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Shi Q, Xia Y, Xue N, Wang Q, Tao Q, Li M, Xu D, Wang X, Kong F, Zhang H, Li G. Modulation of starch synthesis in Arabidopsis via phytochrome B-mediated light signal transduction. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:973-985. [PMID: 38391049 DOI: 10.1111/jipb.13630] [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: 07/17/2023] [Revised: 01/06/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024]
Abstract
Starch is a major storage carbohydrate in plants and is critical in crop yield and quality. Starch synthesis is intricately regulated by internal metabolic processes and external environmental cues; however, the precise molecular mechanisms governing this process remain largely unknown. In this study, we revealed that high red to far-red (high R:FR) light significantly induces the synthesis of leaf starch and the expression of synthesis-related genes, whereas low R:FR light suppress these processes. Arabidopsis phytochrome B (phyB), the primary R and FR photoreceptor, was identified as a critical positive regulator in this process. Downstream of phyB, basic leucine zipper transcription factor ELONGATED HYPOCOTYL5 (HY5) was found to enhance starch synthesis, whereas the basic helix-loop-helix transcription factors PHYTOCHROME INTERACTING FACTORs (PIF3, PIF4, and PIF5) inhibit starch synthesis in Arabidopsis leaves. Notably, HY5 and PIFs directly compete for binding to a shared G-box cis-element in the promoter region of genes encoding starch synthases GBSS, SS3, and SS4, which leads to antagonistic regulation of their expression and, consequently, starch synthesis. Our findings highlight the vital role of phyB in enhancing starch synthesis by stabilizing HY5 and facilitating PIFs degradation under high R:FR light conditions. Conversely, under low R:FR light, PIFs predominantly inhibit starch synthesis. This study provides insight into the physiological and molecular functions of phyB and its downstream transcription factors HY5 and PIFs in starch synthesis regulation, shedding light on the regulatory mechanism by which plants synchronize dynamic light signals with metabolic cues to module starch synthesis.
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Affiliation(s)
- Qingbiao Shi
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
- National Key Laboratory of Wheat Improvement, College of Agronomy, Shandong Agricultural University, Tai'an, 271018, China
| | - Ying Xia
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Na Xue
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Qibin Wang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
- National Key Laboratory of Wheat Improvement, College of Agronomy, Shandong Agricultural University, Tai'an, 271018, China
| | - Qing Tao
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Mingjing Li
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Di Xu
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
- National Key Laboratory of Wheat Improvement, College of Agronomy, Shandong Agricultural University, Tai'an, 271018, China
| | - Xiaofei Wang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Fanying Kong
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Haisen Zhang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Gang Li
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
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2
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Boehlein SK, Pfister B, Hennen-Bierwagen TA, Liu C, Ritter M, Hannah LC, Zeeman SC, Resende MFR, Myers AM. Soluble and insoluble α-glucan synthesis in yeast by enzyme suites derived exclusively from maize endosperm. PLANT PHYSIOLOGY 2023; 193:1456-1478. [PMID: 37339339 PMCID: PMC10517254 DOI: 10.1093/plphys/kiad358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 04/28/2023] [Accepted: 05/23/2023] [Indexed: 06/22/2023]
Abstract
Molecular mechanisms that distinguish the synthesis of semi-crystalline α-glucan polymers found in plant starch granules from the synthesis of water-soluble polymers by nonplant species are not well understood. To address this, starch biosynthetic enzymes from maize (Zea mays L.) endosperm were isolated in a reconstituted environment using yeast (Saccharomyces cerevisiae) as a test bed. Ninety strains were constructed containing unique combinations of 11 synthetic transcription units specifying maize starch synthase (SS), starch phosphorylase (PHO), starch branching enzyme (SBE), or isoamylase-type starch debranching enzyme (ISA). Soluble and insoluble branched α-glucans accumulated in varying proportions depending on the enzyme suite, with ISA function stimulating distribution into the insoluble form. Among the SS isoforms, SSIIa, SSIII, and SSIV individually supported the accumulation of glucan polymer. Neither SSI nor SSV alone produced polymers; however, synergistic effects demonstrated that both isoforms can stimulate α-glucan accumulation. PHO did not support α-glucan production by itself, but it had either positive or negative effects on polymer content depending on which SS or a combination thereof was present. The complete suite of maize enzymes generated insoluble particles resembling native starch granules in size, shape, and crystallinity. Ultrastructural analysis revealed a hierarchical assembly starting with subparticles of approximately 50 nm diameter that coalesce into discrete structures of approximately 200 nm diameter. These are assembled into semi-crystalline α-glucan superstructures up to 4 μm in length filling most of the yeast cytosol. ISA was not essential for the formation of such particles, but their abundance was increased dramatically by ISA presence.
