1
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Sun Z, Li Z, Lin X, Hu Z, Jiang M, Tang B, Zhao Z, Xing M, Yang X, Zhu H. Genome-Wide Identification and Expression Analysis of the Starch Synthase Gene Family in Sweet Potato and Two of Its Closely Related Species. Genes (Basel) 2024; 15:400. [PMID: 38674335 PMCID: PMC11049646 DOI: 10.3390/genes15040400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 03/14/2024] [Accepted: 03/16/2024] [Indexed: 04/28/2024] Open
Abstract
The starch synthase (SS) plays important roles in regulating plant growth and development and responding to adversity stresses. Although the SS family has been studied in many crops, it has not been fully identified in sweet potato and its two related species. In the present study, eight SSs were identified from Ipomoea batatas (I. batata), Ipomoea trifida (I. trifida), and Ipomoea trlioba (I. trlioba), respectively. According to the phylogenetic relationships, they were divided into five subgroups. The protein properties, chromosomal location, phylogenetic relationships, gene structure, cis-elements in the promoter, and interaction network of these proteins were also analyzed; stress expression patterns were systematically analyzed; and real-time polymerase chain reaction (qRT-PCR) analysis was performed. Ipomoea batatas starch synthase (IbSSs) were highly expressed in tuber roots, especially Ipomoea batatas starch synthase 1 (IbSS1) and Ipomoea batatas starch synthase 6 (IbSS6), which may play an important role in root development and starch biosynthesis. At the same time, the SS genes respond to potassium deficiency, hormones, cold, heat, salt, and drought stress. This study offers fresh perspectives for enhancing knowledge about the roles of SSs and potential genes to enhance productivity, starch levels, and resistance to environmental stresses in sweet potatoes.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Hongbo Zhu
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, China; (Z.S.); (Z.L.); (X.L.); (Z.H.); (M.J.); (B.T.); (Z.Z.); (M.X.); (X.Y.)
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2
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Ichikawa S, Sakata M, Oba T, Kodama Y. Fluorescein staining of chloroplast starch granules in living plants. PLANT PHYSIOLOGY 2024; 194:662-672. [PMID: 37792703 PMCID: PMC10828193 DOI: 10.1093/plphys/kiad528] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/08/2023] [Accepted: 09/09/2023] [Indexed: 10/06/2023]
Abstract
Chloroplast starch granules (cpSGs) store energy harvested through photosynthesis in plants, and cpSG dynamics have important roles in plant energy metabolism and stress responses. To date, cpSGs have been visualized using several methods, such as iodine staining; however, no method can be used to specifically visualize cpSGs in living cells from various plant species. Here, we report a simple method to visualize cpSGs in living plant cells in various species by staining with fluorescein, a commonly used fluorescent dye. We show that fluorescein is taken up into chloroplasts and interacts with cpSGs similarly to iodine. Fluorescein also interacts with refined starch in vitro. Using a fluorescein derivative for ultrabright cpSG imaging, we produced high-quality 3D reconstructions of cpSGs and evaluated their accumulation in multiple plant species. As fluorescein is well known and readily purchasable, our fluorescein-based staining method should contribute to all research regarding starch.
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Affiliation(s)
- Shintaro Ichikawa
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
- Graduate School of Regional Development and Creativity, Utsunomiya University, Tochigi 321-8505, Japan
| | - Momoko Sakata
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Toru Oba
- Graduate School of Regional Development and Creativity, Utsunomiya University, Tochigi 321-8505, Japan
- Faculty of Engineering, Utsunomiya University, Tochigi 321-8585, Japan
| | - Yutaka Kodama
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
- Graduate School of Regional Development and Creativity, Utsunomiya University, Tochigi 321-8505, Japan
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
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3
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Sharma M, Abt MR, Eicke S, Ilse TE, Liu C, Lucas MS, Pfister B, Zeeman SC. MFP1 defines the subchloroplast location of starch granule initiation. Proc Natl Acad Sci U S A 2024; 121:e2309666121. [PMID: 38190535 PMCID: PMC10801857 DOI: 10.1073/pnas.2309666121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/07/2023] [Indexed: 01/10/2024] Open
Abstract
Starch is one of the major carbohydrate storage compounds in plants. The biogenesis of starch granules starts with the formation of initials, which subsequently expand into granules. Several coiled-coil domain-containing proteins have been previously implicated with the initiation process, but the mechanisms by which they act remain largely elusive. Here, we demonstrate that one of these proteins, the thylakoid-associated MAR-BINDING FILAMENT-LIKE PROTEIN 1 (MFP1), specifically determines the subchloroplast location of initial formation. The expression of MFP1 variants "mis"-targeted to specific locations within chloroplasts in Arabidopsis results in distinctive shifts in not only how many but also where starch granules are formed. Importantly, "re" localizing MFP1 to the stromal face of the chloroplast's inner envelope is sufficient to generate starch granules in this aberrant position. These findings provide compelling evidence that a single protein MFP1 possesses the capacity to direct the initiation and biosynthesis machinery of starch granules.
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Affiliation(s)
- Mayank Sharma
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Melanie R Abt
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Theresa E Ilse
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Chun Liu
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Miriam S Lucas
- Scientific Center for Optical and Electron Microscopy, ETH Zurich, 8093 Zurich, Switzerland
| | - Barbara Pfister
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, 8092 Zurich, Switzerland
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4
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Kamble NU, Makhamadjonov F, Fahy B, Martins C, Saalbach G, Seung D. Initiation of B-type starch granules in wheat endosperm requires the plastidial α-glucan phosphorylase PHS1. THE PLANT CELL 2023; 35:4091-4110. [PMID: 37595145 PMCID: PMC10615211 DOI: 10.1093/plcell/koad217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/20/2023]
Abstract
The plastidial α-glucan phosphorylase (PHS1) can elongate and degrade maltooligosaccharides (MOSs), but its exact physiological role in plants is poorly understood. Here, we discover a specialized role of PHS1 in establishing the unique bimodal characteristic of starch granules in wheat (Triticum spp.) endosperm. Wheat endosperm contains large A-type granules that initiate at early grain development and small B-type granules that initiate in later grain development. We demonstrate that PHS1 interacts with B-GRANULE CONTENT1 (BGC1), a carbohydrate-binding protein essential for normal B-type granule initiation. Mutants of tetraploid durum wheat (Triticum turgidum) deficient in all homoeologs of PHS1 had normal A-type granules but fewer and larger B-type granules. Grain size and starch content were not affected by the mutations. Further, by assessing granule numbers during grain development in the phs1 mutant and using a double mutant defective in both PHS1 and BGC1, we demonstrate that PHS1 is exclusively involved in B-type granule initiation. The total starch content and number of starch granules per chloroplast in leaves were not affected by loss of PHS1, suggesting that its role in granule initiation in wheat is limited to the endosperm. We therefore propose that the initiation of A- and B-type granules occurs via distinct biochemical mechanisms, where PHS1 plays an exclusive role in B-type granule initiation.
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Affiliation(s)
| | | | - Brendan Fahy
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH,UK
| | - Carlo Martins
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH,UK
| | | | - David Seung
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH,UK
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5
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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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6
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Shoaib N, Mughal N, Liu L, Raza A, Shen L, Yu G. Site-Directed Mutations at Phosphorylation Sites in Zea mays PHO1 Reveal Modulation of Enzymatic Activity by Phosphorylation at S566 in the L80 Region. PLANTS (BASEL, SWITZERLAND) 2023; 12:3205. [PMID: 37765369 PMCID: PMC10536461 DOI: 10.3390/plants12183205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/25/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023]
Abstract
Starch phosphorylase (PHO) is a pivotal enzyme within the GT35-glycogen-phosphorylase (GT; glycosyltransferases) superfamily. Despite the ongoing debate surrounding the precise role of PHO1, evidence points to its substantial influence on starch biosynthesis, supported by its gene expression profile and subcellular localization. Key to PHO1 function is the enzymatic regulation via phosphorylation; a myriad of such modification sites has been unveiled in model crops. However, the functional implications of these sites remain to be elucidated. In this study, we utilized site-directed mutagenesis on the phosphorylation sites of Zea mays PHO1, replacing serine residues with alanine, glutamic acid, and aspartic acid, to discern the effects of phosphorylation. Our findings indicate that phosphorylation exerts no impact on the stability or localization of PHO1. Nonetheless, our enzymatic assays unveiled a crucial role for phosphorylation at the S566 residue within the L80 region of the PHO1 structure, suggesting a potential modulation or enhancement of PHO1 activity. These data advance our understanding of starch biosynthesis regulation and present potential targets for crop yield optimization.
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Affiliation(s)
- Noman Shoaib
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- National Demonstration Center for Experimental Crop Science Education, College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Nishbah Mughal
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Lun Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- National Demonstration Center for Experimental Crop Science Education, College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Ali Raza
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Leiyang Shen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- National Demonstration Center for Experimental Crop Science Education, College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Guowu Yu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- National Demonstration Center for Experimental Crop Science Education, College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
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7
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Westgeest AJ, Dauzat M, Simonneau T, Pantin F. Leaf starch metabolism sets the phase of stomatal rhythm. THE PLANT CELL 2023; 35:3444-3469. [PMID: 37260348 PMCID: PMC10473205 DOI: 10.1093/plcell/koad158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 04/25/2023] [Accepted: 05/15/2023] [Indexed: 06/02/2023]
Abstract
In leaves of C3 and C4 plants, stomata open during the day to favor CO2 entry for photosynthesis and close at night to prevent inefficient transpiration of water vapor. The circadian clock paces rhythmic stomatal movements throughout the diel (24-h) cycle. Leaf transitory starch is also thought to regulate the diel stomatal movements, yet the underlying mechanisms across time (key moments) and space (relevant leaf tissues) remain elusive. Here, we developed PhenoLeaks, a pipeline to analyze the diel dynamics of transpiration, and used it to screen a series of Arabidopsis (Arabidopsis thaliana) mutants impaired in starch metabolism. We detected a sinusoidal, endogenous rhythm of transpiration that overarches days and nights. We determined that a number of severe mutations in starch metabolism affect the endogenous rhythm through a phase shift, resulting in delayed stomatal movements throughout the daytime and diminished stomatal preopening during the night. Nevertheless, analysis of tissue-specific mutations revealed that neither guard-cell nor mesophyll-cell starch metabolisms are strictly required for normal diel patterns of transpiration. We propose that leaf starch influences the timing of transpiration rhythm through an interplay between the circadian clock and sugars across tissues, while the energetic effect of starch-derived sugars is usually nonlimiting for endogenous stomatal movements.
