapevine (Vitis vinifera L.) cultivars, Chasselas and Pinot noir, that were field-grown under well-watered and water-deficient conditions. We tested the hypothesis that the bulk δ13C and δ15N values and the concentrations of epicuticular fatty acids may change in leaves of similar age with the soil water availability. For this purpose, leaves were sampled at the same position in the canopy at different times (phenological stages) during the 2014 growing season. Bulk dry matter of young leaves from flowering to veraison had higher δ13C values, higher total nitrogen content, and lower δ15N values than old leaves. In both cultivars, δ15N values were strongly correlated with plant water deficiency, demonstrating their integration of the plant water stress response. δ13C values recorded the water deficiency only in those plants that had not received foliar organic fertilization. The soil water deficiency triggered the accumulation of C>26 fatty acids in the cuticular waxes. The compound-specific isotope analysis (CSIA) of fatty acids from old leaves showed an increase in δ13C among the C16-C22 chains, including stress signaling linoleic and linolenic acids. Our results provide evidence for leaf 13C-enrichment, 15N-depletion, and enhanced FA-chain elongation and epicuticular accumulation in the grapevine response to water stress. The leaf δ13C and δ15N values, and the concentration of epicuticular fatty acids can be used as reliable and sensitive indicators of plant water deficit even when the level of water stress is low to moderate. They could also be used, particularly the more cost-efficient δ13C and δ15N measurements, for periodic biogeochemical mapping of the plant water availability at the vineyard and regional scale.
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Affiliation(s)
- Jorge E Spangenberg
- Institute of Earth Surface Dynamics (IDYST), University of Lausanne, CH-1015 Lausanne, Switzerland.
| | - Marc Schweizer
- Institute of Earth Surface Dynamics (IDYST), University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Vivian Zufferey
- Institute of Plant Production Sciences (IPV), Agroscope, CH-1009 Pully, Switzerland
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The Phospholipid:Diacylglycerol Acyltransferase-Mediated Acyl-Coenzyme A-Independent Pathway Efficiently Diverts Fatty Acid Flux from Phospholipid into Triacylglycerol in Escherichia coli. Appl Environ Microbiol 2020; 86:AEM.00999-20. [PMID: 32680871 DOI: 10.1128/aem.00999-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/06/2020] [Indexed: 11/20/2022] Open
Abstract
Researchers have long endeavored to accumulate triacylglycerols (TAGs) or their derivatives in easily managed microbes. The attempted production of TAGs in Escherichia coli has revealed barriers to the broad applications of this technology, including low TAG productivity and slow cell growth. We have demonstrated that an acyl-CoA-independent pathway can divert phospholipid flux into TAG formation in E. coli mediated by Chlamydomonas reinhardtii phospholipid:diacylglycerol acyltransferase (CrPDAT) without interfering with membrane functions. We then showed the synergistic effect on TAG accumulation via the acyl-CoA-independent pathway mediated by PDAT and the acyl-CoA-dependent pathway mediated by wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT). Furthermore, CrPDAT led to synchronous TAG accumulation during cell growth, and this could be enhanced by supplementation of arbutin. We also showed that rationally mutated CrPDAT was capable of decreasing TAG lipase activity without impairing PDAT activity. Finally, ScPDAT from Saccharomyces cerevisiae exhibited similar activities as CrPDAT in E. coli Our results suggest that the improvement in accumulation of TAGs and their derivatives can be achieved by fine-tuning of phospholipid metabolism in E. coli Understanding the roles of PDAT in the conversion of phospholipids into TAGs during the logarithmic growth phase may enable a novel strategy for the production of microbial oils.IMPORTANCE Although phospholipid:diacylglycerol acyltransferase (PDAT) activity is presumed to exist in prokaryotic oleaginous bacteria, the corresponding gene has not been identified yet. In this article, we have demonstrated that an acyl-CoA-independent pathway can divert phospholipid flux into TAG formation in Escherichia coli mediated by exogenous CrPDAT from Chlamydomonas reinhardtii without interfering with membrane functions. In addition, the acyl-CoA-independent pathway and the acyl-CoA-dependent pathway had the synergistic effect on TAG accumulation. Overexpression of CrPDAT led to synchronous TAG accumulation during cell growth. In particular, CrPDAT possessed multiple catalytic activities, and the rational mutation of CrPDAT led to the decrease of TAG lipase activity without impairing acyltransferase activity. The present findings suggested that applying PDAT in E. coli or other prokaryotic microbes may be a promising strategy for accumulation of TAGs and their derivatives.