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Affiliation(s)
- Susan K Boehlein
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32601, USA
| | - Barbara Pfister
- Institute of Molecular Plant Biology, ETH Zurich, Zurich 8092, Switzerland
| | - Tracie A Hennen-Bierwagen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Chun Liu
- Institute of Molecular Plant Biology, ETH Zurich, Zurich 8092, Switzerland
| | - Maximilian Ritter
- Institute for Building Materials, Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich 8093, Switzerland
| | - L Curtis Hannah
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32601, USA
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, ETH Zurich, Zurich 8092, Switzerland
| | - Marcio F R Resende
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32601, USA
| | - Alan M Myers
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
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3
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Chang H, Bai J, Zhang H, Huang R, Chu H, Wang Q, Liu H, Cheng J, Jiang H. Origin and evolution of the main starch biosynthetic enzymes. Synth Syst Biotechnol 2023; 8:462-468. [PMID: 37692203 PMCID: PMC10485787 DOI: 10.1016/j.synbio.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 09/12/2023] Open
Abstract
Starch, a semi-crystalline energy storage form primarily found in plant plastids plays a crucial role in various food or no-food applications. Despite the starch biosynthetic pathway's main enzymes have been characterized, their origin and evolution remained a subject of debate. In this study, we conducted the comprehensive phylogenetic and structural analysis of three types of starch biosynthetic enzymes: starch synthase (SS), starch branching enzyme (SBE) and isoamylase-type debranching enzyme (ISA) from 51,151 annotated genomes. Our findings provide valuable insights into the possible scenario for the origin and evolution of the starch biosynthetic pathway. Initially, the ancestor of SBE can be traced back to an unidentified bacterium that existed before the formation of the last eukaryotic common ancestor (LECA) via horizontal gene transfer (HGT). This transfer event likely provided the eukaryote ancestor with the ability to synthesize glycogen. Furthermore, during the emergence of Archaeplastida, one clade of SS was transferred from Deltaproteobacteria by HGT, while ISA and the other clade of SS originated from Chlamydiae through endosymbiosis gene transfer (EGT). Both these transfer events collectively contributed to the establishment of the original starch biosynthetic pathway. Subsequently, after the divergence of Viridiplantae from Rhodophyta, all three enzymes underwent multiple duplications and N-terminus extension domain modifications, resulting in the formation of functionally specialized isoforms and ultimately leading to the complete starch biosynthetic pathway. By shedding light on the evolutionary origins of key enzymes involved in the starch biosynthetic pathway, this study provides important insights into the evolutionary events of plants.
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Affiliation(s)
- Hong Chang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Jie Bai
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Hejian Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Rong Huang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Huanyu Chu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Qian Wang
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Hao Liu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Jian Cheng
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
| | - Huifeng Jiang
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Center of Technology Innovation for Synthetic Biology, Tianjin, 300308, China
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4
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Blennow A, Skryhan K, Tanackovic V, Krunic SL, Shaik SS, Andersen MS, Kirk H, Nielsen KL. Non-GMO potato lines, synthesizing increased amylose and resistant starch, are mainly deficient in isoamylase debranching enzyme. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:2096-2108. [PMID: 32096588 PMCID: PMC7540516 DOI: 10.1111/pbi.13367] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/31/2020] [Accepted: 02/17/2020] [Indexed: 05/04/2023]
Abstract
Solanum tuberosum potato lines with high amylose content were generated by crossing with the wild potato species Solanum sandemanii followed by repeated backcrossing to Solanum tuberosum lines. The trait, termed increased amylose (IAm), was recessive and present after three generations of backcrossing into S. tuberosum lines (6.25% S. sandemanii genes). The tubers of these lines were small, elongated and irregular with small and misshaped starch granules and high sugar content. Additional backcrossing resulted in less irregular tuber morphology, increased starch content (4.3%-9.5%) and increased amylose content (29%-37.9%) but indifferent sugar content. The amylose in the IAm starch granules was mainly located in peripheral spots, and large cavities were found in the granules. Starch pasting was suppressed, and the digestion-resistant starch (RS) content was increased. Comprehensive microarray polymer profiling (CoMPP) analysis revealed specific alterations of major pectic and glycoprotein cell wall components. This complex phenotype led us to search for candidate IAm genes exploiting its recessive trait. Hence, we sequenced genomic DNA of a pool of IAm lines, identified SNPs genome wide against the draft genome sequence of potato and searched for regions of decreased heterozygosity. Three regions, located on chromosomes 3, 7 and 10, respectively, displayed markedly less heterozygosity than average. The only credible starch metabolism-related gene found in these regions encoded the isoamylase-type debranching enzyme Stisa1. Decreased expression of mRNA (>500 fold) and reduced enzyme activity (virtually absent from IAm lines) supported Stisa1 as a candidate gene for IAm.
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Affiliation(s)
- Andreas Blennow
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Katsiaryna Skryhan
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Vanja Tanackovic
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Susanne L. Krunic
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Shahnoor S. Shaik
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | | | | | - Kåre L. Nielsen
- Department of Chemistry and BiologyAalborg UniversityAalborgDenmark
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5
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Pfister B, Zeeman SC, Rugen MD, Field RA, Ebenhöh O, Raguin A. Theoretical and experimental approaches to understand the biosynthesis of starch granules in a physiological context. PHOTOSYNTHESIS RESEARCH 2020; 145:55-70. [PMID: 31955343 PMCID: PMC7308250 DOI: 10.1007/s11120-019-00704-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 12/19/2019] [Indexed: 06/10/2023]
Abstract
Starch, a plant-derived insoluble carbohydrate composed of glucose polymers, is the principal carbohydrate in our diet and a valuable raw material for industry. The properties of starch depend on the arrangement of glucose units within the constituent polymers. However, key aspects of starch structure and the underlying biosynthetic processes are not well understood, limiting progress towards targeted improvement of our starch crops. In particular, the major component of starch, amylopectin, has a complex three-dimensional, branched architecture. This architecture stems from the combined actions of a multitude of enzymes, each having broad specificities that are difficult to capture experimentally. In this review, we reflect on experimental approaches and limitations to decipher the enzymes' specificities and explore possibilities for in silico simulations of these activities. We believe that the synergy between experimentation and simulation is needed for the correct interpretation of experimental data and holds the potential to greatly advance our understanding of the overall starch biosynthetic process. We furthermore propose that the formation of glucan secondary structures, concomitant with its synthesis, is a previously overlooked factor that directly affects amylopectin architecture through its impact on enzyme function.