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Affiliation(s)
| | - Myriam Dauzat
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
| | | | - Florent Pantin
- LEPSE, Univ Montpellier, INRAE, Institut Agro, Montpellier, France
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, Angers F-49000, France
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8
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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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9
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Vandromme C, Spriet C, Putaux JL, Dauvillée D, Courseaux A, D'Hulst C, Wattebled F. Further insight into the involvement of PII1 in starch granule initiation in Arabidopsis leaf chloroplasts. THE NEW PHYTOLOGIST 2023; 239:132-145. [PMID: 37010093 DOI: 10.1111/nph.18923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/25/2023] [Indexed: 06/02/2023]
Abstract
The control of starch granule initiation in plant leaves is a complex process that requires active enzymes like Starch Synthase 4 and 3 (SS4 or SS3) and several noncatalytic proteins such as Protein Involved in starch Initiation 1 (PII1). In Arabidopsis leaves, SS4 is the main enzyme that control starch granule initiation, but in its absence, SS3 partly fulfills this function. How these proteins collectively act to control the initiation of starch granules remains elusive. PII1 and SS4 physically interact, and PII1 is required for SS4 to be fully active. However, Arabidopsis mutants lacking SS4 or PII1 still accumulate starch granules. Combining pii1 KO mutation with either ss3 or ss4 KO mutations provide new insights of how the remaining starch granules are synthesized. The ss3 pii1 line still accumulates starch, while the phenotype of ss4 pii1 is stronger than that of ss4. Our results indicate first that SS4 initiates starch granule synthesis in the absence of PII1 albeit being limited to one large lenticular granule per plastid. Second, that if in the absence of SS4, SS3 is able to initiate starch granules with low efficiency, this ability is further reduced with the additional absence of PII1.
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Affiliation(s)
- Camille Vandromme
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Corentin Spriet
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, US 41 - UAR 2014 - PLBS, F-59000, Lille, France
| | - Jean-Luc Putaux
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000, Grenoble, France
| | - David Dauvillée
- 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
| | - 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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10
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Dong X, Chen L, Yang H, Tian L, Dong F, Chai Y, Qu LQ. Pho1 cooperates with DPE1 to control short maltooligosaccharide mobilization during starch synthesis initiation in rice endosperm. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:47. [PMID: 36912930 DOI: 10.1007/s00122-023-04250-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 10/18/2022] [Indexed: 06/18/2023]
Abstract
Plastidial α-glucan phosphorylase is a key factor that cooperates with plastidial disproportionating enzyme to control short maltooligosaccharide mobilization during the initiation process of starch molecule synthesis in developing rice endosperm. Storage starch synthesis is essential for grain filling. However, little is known about how cereal endosperm controls starch synthesis initiation. One of core events for starch synthesis initiation is short maltooligosaccharide (MOS) mobilization consisting of long MOS primer production and excess MOS breakdown. By mutant analyses and biochemical investigations, we present here functional identifications of plastidial α-glucan phosphorylase (Pho1) and disproportionating enzyme (DPE1) during starch synthesis initiation in rice (Oryza sativa) endosperm. Pho1 deficiency impaired MOS mobilization, triggering short MOS accumulation and starch synthesis reduction during early seed development. The mutant seeds differed significantly in MOS level and starch content at 15 days after flowering and exhibited diverse endosperm phenotypes during mid-late seed development: ranging from pseudonormal to shrunken (Shr), severely or excessively Shr. The level of DPE1 was almost normal in the PN seeds but significantly reduced in the Shr seeds. Overexpression of DPE1 in pho1 resulted in plump seeds only. DPE1 deficiency had no obvious effects on MOS mobilization. Knockout of DPE1 in pho1 completely blocked MOS mobilization, resulting in severely and excessively Shr seeds only. These findings show that Pho1 cooperates with DPE1 to control short MOS mobilization during starch synthesis initiation in rice endosperm.
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Affiliation(s)
- Xiangbai Dong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Liangke Chen
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Huifang Yang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lihong Tian
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Fengqin Dong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yaru Chai
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Le Qing Qu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100093, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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11
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Morita R, Crofts N, Miura S, Ikeda KI, Aoki N, Fukayama H, Fujita N. Characterization of the Functions of Starch Synthase IIIb Expressed in the Vegetative Organs of Rice (Oryza sativa L.). PLANT & CELL PHYSIOLOGY 2023; 64:94-106. [PMID: 36222360 DOI: 10.1093/pcp/pcac143] [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: 08/17/2022] [Revised: 10/08/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Rice is the model C3 crop for investigating the starch biosynthesis mechanism in endosperm because of its importance in grain production. However, little is known about starch biosynthesis in the vegetative organs of rice. In this study, we used novel rice mutants by inserting Tos17 into the starch synthase (SS) IIIb gene, which is mainly expressed in the leaf sheath (LS) and leaf blade (LB), and an ss1 mutant to clarify the differences in roles among SS isozymes during starch biosynthesis. Native polyacrylamide gel electrophoresis (PAGE)/activity staining for SS, using LS and LB of ss mutants, revealed that the lowest migrating SS activity bands on the gel were derived from SSIIIb activity and those of two ss3b mutants were not detected. The apparent amylose content of LS starch of ss3b mutants increased. Moreover, the chain-length distribution and size-exclusion chromatography analysis using ss mutants showed that SSIIIb and SSI synthesize the B2-B3 chain and A-B1 chain of amylopectin in the LS and LB respectively. Interestingly, we also found that starch contents were decreased in the LS and LB of ss3b mutants, although SSI deficiency did not affect the starch levels. All these results indicated that SSIIIb synthesizes the long chain of amylopectin in the LS and LB similar to SSIIIa in the endosperm, while SSI synthesizes the short chain in the vegetative organ as the same in the endosperm.
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Affiliation(s)
- Ryutaro Morita
- Laboratory of Crop Science, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
| | - Naoko Crofts
- Laboratory of Plant Physiology, Department of Biological Production, Akita Prefectural University, 241-438 Kaidobata-Nishi, Shimoshinjo-nakano, Akita, 010-0195 Japan
| | - Satoko Miura
- Laboratory of Plant Physiology, Department of Biological Production, Akita Prefectural University, 241-438 Kaidobata-Nishi, Shimoshinjo-nakano, Akita, 010-0195 Japan
| | - Ken-Ichi Ikeda
- Laboratory of Stress Cytology, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkoudai-chou, Nada-ku, Kobe, Hyogo, 657-8501 Japan
| | - Naohiro Aoki
- Laboratory of Crop Science, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
| | - Hiroshi Fukayama
- Laboratory of Tropical Crop Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkoudai-chou, Nada-ku, Kobe, Hyogo, 657-8501 Japan
| | - Naoko Fujita
- Laboratory of Plant Physiology, Department of Biological Production, Akita Prefectural University, 241-438 Kaidobata-Nishi, Shimoshinjo-nakano, Akita, 010-0195 Japan
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12
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Thieme M, Hochmuth A, Ilse TE, Cuesta-Seijo JA, Stoma S, Meier R, Nørrelykke SF, Pedas PR, Braumann I, Zeeman SC. Detecting variation in starch granule size and morphology by high-throughput microscopy and flow cytometry. Carbohydr Polym 2023; 299:120169. [PMID: 36876784 DOI: 10.1016/j.carbpol.2022.120169] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/29/2022] [Accepted: 09/25/2022] [Indexed: 10/14/2022]
Abstract
Starch forms semi-crystalline, water-insoluble granules, the size and morphology of which vary according to biological origin. These traits, together with polymer composition and structure, determine the physicochemical properties of starch. However, screening methods to identify differences in starch granule size and shape are lacking. Here, we present two approaches for high-throughput starch granule extraction and size determination using flow cytometry and automated, high-throughput light microscopy. We evaluated the practicality of both methods using starch from different species and tissues and demonstrated their effectiveness by screening for induced variation in starch extracted from over 10,000 barley lines, yielding four with heritable changes in the ratio of large A-granules to small B-granules. Analysis of Arabidopsis lines altered in starch biosynthesis further demonstrates the applicability of these approaches. Identifying variation in starch granule size and shape will enable identification of trait-controlling genes for developing crops with desired properties, and could help optimise starch processing.
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Affiliation(s)
- Mercedes Thieme
- Institute of Molecular Plant Biology, ETH Zurich, 8092 Zurich, Switzerland; Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799 Copenhagen V, Denmark.
| | - Anton Hochmuth
- Institute of Molecular Plant Biology, ETH Zurich, 8092 Zurich, Switzerland; Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799 Copenhagen V, Denmark.
| | | | - Jose A Cuesta-Seijo
- Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799 Copenhagen V, Denmark
| | | | - Roger Meier
- ScopeM, ETH Zurich, 8093 Zurich, Switzerland.
| | | | - Pai Rosager Pedas
- Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799 Copenhagen V, Denmark.
| | - Ilka Braumann
- Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799 Copenhagen V, Denmark.
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, ETH Zurich, 8092 Zurich, Switzerland.
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13
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Li X, Apriyanto A, Castellanos JF, Compart J, Muntaha SN, Fettke J. Dpe2/phs1 revealed unique starch metabolism with three distinct phases characterized by different starch granule numbers per chloroplast, allowing insights into the control mechanism of granule number regulation by gene co-regulation and metabolic profiling. FRONTIERS IN PLANT SCIENCE 2022; 13:1039534. [PMID: 36407636 PMCID: PMC9667719 DOI: 10.3389/fpls.2022.1039534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
An Arabidopsis mutant lacking both the cytosolic Disproportionating enzyme 2 (DPE2) and the plastidial glucan Phosphorylase 1 (PHS1) revealed a unique starch metabolism. Dpe2/phs1 has been reported to have only one starch granule number per chloroplast when grown under diurnal rhythm. For this study, we analyzed dpe2/phs1 in details following the mutant development, and found that it showed three distinct periods of granule numbers per chloroplast, while there was no obvious change observed in Col-0. In young plants, the starch granule number was similar to that in Col-0 at first, and then decreased significantly, down to one or no granule per chloroplast, followed by an increase in the granule number. Thus, in dpe2/phs1, control over the starch granule number is impaired, but it is not defective in starch granule initiation. The data also indicate that the granule number is not fixed, and is regulated throughout plant growth. Furthermore, the chloroplasts revealed alterations during these three periods, with a partially strong aberrant morphology in the middle phase. Interestingly, the unique metabolism was perpetuated when starch degradation was further impaired through an additional lack of Isoamylase 3 (ISA3) or Starch excess 4 (SEX4). Transcriptomic studies and metabolic profiling revealed the co-regulation of starch metabolism-related genes and a clear metabolic separation between the periods. Most senescence-induced genes were found to be up-regulated more than twice in the starch-less mature leaves. Thus, dpe2/phs1 is a unique plant material source, with which we may study starch granule number regulation to obtain a more detailed understanding.