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Zhou B, Fei W, Yang S, Yang F, Qu G, Tang W, Ou J, Peng D. Alteration of the fatty acid composition of Brassica napus L. via overexpression of phospholipid: Diacylglycerol acyltransferase 1 from Sapium sebiferum (L.) Roxb. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110562. [PMID: 32771163 DOI: 10.1016/j.plantsci.2020.110562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
Sapium sebiferum (L.) Roxb. plays an important role in traditional Chinese medicine and is one of major woody oil tree in China. Phospholipid: diacylglycerol acyltransferase 1 (PDAT1), as an important catalytic enzyme for the formation of triacylglycerol (TAG), is mainly responsible for the transfer of an acyl group from the sn-2 position of phospholipids to the sn-3 position of sn-1, 2-diacylglycerol (DAG) to produce TAG and sn-1 lysophospholipids. The importance of PDAT1 in triacylglycerol biosynthesis has been illustrated in previous research, and at least 67 PDAT1 sequences have been identified from 31 organisms. However, little is known about the gene encoding PDAT1 in S. sebiferum (SsPDAT1), which is involved in seed oil biosynthesis. To explore the functional characteristics of SsPDAT1, we cloned and analyzed the full-length cDNA in the coding region of SsPDAT1, which consists of 2040 bp and encodes a putative protein of 680 amino acid (aa) residues. Thin-layer chromatography (TLC) analysis showed that recombinant SsPDAT1 could restore TAG accumulation in TAG-deficient mutant yeast (Saccharomyces cerevisiae) H1246, which revealed the enzyme activity of SsPDAT1. Moreover, transgenic Brassica napus L. W10 plants overexpressing SsPDAT1 showed significant increases of 19.6-28.9 % in linoleic acid levels but decreases of 27.3-37.1 % in linolenic acid. Furthermore, the total oil content increased by 8.1 %-10.8 % in SsPDAT1 transgenic seeds. These results confirmed the role of SsPDAT1 in stabilizing oil biosynthesis and suggested that SsPDAT1 could be exploitable to specifically regulate the oil composition of plants. These experimental results provide a new concept that may enable the industrial development of plants with high-linoleic-acid oil through overexpression of SsPDAT1 in S. sebiferum L.
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Affiliation(s)
- Bo Zhou
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, 410018, Changsha, China; Forestry Biotechnology Hunan Key Laboratories, Hunan, Changsha, 410004, China; National Engineering Laboratory of Applied Technology for Forestry and Ecology in Southern China, Changsha, 410004, Hunan, China; Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, 438107, China.
| | - Wenjie Fei
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Shiquan Yang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Feng Yang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Gaoyi Qu
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Weiwei Tang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Jianping Ou
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Dan Peng
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, 410018, Changsha, China.
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Falarz LJ, Xu Y, Caldo KMP, Garroway CJ, Singer SD, Chen G. Characterization of the diversification of phospholipid:diacylglycerol acyltransferases in the green lineage. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2025-2038. [PMID: 32538516 DOI: 10.1111/tpj.14880] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 05/03/2023]
Abstract
Triacylglycerols have important physiological roles in photosynthetic organisms, and are widely used as food, feed and industrial materials in our daily life. Phospholipid:diacylglycerol acyltransferase (PDAT) is the pivotal enzyme catalyzing the acyl-CoA-independent biosynthesis of triacylglycerols, which is unique in plants, algae and fungi, but not in animals, and has essential functions in plant and algal growth, development and stress responses. Currently, this enzyme has yet to be examined in an evolutionary context at the level of the green lineage. Some fundamental questions remain unanswered, such as how PDATs evolved in photosynthetic organisms and whether the evolution of terrestrial plant PDATs from a lineage of charophyte green algae diverges in enzyme function. As such, we used molecular evolutionary analysis and biochemical assays to address these questions. Our results indicated that PDAT underwent divergent evolution in the green lineage: PDATs exist in a wide range of plants and algae, but not in cyanobacteria. Although PDATs exhibit the conservation of several features, phylogenetic and selection-pressure analyses revealed that overall they evolved to be highly divergent, driven by different selection constraints. Positive selection, as one major driving force, may have resulted in enzymes with a higher functional importance in land plants than green algae. Further structural and mutagenesis analyses demonstrated that some amino acid sites under positive selection are critically important to PDAT structure and function, and may be central in lecithin:cholesterol acyltransferase family enzymes in general.