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Affiliation(s)
- Barbara Pfister
- Department of Biology, Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Samuel C Zeeman
- Department of Biology, Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Michael D Rugen
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Oliver Ebenhöh
- Department of Biology, Institute of Quantitative and Theoretical Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
- Department of Biology, Cluster of Excellence on Plant Sciences, Institute of Quantitative and Theoretical Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany
| | - Adélaïde Raguin
- Department of Biology, Institute of Quantitative and Theoretical Biology, Heinrich-Heine University, 40225, Düsseldorf, Germany.
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6
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Smith AM, Zeeman SC. Starch: A Flexible, Adaptable Carbon Store Coupled to Plant Growth. ANNUAL REVIEW OF PLANT BIOLOGY 2020; 71:217-245. [PMID: 32075407 DOI: 10.1146/annurev-arplant-050718-100241] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Research in the past decade has uncovered new and surprising information about the pathways of starch synthesis and degradation. This includes the discovery of previously unsuspected protein families required both for processes and for the long-sought mechanism of initiation of starch granules. There is also growing recognition of the central role of leaf starch turnover in making carbon available for growth across the day-night cycle. Sophisticated systems-level control mechanisms involving the circadian clock set rates of nighttime starch mobilization that maintain a steady supply of carbon until dawn and modulate partitioning of photosynthate into starch in the light, optimizing the fraction of assimilated carbon that can be used for growth. These discoveries also uncover complexities: Results from experiments with Arabidopsis leaves in conventional controlled environments are not necessarily applicable to other organs or species or to growth in natural, fluctuating environments.
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Affiliation(s)
| | - Samuel C Zeeman
- Institute of Plant Molecular Biology, ETH Zürich, 8092 Zürich, Switzerland
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7
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Ren Z, He S, Zhao N, Zhai H, Liu Q. A sucrose non-fermenting-1-related protein kinase-1 gene, IbSnRK1, improves starch content, composition, granule size, degree of crystallinity and gelatinization in transgenic sweet potato. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:21-32. [PMID: 29734529 PMCID: PMC6330544 DOI: 10.1111/pbi.12944] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/16/2018] [Accepted: 04/28/2018] [Indexed: 05/09/2023]
Abstract
Sucrose non-fermenting-1-related protein kinase-1 (SnRK1) is an essential energy-sensing regulator and plays a key role in the global control of carbohydrate metabolism. The SnRK1 gene has been found to increase starch accumulation in several plant species. However, its roles in improving starch quality have not been reported to date. In this study, we found that the IbSnRK1 gene was highly expressed in the storage roots of sweet potato and strongly induced by exogenous sucrose. Its expression followed the circandian rhythm. Its overexpression not only increased starch content, but also decreased proportion of amylose, enlarged granule size and improved degree of crystallinity and gelatinization in transgenic sweet potato, which revealed, for the first time, the important roles of SnRK1 in improving starch quality of plants. The genes involved in starch biosynthesis pathway were systematically up-regulated, and the content of ADP-glucose as an important precursor for starch biosynthesis and the activities of key enzymes were significantly increased in transgenic sweet potato. These findings indicate that IbSnRK1 improves starch content and quality through systematical up-regulation of the genes and the increase in key enzyme activities involved in starch biosynthesis pathway in transgenic sweet potato. This gene has the potential to improve starch content and quality in sweet potato and other plants.
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Affiliation(s)
- Zhitong Ren
- Key Laboratory of Sweetpotato Biology and BiotechnologyMinistry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and UtilizationMinistry of EducationCollege of Agronomy & BiotechnologyChina Agricultural UniversityBeijingChina
| | - Shaozhen He
- Key Laboratory of Sweetpotato Biology and BiotechnologyMinistry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and UtilizationMinistry of EducationCollege of Agronomy & BiotechnologyChina Agricultural UniversityBeijingChina
| | - Ning Zhao
- Key Laboratory of Sweetpotato Biology and BiotechnologyMinistry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and UtilizationMinistry of EducationCollege of Agronomy & BiotechnologyChina Agricultural UniversityBeijingChina
| | - Hong Zhai
- Key Laboratory of Sweetpotato Biology and BiotechnologyMinistry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and UtilizationMinistry of EducationCollege of Agronomy & BiotechnologyChina Agricultural UniversityBeijingChina
| | - Qingchang Liu
- Key Laboratory of Sweetpotato Biology and BiotechnologyMinistry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and UtilizationMinistry of EducationCollege of Agronomy & BiotechnologyChina Agricultural UniversityBeijingChina
- College of AgronomyQingdao Agricultural UniversityQingdaoChina
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8
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Goren A, Ashlock D, Tetlow IJ. Starch formation inside plastids of higher plants. PROTOPLASMA 2018; 255:1855-1876. [PMID: 29774409 DOI: 10.1007/s00709-018-1259-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/03/2018] [Indexed: 05/09/2023]
Abstract
Starch is a water-insoluble polyglucan synthesized inside the plastid stroma within plant cells, serving a crucial role in the carbon budget of the whole plant by acting as a short-term and long-term store of energy. The highly complex, hierarchical structure of the starch granule arises from the actions of a large suite of enzyme activities, in addition to physicochemical self-assembly mechanisms. This review outlines current knowledge of the starch biosynthetic pathway operating in plant cells in relation to the micro- and macro-structures of the starch granule. We highlight the gaps in our knowledge, in particular, the relationship between enzyme function and operation at the molecular level and the formation of the final, macroscopic architecture of the granule.
