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Zhang S, Wu S, Hou Q, Zhao J, Fang C, An X, Wan X. Fatty acid de novo biosynthesis in plastids: Key enzymes and their critical roles for male reproduction and other processes in plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 210:108654. [PMID: 38663264 DOI: 10.1016/j.plaphy.2024.108654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/12/2024]
Abstract
Fatty acid de novo biosynthesis in plant plastids is initiated from acetyl-CoA and catalyzed by a series of enzymes, which is required for the vegetative growth, reproductive growth, seed development, stress response, chloroplast development and other biological processes. In this review, we systematically summarized the fatty acid de novo biosynthesis-related genes/enzymes and their critical roles in various plant developmental processes. Based on bioinformatic analysis, we identified fatty acid synthase encoding genes and predicted their potential functions in maize growth and development, especially in anther and pollen development. Finally, we highlighted the potential applications of these fatty acid synthases in male-sterility hybrid breeding, seed oil content improvement, herbicide and abiotic stress resistance, which provides new insights into future molecular crop breeding.
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Affiliation(s)
- Simiao Zhang
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China
| | - Suowei Wu
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Engineering Laboratory of Main Crop Bio-Tech Breeding, Beijing Solidwill Sci-Tech Co. Ltd., Beijing, 100192, China; Shandong Shouxin Seed Sci-Tech Co. Ltd., Zhucheng City, Shandong Province, 262200, China
| | - Quancan Hou
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China
| | - Junfeng Zhao
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China
| | - Chaowei Fang
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China
| | - Xueli An
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Engineering Laboratory of Main Crop Bio-Tech Breeding, Beijing Solidwill Sci-Tech Co. Ltd., Beijing, 100192, China
| | - Xiangyuan Wan
- Research Institute of Biology and Agriculture, Zhongzhi International Institute of Agricultural Biosciences, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Engineering Laboratory of Main Crop Bio-Tech Breeding, Beijing Solidwill Sci-Tech Co. Ltd., Beijing, 100192, China.
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2
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Liu J, Lim SL, Zhong JY, Lim BL. Bioenergetics of pollen tube growth in Arabidopsis thaliana revealed by ratiometric genetically encoded biosensors. Nat Commun 2022; 13:7822. [PMID: 36535933 PMCID: PMC9763403 DOI: 10.1038/s41467-022-35486-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Pollen tube is the fastest-growing plant cell. Its polarized growth process consumes a tremendous amount of energy, which involves coordinated energy fluxes between plastids, the cytosol, and mitochondria. However, how the pollen tube obtains energy and what the biological roles of pollen plastids are in this process remain obscure. To investigate this energy-demanding process, we developed second-generation ratiometric biosensors for pyridine nucleotides which are pH insensitive between pH 7.0 to pH 8.5. By monitoring dynamic changes in ATP and NADPH concentrations and the NADH/NAD+ ratio at the subcellular level in Arabidopsis (Arabidopsis thaliana) pollen tubes, we delineate the energy metabolism that underpins pollen tube growth and illustrate how pollen plastids obtain ATP, NADPH, NADH, and acetyl-CoA for fatty acid biosynthesis. We also show that fermentation and pyruvate dehydrogenase bypass are not essential for pollen tube growth in Arabidopsis, in contrast to other plant species like tobacco and lily.