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Affiliation(s)
- Lucas J Falarz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Colin J Garroway
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Stacy D Singer
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, T1J 4B1, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
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Abstract
In plants, lipids function in a variety of ways. Lipids are a major component of biological membranes and are used as a compact energy source for seed germination. Fatty acids, the major lipids in plants, are synthesized in plastid and assembled by glycerolipids or triacylglycerols in endoplasmic reticulum. The metabolism of fatty acids and triacylglycerols is well studied in most Arabidopsis model plants by forward and reverse genetics methods. However, research on the diverse functions of lipids in plants, including various crops, has yet to be completed. The papers of this Special Issue cover the core of the field of plant lipid research on the role of galactolipids in the chloroplast biogenesis from etioplasts and the role of acyltransferases and transcription factors involved in fatty acid and triacylglycerol synthesis. This information will contribute to the expansion of plant lipid research.
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Parajuli S, Kannan B, Karan R, Sanahuja G, Liu H, Garcia‐Ruiz E, Kumar D, Singh V, Zhao H, Long S, Shanklin J, Altpeter F. Towards oilcane: Engineering hyperaccumulation of triacylglycerol into sugarcane stems. GCB BIOENERGY 2020; 12:476-490. [DOI: 10.1111/gcbb.12684] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 02/16/2020] [Indexed: 08/30/2024]
Abstract
AbstractMetabolic engineering to divert carbon flux from sucrose to oil in high biomass crop like sugarcane is an emerging strategy to boost lipid yields per hectare for biodiesel production. Sugarcane stems comprise more than 70% of the crops' biomass and can accumulate sucrose in excess of 20% of their extracted juice. The energy content of oils in the form of triacylglycerol (TAG) is more than twofold that of carbohydrates. Here, we report a step change in TAG accumulation in sugarcane stem tissues achieving an average of 4.3% of their dry weight (DW) in replicated greenhouse experiments by multigene engineering. The metabolic engineering included constitutive co‐expression of wrinkled1; diacylglycerol acyltransferase1‐2; cysteine‐oleosin; and ribonucleic acid interference‐suppression of sugar‐dependent1. The TAG content in leaf tissue was also elevated by more than 400‐fold compared to non‐engineered sugarcane to an average of 8.0% of the DW and the amount of total fatty acids reached about 13% of the DW. With increasing TAG accumulation an increase of 18:1 unsaturated fatty acids was observed at the expense of 16:0 and 18:0 saturated fatty acids. Total biomass accumulation, soluble lignin, Brix and juice content were significantly reduced in the TAG hyperaccumulating sugarcane lines. Overcoming this yield drag by engineering lipid accumulation into late stem development will be critical to exceed lipid yields of current oilseed crops.
