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Nwafor CC, Li D, Qin P, Li L, Zhang W, Zhou Y, Xu J, Yin Y, Cao J, He L, Xiang F, Liu C, Guo L, Zhou Y, Cahoon EB, Zhang C. Genetic and Biochemical Investigation of Seed Fatty Acid Accumulation in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2022; 13:942054. [PMID: 35909728 PMCID: PMC9328158 DOI: 10.3389/fpls.2022.942054] [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: 05/18/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
As a vegetable oil, consisting principally of triacylglycerols, is the major storage form of photosynthetically-fixed carbon in oilseeds which are of significant agricultural and industrial value. Photosynthesis in chlorophyll-containing green seeds, along with photosynthesis in leaves and other green organs, generates ATP and reductant (NADPH and NADH) needed for seed fatty acid production. However, contribution of seed photosynthesis to fatty acid accumulation in seeds have not been well-defined. Here, we report the contribution of seed-photosynthesis to fatty acid production by probing segregating green (photosynthetically-competent) and non-green or yellow (photosynthetically-non-competent) seeds in siliques of an Arabidopsis chlorophyll synthase mutant. Using this mutant, we found that yellow seeds lacking photosynthetic capacity reached 80% of amounts of oil in green seeds at maturity. Combining this with studies using shaded siliques, we determined that seed-photosynthesis accounts for 20% and silique and leaf/stem photosynthesis each account for ~40% of the ATP and reductant for seed oil production. Transmission electron microscopy (TEM) and pyridine nucleotides and ATP analyses revealed that seed photosynthesis provides ATP and reductant for oil production mostly during early development, as evidenced by delayed oil accumulation in non-green seeds. Transcriptomic analyses suggests that the oxidative pentose phosphate pathway could be the source of carbon, energy and reductants required for fatty acid synthesis beyond the early stages of seed development.
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Affiliation(s)
- Chinedu Charles Nwafor
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City, Nigeria
| | - Delin Li
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Ping Qin
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Long Li
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wei Zhang
- Department of Biology, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China
| | - Yuanwei Zhou
- Yichang Academy of Agricultural Science, Yichang, China
| | - Jingjing Xu
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yongtai Yin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jianbo Cao
- Public Laboratory of Electron Microscopy, Huazhong Agricultural University, Wuhan, China
| | - Limin He
- Public Laboratory of Electron Microscopy, Huazhong Agricultural University, Wuhan, China
| | - Fu Xiang
- Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains and College of Biology and Agriculture Resource, Huanggang Normal University, Huanggang, China
| | - Chao Liu
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Liang Guo
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yongming Zhou
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Edgar B. Cahoon
- Center for Plant Science Innovation and Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Chunyu Zhang
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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Koperniku A, Garcia AA, Mochly-Rosen D. Boosting the Discovery of Small Molecule Inhibitors of Glucose-6-Phosphate Dehydrogenase for the Treatment of Cancer, Infectious Diseases, and Inflammation. J Med Chem 2022; 65:4403-4423. [PMID: 35239352 PMCID: PMC9553131 DOI: 10.1021/acs.jmedchem.1c01577] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We present an overview of small molecule glucose-6-phosphate dehydrogenase (G6PD) inhibitors that have potential for use in the treatment of cancer, infectious diseases, and inflammation. Both steroidal and nonsteroidal inhibitors have been identified with steroidal inhibitors lacking target selectivity. The main scaffolds encountered in nonsteroidal inhibitors are quinazolinones and benzothiazinones/benzothiazepinones. Three molecules show promise for development as antiparasitic (25 and 29) and anti-inflammatory (32) agents. Regarding modality of inhibition (MOI), steroidal inhibitors have been shown to be uncompetitive and reversible. Nonsteroidal small molecules have exhibited all types of MOI. Strategies to boost the discovery of small molecule G6PD inhibitors include exploration of structure-activity relationships (SARs) for established inhibitors, employment of high-throughput screening (HTS), and fragment-based drug discovery (FBDD) for the identification of new hits. We discuss the challenges and gaps associated with drug discovery efforts of G6PD inhibitors from in silico, in vitro, and in cellulo to in vivo studies.