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14
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Pfister B, Shields JM, Kockmann T, Grossmann J, Abt MR, Stadler M, Zeeman SC. Tuning heterologous glucan biosynthesis in yeast to understand and exploit plant starch diversity. BMC Biol 2022; 20:207. [PMID: 36153520 PMCID: PMC9509603 DOI: 10.1186/s12915-022-01408-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/13/2022] [Indexed: 11/30/2022] Open
Abstract
Background Starch, a vital plant-derived polysaccharide comprised of branched glucans, is essential in nutrition and many industrial applications. Starch is often modified post-extraction to alter its structure and enhance its functionality. Targeted metabolic engineering of crops to produce valuable and versatile starches requires knowledge of the relationships between starch biosynthesis, structure, and properties, but systematic studies to obtain this knowledge are difficult to conduct in plants. Here we used Saccharomyces cerevisiae as a testbed to dissect the functions of plant starch biosynthetic enzymes and create diverse starch-like polymers. Results We explored yeast promoters and terminators to tune the expression levels of the starch-biosynthesis machinery from Arabidopsis thaliana. We systematically modulated the expression of each starch synthase (SS) together with a branching enzyme (BE) in yeast. Protein quantification by parallel reaction monitoring (targeted proteomics) revealed unexpected effects of glucan biosynthesis on protein abundances but showed that the anticipated broad range of SS/BE enzyme ratios was maintained during the biosynthetic process. The different SS/BE ratios clearly influenced glucan structure and solubility: The higher the SS/BE ratio, the longer the glucan chains and the more glucans were partitioned into the insoluble fraction. This effect was irrespective of the SS isoform, demonstrating that the elongation/branching ratio controls glucan properties separate from enzyme specificity. Conclusions Our results provide a quantitative framework for the in silico design of improved starch biosynthetic processes in plants. Our study also exemplifies a workflow for the rational tuning of a complex pathway in yeast, starting from the selection and evaluation of expression modules to multi-gene assembly and targeted protein monitoring during the biosynthetic process. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01408-x.
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15
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Sergeeva EM, Larichev KT, Salina EA, Kochetov AV. Starch metabolism in potato <i>Solanum tuberosum</i> L. Vavilovskii Zhurnal Genet Selektsii 2022; 26:250-263. [PMID: 35774362 PMCID: PMC9168746 DOI: 10.18699/vjgb-22-32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 11/19/2022] Open
Abstract
Starch is a major storage carbohydrate in plants. It is an important source of calories in the human and animal diet. Also, it is widely used in various industries. Native starch consists of water-insoluble semicrystalline granules formed by natural glucose polymers amylose and amylopectin. The physicochemical properties of starch are determined by the amylose:amylopectin ratio in the granule and degrees of their polymerization and phosphorylation. Potato Solanum tuberosum L. is one of the main starch-producing crops. Growing industrial needs necessitate the breeding of plant varieties with increased starch content and specified starch properties. This task demands detailed information on starch metabolism in the producing plant. It is a complex process, requiring the orchestrated work of many enzymes, transporter and targeting proteins, transcription factors, and other regulators. Two types of starch are recognized with regard to their biological functions. Transitory starch is synthesized in chloroplasts of photosynthetic organs and degraded in the absence of light, providing carbohydrates for cell needs. Storage starch is synthesized and stored in amyloplasts of storage organs: grains and tubers. The main enzymatic reactions of starch biosynthesis and degradation, as well as carbohydrate transport and metabolism, are well known in the case of transitory starch of the model plant Arabidopsis thaliana. Less is known about features of starch metabolism in storage organs, in particular, potato tubers. Several issues remain obscure: the roles of enzyme isoforms and different regulatory factors in tissues at various plant developmental stages and under different environmental conditions; alternative enzymatic processes; targeting and transport proteins. In this review, the key enzymatic reactions of plant carbohydrate metabolism, transitory and storage starch biosynthesis,
and starch degradation are discussed, and features specific for potato are outlined. Attention is also paid to the
known regulatory factors affecting starch metabolism
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Affiliation(s)
- E. M. Sergeeva
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences
| | - K. T. Larichev
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences
| | - E. A. Salina
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences
| | - A. V. Kochetov
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences
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16
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Muntaha SN, Li X, Compart J, Apriyanto A, Fettke J. Carbon pathways during transitory starch degradation in Arabidopsis differentially affect the starch granule number and morphology in the dpe2/phs1 mutant background. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 180:35-41. [PMID: 35378390 DOI: 10.1016/j.plaphy.2022.03.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/24/2022] [Accepted: 03/26/2022] [Indexed: 06/14/2023]
Abstract
The Arabidopsis knockout mutant lacking both the cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) had a dwarf-growth phenotype, a reduced and uneven distribution of starch within the plant rosettes, and a lower starch granule number per chloroplast under standard growth conditions. In contrast, a triple mutant impaired in starch degradation by its additional lack of the glucan, water dikinase (GWD) showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to the wild type. We concluded that ongoing starch degradation is mainly responsible for the observed phenotype of dpe2/phs1. Next, we generated two further triple mutants lacking either the phosphoglucan, water dikinase (PWD), or the disproportionating enzyme 1 (DPE1) in the background of the double mutant. Analysis of the starch metabolism revealed that even minor ongoing starch degradation observed in dpe2/phs1/pwd maintained the double mutant phenotype. In contrast, an additional blockage in the glucose pathway of starch breakdown, as in dpe2/phs1/dpe1, resulted in a nearly starch-free phenotype and massive chloroplast degradation. The characterized mutants were discussed in the context of starch granule formation.
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Affiliation(s)
- Sidratul Nur Muntaha
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Xiaoping Li
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Julia Compart
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Ardha Apriyanto
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, Germany.
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17
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Kim I, Kim HU. The mysterious role of fibrillin in plastid metabolism: current advances in understanding. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2751-2764. [PMID: 35560204 DOI: 10.1093/jxb/erac087] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Fibrillins (FBNs) are a family of genes in cyanobacteria, algae, and plants. The proteins they encode possess a lipid-binding motif, exist in various types of plastids, and are associated with lipid bodies called plastoglobules, implicating them in lipid metabolism. FBNs present in the thylakoid and stroma are involved in the storage, transport, and synthesis of lipid molecules for photoprotective functions against high-light stress. In this review, the diversity of subplastid locations in the evolution of FBNs, regulation of FBNs expression by various stresses, and the role of FBNs in plastid lipid metabolism are comprehensively summarized and directions for future research are discussed.
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Affiliation(s)
- Inyoung Kim
- Department of Molecular Biology, Sejong University, Seoul, South Korea
| | - Hyun Uk Kim
- Department of Molecular Biology, Sejong University, Seoul, South Korea
- Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul, South Korea
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18
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Sharma V, Fandade V, Kumar P, Parveen A, Madhawan A, Bathla M, Mishra A, Sharma H, Rishi V, Satbhai SB, Roy J. Protein targeting to starch 1, a functional protein of starch biosynthesis in wheat (Triticum aestivum L.). PLANT MOLECULAR BIOLOGY 2022; 109:101-113. [PMID: 35332427 DOI: 10.1007/s11103-022-01260-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
TaPTST1, a wheat homolog of AtPTST1 containing CBM can interact with GBSSI and regulate starch metabolism in wheat endosperm. In cereal endosperm, native starch comprising amylose and amylopectin is synthesized by the coordinated activities of several pathway enzymes. Amylose in starch influences its physio-chemical properties resulting in several human health benefits. The Granule-Bound Starch Synthase I (GBSSI) is the most abundant starch-associated protein. GBSSI lacks dedicated Carbohydrate-binding module (CBM). Previously, Protein Targeting To Starch 1 (PTST1) was identified as a crucial protein for the localization of GBSSI to the starch granules in Arabidopsis. The function of its homologous protein in the wheat endosperm is not known. In this study, TaPTST1, an AtPTST1 homolog, containing a CBM and a coiled-coil domain was identified in wheat. Protein-coding nucleotide sequence of TaPTST1 from Indian wheat variety 'C 306' was cloned and characterized. Homology modelling and molecular docking suggested the potential interaction of TaPTST1 with glucans and GBSSI. The TaPTST1 expression was higher in wheat grain than the other tissues, suggesting a grain-specific function. In vitro binding assays demonstrated different binding affinities of TaPTST1 for native starch, amylose, and amylopectin. Furthermore, the immunoaffinity pull-down assay revealed that TaPTST1 directly interacts with GBSSI, and the interaction is mediated by a coiled-coil domain. The direct protein-protein interaction was further confirmed by bimolecular fluorescence complementation assay (BiFC) in planta. Based on our findings we postulate a functional role for TaPTST1 in starch metabolism by targeting GBSSI to starch granules in wheat endosperm.
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Affiliation(s)
- Vinita Sharma
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
- Department of Biological Sciences, Indian Institute of Science Education & Research (IISER) Mohali, Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Vikas Fandade
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Prashant Kumar
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Afsana Parveen
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Akansha Madhawan
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Manik Bathla
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Ankita Mishra
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Himanshu Sharma
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Vikas Rishi
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Santosh B Satbhai
- Department of Biological Sciences, Indian Institute of Science Education & Research (IISER) Mohali, Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India
| | - Joy Roy
- National Agri-Food Biotechnology Institute (NABI), Sector-81, SAS Nagar, Mohali, Punjab, 140 306, India.
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19
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He S, Hao X, Wang S, Zhou W, Ma Q, Lu X, Chen L, Zhang P. Starch synthase II plays a crucial role in starch biosynthesis and the formation of multienzyme complexes in cassava storage roots. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2540-2557. [PMID: 35134892 DOI: 10.1093/jxb/erac022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Starch is a glucose polymer synthesized by green plants for energy storage and is crucial for plant growth and reproduction. The biosynthesis of starch polysaccharides is mediated by members of the large starch synthase (SS) protein superfamily. Here, we showed that in cassava storage roots, soluble starch synthase II (MeSSII) plays an important role in starch biosynthesis and the formation of protein complexes with other starch biosynthetic enzymes by directly interacting with MeSSI, MeSBEII, and MeISAII. MeSSII-RNAi cassava lines showed increased amylose content and reduced biosynthesis of the intermediate chain of amylopectin (B1 type) in their storage roots, leading to altered starch physicochemical properties. Furthermore, gel permeation chromatography analysis of starch biosynthetic enzymes between wild type and MeSSII-RNAi lines confirmed the key role of MeSSII in the organization of heteromeric starch synthetic protein complexes. The lack of MeSSII in cassava also reduced the capacity of MeSSI, MeSBEII, MeISAI, and MeISAII to bind to starch granules. These findings shed light on the key components of the starch biosynthesis machinery in root crops.