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Affiliation(s)
- Asena Goren
- Department of Mathematics and Statistics, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Daniel Ashlock
- Department of Mathematics and Statistics, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Ian J Tetlow
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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9
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Panpetch P, Field RA, Limpaseni T. Cloning of the full-length isoamylase3 gene from cassava Manihot esculenta Crantz 'KU50' and its heterologous expression in E. coli. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 132:281-286. [PMID: 30240990 DOI: 10.1016/j.plaphy.2018.09.010] [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: 06/18/2018] [Revised: 09/07/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
Isoamylase (EC.3.2.1.68), an essential enzyme in starch metabolism, catalyses the cleavage of α-1,6 glucosidic linkages of branched α-polyglucans such as beta-limit dextrin and amylopectin, but not pullulan. Three different isoamylase isoforms have been reported in plants and algae. We herein report on the first success in preparation of full-length isoamylase3 gene (MeISA3) of cassava Manihot esculenta Crantz 'KU50' from 5' Rapid Amplification of cDNA Ends (5' RACE). The MeISA3 was cloned to pET21b and expressed in E. coli. The HistrapTM-purified rMeISA3 appeared as a single band protein with approximate molecular size of 75 kDa on SDS-PAGE and Western blot, while 80 kDa was shown by gel filtration chromatography. This indicated the existence of a monomeric enzyme. Biochemical characterisation of rMeISA3 showed that the enzyme was specific towards beta-limit dextrin, with optimal activity at 37 °C pH 6.0. Activity of rMeISA3 could be significantly promoted by Mg2+ and Co2+. rMeISA3 debranched glucan chains of amylopectin were confirmed by HPAEC-PAD analysis.
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Affiliation(s)
- Pawinee Panpetch
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich, NR4 7UH, United Kingdom
| | - Tipaporn Limpaseni
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
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10
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Panpetch P, Field RA, Limpaseni T. Heterologous co-expression in E. coli of isoamylase genes from cassava Manihot esculenta Crantz 'KU50' achieves enzyme-active heteromeric complex formation. PLANT MOLECULAR BIOLOGY 2018; 96:417-427. [PMID: 29380100 DOI: 10.1007/s11103-018-0707-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 01/20/2018] [Indexed: 06/07/2023]
Abstract
Cloning of two isoamylase genes, MeISA1 and MeISA2, from cassava (Manihot esculenta Crantz) tubers, accompanied by their co-expression in E. coli demonstrates a requirement for heteromeric complex formation to achieve debranching activity. Starch debranching enzyme (DBE) or isoamylase (ISA) (EC.3.2.1.68), an important enzyme in starch metabolism, catalyses the hydrolysis of α-1,6 glycosidic linkages of amylopectin. Isoforms of ISAs have been reported in higher plants and algae (Fujita et al. in Planta 208:283-293, 1999; Hussain et al. in Plant Cell 15:133-149, 2003; Ishizaki et al. in Agric Biol Chem 47:771-779, 1983; Mouille et al. in Plant Cell 8:1353-1366, 1996). In the current work, cassava ISA genes were isolated from cDNA generated from total RNA from tubers of Manihot esculanta Crantz cultivar KU50. MeISA1 and MeISA2 were successfully amplified and cloned into a pETDuet1 vector. The putative MeISA1 and MeISA2 proteins comprised 763 and 882 amino acids, with substantial similarity to StISA1 and StISA2 from potato (84.4% and 68.9%, respectively). Recombinant MeISA1 and MeISA2 were co-expressed in Escherichia coli SoluBL21 (DE3). HistrapTM-Purified rMeISA1 and rMeISA2 showed approximate molecular weights of 87 and 99 kDa, respectively, by SDS-PAGE. Debranching activity was only detectable in the column fractions where both recombinant ISA isoforms were present. The heteromeric DBE from crude extracts of 4-5 h induced cultures analysed by gel filtration chromatography and western blot showed combinations of rMeISA1 and rMeISA2 at ratios of 1:1 to 4:1. Pooled fractions with DBE activity were used for enzyme characterisation, which showed that the enzyme was specific for amylopectin, with optimum activity at 37 °C and pH 7.0. Enzyme activity was enhanced by Co2+, Mg2+ and Ca2+, but was strongly inhibited by Cu2+. Debranched amylopectin products showed chain length distributions typical of plant DBE.
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Affiliation(s)
- Pawinee Panpetch
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich, NR4 7UH, UK
| | - Tipaporn Limpaseni
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
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11
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Abstract
The starch-rich endosperms of the Poaceae, which includes wild grasses and their domesticated descendents the cereals, have provided humankind and their livestock with the bulk of their daily calories since the dawn of civilization up to the present day. There are currently unprecedented pressures on global food supplies, largely resulting from population growth, loss of agricultural land that is linked to increased urbanization, and climate change. Since cereal yields essentially underpin world food and feed supply, it is critical that we understand the biological factors contributing to crop yields. In particular, it is important to understand the biochemical pathway that is involved in starch biosynthesis, since this pathway is the major yield determinant in the seeds of six out of the top seven crops grown worldwide. This review outlines the critical stages of growth and development of the endosperm tissue in the Poaceae, including discussion of carbon provision to the growing sink tissue. The main body of the review presents a current view of our understanding of storage starch biosynthesis, which occurs inside the amyloplasts of developing endosperms.