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Affiliation(s)
- Ana Koperniku
- Department of Chemical and Systems Biology, School of Medicine, Stanford University, 269 Campus Dr, Stanford, CA 94305, USA
- Corresponding Author: Ana Koperniku,
| | - Adriana A. Garcia
- Department of Chemical and Systems Biology, School of Medicine, Stanford University, 269 Campus Dr, Stanford, CA 94305, USA
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, School of Medicine, Stanford University, 269 Campus Dr, Stanford, CA 94305, USA
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Cormier MA, Werner RA, Leuenberger MC, Kahmen A. 2H-enrichment of cellulose and n-alkanes in heterotrophic plants. Oecologia 2019; 189:365-373. [DOI: 10.1007/s00442-019-04338-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 01/11/2019] [Indexed: 11/30/2022]
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Cormier MA, Werner RA, Sauer PE, Gröcke DR, Leuenberger MC, Wieloch T, Schleucher J, Kahmen A. 2 H-fractionations during the biosynthesis of carbohydrates and lipids imprint a metabolic signal on the δ 2 H values of plant organic compounds. THE NEW PHYTOLOGIST 2018; 218:479-491. [PMID: 29460486 DOI: 10.1111/nph.15016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 12/23/2017] [Indexed: 06/08/2023]
Abstract
Hydrogen (H) isotope ratio (δ2 H) analyses of plant organic compounds have been applied to assess ecohydrological processes in the environment despite a large part of the δ2 H variability observed in plant compounds not being fully elucidated. We present a conceptual biochemical model based on empirical H isotope data that we generated in two complementary experiments that clarifies a large part of the unexplained variability in the δ2 H values of plant organic compounds. The experiments demonstrate that information recorded in the δ2 H values of plant organic compounds goes beyond hydrological signals and can also contain important information on the carbon and energy metabolism of plants. Our model explains where 2 H-fractionations occur in the biosynthesis of plant organic compounds and how these 2 H-fractionations are tightly coupled to a plant's carbon and energy metabolism. Our model also provides a mechanistic basis to introduce H isotopes in plant organic compounds as a new metabolic proxy for the carbon and energy metabolism of plants and ecosystems. Such a new metabolic proxy has the potential to be applied in a broad range of disciplines, including plant and ecosystem physiology, biogeochemistry and palaeoecology.
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Affiliation(s)
- Marc-André Cormier
- Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, 4056, Basel, Switzerland
| | - Roland A Werner
- Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Peter E Sauer
- Department of Geological Sciences, Indiana University, Bloomington, IN, 47405-1405, USA
| | - Darren R Gröcke
- Stable Isotope Biogeochemistry Laboratory, Science Laboratories, Durham University, South Road, Durham, DH1 3LE, UK
| | - Markus C Leuenberger
- Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | - Thomas Wieloch
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87, Umeå, Sweden
| | - Jürgen Schleucher
- Department of Medical Biochemistry and Biophysics, Umeå University, 901 87, Umeå, Sweden
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, 4056, Basel, Switzerland
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Popova TN, Pinheiro de Carvalho MA. Citrate and isocitrate in plant metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1364:307-25. [PMID: 9630693 DOI: 10.1016/s0005-2728(98)00008-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The relevance of citrate and isocitrate metabolism in plants is discussed in connection with the different pathways for their conversions. The routes for citrate and isocitrate conversions are incorporated into the system of cross-linked metabolic processes and may provide carbon skeletons for nitrogen assimilation and reducing equivalents for biosynthetic reactions, support the functioning of the glyoxylate cycle and play an important role in the TCA and energy metabolism as a whole. The possibility of the coupling of citrate and isocitrate metabolism with various electron transport systems is discussed from the point of view of the efficiency of the balancing cellular NAD(P)H/NAD(P)+ and ATP/ADP ratios. The role of citrate and isocitrate and their derivations as potent effectors of some enzymes is considered. Special attention is paid to the enzymes associated with citrate and isocitrate metabolism and to the mechanisms which regulate their activity. The possibilities of the coordination of the main processes of energy and biosynthetic metabolism at the level of citrate and isocitrate distribution are discussed.
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Affiliation(s)
- T N Popova
- Department of Plant Physiology and Biochemistry, Voronezh State University, 394693 Voronezh, Russian Federation.
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Abstract
All plant cells produce fatty acids from acetyl-CoA by a common pathway localized in plastids. Although the biochemistry of this pathway is now well understood, much less is known about how plants control the very different amounts and types of lipids produced in different tissues. Thus, a central challenge for plant lipid research is to provide a molecular understanding of how plants regulate the major differences in lipid metabolism found, for example, in mesophyll, epidermal, or developing seed cells. Acetyl-CoA carboxylase (ACCase) is one control point that regulates rates of fatty acid synthesis. However, the biochemical modulators that act on ACCase and the factors that in turn control these modulators are poorly understood. In addition, little is known about how the expression of genes involved in fatty acid synthesis is controlled. This review evaluates current knowledge of regulation of plant fatty metabolism and attempts to identify the major unanswered questions.