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Affiliation(s)
- Saroj Parajuli
- Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA
| | - Baskaran Kannan
- Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Gainesville FL USA
| | - Ratna Karan
- Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA
| | - Georgina Sanahuja
- Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA
| | - Hui Liu
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Upton NY USA
- Biosciences Department Brookhaven National Laboratory Upton NY USA
| | - Eva Garcia‐Ruiz
- Department of Chemical and Biomolecular Engineering University of Illinois at Urbana‐Champaign Urbana IL USA
| | - Deepak Kumar
- Department of Agricultural and Biological Engineering University of Illinois at Urbana‐Champaign Urbana IL USA
| | - Vijay Singh
- Department of Agricultural and Biological Engineering University of Illinois at Urbana‐Champaign Urbana IL USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering University of Illinois at Urbana‐Champaign Urbana IL USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA
| | - Stephen Long
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Urbana IL USA
- Departments of Plant Biology and Crop Sciences Institute for Genomic Biology University of Illinois at Urbana‐Champaign Urbana IL USA
| | - John Shanklin
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Upton NY USA
- Biosciences Department Brookhaven National Laboratory Upton NY USA
| | - Fredy Altpeter
- Agronomy Department Plant Molecular and Cellular Biology Program Genetics Institute University of Florida, IFAS Gainesville FL USA
- DOE Center for Advanced Bioenergy and Bioproducts Innovation Gainesville FL USA
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Study of Synthesis Pathways of the Essential Polyunsaturated Fatty Acid 20:5n-3 in the Diatom Chaetoceros Muelleri Using 13C-Isotope Labeling. Biomolecules 2020; 10:biom10050797. [PMID: 32455747 PMCID: PMC7277837 DOI: 10.3390/biom10050797] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 12/12/2022] Open
Abstract
The present study sought to characterize the synthesis pathways producing the essential polyunsaturated fatty acid (PUFA) 20:5n-3 (EPA). For this, the incorporation of 13C was experimentally monitored into 10 fatty acids (FA) during the growth of the diatom Chaetoceros muelleri for 24 h. Chaetoceros muelleri preferentially and quickly incorporated 13C into C18 PUFAs such as 18:2n-6 and 18:3n-6 as well as 16:0 and 16:1n-7, which were thus highly 13C-enriched. During the experiment, 20:5n-3 and 16:3n-4 were among the least-enriched fatty acids. The calculation of the enrichment percentage ratio of a fatty acid B over its suspected precursor A allowed us to suggest that the diatom produced 20:5n-3 (EPA) by a combination between the n-3 (via 18:4n-3) and n-6 (via 18:3n-6 and 20:4n-6) synthesis pathways as well as the alternative ω-3 desaturase pathway (via 20:4n-6). In addition, as FA from polar lipids were generally more enriched in 13C than FA from neutral lipids, particularly for 18:1n-9, 18:2n-6 and 18:3n-6, the existence of acyl-editing mechanisms and connectivity between polar and neutral lipid fatty acid pools were also hypothesized. Because 16:3n-4 and 20:5n-3 presented the same concentration and enrichment dynamics, a structural and metabolic link was proposed between these two PUFAs in C. muelleri.
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Screening High CO 2-Tolerant Oleaginous Microalgae from Genera Desmodesmus and Scenedesmus. Appl Biochem Biotechnol 2020; 192:211-229. [PMID: 32358786 DOI: 10.1007/s12010-020-03319-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/23/2020] [Indexed: 01/12/2023]
Abstract
Microalgae from genus Scenedesmus sensu lato (including Desmodesmus and Scenedesmus) were reported to be particularly suitable candidates for CO2 biomitigation. In this study, 16 strains from Scenedesmus sensu lato were obtained from different climate zones of China and their phylogenetic positions were determined. Seven strains out of the 16 showed high CO2 tolerance and grew much faster under 20% CO2 than air condition. Two representatives from genera Desmodesmus (NMD46) and Scenedesmus (HBX310) respectively were selected due to their higher lipid productivity, and the maximum value of 146 mg L-1 day-1 was achieved in NMD46. Triacylglycerols increased with the rising of CO2 levels from 0.04 to 15% in NMD46, while they changed little in HBX310. High CO2 level decreased the polyunsaturated fatty acid content in NMD46 but increased it in HBX310. NMD46 is more suitable for standardized biodiesel production in view of its lipid and fatty acid composition responses to high CO2.