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Affiliation(s)
- Jinhong Liu
- grid.194645.b0000000121742757School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Shey-Li Lim
- grid.194645.b0000000121742757School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Jia Yi Zhong
- grid.194645.b0000000121742757School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Boon Leong Lim
- grid.194645.b0000000121742757School of Biological Sciences, University of Hong Kong, Hong Kong, China ,grid.194645.b0000000121742757HKU Shenzhen Institute of Research and Innovation, Shenzhen, China ,grid.10784.3a0000 0004 1937 0482State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
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Sánchez R, González-Thuillier I, Venegas-Calerón M, Garcés R, Salas JJ, Martínez-Force E. The Sunflower WRINKLED1 Transcription Factor Regulates Fatty Acid Biosynthesis Genes through an AW Box Binding Sequence with a Particular Base Bias. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11070972. [PMID: 35406952 PMCID: PMC9002759 DOI: 10.3390/plants11070972] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 03/24/2022] [Accepted: 03/30/2022] [Indexed: 06/12/2023]
Abstract
Sunflower is an important oilseed crop in which the biochemical pathways leading to seed oil synthesis and accumulation have been widely studied. However, how these pathways are regulated is less well understood. The WRINKLED1 (WRI1) transcription factor is considered a key regulator in the control of triacylglycerol biosynthesis, acting through the AW box binding element (CNTNG(N)7CG). Here, we identified the sunflower WRI1 gene and characterized its activity in electrophoretic mobility shift assays. We studied its role as a co-regulator of sunflower genes involved in plastidial fatty acid synthesis. Sunflower WRI1-targets included genes encoding the pyruvate dehydrogenase complex, the α-CT and BCCP genes, genes encoding ACPs and the fatty acid synthase complex, together with the FATA1 gene. As such, sunflower WRI1 regulates genes involved in seed plastidial fatty acid biosynthesis in a coordinated manner, establishing a WRI1 push and pull strategy that drives oleic acid synthesis for its export into the cytosol. We also determined the base bias at the N positions in the active sunflower AW box motif. The sunflower AW box is sequence-sensitive at the non-conserved positions, enabling WRI1-binding. Moreover, sunflower WRI1 could bind to a non-canonical AW-box motif, opening the possibility of searching for new target genes.
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Affiliation(s)
- Rosario Sánchez
- Instituto de la Grasa (CSIC), Pablo de Olavide University Campus, Building 46, Carretera de Utrera km 1, 41013 Seville, Spain; (R.S.); (I.G.-T.); (M.V.-C.); (R.G.); (J.J.S.)
| | - Irene González-Thuillier
- Instituto de la Grasa (CSIC), Pablo de Olavide University Campus, Building 46, Carretera de Utrera km 1, 41013 Seville, Spain; (R.S.); (I.G.-T.); (M.V.-C.); (R.G.); (J.J.S.)
- Jealotts Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Mónica Venegas-Calerón
- Instituto de la Grasa (CSIC), Pablo de Olavide University Campus, Building 46, Carretera de Utrera km 1, 41013 Seville, Spain; (R.S.); (I.G.-T.); (M.V.-C.); (R.G.); (J.J.S.)
| | - Rafael Garcés
- Instituto de la Grasa (CSIC), Pablo de Olavide University Campus, Building 46, Carretera de Utrera km 1, 41013 Seville, Spain; (R.S.); (I.G.-T.); (M.V.-C.); (R.G.); (J.J.S.)
| | - Joaquín J. Salas
- Instituto de la Grasa (CSIC), Pablo de Olavide University Campus, Building 46, Carretera de Utrera km 1, 41013 Seville, Spain; (R.S.); (I.G.-T.); (M.V.-C.); (R.G.); (J.J.S.)
| | - Enrique Martínez-Force
- Instituto de la Grasa (CSIC), Pablo de Olavide University Campus, Building 46, Carretera de Utrera km 1, 41013 Seville, Spain; (R.S.); (I.G.-T.); (M.V.-C.); (R.G.); (J.J.S.)
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Clark TJ, Schwender J. Elucidation of Triacylglycerol Overproduction in the C 4 Bioenergy Crop Sorghum bicolor by Constraint-Based Analysis. FRONTIERS IN PLANT SCIENCE 2022; 13:787265. [PMID: 35251073 PMCID: PMC8892208 DOI: 10.3389/fpls.2022.787265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Upregulation of triacylglycerols (TAGs) in vegetative plant tissues such as leaves has the potential to drastically increase the energy density and biomass yield of bioenergy crops. In this context, constraint-based analysis has the promise to improve metabolic engineering strategies. Here we present a core metabolism model for the C4 biomass crop Sorghum bicolor (iTJC1414) along with a minimal model for photosynthetic CO2 assimilation, sucrose and TAG biosynthesis in C3 plants. Extending iTJC1414 to a four-cell diel model we simulate C4 photosynthesis in mature leaves with the principal photo-assimilatory product being replaced by TAG produced at different levels. Independent of specific pathways and per unit carbon assimilated, energy content and biosynthetic demands in reducing equivalents are about 1.3 to 1.4 times higher for TAG than for sucrose. For plant generic pathways, ATP- and NADPH-demands per CO2 assimilated are higher by 1.3- and 1.5-fold, respectively. If the photosynthetic supply in ATP and NADPH in iTJC1414 is adjusted to be balanced for sucrose as the sole photo-assimilatory product, overproduction of TAG is predicted to cause a substantial surplus in photosynthetic ATP. This means that if TAG synthesis was the sole photo-assimilatory process, there could be an energy imbalance that might impede the process. Adjusting iTJC1414 to a photo-assimilatory rate that approximates field conditions, we predict possible daily rates of TAG accumulation, dependent on varying ratios of carbon partitioning between exported assimilates and accumulated oil droplets (TAG, oleosin) and in dependence of activation of futile cycles of TAG synthesis and degradation. We find that, based on the capacity of leaves for photosynthetic synthesis of exported assimilates, mature leaves should be able to reach a 20% level of TAG per dry weight within one month if only 5% of the photosynthetic net assimilation can be allocated into oil droplets. From this we conclude that high TAG levels should be achievable if TAG synthesis is induced only during a final phase of the plant life cycle.