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12
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Findinier J, Tunçay H, Schulz-Raffelt M, Deschamps P, Spriet C, Lacroix JM, Duchêne T, Szydlowski N, Li-Beisson Y, Peltier G, D'Hulst C, Wattebled F, Dauvillée D. The Chlamydomonas mex1 mutant shows impaired starch mobilization without maltose accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5177-5189. [PMID: 29040651 DOI: 10.1093/jxb/erx343] [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] [Indexed: 05/08/2023]
Abstract
The MEX1 locus of Chlamydomonas reinhardtii was identified in a genetic screen as a factor that affects starch metabolism. Mutation of MEX1 causes a slow-down in the mobilization of storage polysaccharide. Cosegregation and functional complementation analyses were used to assess the involvement of the Mex1 protein in starch degradation. Heterologous expression experiments performed in Escherichia coli and Arabidopsis thaliana allowed us to test the capacity of the algal protein in maltose export. In contrast to the A. thaliana mex1 mutant, the mutation in C. reinhardtii does not lead to maltose accumulation and growth impairment. Although localized in the plastid envelope, the algal protein does not transport maltose efficiently across the envelope, but partly complements the higher plant mutant. Both Mex orthologs restore the growth of the E. coli ptsG mutant strain on glucose-containing medium, revealing the capacity of these proteins to transport this hexose. These findings suggest that Mex1 is essential for starch mobilization in both Chlamydomonas and Arabidopsis, and that this protein family may support several functions and not only be restricted to maltose export across the plastidial envelope.
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Affiliation(s)
- Justin Findinier
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Hande Tunçay
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Miriam Schulz-Raffelt
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Philippe Deschamps
- Université Paris-Sud 11, CNRS UMR 8079 Unité d'Ecologie, Systématique et Evolution, 91400 Orsay, France
| | - Corentin Spriet
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Jean-Marie Lacroix
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Thierry Duchêne
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Nicolas Szydlowski
- Université de Lille, CNRS, USR 3290-MSAP-Miniaturisation pour la Synthèse l'Analyse et la Protéomique, 59000 Lille, France
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l'Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Christophe D'Hulst
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - Fabrice Wattebled
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
| | - David Dauvillée
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, 59000 Lille, France
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13
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Guan X, Okazaki Y, Lithio A, Li L, Zhao X, Jin H, Nettleton D, Saito K, Nikolau BJ. Discovery and Characterization of the 3-Hydroxyacyl-ACP Dehydratase Component of the Plant Mitochondrial Fatty Acid Synthase System. PLANT PHYSIOLOGY 2017; 173:2010-2028. [PMID: 28202596 PMCID: PMC5373057 DOI: 10.1104/pp.16.01732] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/08/2017] [Indexed: 05/06/2023]
Abstract
We report the characterization of the Arabidopsis (Arabidopsis thaliana) 3-hydroxyacyl-acyl carrier protein dehydratase (mtHD) component of the mitochondrial fatty acid synthase (mtFAS) system, encoded by AT5G60335. The mitochondrial localization and catalytic capability of mtHD were demonstrated with a green fluorescent protein transgenesis experiment and by in vivo complementation and in vitro enzymatic assays. RNA interference (RNAi) knockdown lines with reduced mtHD expression exhibit traits typically associated with mtFAS mutants, namely a miniaturized morphological appearance, reduced lipoylation of lipoylated proteins, and altered metabolomes consistent with the reduced catalytic activity of lipoylated enzymes. These alterations are reversed when mthd-rnai mutant plants are grown in a 1% CO2 atmosphere, indicating the link between mtFAS and photorespiratory deficiency due to the reduced lipoylation of glycine decarboxylase. In vivo biochemical feeding experiments illustrate that sucrose and glycolate are the metabolic modulators that mediate the alterations in morphology and lipid accumulation. In addition, both mthd-rnai and mtkas mutants exhibit reduced accumulation of 3-hydroxytetradecanoic acid (i.e. a hallmark of lipid A-like molecules) and abnormal chloroplastic starch granules; these changes are not reversible by the 1% CO2 atmosphere, demonstrating two novel mtFAS functions that are independent of photorespiration. Finally, RNA sequencing analysis revealed that mthd-rnai and mtkas mutants are nearly equivalent to each other in altering the transcriptome, and these analyses further identified genes whose expression is affected by a functional mtFAS system but independent of photorespiratory deficiency. These data demonstrate the nonredundant nature of the mtFAS system, which contributes unique lipid components needed to support plant cell structure and metabolism.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Blotting, Western
- Carbon Dioxide/metabolism
- Fatty Acid Synthase, Type II/genetics
- Fatty Acid Synthase, Type II/metabolism
- Fatty Acid Synthases/genetics
- Fatty Acid Synthases/metabolism
- Gene Expression Regulation, Plant
- Glycolates/metabolism
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Hydro-Lyases/genetics
- Hydro-Lyases/metabolism
- Metabolomics/methods
- Microscopy, Confocal
- Microscopy, Electron, Transmission
- Mitochondria/enzymology
- Mitochondria/ultrastructure
- Mutation
- Myristic Acids/metabolism
- Plants, Genetically Modified
- RNA Interference
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, RNA/methods
- Sequence Homology, Amino Acid
- Sucrose/metabolism
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Affiliation(s)
- Xin Guan
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Yozo Okazaki
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Andrew Lithio
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Ling Li
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Xuefeng Zhao
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Huanan Jin
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Dan Nettleton
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Kazuki Saito
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
| | - Basil J Nikolau
- Department of Biochemistry, Biophysics, and Molecular Biology (X.G., H.J., B.J.N.), National Science Foundation Engineering Research Center for Biorenewable Chemicals (X.G., B.J.N.), Department of Statistics (A.L., D.N.), Department of Genetics, Development, and Cellular Biology (L.L.), Laurence H. Baker Center for Bioinformatics and Biological Statistics (X.Z.), and Center for Metabolic Biology (B.J.N.), Iowa State University, Ames, Iowa 50011;
- Metabolomics Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan (Y.O., K.S.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan (K.S.)