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Affiliation(s)
- Shutao He
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaomeng Hao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shanshan Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenzhi Zhou
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Qiuxiang Ma
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xinlu Lu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Luonan Chen
- Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Key Laboratory of Systems Health Science of Zhejiang Province, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, Zhuhai, Guangdong, China
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
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20
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Hedin N, Velazquez MB, Barchiesi J, Gomez-Casati DF, Busi MV. CBM20CP, a novel functional protein of starch metabolism in green algae. PLANT MOLECULAR BIOLOGY 2022; 108:363-378. [PMID: 34546521 DOI: 10.1007/s11103-021-01190-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 08/20/2021] [Indexed: 05/29/2023]
Abstract
Ostreococcus tauri is a picoalga that contains a small and compact genome, which resembles that of higher plants in the multiplicity of enzymes involved in starch synthesis (ADP-glucose pyrophosphorylase, ADPGlc PPase; granule bound starch synthase, GBSS; starch synthases, SSI, SSII, SSIII; and starch branching enzyme, SBE, between others), except starch synthase IV (SSIV). Although its genome is fully sequenced, there are still many genes and proteins to which no function was assigned. Here, we identify the OT_ostta06g01880 gene that encodes CBM20CP, a plastidial protein which contains a central carbohydrate binding domain of the CBM20 family, and a coiled coil domain at the C-terminus that lacks catalytic activity. We demonstrate that CBM20CP has the ability to bind starch, amylose and amylopectin with different affinities. Furthermore, this protein interacts with OsttaSSIII-B, increasing its binding to starch granules, its catalytic efficiency and promoting granule growth. The results allow us to postulate a functional role for CBM20CP in starch metabolism in green algae. KEY MESSAGE: CBM20CP, a plastidial protein that has a modular structure but lacks catalytic activity, regulates the synthesis of starch in Ostreococcus tauri.
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Affiliation(s)
- Nicolas Hedin
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Maria B Velazquez
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Julieta Barchiesi
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Diego F Gomez-Casati
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Maria V Busi
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina.
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21
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Qu J, Zhong Y, Ding L, Liu X, Xu S, Guo D, Blennow A, Xue J. Biosynthesis, structure and functionality of starch granules in maize inbred lines with different kernel dehydration rate. Food Chem 2022; 368:130796. [PMID: 34418691 DOI: 10.1016/j.foodchem.2021.130796] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 08/04/2021] [Accepted: 08/04/2021] [Indexed: 11/25/2022]
Abstract
In this study, we report important relationships between kernel starch and kernel dehydration rate for eight maize inbred lines with different dehydration characteristics. High-throughput RNA sequencing data of starch biosynthesis-related genes showed that kernel moisture content and dehydration rate were both associated with differential expression of most starch biosynthetic genes. Especially, kernel moisture content was positively correlated with the increased expression of SBEI and SBEIIb, thereby potentially inducing biosynthesis of amylose with low molecular weight and amylopectin with low content of amylopectin chains with degree of polymerization (DP) 6-12 in inbred lines with fast kernel dehydration rate. We found a negative correlation between short amylopectin chains (DP 6-12) and the starch retrogradation rate. Hence, a low amount of amylopectin chains with DP 6-12 in the inbred lines with fast kernel dehydration rate was a plausible reason for their high short- and long-term retrogradation.
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Affiliation(s)
- Jianzhou Qu
- Key Laboratory of Biology and Genetic Improvement of Maize in Arid Area of Northwest Region, College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China; Maize Engineering Technology Research Centre of Shaanxi Province, Yanglin 712100, Shaanxi, China
| | - Yuyue Zhong
- Key Laboratory of Biology and Genetic Improvement of Maize in Arid Area of Northwest Region, College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China; Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Denmark
| | - Li Ding
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Denmark
| | - Xingxun Liu
- Lab of Food Soft Matter Structure and Advanced Manufacturing, College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Shutu Xu
- Key Laboratory of Biology and Genetic Improvement of Maize in Arid Area of Northwest Region, College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China; Maize Engineering Technology Research Centre of Shaanxi Province, Yanglin 712100, Shaanxi, China
| | - Dongwei Guo
- Key Laboratory of Biology and Genetic Improvement of Maize in Arid Area of Northwest Region, College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China; Maize Engineering Technology Research Centre of Shaanxi Province, Yanglin 712100, Shaanxi, China
| | - Andreas Blennow
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Denmark.
| | - Jiquan Xue
- Key Laboratory of Biology and Genetic Improvement of Maize in Arid Area of Northwest Region, College of Agronomy, Northwest A&F University, Yangling 712100, Shaanxi, China; Maize Engineering Technology Research Centre of Shaanxi Province, Yanglin 712100, Shaanxi, China.
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22
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Li R, Zheng W, Jiang M, Zhang H. A review of starch biosynthesis in cereal crops and its potential breeding applications in rice ( Oryza Sativa L.). PeerJ 2022; 9:e12678. [PMID: 35036154 PMCID: PMC8710062 DOI: 10.7717/peerj.12678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/02/2021] [Indexed: 11/20/2022] Open
Abstract
Starch provides primary storage of carbohydrates, accounting for approximately 85% of the dry weight of cereal endosperm. Cereal seeds contribute to maximum annual starch production and provide the primary food for humans and livestock worldwide. However, the growing demand for starch in food and industry and the increasing loss of arable land with urbanization emphasizes the urgency to understand starch biosynthesis and its regulation. Here, we first summarized the regulatory signaling pathways about leaf starch biosynthesis. Subsequently, we paid more attention to how transcriptional factors (TFs) systematically respond to various stimulants via the regulation of the enzymes during starch biosynthesis. Finally, some strategies to improve cereal yield and quality were put forward based on the previous reports. This review would collectively help to design future studies on starch biosynthesis in cereal crops.
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Affiliation(s)
- Ruiqing Li
- State Key Laboratory of Rice Biology and Chinese National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, China.,College of Agronomy, Anhui Agricultural University, Hefei, China
| | - Wenyin Zheng
- College of Agronomy, Anhui Agricultural University, Hefei, China
| | - Meng Jiang
- State Key Laboratory of Rice Biology, Institute of Crop Sciences, Zhejiang University, Hangzhou, China
| | - Huali Zhang
- State Key Laboratory of Rice Biology and Chinese National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, China
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23
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Bürgy L, Eicke S, Kopp C, Jenny C, Lu KJ, Escrig S, Meibom A, Zeeman SC. Coalescence and directed anisotropic growth of starch granule initials in subdomains of Arabidopsis thaliana chloroplasts. Nat Commun 2021; 12:6944. [PMID: 34836943 PMCID: PMC8626487 DOI: 10.1038/s41467-021-27151-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 11/01/2021] [Indexed: 12/29/2022] Open
Abstract
Living cells orchestrate enzyme activities to produce myriads of biopolymers but cell-biological understanding of such processes is scarce. Starch, a plant biopolymer forming discrete, semi-crystalline granules within plastids, plays a central role in glucose storage, which is fundamental to life. Combining complementary imaging techniques and Arabidopsis genetics we reveal that, in chloroplasts, multiple starch granules initiate in stromal pockets between thylakoid membranes. These initials coalesce, then grow anisotropically to form lenticular granules. The major starch polymer, amylopectin, is synthesized at the granule surface, while the minor amylose component is deposited internally. The non-enzymatic domain of STARCH SYNTHASE 4, which controls the protein's localization, is required for anisotropic growth. These results present us with a conceptual framework for understanding the biosynthesis of this key nutrient.
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Affiliation(s)
- Léo Bürgy
- Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Christophe Kopp
- Laboratory for Biological Geochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Camilla Jenny
- Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Kuan Jen Lu
- Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Stephane Escrig
- Laboratory for Biological Geochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Anders Meibom
- Laboratory for Biological Geochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Centre for Advanced Surface Analysis, University of Lausanne, Lausanne, Switzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, ETH Zurich, 8092, Zurich, Switzerland.
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24
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Abstract
Nature has developed starch granules varying in size from less than 1 μm to more than 100 μm. The granule size is an important factor affecting the functional properties and the applicability of starch for food and non-food applications. Within the same botanical species, the range of starch granule size can be up to sevenfold. This review critically evaluated the biological and environmental factors affecting the size of starch granules, the methods for the separation of starch granules and the measurement of size distribution. Further, the structure at different length scales and properties of starch-based on the granule size is elucidated by specifying the typical applications of granules with varying sizes. An amylopectin cluster model showing the arrangement of amylopectin from inside toward the granule surface is proposed with the hypothesis that the steric hindrance for the growth of lamellar structure may limit the size of starch granules.
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Affiliation(s)
- Ming Li
- Laboratory of Cereal Processing and Quality Control, Institute of Food Science and Technology, CAAS/Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Venea Dara Daygon
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St Lucia, Queensland, Australia
| | - Vicky Solah
- College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Western Australia, Australia
| | - Sushil Dhital
- Department of Chemical and Biological Engineering, Monash University, Clayton, Victoria, Australia
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25
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Shoaib N, Liu L, Ali A, Mughal N, Yu G, Huang Y. Molecular Functions and Pathways of Plastidial Starch Phosphorylase (PHO1) in Starch Metabolism: Current and Future Perspectives. Int J Mol Sci 2021; 22:ijms221910450. [PMID: 34638789 PMCID: PMC8509025 DOI: 10.3390/ijms221910450] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 12/17/2022] Open
Abstract
Starch phosphorylase is a member of the GT35-glycogen-phosphorylase superfamily. Glycogen phosphorylases have been researched in animals thoroughly when compared to plants. Genetic evidence signifies the integral role of plastidial starch phosphorylase (PHO1) in starch biosynthesis in model plants. The counterpart of PHO1 is PHO2, which specifically resides in cytosol and is reported to lack L80 peptide in the middle region of proteins as seen in animal and maltodextrin forms of phosphorylases. The function of this extra peptide varies among species and ranges from the substrate of proteasomes to modulate the degradation of PHO1 in Solanum tuberosum to a non-significant effect on biochemical activity in Oryza sativa and Hordeum vulgare. Various regulatory functions, e.g., phosphorylation, protein–protein interactions, and redox modulation, have been reported to affect the starch phosphorylase functions in higher plants. This review outlines the current findings on the regulation of starch phosphorylase genes and proteins with their possible role in the starch biosynthesis pathway. We highlight the gaps in present studies and elaborate on the molecular mechanisms of phosphorylase in starch metabolism. Moreover, we explore the possible role of PHO1 in crop improvement.
