151
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Peng C, Wang Y, Liu F, Ren Y, Zhou K, Lv J, Zheng M, Zhao S, Zhang L, Wang C, Jiang L, Zhang X, Guo X, Bao Y, Wan J. FLOURY ENDOSPERM6 encodes a CBM48 domain-containing protein involved in compound granule formation and starch synthesis in rice endosperm. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 77:917-30. [PMID: 24456533 DOI: 10.1111/tpj.12444] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 12/23/2013] [Accepted: 01/13/2014] [Indexed: 05/18/2023]
Abstract
Starch is the most widespread form of energy storage in the plant kingdom. Although many enzymes and related factors have been identified for starch biosynthesis, unknown players remain to be identified, given that it is a complicated and sophisticated process. The endosperm of rice (Oryza sativa) has been used for the study of starch synthesis. Here, we report the cloning and characterization of the FLOURY ENDOSPERM6 (FLO6) gene in rice. In the flo6 mutant, the starch content is decreased and the normal physicochemical features of starch are changed. Significantly, flo6 mutant endosperm cells show obvious defects in compound granule formation. Map-based cloning showed that FLO6 encodes a protein of unknown function. It harbors an N-terminal transit peptide that ensures its correct localization and functions in the plastid, and a C-terminal carbohydrate-binding module 48 (CBM48) domain that binds to starch. Furthermore, FLO6 can interact with isoamylase1 (ISA1) both in vitro and in vivo, whereas ISA1 does not bind to starch directly. We thus propose that FLO6 may act as a starch-binding protein involved in starch synthesis and compound granule formation through a direct interaction with ISA1 in developing rice seeds. Our data provide a novel insight into the role of proteins with the CBM48 domain in plant species.
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Affiliation(s)
- Cheng Peng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
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Matsushima R, Maekawa M, Kusano M, Kondo H, Fujita N, Kawagoe Y, Sakamoto W. Amyloplast-localized SUBSTANDARD STARCH GRAIN4 protein influences the size of starch grains in rice endosperm. PLANT PHYSIOLOGY 2014; 164:623-36. [PMID: 24335509 PMCID: PMC3912094 DOI: 10.1104/pp.113.229591] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/13/2013] [Indexed: 05/18/2023]
Abstract
Starch is a biologically and commercially important polymer of glucose and is synthesized to form starch grains (SGs) inside amyloplasts. Cereal endosperm accumulates starch to levels that are more than 90% of the total weight, and most of the intracellular space is occupied by SGs. The size of SGs differs depending on the plant species and is one of the most important factors for industrial applications of starch. However, the molecular machinery that regulates the size of SGs is unknown. In this study, we report a novel rice (Oryza sativa) mutant called substandard starch grain4 (ssg4) that develops enlarged SGs in the endosperm. Enlargement of SGs in ssg4 was also observed in other starch-accumulating tissues such as pollen grains, root caps, and young pericarps. The SSG4 gene was identified by map-based cloning. SSG4 encodes a protein that contains 2,135 amino acid residues and an amino-terminal amyloplast-targeted sequence. SSG4 contains a domain of unknown function490 that is conserved from bacteria to higher plants. Domain of unknown function490-containing proteins with lengths greater than 2,000 amino acid residues are predominant in photosynthetic organisms such as cyanobacteria and higher plants but are minor in proteobacteria. The results of this study suggest that SSG4 is a novel protein that influences the size of SGs. SSG4 will be a useful molecular tool for future starch breeding and biotechnology.