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14
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Ma L, Xue N, Fu X, Zhang H, Li G. Arabidopsis thaliana FAR-RED ELONGATED HYPOCOTYLS3 (FHY3) and FAR-RED-IMPAIRED RESPONSE1 (FAR1) modulate starch synthesis in response to light and sugar. THE NEW PHYTOLOGIST 2017; 213:1682-1696. [PMID: 27859295 DOI: 10.1111/nph.14300] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 09/22/2016] [Indexed: 05/25/2023]
Abstract
In living organisms, daily light/dark cycles profoundly affect cellular processes. In plants, optimal growth and development, and adaptation to daily light-dark cycles, require starch synthesis and turnover. However, the underlying molecular mechanisms coordinating daily starch metabolism remain poorly understood. To explore the roles of Arabidopsis thaliana light signal transduction proteins FAR-RED ELONGATED HYPOCOTYLS3 (FHY3) and FAR-RED-IMPAIRED RESPONSE1 (FAR1) in starch metabolism, the contents of starch and water-soluble polysaccharides, and the structure of starch granules were investigated in fhy3, far1 and fhy3 far1 mutant plants. Disruption of FHY3 or FAR1 reduced starch accumulation and altered starch granule structure in the fhy3-4, far1-2, and fhy3-4 far1-2 mutant plants. Furthermore, molecular and genetic evidence revealed that the gene encoding the starch-debranching enzyme ISOAMYLASE2 (ISA2) is a direct target of FHY3 and FAR1, and functions in light-induced starch synthesis. Our data establish the first molecular link between light signal transduction and starch synthesis, suggesting that the light-signaling proteins FHY3 and FAR1 influence starch synthesis and starch granule formation through transcriptional activation of ISA2.
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Affiliation(s)
- Lin Ma
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Na Xue
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Xiaoyu Fu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Haisen Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Gang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
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15
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Amylopectin small chain glucans form structure fingerprint that determines botanical origin of starch. Carbohydr Polym 2017; 158:112-123. [DOI: 10.1016/j.carbpol.2016.11.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/16/2016] [Accepted: 11/20/2016] [Indexed: 01/02/2023]
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16
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Abstract
Starch-rich crops form the basis of our nutrition, but plants have still to yield all their secrets as to how they make this vital substance. Great progress has been made by studying both crop and model systems, and we approach the point of knowing the enzymatic machinery responsible for creating the massive, insoluble starch granules found in plant tissues. Here, we summarize our current understanding of these biosynthetic enzymes, highlighting recent progress in elucidating their specific functions. Yet, in many ways we have only scratched the surface: much uncertainty remains about how these components function together and are controlled. We flag-up recent observations suggesting a significant degree of flexibility during the synthesis of starch and that previously unsuspected non-enzymatic proteins may have a role. We conclude that starch research is not yet a mature subject and that novel experimental and theoretical approaches will be important to advance the field.
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Affiliation(s)
- Barbara Pfister
- Department of Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Samuel C Zeeman
- Department of Biology, ETH Zurich, 8092, Zurich, Switzerland.
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17
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Boyer L, Roussel X, Courseaux A, Ndjindji OM, Lancelon-Pin C, Putaux JL, Tetlow IJ, Emes MJ, Pontoire B, D' Hulst C, Wattebled F. Expression of Escherichia coli glycogen branching enzyme in an Arabidopsis mutant devoid of endogenous starch branching enzymes induces the synthesis of starch-like polyglucans. PLANT, CELL & ENVIRONMENT 2016; 39:1432-1447. [PMID: 26715025 DOI: 10.1111/pce.12702] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 12/08/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
Starch synthesis requires several enzymatic activities including branching enzymes (BEs) responsible for the formation of α(1 → 6) linkages. Distribution and number of these linkages are further controlled by debranching enzymes that cleave some of them, rendering the polyglucan water-insoluble and semi-crystalline. Although the activity of BEs and debranching enzymes is mandatory to sustain normal starch synthesis, the relative importance of each in the establishment of the plant storage polyglucan (i.e. water insolubility, crystallinity and presence of amylose) is still debated. Here, we have substituted the activity of BEs in Arabidopsis with that of the Escherichia coli glycogen BE (GlgB). The latter is the BE counterpart in the metabolism of glycogen, a highly branched water-soluble and amorphous storage polyglucan. GlgB was expressed in the be2 be3 double mutant of Arabidopsis, which is devoid of BE activity and consequently free of starch. The synthesis of a water-insoluble, partly crystalline, amylose-containing starch-like polyglucan was restored in GlgB-expressing plants, suggesting that BEs' origin only has a limited impact on establishing essential characteristics of starch. Moreover, the balance between branching and debranching is crucial for the synthesis of starch, as an excess of branching activity results in the formation of highly branched, water-soluble, poorly crystalline polyglucan.