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Affiliation(s)
- Teresa J. Clark
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Jorg Schwender
- Biology Department, Brookhaven National Laboratory, Upton, NY, United States
- Department of Energy Center for Advanced Bioenergy and Bioproducts Innovation, Upton, NY, United States
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González-Thuillier I, Venegas-Calerón M, Moreno-Pérez AJ, Salas JJ, Garcés R, von Wettstein-Knowles P, Martínez-Force E. Sunflower (Helianthus annuus) fatty acid synthase complex: β-Ketoacyl-[acyl carrier protein] reductase genes. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 166:689-699. [PMID: 34214779 DOI: 10.1016/j.plaphy.2021.06.048] [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: 04/13/2021] [Revised: 06/10/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Fatty acids play many roles in plants, but the function of some key genes involved in fatty acid biosynthesis in plant development are not yet properly understood. Here, we clone two β-ketoacyl-[ACP] reductase (KAR) genes from sunflower, HaKAR1 and HaKAR2, and characterize their functional roles. The enzymes cloned were the only two copies present in the sunflower genome. Both displayed a high degree of similarity, but their promoters infer different regulation. The two sunflower KAR genes were constitutively expressed in all tissues examined, being maximum in developing cotyledons at the start of oil synthesis. Over-expression of HaKAR1 in E. coli changed the fatty acid composition by promoting the elongation of C16:0 to C18:0 fatty acids. The enzymatic characterization of HaKAR1 revealed similar kinetic parameters to homologues from other oil accumulating species. The results point to a partially functional redundancy between HaKAR1 and HaKAR2. This study clearly revealed that these genes play a prominent role in de novo fatty acids synthesis in sunflower seeds.
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Affiliation(s)
- Irene González-Thuillier
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain; Biosciences, Jealotts Hill Research Station, Warfield, Bracknell, RG42 6EY, UK
| | - Mónica Venegas-Calerón
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain.
| | - Antonio J Moreno-Pérez
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain
| | - Joaquín J Salas
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain
| | - Rafael Garcés
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain
| | | | - Enrique Martínez-Force
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Sevilla, Spain
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6
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Huang H, Liang J, Tan Q, Ou L, Li X, Zhong C, Huang H, Møller IM, Wu X, Song S. Insights into triterpene synthesis and unsaturated fatty-acid accumulation provided by chromosomal-level genome analysis of Akebia trifoliata subsp. australis. HORTICULTURE RESEARCH 2021; 8:33. [PMID: 33518712 PMCID: PMC7848005 DOI: 10.1038/s41438-020-00458-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 11/16/2020] [Accepted: 11/20/2020] [Indexed: 05/10/2023]
Abstract
Akebia trifoliata subsp. australis is a well-known medicinal and potential woody oil plant in China. The limited genetic information available for A. trifoliata subsp. australis has hindered its exploitation. Here, a high-quality chromosome-level genome sequence of A. trifoliata subsp. australis is reported. The de novo genome assembly of 682.14 Mb was generated with a scaffold N50 of 43.11 Mb. The genome includes 25,598 protein-coding genes, and 71.18% (485.55 Mb) of the assembled sequences were identified as repetitive sequences. An ongoing massive burst of long terminal repeat (LTR) insertions, which occurred ~1.0 million years ago, has contributed a large proportion of LTRs in the genome of A. trifoliata subsp. australis. Phylogenetic analysis shows that A. trifoliata subsp. australis is closely related to Aquilegia coerulea and forms a clade with Papaver somniferum and Nelumbo nucifera, which supports the well-established hypothesis of a close relationship between basal eudicot species. The expansion of UDP-glucoronosyl and UDP-glucosyl transferase gene families and β-amyrin synthase-like genes and the exclusive contraction of terpene synthase gene families may be responsible for the abundant oleanane-type triterpenoids in A. trifoliata subsp. australis. Furthermore, the acyl-ACP desaturase gene family, including 12 stearoyl-acyl-carrier protein desaturase (SAD) genes, has expanded exclusively. A combined transcriptome and fatty-acid analysis of seeds at five developmental stages revealed that homologs of SADs, acyl-lipid desaturase omega fatty acid desaturases (FADs), and oleosins were highly expressed, consistent with the rapid increase in the content of fatty acids, especially unsaturated fatty acids. The genomic sequences of A. trifoliata subsp. australis will be a valuable resource for comparative genomic analyses and molecular breeding.