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153
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Biselli C, Cavalluzzo D, Perrini R, Gianinetti A, Bagnaresi P, Urso S, Orasen G, Desiderio F, Lupotto E, Cattivelli L, Valè G. Improvement of marker-based predictability of Apparent Amylose Content in japonica rice through GBSSI allele mining. RICE (NEW YORK, N.Y.) 2014; 7:1. [PMID: 26055995 PMCID: PMC3904453 DOI: 10.1186/1939-8433-7-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/26/2013] [Indexed: 05/05/2023]
Abstract
BACKGROUND Apparent Amylose Content (AAC), regulated by the Waxy gene, represents the key determinant of rice cooking properties. In occidental countries high AAC rice represents the most requested market class but the availability of molecular markers allowing specific selection of high AAC varieties is limited. RESULTS In this study, the effectiveness of available molecular markers in predicting AAC was evaluated in a collection of 127 rice accessions (125 japonica ssp. and 2 indica ssp.) characterized by AAC values from glutinous to 26%. The analyses highlighted the presence of several different allelic patterns identifiable by a few molecular markers, and two of them, i.e., the SNPs at intron1 and exon 6, were able to explain a maximum of 79.5% of AAC variation. However, the available molecular markers haplotypes did not provide tools for predicting accessions with AAC higher than 24.5%. To identify additional polymorphisms, the re-sequencing of the Waxy gene and 1kbp of the putative upstream regulatory region was performed in 21 genotypes representing all the AAC classes identified. Several previously un-characterized SNPs were identified and four of them were used to develop dCAPS markers. CONCLUSIONS The addition of the SNPs newly identified slightly increased the AAC explained variation and allowed the identification of a haplotype almost unequivocally associated to AAC higher than 24.5%. Haplotypes at the waxy locus were also associated to grain length and length/width (L/W) ratio. In particular, the SNP at the first intron, which identifies the Wxa and Wxb alleles, was associated with differences in the width of the grain, the L/W ratio and the length of the kernel, most likely as a result of human selection.
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Affiliation(s)
- Chiara Biselli
- Rice Research Unit, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, S.S. 11 to Torino, Km 2,5, 13100 Vercelli, Italy
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
| | - Daniela Cavalluzzo
- Rice Research Unit, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, S.S. 11 to Torino, Km 2,5, 13100 Vercelli, Italy
| | - Rosaria Perrini
- Rice Research Unit, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, S.S. 11 to Torino, Km 2,5, 13100 Vercelli, Italy
| | - Alberto Gianinetti
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
| | - Paolo Bagnaresi
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
| | - Simona Urso
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
| | - Gabriele Orasen
- Rice Research Unit, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, S.S. 11 to Torino, Km 2,5, 13100 Vercelli, Italy
| | - Francesca Desiderio
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
| | - Elisabetta Lupotto
- Department of Plant Biology and Crop Production, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Roma, Italy
| | - Luigi Cattivelli
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
| | - Giampiero Valè
- Rice Research Unit, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, S.S. 11 to Torino, Km 2,5, 13100 Vercelli, Italy
- Genomics Research Centre, CRA-Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Via S. Protaso 302, 29017 Fiorenzuola d’Arda, Piacenza, Italy
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154
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Busi MV, Gomez-Casati DF, Martín M, Barchiesi J, Grisolía MJ, Hedín N, Carrillo JB. Starch Metabolism in Green Plants. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_78-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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155
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Ma J, Jiang QT, Zhang XW, Lan XJ, Pu ZE, Wei YM, Liu C, Lu ZX, Zheng YL. Structure and expression of barley starch phosphorylase genes. PLANTA 2013; 238:1081-93. [PMID: 24002549 DOI: 10.1007/s00425-013-1953-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 08/22/2013] [Indexed: 05/26/2023]
Abstract
The function of starch phosphorylase has long been debated on the regulation of starch metabolism during the growth and development of plants. In this study, we isolated starch phosphorylase genes (Pho1 and Pho2) from barley, characterized their gene and protein structures, predicated their promoter's cis-elements and analyzed expression patterns. Multiple alignments of these genes showed that (1) both Pho1 and Pho2 genes possess 15 exons and 14 introns in all but three of the species analyzed, Aegilops tauschii (for Pho1 which contains 16 exons and 15 introns), potato (for Pho1b which contains 14 exons and 13 introns), and Triticum uraru (for Pho2 which contains 15 exons and 14 introns); (2) the exon-intron junctions of Pho1 and Pho2 flanking the ligand-binding sites are more conservative than the other regions. Analysis of protein sequences revealed that Pho1 and Pho2 were highly homologous except for two regions, the N terminal domain and the L78 insertion region. The results of real-time quantitative PCR (RT-qPCR) indicated that Pho2 is mainly expressed in germinating seeds, and the expression of Pho1 is similar to that of starch synthesis genes during seed development in barley. Microarray-based analysis indicated that the accumulation of Pho1 or Pho2 transcripts exhibited uniform pattern both in various tissues and various stages of seed development among species of barley, rice, and Arabidopsis. Pho1 of barley was significantly down-regulated under cold and drought treatments, and up-regulated under stem rust infection. Pho2 exhibited similar expression to Pho1 in barley. However, significant difference in expression was not detected for either Pho1 or Pho2 under any of the investigated abiotic stresses. In Arabidopsis, significant down-regulation was detected for Pho1 (PHS1) under abscisic acid (ABA) and for Pho2 (PHS2) under cold, salt, and ABA. Our results provide valuable information to genetically manipulate phosphorylase genes and to further elucidate their regulatory mechanism in the starch biosynthetic pathway.