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Affiliation(s)
- Laura Boyer
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Xavier Roussel
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Adeline Courseaux
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Ofilia M Ndjindji
- Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000, Grenoble, France
- CNRS, CERMAV, F-38000, Grenoble, France
| | - Christine Lancelon-Pin
- Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000, Grenoble, France
- CNRS, CERMAV, F-38000, Grenoble, France
| | - Jean-Luc Putaux
- Université Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV), F-38000, Grenoble, France
- CNRS, CERMAV, F-38000, Grenoble, France
| | - Ian J Tetlow
- Department of Molecular and Cellular Biology, Science Complex, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Michael J Emes
- Department of Molecular and Cellular Biology, Science Complex, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | | | - Christophe D' Hulst
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Fabrice Wattebled
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
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18
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Liu F, Zhao Q, Mano N, Ahmed Z, Nitschke F, Cai Y, Chapman KD, Steup M, Tetlow IJ, Emes MJ. Modification of starch metabolism in transgenic Arabidopsis thaliana increases plant biomass and triples oilseed production. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:976-985. [PMID: 26285603 DOI: 10.1111/pbi.12453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/25/2015] [Accepted: 06/27/2015] [Indexed: 06/04/2023]
Abstract
We have identified a novel means to achieve substantially increased vegetative biomass and oilseed production in the model plant Arabidopsis thaliana. Endogenous isoforms of starch branching enzyme (SBE) were substituted by either one of the endosperm-expressed maize (Zea mays L.) branching isozymes, ZmSBEI or ZmSBEIIb. Transformants were compared with the starch-free background and with the wild-type plants. Each of the maize-derived SBEs restored starch biosynthesis but both morphology and structure of starch particles were altered. Altered starch metabolism in the transformants is associated with enhanced biomass formation and more-than-trebled oilseed production while maintaining seed oil quality. Enhanced oilseed production is primarily due to an increased number of siliques per plant whereas oil content and seed number per silique are essentially unchanged or even modestly decreased. Introduction of cereal starch branching isozymes into oilseed plants represents a potentially useful strategy to increase biomass and oilseed production in related crops and manipulate the structure and properties of leaf starch.
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Affiliation(s)
- Fushan Liu
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
| | - Qianru Zhao
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
| | - Noel Mano
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
| | - Zaheer Ahmed
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
| | - Felix Nitschke
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Yinqqi Cai
- Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX, USA
| | - Kent D Chapman
- Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX, USA
| | - Martin Steup
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
| | - Ian J Tetlow
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
| | - Michael J Emes
- Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada
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19
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Convergent Evolution of Starch Metabolism in Cyanobacteria and Archaeplastida. Evol Biol 2016. [DOI: 10.1007/978-3-319-41324-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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20
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Lu KJ, Streb S, Meier F, Pfister B, Zeeman SC. Molecular Genetic Analysis of Glucan Branching Enzymes from Plants and Bacteria in Arabidopsis Reveals Marked Differences in Their Functions and Capacity to Mediate Starch Granule Formation. PLANT PHYSIOLOGY 2015; 169:1638-1655. [PMID: 26358415 PMCID: PMC4634060 DOI: 10.1104/pp.15.00792] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/04/2015] [Indexed: 06/05/2023]
Abstract
The major component of starch is the branched glucan amylopectin, the branching pattern of which is one of the key factors determining its ability to form semicrystalline starch granules. Here, we investigated the functions of different branching enzyme (BE) types by expressing proteins from maize (Zea mays BE2a), potato (Solanum tuberosum BE1), and Escherichia coli (glycogen BE [EcGLGB]) in Arabidopsis (Arabidopsis thaliana) mutant plants that are deficient in their endogenous BEs and therefore, cannot make starch. The expression of each of these three BE types restored starch biosynthesis to differing degrees. Full complementation was achieved using the class II BE ZmBE2a, which is most similar to the two endogenous Arabidopsis isoforms. Expression of the class I BE from potato, StBE1, resulted in partial complementation and high amylose starch. Expression of the glycogen BE EcGLGB restored only minimal amounts of starch production, which had unusual chain length distribution, branch point distribution, and granule morphology. Nevertheless, each type of BE together with the starch synthases and debranching enyzmes were able to create crystallization-competent amylopectin polymers. These data add to the knowledge of how the properties of the BE influence the final composition of starch and fine structure of amylopectin.