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Affiliation(s)
- Hui Huang
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Juan Liang
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
| | - Qi Tan
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
| | - Linfeng Ou
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
| | - Xiaolin Li
- State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Science, Beijing, 100700, China
| | - Caihong Zhong
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
| | - Huilin Huang
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
| | - Ian Max Møller
- Department of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200, Slagelse, Denmark
| | - Xianjin Wu
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China
| | - Songquan Song
- Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418000, China.
- Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
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An extreme-phenotype genome-wide association study identifies candidate cannabinoid pathway genes in Cannabis. Sci Rep 2020; 10:18643. [PMID: 33122674 PMCID: PMC7596533 DOI: 10.1038/s41598-020-75271-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023] Open
Abstract
Cannabis produces a class of isoprenylated resorcinyl polyketides known as cannabinoids, a subset of which are medically important and exclusive to this plant. The cannabinoid alkyl group is a critical structural feature that governs therapeutic activity. Genetic enhancement of the alkyl side-chain could lead to the development of novel chemical phenotypes (chemotypes) for pharmaceutical end-use. However, the genetic determinants underlying in planta variation of cannabinoid alkyl side-chain length remain uncharacterised. Using a diversity panel derived from the Ecofibre Cannabis germplasm collection, an extreme-phenotype genome-wide association study (XP-GWAS) was used to enrich for alkyl cannabinoid polymorphic regions. Resequencing of chemotypically extreme pools revealed a known cannabinoid synthesis pathway locus as well as a series of chemotype-associated genomic regions. One of these regions contained a candidate gene encoding a β-keto acyl carrier protein (ACP) reductase (BKR) putatively associated with polyketide fatty acid starter unit synthesis and alkyl side-chain length. Association analysis revealed twenty-two polymorphic variants spanning the length of this gene, including two nonsynonymous substitutions. The success of this first reported application of XP-GWAS for an obligate outcrossing and highly heterozygote plant genus suggests that this approach may have generic application for other plant species.
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Aznar-Moreno JA, Sánchez R, Gidda SK, Martínez-Force E, Moreno-Pérez AJ, Venegas Calerón M, Garcés R, Mullen RT, Salas JJ. New Insights Into Sunflower ( Helianthus annuus L.) FatA and FatB Thioesterases, Their Regulation, Structure and Distribution. FRONTIERS IN PLANT SCIENCE 2018; 9:1496. [PMID: 30459777 PMCID: PMC6232763 DOI: 10.3389/fpls.2018.01496] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/25/2018] [Indexed: 05/13/2023]
Abstract
Sunflower seeds (Helianthus annuus L.) accumulate large quantities of triacylglycerols (TAG) between 12 and 28 days after flowering (DAF). This is the period of maximal acyl-acyl carrier protein (acyl-ACP) thioesterase activity in vitro, the enzymes that terminate the process of de novo fatty acid synthesis by catalyzing the hydrolysis of the acyl-ACPs synthesized by fatty acid synthase. Fatty acid thioesterases can be classified into two families with distinct substrate specificities, namely FatA and FatB. Here, some new aspects of these enzymes have been studied, assessing how both enzymes contribute to the acyl composition of sunflower oil, not least through the changes in their expression during the process of seed filling. Moreover, the binding pockets of these enzymes were modeled based on new data from plant thioesterases, revealing important differences in their volume and geometry. Finally, the subcellular location of the two enzymes was evaluated and while both possess an N-terminal plastid transit peptide, only in FatB contains a hydrophobic sequence that could potentially serve as a transmembrane domain. Indeed, using in vivo imaging and organelle fractionation, H. annuus thioesterases, HaFatA and HaFatB, appear to be differentially localized in the plastid stroma and membrane envelope, respectively. The divergent roles fulfilled by HaFatA and HaFatB in oil biosynthesis are discussed in the light of our data.