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Affiliation(s)
- Noman Shoaib
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China; (N.S.); (L.L.); (N.M.)
| | - Lun Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China; (N.S.); (L.L.); (N.M.)
| | - Asif Ali
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
| | - Nishbah Mughal
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China; (N.S.); (L.L.); (N.M.)
| | - Guowu Yu
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China; (N.S.); (L.L.); (N.M.)
- Correspondence: (G.Y.); (Y.H.); Tel.: +86-180-0803-9351 (G.Y.); +86-028-8629-0868 (Y.H.)
| | - Yubi Huang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China; (N.S.); (L.L.); (N.M.)
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Correspondence: (G.Y.); (Y.H.); Tel.: +86-180-0803-9351 (G.Y.); +86-028-8629-0868 (Y.H.)
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26
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Liu Q, Zhou Y, Fettke J. Starch Granule Size and Morphology of Arabidopsis thaliana Starch-Related Mutants Analyzed during Diurnal Rhythm and Development. Molecules 2021; 26:molecules26195859. [PMID: 34641402 PMCID: PMC8510473 DOI: 10.3390/molecules26195859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 11/23/2022] Open
Abstract
Transitory starch plays a central role in the life cycle of plants. Many aspects of this important metabolism remain unknown; however, starch granules provide insight into this persistent metabolic process. Therefore, monitoring alterations in starch granules with high temporal resolution provides one significant avenue to improve understanding. Here, a previously established method that combines LCSM and safranin-O staining for in vivo imaging of transitory starch granules in leaves of Arabidopsis thaliana was employed to demonstrate, for the first time, the alterations in starch granule size and morphology that occur both throughout the day and during leaf aging. Several starch-related mutants were included, which revealed differences among the generated granules. In ptst2 and sex1-8, the starch granules in old leaves were much larger than those in young leaves; however, the typical flattened discoid morphology was maintained. In ss4 and dpe2/phs1/ss4, the morphology of starch granules in young leaves was altered, with a more rounded shape observed. With leaf development, the starch granules became spherical exclusively in dpe2/phs1/ss4. Thus, the presented data provide new insights to contribute to the understanding of starch granule morphogenesis.
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Affiliation(s)
- Qingting Liu
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25 Building 20, 14476 Potsdam-Golm, Germany;
| | - Yuan Zhou
- Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476 Potsdam, Germany;
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25 Building 20, 14476 Potsdam-Golm, Germany;
- Correspondence: ; Tel.: +49-331-977-2653
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27
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Mérida A, Fettke J. Starch granule initiation in Arabidopsis thaliana chloroplasts. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:688-697. [PMID: 34051021 DOI: 10.1111/tpj.15359] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/14/2021] [Accepted: 05/22/2021] [Indexed: 06/12/2023]
Abstract
The initiation of starch granule formation and the mechanism controlling the number of granules per plastid have been some of the most elusive aspects of starch metabolism. This review covers the advances made in the study of these processes. The analyses presented herein depict a scenario in which starch synthase isoform 4 (SS4) provides the elongating activity necessary for the initiation of starch granule formation. However, this protein does not act alone; other polypeptides are required for the initiation of an appropriate number of starch granules per chloroplast. The functions of this group of polypeptides include providing suitable substrates (maltooligosaccharides) to SS4, the localization of the starch initiation machinery to the thylakoid membranes, and facilitating the correct folding of SS4. The number of starch granules per chloroplast is tightly regulated and depends on the developmental stage of the leaves and their metabolic status. Plastidial phosphorylase (PHS1) and other enzymes play an essential role in this process since they are necessary for the synthesis of the substrates used by the initiation machinery. The mechanism of starch granule formation initiation in Arabidopsis seems to be generalizable to other plants and also to the synthesis of long-term storage starch. The latter, however, shows specific features due to the presence of more isoforms, the absence of constantly recurring starch synthesis and degradation, and the metabolic characteristics of the storage sink organs.
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Affiliation(s)
- Angel Mérida
- Institute of Plant Biochemistry and Photosynthesis (IBVF), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Sevilla (US), Avda Américo Vespucio, 49, Sevilla, 41092, Spain
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, Potsdam-Golm, 14476, Germany
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28
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Hawkins E, Chen J, Watson-Lazowski A, Ahn-Jarvis J, Barclay JE, Fahy B, Hartley M, Warren FJ, Seung D. STARCH SYNTHASE 4 is required for normal starch granule initiation in amyloplasts of wheat endosperm. THE NEW PHYTOLOGIST 2021; 230:2371-2386. [PMID: 33714222 DOI: 10.1111/nph.17342] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 03/05/2021] [Indexed: 05/26/2023]
Abstract
Starch granule initiation is poorly understood at the molecular level. The glucosyltransferase, STARCH SYNTHASE 4 (SS4), plays a central role in granule initiation in Arabidopsis leaves, but its function in cereal endosperms is unknown. We investigated the role of SS4 in wheat, which has a distinct spatiotemporal pattern of granule initiation during grain development. We generated TILLING mutants in tetraploid wheat (Triticum turgidum) that are defective in both SS4 homoeologs. The morphology of endosperm starch was examined in developing and mature grains. SS4 deficiency led to severe alterations in endosperm starch granule morphology. During early grain development, while the wild-type initiated single 'A-type' granules per amyloplast, most amyloplasts in the mutant formed compound granules due to multiple initiations. This phenotype was similar to mutants deficient in B-GRANULE CONTENT 1 (BGC1). SS4 deficiency also reduced starch content in leaves and pollen grains. We propose that SS4 and BGC1 are required for the proper control of granule initiation during early grain development that leads to a single A-type granule per amyloplast. The absence of either protein results in a variable number of initiations per amyloplast and compound granule formation.
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Affiliation(s)
- Erica Hawkins
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Jiawen Chen
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | | | | | | | - Brendan Fahy
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Matthew Hartley
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | | | - David Seung
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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29
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Starch Granules in Arabidopsis thaliana Mesophyll and Guard Cells Show Similar Morphology but Differences in Size and Number. Int J Mol Sci 2021; 22:ijms22115666. [PMID: 34073516 PMCID: PMC8199161 DOI: 10.3390/ijms22115666] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/17/2021] [Accepted: 05/21/2021] [Indexed: 01/08/2023] Open
Abstract
Transitory starch granules result from complex carbon turnover and display specific situations during starch synthesis and degradation. The fundamental mechanisms that specify starch granule characteristics, such as granule size, morphology, and the number per chloroplast, are largely unknown. However, transitory starch is found in the various cells of the leaves of Arabidopsis thaliana, but comparative analyses are lacking. Here, we adopted a fast method of laser confocal scanning microscopy to analyze the starch granules in a series of Arabidopsis mutants with altered starch metabolism. This allowed us to separately analyze the starch particles in the mesophyll and in guard cells. In all mutants, the guard cells were always found to contain more but smaller plastidial starch granules than mesophyll cells. The morphological properties of the starch granules, however, were indiscernible or identical in both types of leaf cells.
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30
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Chen J, Hawkins E, Seung D. Towards targeted starch modification in plants. CURRENT OPINION IN PLANT BIOLOGY 2021; 60:102013. [PMID: 33677239 DOI: 10.1016/j.pbi.2021.102013] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/23/2021] [Accepted: 01/24/2021] [Indexed: 06/12/2023]
Abstract
Genetic approaches to modify starch in crops have been limited by our knowledge of starch biosynthesis. Recent advances in Arabidopsis have revealed key genetic components determining the size, shape and number of granules in a plastid. This has opened the doors to new discoveries on granule initiation in crop species. In parallel, advances in genomic resources and gene editing technologies allow targeted manipulation of starch biosynthesis genes in isogenic crop backgrounds. Such technologies have been successfully deployed to alter starch composition, and can now be used to modify other starch traits. This will allow the complex relationships between starch structure and physicochemical properties to be elucidated, which will facilitate the rational manipulation of starches in crops.
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Affiliation(s)
- Jiawen Chen
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Erica Hawkins
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - David Seung
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
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31
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Gámez-Arjona FM, Mérida Á. Interplay Between the N-Terminal Domains of Arabidopsis Starch Synthase 3 Determines the Interaction of the Enzyme With the Starch Granule. FRONTIERS IN PLANT SCIENCE 2021; 12:704161. [PMID: 34630454 PMCID: PMC8494965 DOI: 10.3389/fpls.2021.704161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/27/2021] [Indexed: 05/04/2023]
Abstract
The elongation of the linear chains of starch is undertaken by starch synthases. class 3 of starch synthase (SS3) has a specific feature: a long N-terminal region containing starch binding domains (SBDs). In this work, we analyze in vivo the contribution of these domains to the localization pattern of the enzyme. For this purpose, we divided the N-terminal region of Arabidopsis SS3 in three domains: D1, D2, and D3 (each of which contains an SBD and a coiled-coil site). Our analyses indicate that the N-terminal region is sufficient to determine the same localization pattern observed with the full-length protein. D2 binds tightly the polypeptide to the polymer and it is necessary the contribution of D1 and D3 to avoid the polypeptide to be trapped in the growing polymer. The localization pattern of Arabidopsis SS3 appears to be the result of the counterbalanced action of the different domains present in its N-terminal region.
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32
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Seung D. Amylose in starch: towards an understanding of biosynthesis, structure and function. THE NEW PHYTOLOGIST 2020; 228:1490-1504. [PMID: 32767769 DOI: 10.1111/nph.16858] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/13/2020] [Indexed: 05/20/2023]
Abstract
Starch granules are composed of two distinct glucose polymers - amylose and amylopectin. Amylose constitutes 5-35% of most natural starches and has a major influence over starch properties in foods. Its synthesis and storage occurs within the semicrystalline amylopectin matrix of starch granules, this poses a great challenge for biochemical and structural analyses. However, the last two decades have seen vast progress in understanding amylose synthesis, including new insights into the action of GRANULE BOUND STARCH SYNTHASE (GBSS), the major glucosyltransferase that synthesises amylose, and the discovery of PROTEIN TARGETING TO STARCH1 (PTST1) that targets GBSS to starch granules. Advances in analytical techniques have resolved the fine structure of amylose, raising new questions on how structure is determined during biosynthesis. Furthermore, the discovery of wild plants that do not produce amylose revives a long-standing question of why starch granules contain amylose, rather than amylopectin alone. Overall, these findings contribute towards a full understanding of amylose biosynthesis, structure and function that will be essential for future approaches to improve starch quality in crops.
