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Lusk HJ, Neumann N, Colter M, Roth MR, Tamura P, Yao L, Shiva S, Shah J, Schrick K, Durrett TP, Welti R. Lipidomic Analysis of Arabidopsis T-DNA Insertion Lines Leads to Identification and Characterization of C-Terminal Alterations in FATTY ACID DESATURASE 6. PLANT & CELL PHYSIOLOGY 2022; 63:1193-1204. [PMID: 35726963 PMCID: PMC9474942 DOI: 10.1093/pcp/pcac088] [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: 04/18/2022] [Revised: 06/15/2022] [Accepted: 06/20/2022] [Indexed: 05/27/2023]
Abstract
Mass-spectrometry-based screening of lipid extracts of wounded and unwounded leaves from a collection of 364 Arabidopsis thaliana T-DNA insertion lines produced lipid profiles that were scored on the number and significance of their differences from the leaf lipid profiles of wild-type plants. The analysis identified Salk_109175C, which displayed alterations in leaf chloroplast glycerolipid composition, including a decreased ratio between two monogalactosyldiacylglycerol (MGDG) molecular species, MGDG(18:3/16:3) and MGDG(18:3/18:3). Salk_109175C has a confirmed insertion in the At5g64790 locus; the insertion did not co-segregate with the recessive lipid phenotype in the F2 generation of a wild-type (Columbia-0) × Salk_109175C cross. The altered lipid compositional phenotype mapped to the At4g30950 locus, which encodes the plastidial ω-6 desaturase FATTY ACID DESATURASE 6 (FAD6). Sequencing revealed a splice-site mutation, leading to the in-frame deletion of 13 amino acids near the C-terminal end of the 448 amino acid protein. Heterologous expression in yeast showed that this deletion eliminates desaturase activity and reduces protein stability. Sequence comparison across species revealed that several amino acids within the deletion are conserved in plants and cyanobacteria. Individual point mutations in four conserved residues resulted in 77-97% reductions in desaturase activity, while a construct with all four alanine substitutions lacked activity. The data suggest that the deleted region of FAD6, which is on the C-terminal side of the four putative transmembrane segments and the histidine boxes putatively involved in catalysis, is critical for FAD6 function.
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Affiliation(s)
| | | | - Madeline Colter
- Division of Biology, Kansas State University, 1717 Claflin Rd., Manhattan, KS 66506, USA
| | - Mary R Roth
- Division of Biology, Kansas State University, 1717 Claflin Rd., Manhattan, KS 66506, USA
| | - Pamela Tamura
- Division of Biology, Kansas State University, 1717 Claflin Rd., Manhattan, KS 66506, USA
| | - Libin Yao
- Division of Biology, Kansas State University, 1717 Claflin Rd., Manhattan, KS 66506, USA
| | - Sunitha Shiva
- Division of Biology, Kansas State University, 1717 Claflin Rd., Manhattan, KS 66506, USA
- Eurofins Scientific, 4780 Discovery Drive, Columbia, MO 65201, USA
| | - Jyoti Shah
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, 1155 Union Circle #305220, Denton, TX 76203-5017, USA
| | - Kathrin Schrick
- Division of Biology, Kansas State University, 1717 Claflin Rd., Manhattan, KS 66506, USA
| | - Timothy P Durrett
- *Corresponding authors: Timothy Durrett, E-mail, ; Ruth Welti, E-mail,
| | - Ruth Welti
- *Corresponding authors: Timothy Durrett, E-mail, ; Ruth Welti, E-mail,
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Omega-3 fatty acid desaturase gene family from two ω-3 sources, Salvia hispanica and Perilla frutescens: Cloning, characterization and expression. PLoS One 2018; 13:e0191432. [PMID: 29351555 PMCID: PMC5774782 DOI: 10.1371/journal.pone.0191432] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 01/04/2018] [Indexed: 11/19/2022] Open
Abstract
Omega-3 fatty acid desaturase (ω-3 FAD, D15D) is a key enzyme for α-linolenic acid (ALA) biosynthesis. Both chia (Salvia hispanica) and perilla (Perilla frutescens) contain high levels of ALA in seeds. In this study, the ω-3 FAD gene family was systematically and comparatively cloned from chia and perilla. Perilla FAD3, FAD7, FAD8 and chia FAD7 are encoded by single-copy (but heterozygous) genes, while chia FAD3 is encoded by 2 distinct genes. Only 1 chia FAD8 sequence was isolated. In these genes, there are 1 to 6 transcription start sites, 1 to 8 poly(A) tailing sites, and 7 introns. The 5'UTRs of PfFAD8a/b contain 1 to 2 purine-stretches and 2 pyrimidine-stretches. An alternative splice variant of ShFAD7a/b comprises a 5'UTR intron. Their encoded proteins harbor an FA_desaturase conserved domain together with 4 trans-membrane helices and 3 histidine boxes. Phylogenetic analysis validated their identity of dicot microsomal or plastidial ω-3 FAD proteins, and revealed some important evolutionary features of plant ω-3 FAD genes such as convergent evolution across different phylums, single-copy status in algae, and duplication events in certain taxa. The qRT-PCR assay showed that the ω-3 FAD genes of two species were expressed at different levels in various organs, and they also responded to multiple stress treatments. The functionality of the ShFAD3 and PfFAD3 enzymes was confirmed by yeast expression. The systemic molecular and functional features of the ω-3 FAD gene family from chia and perilla revealed in this study will facilitate their use in future studies on genetic improvement of ALA traits in oilseed crops.