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Affiliation(s)
- Jose A. Aznar-Moreno
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
| | - Rosario Sánchez
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Satinder K. Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | | | | | - Mónica Venegas Calerón
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Rafael Garcés
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Robert T. Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Joaquín J. Salas
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
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9
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Aznar-Moreno JA, Venegas-Calerón M, Martínez-Force E, Garcés R, Salas JJ. Acyl carrier proteins from sunflower (Helianthus annuus L.) seeds and their influence on FatA and FatB acyl-ACP thioesterase activities. PLANTA 2016; 244:479-90. [PMID: 27095109 DOI: 10.1007/s00425-016-2521-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/04/2016] [Indexed: 05/13/2023]
Abstract
The kinetics of acyl-ACP thioesterases from sunflower importantly changed when endogenous ACPs were used. Sunflower FatB was much more specific towards saturated acyl-ACPs when assayed with them. Acyl carrier proteins (ACPs) are small (~9 kDa), soluble, acidic proteins involved in fatty acid synthesis in plants and bacteria. ACPs bind to fatty acids through a thioester bond, generating the acyl-ACP lipoproteins that are substrates for fatty acid synthase (FAS) complexes, and that are required for fatty acid chain elongation, acting as important intermediates in de novo fatty acid synthesis in plants. Plants, usually express several ACP isoforms with distinct functionalities. We report here the cloning of three ACPs from developing sunflower seeds: HaACP1, HaACP2, and HaACP3. These proteins were plastidial ACPs expressed strongly in seeds, and as such they are probably involved in the synthesis of sunflower oil. The recombinant sunflower ACPs were expressed in bacteria but they were lethal to the prokaryote host. Thus, they were finally produced using the GST gene fusion system, which allowed the apo-enzyme to be produced and later activated to the holo form. Radiolabelled acyl-ACPs from the newly cloned holo-ACP forms were also synthesized and used to characterize the activity of recombinant sunflower FatA and FatB thioesterases, important enzymes in plant fatty acids synthesis. The activity of these enzymes changed significantly when the endogenous ACPs were used. Thus, FatA importantly increased its activity levels, whereas FatB displayed a different specificity profile, with much high activity levels towards saturated acyl-CoA derivatives. All these data pointed to an important influence of the ACP moieties on the activity of enzymes involved in lipid synthesis.
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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
| | - Enrique Martínez-Force
- 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
| | - Joaquín J Salas
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1, 41013, Seville, Spain.
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10
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González-Thuillier I, Venegas-Calerón M, Sánchez R, Garcés R, von Wettstein-Knowles P, Martínez-Force E. Sunflower (Helianthus annuus) fatty acid synthase complex: β-hydroxyacyl-[acyl carrier protein] dehydratase genes. PLANTA 2016; 243:397-410. [PMID: 26433735 DOI: 10.1007/s00425-015-2410-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/14/2015] [Indexed: 05/19/2023]
Abstract
Two sunflower hydroxyacyl-[acyl carrier protein] dehydratases evolved into two different isoenzymes showing distinctive expression levels and kinetics' efficiencies. β-Hydroxyacyl-[acyl carrier protein (ACP)]-dehydratase (HAD) is a component of the type II fatty acid synthase complex involved in 'de novo' fatty acid biosynthesis in plants. This complex, formed by four intraplastidial proteins, is responsible for the sequential condensation of two-carbon units, leading to 16- and 18-C acyl-ACP. HAD dehydrates 3-hydroxyacyl-ACP generating trans-2-enoyl-ACP. With the aim of a further understanding of fatty acid biosynthesis in sunflower (Helianthus annuus) seeds, two β-hydroxyacyl-[ACP] dehydratase genes have been cloned from developing seeds, HaHAD1 (GenBank HM044767) and HaHAD2 (GenBank GU595454). Genomic DNA gel blot analyses suggest that both are single copy genes. Differences in their expression patterns across plant tissues were detected. Higher levels of HaHAD2 in the initial stages of seed development inferred its key role in seed storage fatty acid synthesis. That HaHAD1 expression levels remained constant across most tissues suggest a housekeeping function. Heterologous expression of these genes in E. coli confirmed both proteins were functional and able to interact with the bacterial complex 'in vivo'. The large increase of saturated fatty acids in cells expressing HaHAD1 and HaHAD2 supports the idea that these HAD genes are closely related to the E. coli FabZ gene. The proposed three-dimensional models of HaHAD1 and HaHAD2 revealed differences at the entrance to the catalytic tunnel attributable to Phe166/Val1159, respectively. HaHAD1 F166V was generated to study the function of this residue. The 'in vitro' enzymatic characterization of the three HAD proteins demonstrated all were active, with the mutant having intermediate K m and V max values to the wild-type proteins.