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Affiliation(s)
- Kuan-Jen Lu
- Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | | | - Florence Meier
- Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
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21
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Schwarte S, Wegner F, Havenstein K, Groth D, Steup M, Tiedemann R. Sequence variation, differential expression, and divergent evolution in starch-related genes among accessions of Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2015; 87:489-519. [PMID: 25663508 DOI: 10.1007/s11103-015-0293-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 01/26/2015] [Indexed: 06/04/2023]
Abstract
Transitory starch metabolism is a nonlinear and highly regulated process. It originated very early in the evolution of chloroplast-containing cells and is largely based on a mosaic of genes derived from either the eukaryotic host cell or the prokaryotic endosymbiont. Initially located in the cytoplasm, starch metabolism was rewired into plastids in Chloroplastida. Relocation was accompanied by gene duplications that occurred in most starch-related gene families and resulted in subfunctionalization of the respective gene products. Starch-related isozymes were then evolutionary conserved by constraints such as internal starch structure, posttranslational protein import into plastids and interactions with other starch-related proteins. 25 starch-related genes in 26 accessions of Arabidopsis thaliana were sequenced to assess intraspecific diversity, phylogenetic relationships, and modes of selection. Furthermore, sequences derived from additional 80 accessions that are publicly available were analyzed. Diversity varies significantly among the starch-related genes. Starch synthases and phosphorylases exhibit highest nucleotide diversities, while pyrophosphatases and debranching enzymes are most conserved. The gene trees are most compatible with a scenario of extensive recombination, perhaps in a Pleistocene refugium. Most genes are under purifying selection, but disruptive selection was inferred for a few genes/substitutiones. To study transcript levels, leaves were harvested throughout the light period. By quantifying the transcript levels and by analyzing the sequence of the respective accessions, we were able to estimate whether transcript levels are mainly determined by genetic (i.e., accession dependent) or physiological (i.e., time dependent) parameters. We also identified polymorphic sites that putatively affect pattern or the level of transcripts.
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Affiliation(s)
- Sandra Schwarte
- Evolutionary Biology, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, Building 26, 14476, Potsdam, Germany,
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Kang G, Peng X, Wang L, Yang Y, Shao R, Xie Y, Ma D, Wang C, Guo T, Zhu Y. Ultrastructural observation of mesophyll cells and temporal expression profiles of the genes involved in transitory starch metabolism in flag leaves of wheat after anthesis. PHYSIOLOGIA PLANTARUM 2015; 153:12-29. [PMID: 24853500 DOI: 10.1111/ppl.12233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 04/27/2014] [Indexed: 05/08/2023]
Abstract
Transitory starch in cereal plant leaves is synthesized during the day and remobilized at night to provide a carbon source for growth and grain filling, but its mechanistic basis is still poorly understood. The objective of this study is to explore the regulatory mechanism for starch biosynthesis and degradation in plant source organs. Using transmission electron microscopy, we observed that during the day after anthesis, starch granules in mesophyll cells of wheat flag leaves accumulated in chloroplasts and the number of starch granules gradually decreased with wheat leaf growth. During the night, starch granules synthesized in chloroplasts during the day were completely or partially degraded. The transcript levels of 26 starch synthesis-related genes and 16 starch breakdown-related genes were further measured using quantitative real-time reverse transcription polymerase chain reaction. Expression profile analysis revealed that starch metabolism genes were clustered into two groups based on their temporal expression patterns. The genes in the first group were highly expressed and presumed to play crucial roles in starch metabolism. The genes in the other group were not highly expressed in flag leaves and may have minor functions in starch metabolism in leaf tissue. The functions of most of these genes in leaves were further discussed. The starch metabolism-related genes that are predominantly expressed in wheat flag leaves differ from those expressed in wheat grain, indicating that two different pathways for starch metabolism operate in these tissues. This provides specific information on the molecular mechanisms of transitory starch metabolism in higher plants.
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Affiliation(s)
- Guozhang Kang
- The Collaborative Innovation Center of Henan Food Crops, Henan Agricultural University, Zhengzhou, 450002, China
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Streb S, Zeeman SC. Replacement of the endogenous starch debranching enzymes ISA1 and ISA2 of Arabidopsis with the rice orthologs reveals a degree of functional conservation during starch synthesis. PLoS One 2014; 9:e92174. [PMID: 24642810 PMCID: PMC3958451 DOI: 10.1371/journal.pone.0092174] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 02/20/2014] [Indexed: 11/19/2022] Open
Abstract
This study tested the interchangeability of enzymes in starch metabolism between dicotyledonous and monocotyledonous plant species. Amylopectin - a branched glucose polymer - is the major component of starch and is responsible for its semi-crystalline property. Plants synthesize starch with distinct amylopectin structures, varying between species and tissues. The structure determines starch properties, an important characteristic for cooking and nutrition, and for the industrial uses of starch. Amylopectin synthesis involves at least three enzyme classes: starch synthases, branching enzymes and debranching enzymes. For all three classes, several enzyme isoforms have been identified. However, it is not clear which enzyme(s) are responsible for the large diversity of amylopectin structures. Here, we tested whether the specificities of the debranching enzymes (ISA1 and ISA2) are major determinants of species-dependent differences in amylopectin structure by replacing the dicotyledonous Arabidopsis isoamylases (AtISA1 and AtISA2) with the monocotyledonous rice (Oryza sativa) isoforms. We demonstrate that the ISA1 and ISA2 are sufficiently well conserved between these species to form heteromultimeric chimeric Arabidopsis/rice isoamylase enzymes. Furthermore, we were able to reconstitute the endosperm-specific rice OsISA1 homomultimeric complex in Arabidopsis isa1isa2 mutants. This homomultimer was able to facilitate normal rates of starch synthesis. The resulting amylopectin structure had small but significant differences in comparison to wild-type Arabidopsis amylopectin. This suggests that ISA1 and ISA2 have a conserved function between plant species with a major role in facilitating the crystallization of pre-amylopectin synthesized by starch synthases and branching enzymes, but also influencing the final structure of amylopectin.
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Affiliation(s)
- Sebastian Streb
- Institute for Agricultural Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
- * E-mail:
| | - Samuel C. Zeeman
- Institute for Agricultural Sciences, Department of Biology, ETH Zurich, Zurich, Switzerland
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