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Venegas-Calerón M, Sánchez R, Salas JJ, Garcés R, Martínez-Force E. Molecular and biochemical characterization of the OLE-1 high-oleic castor seed (Ricinus communis L.) mutant. PLANTA 2016; 244:245-58. [PMID: 27056057 DOI: 10.1007/s00425-016-2508-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 03/24/2016] [Indexed: 06/05/2023]
Abstract
MAIN CONCLUSION The natural OLE-1 high-oleic castor mutant has been characterized, demonstrating that point mutations in the FAH12 gene are responsible for the high-oleic phenotype. The contribution of each mutation was evaluated by heterologous expression in yeast, and lipid studies in developing OLE-1 seeds provided new evidence of unusual fatty acids channeling into TAGs. Ricinus communis L. is a plant of the Euphorbiaceae family well known for producing seeds whose oil has a very high ricinoleic (12-hydroxyoctadecenoic) acid content. Castor oil is considered the only commercially renewable source of hydroxylated fatty acids, which have many applications as chemical reactants. Accordingly, there has been great interest in the field of plant lipid biotechnology to define how ricinoleic acid is synthesized, which could also provide information that might serve to increase the content of other unusual fatty acids in oil crops. Accordingly, we set out to study the biochemistry of castor oil synthesis by characterizing a natural castor bean mutant deficient in ricinoleic acid synthesis (OLE-1). This mutant accumulates high levels of oleic acid and displays remarkable alterations in its seed lipid composition. To identify enzymes that are critical for this phenotype in castor oil, we cloned and sequenced the oleate desaturase (FAD2) and hydroxylase (FAH12) genes from wild-type and OLE-1 castor bean plants and analyzed their expression in different tissues. Heterologous expression in yeast confirmed that three modifications to the OLE-1 FAH12 protein were responsible for its weaker hydroxylase activity. In addition, we studied the expression of the genes involved in this biosynthetic pathway at different developmental stages, as well as that of other genes involved in lipid biosynthesis, both in wild-type and mutant seeds.
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Affiliation(s)
- Mónica Venegas-Calerón
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Seville, Spain.
| | - Rosario Sánchez
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Seville, Spain
| | - Joaquín J Salas
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Seville, Spain
| | - Rafael Garcés
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Seville, Spain
| | - Enrique Martínez-Force
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Seville, Spain
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Bhunia RK, Chakraborty A, Kaur R, Maiti MK, Sen SK. Enhancement of α-linolenic acid content in transgenic tobacco seeds by targeting a plastidial ω-3 fatty acid desaturase (fad7) gene of Sesamum indicum to ER. PLANT CELL REPORTS 2016; 35:213-26. [PMID: 26521211 DOI: 10.1007/s00299-015-1880-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/25/2015] [Accepted: 10/07/2015] [Indexed: 05/10/2023]
Abstract
KEY MESSAGE Expression of sesame plastidial FAD7 desaturase modified with the endoplasmic reticulum targeting and retention signals, enhances the α-linolenic acid accumulation in seeds of Nicotiana tabacum. In plants, plastidial ω-3 fatty acid desaturase-7 (FAD7) catalyzes the formation of C16 and C18 trienoic fatty acids using organellar glycerolipids and participate in the membrane lipid formation. The plastidial ω-3 desaturases (FAD7) share high sequence homology with the microsomal ω-3 desaturases (FAD3) at the amino acid level except the N-terminal organelle transit peptide. In the present study, the predicted N-terminal plastidial signal peptide of fad7 gene was replaced by the endoplasmic reticulum signal peptide and an endoplasmic reticulum retention signal was placed at the C-terminal. The expression of the modified sesame ω-3 desaturase increases the α-linolenic acid content in the range of 4.78-6.77 % in the seeds of transgenic tobacco plants with concomitant decrease in linoleic acid content. The results suggested the potential of the engineered plastidial ω-3 desaturase from sesame to influence the profile of α-linolenic acid in tobacco plant by shifting the carbon flux from linoleic acid, and thus it can be used in suitable genetic engineering strategy to increase the α-linolenic acid content in sesame and other vegetable oils.