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Affiliation(s)
- Irene González-Thuillier
- Instituto de la Grasa (CSIC), Edificio 46, Campus Universitario Pablo de Olavide, Carretera de Utrera Km 1., 41013, Seville, Spain
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, AL5 2JQ, Herts, UK
| | - 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
| | - 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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Dayan FE, Owens DK, Watson SB, Asolkar RN, Boddy LG. Sarmentine, a natural herbicide from Piper species with multiple herbicide mechanisms of action. FRONTIERS IN PLANT SCIENCE 2015; 6:222. [PMID: 25904929 PMCID: PMC4389368 DOI: 10.3389/fpls.2015.00222] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/20/2015] [Indexed: 05/11/2023]
Abstract
Sarmentine, 1-(1-pyrrolidinyl)-(2E,4E)-2,4-decadien-1-one, is a natural amide isolated from the fruits of Piper species. The compound has a number of interesting biological properties, including its broad-spectrum activity on weeds as a contact herbicide. Initial studies highlighted a similarity in response between plants treated with sarmentine and herbicidal soaps such as pelargonic acid (nonanoic acid). However, little was known about the mechanism of action leading to the rapid desiccation of foliage treated by sarmentine. In cucumber cotyledon disc-assays, sarmentine induced rapid light-independent loss of membrane integrity at 100 μM or higher concentration, whereas 3 mM pelargonic acid was required for a similar effect. Sarmentine was between 10 and 30 times more active than pelargonic acid on wild mustard, velvetleaf, redroot pigweed and crabgrass. Additionally, the potency of 30 μM sarmentine was greatly stimulated by light, suggesting that this natural product may also interfere with photosynthetic processes. This was confirmed by observing a complete inhibition of photosynthetic electron transport at that concentration. Sarmentine also acted as an inhibitor of photosystem II (PSII) on isolated thylakoid membranes by competing for the binding site of plastoquinone. This can be attributed in part to structural similarities between herbicides like sarmentine and diuron. While this mechanism of action accounts for the light stimulation of the activity of sarmentine, it does not account for its ability to destabilize membranes in darkness. In this respect, sarmentine has some structural similarity to crotonoyl-CoA, the substrate of enoyl-ACP reductase, a key enzyme in the early steps of fatty acid synthesis. Inhibitors of this enzyme, such as triclosan, cause rapid loss of membrane integrity in the dark. Sarmentine inhibited the activity of enoyl-ACP reductase, with an I 50app of 18.3 μM. Therefore, the herbicidal activity of sarmentine appears to be a complex process associated with multiple mechanisms of action.
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Affiliation(s)
- Franck E. Dayan
- Natural Products Utilization Research Unit, US Department of Agriculture-Agricultural Research Service, Thad Cochran Center, University of MississippiMS, USA
| | - Daniel K. Owens
- Natural Products Utilization Research Unit, US Department of Agriculture-Agricultural Research Service, Thad Cochran Center, University of MississippiMS, USA
| | - Susan B. Watson
- Natural Products Utilization Research Unit, US Department of Agriculture-Agricultural Research Service, Thad Cochran Center, University of MississippiMS, USA
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