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Affiliation(s)
- David Seung
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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33
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Cho YG, Kang KK. Functional Analysis of Starch Metabolism in Plants. PLANTS 2020; 9:plants9091152. [PMID: 32899939 PMCID: PMC7569781 DOI: 10.3390/plants9091152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/04/2020] [Indexed: 01/02/2023]
Abstract
In plants, starch is synthesized in leaves during the day-time from fixed carbon through photosynthesis and is mobilized at night to support continued respiration, sucrose export, and growth in the dark. The main crops where starch is biosynthesized and stored are corn, rice, wheat, and potatoes, and they are mainly used as food resources for humankind. There are many genes that are involved in starch biosynthesis from cytosol to storage organs in plants. ADP-glucose, UDP- glucose, and glucose-6-phosphate are synthesized catalyzed by UDP-invertase, AGPase, hexokinase, and P- hexose-isomerase in cytosol. Starch composed of amylopectin and amylose is synthesized by starch synthase, granule bound starch synthase, starch-branching enzyme, debranching enzyme, and pullulanase, which is primarily responsible for starch production in storage organs. Recently, it has been uncovered that structural genes are controlled by proteins derived from other genes such as transcription factors. To obtain more precise information on starch metabolism, the functions of genes and transcription factors need to be studied to understand their roles and functions in starch biosynthesis in plants. However, the roles of genes related to starch biosynthesis are not yet clearly understood. The papers of this special issue contain reviews and research articles on these topics and will be a useful resource for researchers involved in the quality improvement of starch storage crops.
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Affiliation(s)
- Yong-Gu Cho
- Department of Crop Science, Chungbuk National University, Cheongju 28644, Korea
- Correspondence: (Y.-G.C.); (K.-K.K.)
| | - Kwon-Kyoo Kang
- Division of Horticultural Biotechnology, Hankyong National University, Anseong 17579, Korea
- Correspondence: (Y.-G.C.); (K.-K.K.)
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34
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Xu L, You H, Zhang O, Xiang X. Genetic Effects of Soluble Starch Synthase IV-2 and It with ADPglucose Pyrophorylase Large Unit and Pullulanase on Rice Qualities. RICE (NEW YORK, N.Y.) 2020; 13:46. [PMID: 32661799 PMCID: PMC7359214 DOI: 10.1186/s12284-020-00409-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/06/2020] [Indexed: 05/27/2023]
Abstract
BACKGROUND Rice amylose content and amylopectin structure corporately determine rice eating and cooking qualities (ECQs). Soluble starch synthase (SS) IV-2 is a member of the soluble starch synthesis gene family but with unknown effects on ECQs. RESULTS In this study, three populations derived from a cross of two parents who possess the same major genes of starch bio-synthesis were employed to investigate the influence of SSIV-2 and its combined effects with ADPglucose pyrophorylase large unit (AGPlar) and Pullulanase (PUL) on ECQs. The results illustrated that the polymorphism of SSIV-2 alleles significantly affected gel consistency (GC), gelatinization temperature (GT), percent of retrogradation (PR) and three crucial rapid viscosity analysis (RVA) profile parameters: peak viscosity (PKV), breakdown viscosity (BDV) and setback viscosity (SBV). And SSIV-2 allele derived from CG173R had better quality traits with lower GT, SBV and PR. Moreover, its interaction with AGPlar was responsible for the variations of GC, apparent amylose content (AAC), GT, PR and all RVA parameters except for pasting temperature (PaT) and peak time (PeT), in terms of GC, PKV and CSV, AGPlar derived from CG173R had an epistatic effect on SSIV-2; additionally, interaction of SSIV-2 and PUL mainly affected GC, AAC, PKV, CPV, CSV and SBV. I-C and C-1 (I, allele of AGPlar from Guangzhan 63S; C, allele of SSIV-2 from CG173R; 1, allele of PUL from Guangzhan 63S) combinations had better ECQs. CONCLUSIONS SSIV-2 alleles significantly affect rice quality, especially the parameters relevant to gelatinized and thermal characteristics of starch (GC, PR, GT, PKV, BDV and SBV) under the same major genes (Waxy and SSII-3) background. It indicates that SSIV-2 functions elongation of starch chain. These findings suggest that the effects of SSIV-2 and its interaction with AGPlar and PUL are vital for rice quality breeding with the same major genes.
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Affiliation(s)
- Liang Xu
- Lab of Plant Molecular Genetics and Breeding, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China
| | - Hui You
- Lab of Plant Molecular Genetics and Breeding, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China
| | - Ouling Zhang
- Lab of Plant Molecular Genetics and Breeding, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China
| | - Xunchao Xiang
- Lab of Plant Molecular Genetics and Breeding, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China.
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35
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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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Abt MR, Zeeman SC. Evolutionary innovations in starch metabolism. CURRENT OPINION IN PLANT BIOLOGY 2020; 55:109-117. [PMID: 32428846 DOI: 10.1016/j.pbi.2020.03.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/29/2020] [Accepted: 03/02/2020] [Indexed: 05/23/2023]
Abstract
The traditional view of starch metabolism has focused on the multiplicity of enzymes and enzyme isoforms contributing to the production of the constituent polymers, amylopectin and amylose. However, knowledge of these enzymes has not provided a full insight into many aspects of starch biosynthesis. This enzyme-centered view has recently been augmented by the discovery and characterization of novel proteins with proposed regulatory, scaffolding, and interactive roles. This begins to reveal an unprecedented level of complexity beyond mere glucan biosynthesis, enabling us to envisage how starch granules are initiated and grow into specific forms, allowing it to serve biological roles beyond just carbohydrate storage. This review focuses on very recent findings in this vibrant field, highlighting the evolutionary novelty.
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Affiliation(s)
- Melanie R Abt
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, Universitätstrasse 2, 8092 Zurich, Switzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, Department of Biology, ETH Zurich, Universitätstrasse 2, 8092 Zurich, Switzerland.
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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: 69] [Impact Index Per Article: 17.3] [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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Chia T, Chirico M, King R, Ramirez-Gonzalez R, Saccomanno B, Seung D, Simmonds J, Trick M, Uauy C, Verhoeven T, Trafford K. A carbohydrate-binding protein, B-GRANULE CONTENT 1, influences starch granule size distribution in a dose-dependent manner in polyploid wheat. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:105-115. [PMID: 31633795 DOI: 10.1093/jxb/erz405] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/29/2019] [Indexed: 05/19/2023]
Abstract
In Triticeae endosperm (e.g. wheat and barley), starch granules have a bimodal size distribution (with A- and B-type granules) whereas in other grasses the endosperm contains starch granules with a unimodal size distribution. Here, we identify the gene, BGC1 (B-GRANULE CONTENT 1), responsible for B-type starch granule content in Aegilops and wheat. Orthologues of this gene are known to influence starch synthesis in diploids such as rice, Arabidopsis, and barley. However, using polyploid Triticeae species, we uncovered a more complex biological role for BGC1 in starch granule initiation: BGC1 represses the initiation of A-granules in early grain development but promotes the initiation of B-granules in mid grain development. We provide evidence that the influence of BGC1 on starch synthesis is dose dependent and show that three very different starch phenotypes are conditioned by the gene dose of BGC1 in polyploid wheat: normal bimodal starch granule morphology; A-granules with few or no B-granules; or polymorphous starch with few normal A- or B-granules. We conclude from this work that BGC1 participates in controlling B-type starch granule initiation in Triticeae endosperm and that its precise effect on granule size and number varies with gene dose and stage of development.
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Affiliation(s)
| | | | - Rob King
- Rothamsted Research, West Common, Harpenden, UK
| | | | | | - David Seung
- John Innes Centre, Norwich Research Park, Norwich, UK
| | | | - Martin Trick
- John Innes Centre, Norwich Research Park, Norwich, UK
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Lloyd JR. The A to B of starch granule formation in wheat endosperm. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1-3. [PMID: 31841166 PMCID: PMC6913706 DOI: 10.1093/jxb/erz414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This article comments on: Chia T, Chirico M, King R et al. 2019. A carbohydrate-binding protein, B-granule content 1 influences starch granule-size distribution in a dose dependent manner in polyploid wheat. Journal of Experimental Botany 70, 105–115.
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Affiliation(s)
- James R Lloyd
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
- Correspondence:
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Cheng Y, Jiang S, Zhang X, He H, Liu J. Whole-Genome Re-Sequencing of Corylus heterophylla Blank-Nut Mutants Reveals Sequence Variations in Genes Associated With Embryo Abortion. FRONTIERS IN PLANT SCIENCE 2019; 10:1465. [PMID: 31798613 PMCID: PMC6863972 DOI: 10.3389/fpls.2019.01465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 10/22/2019] [Indexed: 05/20/2023]
Abstract
Yield loss in the economically important hazelnut (Corylus spp.) occurs through the frequent formation of blank nuts. Although the condition is associated with embryo abortion, we have not yet identified the regulatory genes involved. Therefore, this study aimed to determine the genes related to embryo abortion in hazel. We performed whole-genome re-sequencing and single-nucleotide polymorphism (SNP) analysis on four mutant hazelnut trees (Empty1 to Empty4, C. heterophylla) bearing blank nuts and four wild-type trees (Full1 to Full4, C. heterophylla). A paired comparison of Empty1 vs. Full1, Empty2 vs. Full2, Empty3 vs. Full3, and Empty4 vs. Full4, along with the intersection of Empty1 to Empty4, revealed 3 081 common SNPs in the four blank-nut mutants. Of these, 215 synonymous SNPs in exonic regions were distributed across 178 candidate genes. Heterozygosity analysis showed that average homozygous and heterozygous SNP ratios were respectively 0.409 and 0.591 in the samples. According to Gene Ontology classification, candidate genes were enriched in the categories of binding, catalysis, molecular transducer, transporter, and molecular function regulator. Among these, 18 of 178 genes had homozygous SNPs in Empty1-4. Cis elements in the promoter region of starch synthase 4 (SS4) contain the RY-element, implying seed-specific expression. Starch granules were absent from Empty1-4 cotyledon cells, but abundantly present in Full1-Full4 cotyledon cells. The blank-nut phenotype has heavier nut shells. Overall, we conclude that single-nucleotide variants of Acetyl-CoA carboxylase 1 (ACC1), intracellular sodium/hydrogen exchanger 2 (NHX2), UDP-glycosyltransferase 74E2 (UGT74E2), DEFECTIVE IN MERISTEM SILENCING 3 (DMS3), DETOXIFICATION 43 (FRD3), and SS4 may induce embryo abortion, leading to blank-nut formation. Our results will benefit future research on how the gain or loss of candidate genes influences seed development. Moreover, our study provides novel prospects for seedless cultivar development.