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Affiliation(s)
- Rupam Kumar Bhunia
- Advanced Laboratory for Plant Genetic Engineering, Indian Institute of Technology, Kharagpur, 721302, India
- Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur, 721302, India
- Department of Biochemistry, Biophysics and Molecular Biology (BBMB), Iowa State University, Ames, IA, 50011, USA
| | - Anirban Chakraborty
- Advanced Laboratory for Plant Genetic Engineering, Indian Institute of Technology, Kharagpur, 721302, India
| | - Ranjeet Kaur
- Advanced Laboratory for Plant Genetic Engineering, Indian Institute of Technology, Kharagpur, 721302, India
- Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur, 721302, India
| | - Mrinal K Maiti
- Advanced Laboratory for Plant Genetic Engineering, Indian Institute of Technology, Kharagpur, 721302, India
- Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur, 721302, India
- Department of Biotechnology, Indian Institute of Technology, Kharagpur, 721302, India
| | - Soumitra Kumar Sen
- Advanced Laboratory for Plant Genetic Engineering, Indian Institute of Technology, Kharagpur, 721302, India.
- Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur, 721302, India.
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Sánchez G, Venegas-Calerón M, Salas JJ, Monforte A, Badenes ML, Granell A. An integrative "omics" approach identifies new candidate genes to impact aroma volatiles in peach fruit. BMC Genomics 2013; 14:343. [PMID: 23701715 PMCID: PMC3685534 DOI: 10.1186/1471-2164-14-343] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 05/15/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ever since the recent completion of the peach genome, the focus of genetic research in this area has turned to the identification of genes related to important traits, such as fruit aroma volatiles. Of the over 100 volatile compounds described in peach, lactones most likely have the strongest effect on fruit aroma, while esters, terpenoids, and aldehydes have minor, yet significant effects. The identification of key genes underlying the production of aroma compounds is of interest for any fruit-quality improvement strategy. RESULTS Volatile (52 compounds) and gene expression (4348 genes) levels were profiled in peach fruit from a maturity time-course series belonging to two peach genotypes that showed considerable differences in maturation characteristics and postharvest ripening. This data set was analyzed by complementary correlation-based approaches to discover the genes related to the main aroma-contributing compounds: lactones, esters, and phenolic volatiles, among others. As a case study, one of the candidate genes was cloned and expressed in yeast to show specificity as an ω-6 Oleate desaturase, which may be involved in the production of a precursor of lactones/esters. CONCLUSIONS Our approach revealed a set of genes (an alcohol acyl transferase, fatty acid desaturases, transcription factors, protein kinases, cytochromes, etc.) that are highly associated with peach fruit volatiles, and which could prove useful in breeding or for biotechnological purposes.
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Affiliation(s)
- Gerardo Sánchez
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Ingeniero Fausto Elio s/n, Valencia 46022, Spain.
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Cold-induced accumulation of ω-3 polyunsaturated fatty acid in a liverwort, Marchantia polymorpha L. Biosci Biotechnol Biochem 2012; 76:785-90. [PMID: 22484954 DOI: 10.1271/bbb.110915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The liverwort Marchantia polymorpha L. synthesizes various long-chain polyunsaturated fatty acids including arachidonic acid and eicosapentaenoic acid, neither of which is produced by higher plants. Here we report the effects of temperature on long-chain polyunsaturated fatty acid accumulation in the liverwort. The accumulation of ω-3 polyunsaturated fatty acids increased significantly as the growth temperature decreased. Specifically, the relative content of eicosapentaenoic acid to total fatty acids at 5 °C was approximately 3-fold higher than at 25 °C. On the other hand, the accumulation of ω-6 polyunsaturated fatty acids decreased at low temperatures. An analysis of gene expression indicated that the mRNA of the MpFAD3 gene for ER ω-3 desaturase increased significantly at 5 °C. These results indicate that in the liverwort the n-3 pathway was enhanced at low temperature, mainly via expression of the cold-induced ω-3 desaturase gene, leading to increased accumulation of eicosapentaenoic acid.
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