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Affiliation(s)
- John B. Ohlrogge
- Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, Chemistry Department, Miami University, Oxford, Ohio 45056
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Eichhorn M, Corbus B. Die Glucose-6-phosphat Dehydrogenase im Stoffwechsel photoautotropher Organismen. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/s0015-3796(88)80001-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Camp PJ, Randall DD. Purification and Characterization of the Pea Chloroplast Pyruvate Dehydrogenase Complex : A Source of Acetyl-CoA and NADH for Fatty Acid Biosynthesis. PLANT PHYSIOLOGY 1985; 77:571-7. [PMID: 16664100 PMCID: PMC1064566 DOI: 10.1104/pp.77.3.571] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The pyruvate dehydrogenase complex has been purified 76-fold, to a specific activity of 0.6 mumoles per minute per milligram protein, beginning with isolated pea (Pisum sativum L. var Little Marvel) chloroplasts. Purification was accomplished by rate zonal sedimentation, polyethyleneglycol precipitation, and ethyl-agarose affinity chromatography. Characterization of the substrates as pyruvate, NAD(+), and coenzyme-A and the products as NADH, CO(2), and acetyl-CoA, in a 1:1:1 stoichiometry unequivocally established that activity was the result of the pyruvate dehydrogenase complex. Immunochemical analysis demonstrated significant differences in structure and organization between the chloroplast pyruvate dehydrogenase complex and the more thoroughly characterized mitochondrial complex. Chloroplast complex has a higher magnesium requirement and a more alkaline pH optimum than mitochondrial complex, and these properties are consistent with light-mediated regulation in vivo. The chloroplast pyruvate dehydrogenase complex is not, however, regulated by ATP-dependent inactivation. The properties and subcellular localization of the chloroplast pyruvate dehydrogenase complex are consistent with its role of providing acetyl-CoA and NADH for fatty acid synthesis.
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Affiliation(s)
- P J Camp
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211
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Monga P, Munshi S, Sukhija P. Lipid biosynthesis in the developing sunflower (Helianthus annuus L.) seeds. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/0304-4211(83)90070-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Changes in the activity and the function of the pentose phosphate pathway during germination of black gram (Phaseolus mungo) seeds. ACTA ACUST UNITED AC 1977. [DOI: 10.1016/0020-711x(77)90047-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Krasnuk M, Jung GA, Witham FH. Electrophoretic studies of several dehydrogenases in relation to the cold tolerance of alfalfa. Cryobiology 1976; 13:375-93. [PMID: 6212 DOI: 10.1016/0011-2240(76)90121-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Nyc JF, Brody S. Effects of mutations and growth conditions on lipid synthesis in Neurospora crassa. J Bacteriol 1971; 108:1310-7. [PMID: 4400392 PMCID: PMC247220 DOI: 10.1128/jb.108.3.1310-1317.1971] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A morphological mutant (col-2) of Neurospora, which is partially deficient in glucose-6-phosphate dehydrogenase (G-6-PD) activity and has lower levels of reduced nicotinamide adenine dinucleotide phosphate (NADPH), accumulated three-fold more triglycerides during log-phase growth than the wild-type strain. Increased lipid deposition was not found in other strains that included slow-growing morphological mutants, NADPH-deficient strains, G-6-PD-deficient mutants, wild-type revertants from col-2, and a cel, col-2 double mutant. The cel, col-2 strain was supplemented with an exogenous source of fatty acids because it cannot synthesize these lipid moieties. The observed normal lipid content of this strain suggests that the lipid deposition in col-2 on glucose is due to an overstimulation of fatty acid synthesis and not a deficiency in fatty acid breakdown. The neutral lipid levels in both wild type and col-2 were decreased to identical levels when grown on glutamate as a carbon source. This effect was not due to changes in glutamic dehydrogenase levels. The omission of citrate from the glutamate medium reduced wild-type neutral lipid levels even further, but had no effect on col-2. The variations with time in the neutral lipid levels of col-2 upon changes in these carbon sources are presented, as well as a discussion of the possible types of regulatory effects unique to the col-2 mutation which might affect fatty acid synthesis.
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