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Vandromme C, Kasprowicz A, Courseaux A, Trinel D, Facon M, Putaux JL, D’Hulst C, Wattebled F, Spriet C. NegFluo, a Fast and Efficient Method to Determine Starch Granule Size and Morphology In Situ in Plant Chloroplasts. FRONTIERS IN PLANT SCIENCE 2019; 10:1075. [PMID: 31552073 PMCID: PMC6746253 DOI: 10.3389/fpls.2019.01075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
Starch granules that accumulate in the plastids of plants vary in size, shape, phosphate, or protein content according to their botanical origin. Depending on their size, the applications in food and nonfood industries differ. Being able to master starch granule size for a specific plant, without alteration of other characteristics (phosphate content, protein content, etc.), is challenging. The development of a simple and effective screening method to determine the size and shape of starch granules in a plant population is therefore of prime interest. In this study, we propose a new method, NegFluo, that combines negative confocal autofluorescence imaging in leaf and machine learning (ML)-based image analysis. It provides a fast, automated, and easy-to-use pipeline for both in situ starch granule imaging and its morphological analysis. NegFluo was applied to Arabidopsis leaves of wild-type and ss4 mutant plants. We validated its accuracy by comparing morphological quantifications using NegFluo and state-of-the-art methods relying either on starch granule purification or on preparation-intensive electron microscopy combined with manual image analysis. NegFluo thus opens the way to fast in situ analysis of starch granules.
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Affiliation(s)
- Camille Vandromme
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Angelina Kasprowicz
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Adeline Courseaux
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Dave Trinel
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Maud Facon
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | | | - Christophe D’Hulst
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Fabrice Wattebled
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Corentin Spriet
- Univ. Lille, CNRS, UMR8576 – UGSF – Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
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Intra-Sample Heterogeneity of Potato Starch Reveals Fluctuation of Starch-Binding Proteins According to Granule Morphology. PLANTS 2019; 8:plants8090324. [PMID: 31487879 PMCID: PMC6784226 DOI: 10.3390/plants8090324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 11/26/2022]
Abstract
Starch granule morphology is highly variable depending on the botanical origin. Moreover, all investigated plant species display intra-tissular variability of granule size. In potato tubers, the size distribution of starch granules follows a unimodal pattern with diameters ranging from 5 to 100 µm. Several evidences indicate that granule morphology in plants is related to the complex starch metabolic pathway. However, the intra-sample variability of starch-binding metabolic proteins remains unknown. Here, we report on the molecular characterization of size-fractionated potato starch granules with average diameters of 14.2 ± 3.7 µm, 24.5 ± 6.5 µm, 47.7 ± 12.8 µm, and 61.8 ± 17.4 µm. In addition to changes in the phosphate contents as well as small differences in the amylopectin structure, we found that the starch-binding protein stoichiometry varies significantly according to granule size. Label-free quantitative proteomics of each granule fraction revealed that individual proteins can be grouped according to four distinct abundance patterns. This study corroborates that the starch proteome may influence starch granule growth and architecture and opens up new perspectives in understanding the dynamics of starch biosynthesis.
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Veillet F, Chauvin L, Kermarrec MP, Sevestre F, Merrer M, Terret Z, Szydlowski N, Devaux P, Gallois JL, Chauvin JE. The Solanum tuberosum GBSSI gene: a target for assessing gene and base editing in tetraploid potato. PLANT CELL REPORTS 2019; 38:1065-1080. [PMID: 31101972 DOI: 10.1007/s00299-019-02426-w] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/08/2019] [Accepted: 05/08/2019] [Indexed: 05/20/2023]
Abstract
The StGBSSI gene was successfully and precisely edited in the tetraploid potato using gene and base-editing strategies, leading to plants with impaired amylose biosynthesis. Genome editing has recently become a method of choice for basic research and functional genomics, and holds great potential for molecular plant-breeding applications. The powerful CRISPR-Cas9 system that typically produces double-strand DNA breaks is mainly used to generate knockout mutants. Recently, the development of base editors has broadened the scope of genome editing, allowing precise and efficient nucleotide substitutions. In this study, we produced mutants in two cultivated elite cultivars of the tetraploid potato (Solanum tuberosum) using stable or transient expression of the CRISPR-Cas9 components to knock out the amylose-producing StGBSSI gene. We set up a rapid, highly sensitive and cost-effective screening strategy based on high-resolution melting analysis followed by direct Sanger sequencing and trace chromatogram analysis. Most mutations consisted of small indels, but unwanted insertions of plasmid DNA were also observed. We successfully created tetra-allelic mutants with impaired amylose biosynthesis, confirming the loss of function of the StGBSSI protein. The second main objective of this work was to demonstrate the proof of concept of CRISPR-Cas9 base editing in the tetraploid potato by targeting two loci encoding catalytic motifs of the StGBSSI enzyme. Using a cytidine base editor (CBE), we efficiently and precisely induced DNA substitutions in the KTGGL-encoding locus, leading to discrete variation in the amino acid sequence and generating a loss-of-function allele. The successful application of base editing in the tetraploid potato opens up new avenues for genome engineering in this species.
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Affiliation(s)
- Florian Veillet
- INRA, Agrocampus Ouest, Université Rennes 1, UMR 1349 IGEPP, Domaine de Kéraïber, 29260, Ploudaniel, France.
| | - Laura Chauvin
- INRA, Agrocampus Ouest, Université Rennes 1, UMR 1349 IGEPP, Domaine de Kéraïber, 29260, Ploudaniel, France
| | - Marie-Paule Kermarrec
- INRA, Agrocampus Ouest, Université Rennes 1, UMR 1349 IGEPP, Domaine de Kéraïber, 29260, Ploudaniel, France
| | - François Sevestre
- Unité de Glycobiologie Structurale et Fonctionnelle, Univ. Lille, CNRS, UMR8576, UGSF, Lille, France
- Univ. Lille, CNRS, USR 3290, MSAP, Miniaturisation pour la Synthèse, l'Analyse et la Protéomique, Lille, France
| | - Mathilde Merrer
- INRA, Agrocampus Ouest, Université Rennes 1, UMR 1349 IGEPP, Domaine de Kéraïber, 29260, Ploudaniel, France
| | - Zoé Terret
- GAFL, INRA, Montfavet, France
- SYNGENTA SEEDS SAS, 346 Route des Pasquiers, 84260, Sarrians, France
| | - Nicolas Szydlowski
- Unité de Glycobiologie Structurale et Fonctionnelle, Univ. Lille, CNRS, UMR8576, UGSF, Lille, France
- Univ. Lille, CNRS, USR 3290, MSAP, Miniaturisation pour la Synthèse, l'Analyse et la Protéomique, Lille, France
| | - Pierre Devaux
- Germicopa Breeding, Kerguivarc'h, 29520, Chateauneuf Du Faou, France
| | | | - Jean-Eric Chauvin
- INRA, Agrocampus Ouest, Université Rennes 1, UMR 1349 IGEPP, Domaine de Kéraïber, 29260, Ploudaniel, France
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Chloroplast Signaling Gates Thermotolerance in Arabidopsis. Cell Rep 2019; 22:1657-1665. [PMID: 29444421 PMCID: PMC5847188 DOI: 10.1016/j.celrep.2018.01.054] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 11/17/2017] [Accepted: 01/18/2018] [Indexed: 11/23/2022] Open
Abstract
Temperature is a key environmental variable influencing plant growth and survival. Protection against high temperature stress in eukaryotes is coordinated by heat shock factors (HSFs), transcription factors that activate the expression of protective chaperones such as HEAT SHOCK PROTEIN 70 (HSP70); however, the pathway by which temperature is sensed and integrated with other environmental signals into adaptive responses is not well understood. Plants are exposed to considerable diurnal variation in temperature, and we have found that there is diurnal variation in thermotolerance in Arabidopsis thaliana, with maximal thermotolerance coinciding with higher HSP70 expression during the day. In a forward genetic screen, we identified a key role for the chloroplast in controlling this response, suggesting that light-induced chloroplast signaling plays a key role. Consistent with this, we are able to globally activate binding of HSFA1a to its targets by altering redox status in planta independently of a heat shock. There is a diurnal pattern of basal thermotolerance in Arabidopsis Thermotolerance correlates with diurnal expression patterns of heat-associated genes Chloroplast mutants have greater heat shock gene expression and thermotolerance A chloroplast generated light signal gates HSFA1 and heat shock gene expression
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Irshad A, Guo H, Zhang S, Gu J, Zhao L, Xie Y, Xiong H, Zhao S, Ding Y, Ma Y, Liu L. EcoTILLING Reveals Natural Allelic Variations in Starch Synthesis Key Gene TaSSIV and Its Haplotypes Associated with Higher Thousand Grain Weight. Genes (Basel) 2019; 10:genes10040307. [PMID: 31003564 PMCID: PMC6523294 DOI: 10.3390/genes10040307] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 01/18/2023] Open
Abstract
Wheat is a staple food commodity grown worldwide, and wheat starch is a valuable source of energy and carbon that constitutes 80% of the grain weight. Manipulation of genes involved in starch synthesis significantly affects wheat grain weight and yield. TaSSIV plays an important role in starch synthesis and its main function is granule formation. To mine and stack more favorable alleles, single nucleotide polymorphisms (SNPs) of TaSSIV-A, B, and D were investigated across 362 wheat accessions by Ecotype-Targeting Induced Local Lesions IN Genome (EcoTILLING). As a result, a total of 38 SNPs in the amplified regions of three TaSSIV genes were identified, of which 10, 15, and 13 were in TaSSIV-A, B, and D, respectively. These 38 SNPs were evaluated by using KASP and six SNPs showed an allele frequency >5% whereas the rest were <5%, i.e., considered to be minor alleles. In the Chinese mini core collection, three haplotypes were detected for TaSSIV–A and three for TaSSIV–B. The results of an association study in the Chinese mini core collection with thousand grain weight (TGW) and spike length (SPL) showed that Hap-2-1A was significantly associated with TGW and Hap-3-1B with SPL. Allelic frequency and geographic distribution indicated that the favored haplotype (Hap-2-1A) has been positively selected in Chinese wheat breeding. These results suggested that the Kompetitive Allele Specific PCR (KASP) markers can be applied in starch improvement to ultimately improve wheat yield by marker assisted selection in wheat breeding.