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The Role of Triacylglycerol in Plant Stress Response. PLANTS 2020; 9:plants9040472. [PMID: 32276473 PMCID: PMC7238164 DOI: 10.3390/plants9040472] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 12/12/2022]
Abstract
Vegetable oil is mainly composed of triacylglycerol (TAG), a storage lipid that serves as a major commodity for food and industrial purposes, as well as an alternative biofuel source. While TAG is typically not produced at significant levels in vegetative tissues, emerging evidence suggests that its accumulation in such tissues may provide one mechanism by which plants cope with abiotic stress. Different types of abiotic stress induce lipid remodeling through the action of specific lipases, which results in various alterations in membrane lipid composition. This response induces the formation of toxic lipid intermediates that cause membrane damage or cell death. However, increased levels of TAG under stress conditions are believed to function, at least in part, as a means of sequestering these toxic lipid intermediates. Moreover, the lipid droplets (LDs) in which TAG is enclosed also function as a subcellular factory to provide binding sites and substrates for the biosynthesis of bioactive compounds that protect against insects and fungi. Though our knowledge concerning the role of TAG in stress tolerance is expanding, many gaps in our understanding of the mechanisms driving these processes are still evident. In this review, we highlight progress that has been made to decipher the role of TAG in plant stress response, and we discuss possible ways in which this information could be utilized to improve crops in the future.
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Xu XY, Akbar S, Shrestha P, Venugoban L, Devilla R, Hussain D, Lee J, Rug M, Tian L, Vanhercke T, Singh SP, Li Z, Sharp PJ, Liu Q. A Synergistic Genetic Engineering Strategy Induced Triacylglycerol Accumulation in Potato ( Solanum tuberosum) Leaf. FRONTIERS IN PLANT SCIENCE 2020; 11:215. [PMID: 32210994 PMCID: PMC7069356 DOI: 10.3389/fpls.2020.00215] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 02/12/2020] [Indexed: 05/23/2023]
Abstract
Potato is the 4th largest staple food in the world currently. As a high biomass crop, potato harbors excellent potential to produce energy-rich compounds such as triacylglycerol as a valuable co-product. We have previously reported that transgenic potato tubers overexpressing WRINKLED1, DIACYLGLYCEROL ACYLTRANSFERASE 1, and OLEOSIN genes produced considerable levels of triacylglycerol. In this study, the same genetic engineering strategy was employed on potato leaves. The overexpression of Arabidopsis thaliana WRINKED1 under the transcriptional control of a senescence-inducible promoter together with Arabidopsis thaliana DIACYLGLYCEROL ACYLTRANSFERASE 1 and Sesamum indicum OLEOSIN driven by the Cauliflower Mosaic Virus 35S promoter and small subunit of Rubisco promoter respectively, resulted in an approximately 30- fold enhancement of triacylglycerols in the senescent transgenic potato leaves compared to the wild type. The increase of triacylglycerol in the transgenic potato leaves was accompanied by perturbations of carbohydrate accumulation, apparent in a reduction in starch content and increased total soluble sugars, as well as changes of polar membrane lipids at different developmental stages. Microscopic and biochemical analysis further indicated that triacylglycerols and lipid droplets could not be produced in chloroplasts, despite the increase and enlargement of plastoglobuli at the senescent stage. Possibly enhanced accumulation of fatty acid phytyl esters in the plastoglobuli were reflected in transgenic potato leaves relative to wild type. It is likely that the plastoglobuli may have hijacked some of the carbon as the result of WRINKED1 expression, which could be a potential factor restricting the effective accumulation of triacylglycerols in potato leaves. Increased lipid production was also observed in potato tubers, which may have affected the tuberization to a certain extent. The expression of transgenes in potato leaf not only altered the carbon partitioning in the photosynthetic source tissue, but also the underground sink organs which highly relies on the leaves in development and energy deposition.
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Affiliation(s)
- Xiao-yu Xu
- CSIRO Agriculture and Food, Canberra, ACT, Australia
- Plant Breeding Institute and Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, Australia
| | - Sehrish Akbar
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | | | | | | | - Dawar Hussain
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Jiwon Lee
- Center for Advanced Microscopy, The Australian National University, Canberra, ACT, Australia
| | - Melanie Rug
- Center for Advanced Microscopy, The Australian National University, Canberra, ACT, Australia
| | - Lijun Tian
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | | | | | - Zhongyi Li
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Peter J. Sharp
- Plant Breeding Institute and Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, Australia
| | - Qing Liu
- CSIRO Agriculture and Food, Canberra, ACT, Australia
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