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Affiliation(s)
- Ahsan Irshad
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Huijun Guo
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Shunlin Zhang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Jiayu Gu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Linshu Zhao
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Yongdun Xie
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Hongchun Xiong
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Shirong Zhao
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Yuping Ding
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Youzhi Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
| | - Luxiang Liu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/National Engineering Laboratory of Crop Molecular Breeding/National Center of Space Mutagenesis for Crop Improvement, Beijing 100081, China.
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Findinier J, Laurent S, Duchêne T, Roussel X, Lancelon-Pin C, Cuiné S, Putaux JL, Li-Beisson Y, D'Hulst C, Wattebled F, Dauvillée D. Deletion of BSG1 in Chlamydomonas reinhardtii leads to abnormal starch granule size and morphology. Sci Rep 2019; 9:1990. [PMID: 30760823 PMCID: PMC6374437 DOI: 10.1038/s41598-019-39506-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 01/03/2019] [Indexed: 11/09/2022] Open
Abstract
Chlamydomonas reinhardtii represents an ideal model microbial system to decipher starch metabolism. In this green algae, in cells growing in photosynthetic conditions, starch mainly accumulates as a sheath surrounding the pyrenoid while in cells subjected to a nutrient starvation, numerous starch granules are filling up the plastid stroma. The mechanisms underlying and regulating this switch from photosynthetic to storage starch metabolisms are not known. In this work, we have isolated a Chlamydomonas mutant strain containing a deletion in chromosome 2 which displays abnormal starch granule distribution. Under nitrogen starvation, this strain contains an additional starch granules population. These granules are twice as big as the wild-type granules and display characteristics of photosynthetic starch. Genetic and functional complementation analyses allowed us to identify the gene responsible for this original phenotype which was called BSG1 for "Bimodal Starch Granule". Possible roles of BSG1 in starch metabolism modifications during the transition from photosynthetic to starved growth conditions are discussed.
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Affiliation(s)
- Justin Findinier
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Sylvain Laurent
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Thierry Duchêne
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Xavier Roussel
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | | | - Stéphan Cuiné
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108, Saint-Paul-lez-Durance, France
| | - Jean-Luc Putaux
- University Grenoble Alpes, CNRS, CERMAV, F-38000, Grenoble, France
| | - Yonghua Li-Beisson
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108, Saint-Paul-lez-Durance, France
| | - Christophe D'Hulst
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Fabrice Wattebled
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - David Dauvillée
- University Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France.
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Seung D, Smith AM. Starch granule initiation and morphogenesis-progress in Arabidopsis and cereals. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:771-784. [PMID: 30452691 DOI: 10.1093/jxb/ery412] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/06/2018] [Indexed: 05/13/2023]
Abstract
Starch, the major storage carbohydrate in plants, is synthesized in plastids as semi-crystalline, insoluble granules. Many organs and cell types accumulate starch at some point during their development and maturation. The biosynthesis of the starch polymers, amylopectin and amylose, is relatively well understood and mostly conserved between organs and species. However, we are only beginning to understand the mechanism by which starch granules are initiated, and the factors that control the number of granules per plastid and the size/shape of granules. Here, we review recent progress in understanding starch granule initiation and morphogenesis. In Arabidopsis, granule initiation requires several newly discovered proteins with specific locations within the chloroplast, and also on the availability of maltooligosaccharides which act as primers for initiation. We also describe progress in understanding granule biogenesis in the endosperm of cereal grains-within which there is large interspecies variation in granule initiation patterns and morphology. Investigating whether this diversity results from differences between species in the functions of known proteins, and/or from the presence of novel, unidentified proteins, is a promising area of future research. Expanding our knowledge in these areas will lead to new strategies for improving the quality of cereal crops by modifying starch granule size and shape in vivo.
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Affiliation(s)
- David Seung
- John Innes Centre, Norwich Research Park, Norwich, UK
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Vandromme C, Spriet C, Dauvillée D, Courseaux A, Putaux JL, Wychowski A, Krzewinski F, Facon M, D'Hulst C, Wattebled F. PII1: a protein involved in starch initiation that determines granule number and size in Arabidopsis chloroplast. THE NEW PHYTOLOGIST 2019; 221:356-370. [PMID: 30055112 DOI: 10.1111/nph.15356] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/17/2018] [Indexed: 06/08/2023]
Abstract
The initiation of starch granule formation is still poorly understood. However, the soluble starch synthase 4 (SS4) appears to be a major component of this process since it is required to synthesize the correct number of starch granules in the chloroplasts of Arabidopsis thaliana plants. A yeast two-hybrid screen allowed the identification of several putative SS4 interacting partners. We identified the product of At4g32190 locus as a chloroplast-targeted PROTEIN INVOLVED IN STARCH INITIATION (named PII1). Arabidopsis mutants devoid of PII1 display an alteration of the starch initiation process and accumulate, on average, one starch granule per plastid instead of the five to seven granules found in plastids of wild-type plants. These granules are larger than in wild-type, and they remain flat and lenticular. pii1 mutants display wild-type growth rates and accumulate standard starch amounts. Moreover, starch characteristics, such as amylopectin chain length distribution, remain unchanged. Our results reveal the involvement of PII1 in the starch priming process in Arabidopsis leaves through interaction with SS4.
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Affiliation(s)
- Camille Vandromme
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Corentin Spriet
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - David Dauvillée
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Adeline Courseaux
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Jean-Luc Putaux
- Université Grenoble Alpes, CNRS, CERMAV, F-38000, Grenoble, France
| | - Adeline Wychowski
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Frédéric Krzewinski
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Maud Facon
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Christophe D'Hulst
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
| | - Fabrice Wattebled
- Univ. Lille, CNRS, UMR8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France
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Wilkens C, Svensson B, Møller MS. Functional Roles of Starch Binding Domains and Surface Binding Sites in Enzymes Involved in Starch Biosynthesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1652. [PMID: 30483298 PMCID: PMC6243121 DOI: 10.3389/fpls.2018.01652] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/24/2018] [Indexed: 05/07/2023]
Abstract
Biosynthesis of starch is catalyzed by a cascade of enzymes. The activity of a large number of these enzymes depends on interaction with polymeric substrates via carbohydrate binding sites, which are situated outside of the catalytic site and its immediate surroundings including the substrate-binding crevice. Such secondary binding sites can belong to distinct starch binding domains (SBDs), classified as carbohydrate binding modules (CBMs), or be surface binding sites (SBSs) exposed on the surface of catalytic domains. Currently in the Carbohydrate-Active enZYmes (CAZy) database SBDs are found in 13 CBM families. Four of these families; CBM20, CBM45, CBM48, and CBM53 are represented in enzymes involved in starch biosynthesis, namely starch synthases, branching enzymes, isoamylases, glucan, water dikinases, and α-glucan phosphatases. A critical role of the SBD in activity has not been demonstrated for any of these enzymes. Among the well-characterized SBDs important for starch biosynthesis are three CBM53s of Arabidopsis thaliana starch synthase III, which have modest affinity. SBSs, which are overall less widespread than SBDs, have been reported in some branching enzymes, isoamylases, synthases, phosphatases, and phosphorylases active in starch biosynthesis. SBSs appear to exert roles similar to CBMs. SBSs, however, have also been shown to modulate specificity for example by discriminating the length of chains transferred by branching enzymes. Notably, the difference in rate of occurrence between SBDs and SBSs may be due to lack of awareness of SBSs. Thus, SBSs as opposed to CBMs are not recognized at the protein sequence level, which hampers their identification. Moreover, only a few SBSs in enzymes involved in starch biosynthesis have been functionally characterized, typically by structure-guided site-directed mutagenesis. The glucan phosphatase Like SEX4 2 from A. thaliana has two SBSs with weak affinity for β-cyclodextrin, amylose and amylopectin, which were indicated by mutational analysis to be more important than the active site for initial substrate recognition. The present review provides an update on occurrence of functional SBDs and SBSs in enzymes involved in starch biosynthesis.
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Affiliation(s)
- Casper Wilkens
- Enzyme Technology, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Marie Sofie Møller
- Enzyme and Protein Chemistry, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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Liu M, Ma Z, Zheng T, Sun W, Zhang Y, Jin W, Zhan J, Cai Y, Tang Y, Wu Q, Tang Z, Bu T, Li C, Chen H. Insights into the correlation between Physiological changes in and seed development of tartary buckwheat (Fagopyrum tataricum Gaertn.). BMC Genomics 2018; 19:648. [PMID: 30170551 PMCID: PMC6119279 DOI: 10.1186/s12864-018-5036-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 08/24/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tartary buckwheat (Fagopyrum tataricum Gaertn.) is a widely cultivated medicinal and edible crop with excellent economic and nutritional value. The development of tartary buckwheat seeds is a very complex process involving many expression-dependent physiological changes and regulation of a large number of genes and phytohormones. In recent years, the gene regulatory network governing the physiological changes occurring during seed development have received little attention. RESULTS Here, we characterized the seed development of tartary buckwheat using light and electron microscopy and measured phytohormone and nutrient accumulation by using high performance liquid chromatography (HPLC) and by profiling the expression of key genes using RNA sequencing with the support of the tartary buckwheat genome. We first divided the development of tartary buckwheat seed into five stages that include complex changes in development, morphology, physiology and phytohormone levels. At the same time, the contents of phytohormones (gibberellin, indole-3-acetic acid, abscisic acid, and zeatin) and nutrients (rutin, starch, total proteins and soluble sugars) at five stages were determined, and their accumulation patterns in the development of tartary buckwheat seeds were analyzed. Second, gene expression patterns of tartary buckwheat samples were compared during three seed developmental stages (13, 19, and 25 days postanthesis, DPA), and 9 765 differentially expressed genes (DEGs) were identified. We analyzed the overlapping DEGs in different sample combinations and measured 665 DEGs in the three samples. Furthermore, expression patterns of DEGs related to phytohormones, flavonoids, starch, and storage proteins were analyzed. Third, we noted the correlation between the trait (physiological changes, nutrient changes) and metabolites during seed development, and discussed the key genes that might be involved in the synthesis and degradation of each of them. CONCLUSION We provided abundant genomic resources for tartary buckwheat and Polygonaceae communities and revealed novel molecular insights into the correlations between the physiological changes and seed development of tartary buckwheat.
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Affiliation(s)
- Moyang Liu
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Zhaotang Ma
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Tianrun Zheng
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Wenjun Sun
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Yanjun Zhang
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Weiqiong Jin
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Junyi Zhan
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Yuntao Cai
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Yujia Tang
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Qi Wu
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Zizhong Tang
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Tongliang Bu
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Chenglei Li
- College of Life Science, Sichuan Agricultural University, Ya’an, China
| | - Hui Chen
- College of Life Science, Sichuan Agricultural University, Ya’an, China
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