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Affiliation(s)
- Jian Ma
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
- CSIRO Plant Industry, 306 Carmody Road, St Lucia, QLD, 4067, Australia
| | - Qian-Tao Jiang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Xiao-Wei Zhang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Xiu-Jin Lan
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Zhi-En Pu
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Yu-Ming Wei
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Chunji Liu
- CSIRO Plant Industry, 306 Carmody Road, St Lucia, QLD, 4067, Australia.
| | - Zhen-Xiang Lu
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, T1J 4B1, Canada
| | - You-Liang Zheng
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
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156
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Purification and characterization of 1,3-β-D-glucan phosphorylase from Ochromonas danica. Biosci Biotechnol Biochem 2013; 77:1949-54. [PMID: 24018693 DOI: 10.1271/bbb.130411] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
1,3-β-D-glucan phosphorylase (BGP) is an enzyme that catalyzes the reversible phosphorolysis of 1,3-β-glucosidic linkages to form α-D-glucose 1-phosphate (G1P). Here we report on the purification and characterization of BGP from Ochromonas danica (OdBGP). The purified enzyme preparation showed three bands (113, 118, and 124 kDa) on SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature were 5.5 and 25 °C-30 °C. OdBGP phosphorolysed laminaritriose, larger laminarioligosaccharides, and laminarin, but not laminaribiose. In the synthesis reaction, laminarin and laminarioligosaccharides served as good acceptors, but OdBGP did not act on glucose. Kinetic analysis indicated that the phosphorolysis reaction of OdBGP follows a sequential Bi Bi mechanism. The equilibrium of the enzymatic reaction indicated that OdBGP favors the reaction in the synthetic direction. Overnight incubation of OdBGP with laminaribiose and G1P resulted in the formation of precipitates, which were probably 1,3-β-glucans.
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157
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Liu DR, Huang WX, Cai XL. Oligomerization of rice granule-bound starch synthase 1 modulates its activity regulation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 210:141-50. [PMID: 23849121 DOI: 10.1016/j.plantsci.2013.05.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 05/16/2013] [Accepted: 05/17/2013] [Indexed: 05/23/2023]
Abstract
Granule-bound starch synthase 1 (GBSS1) is responsible for amylose synthesis in cereals, and this enzyme is regulated at the transcriptional and post-transcriptional levels. In this study, we show that GBSS1 from Oryza sativa L. (OsGBSS1) can form oligomers in rice endosperm, and oligomerized OsGBSS1 exhibits much higher specific enzymatic activity than the monomer. A monomer-oligomer transition equilibrium for OsGBSS1 occurs in the endosperm during development. Redox potential is a key factor affecting the oligomer percentage as well as the enzymatic activity of OsGBSS1. Adenosine diphosphate glucose, the direct donor of glucose, also impacts OsGBSS1 oligomerization in a concentration-dependent manner. OsGBSS1 oligomerization is influenced by phosphorylation status, which was strongly enhanced by Mitogen-activated protein kinase (MAPK) and ATP treatment and was sharply weakened by protein phosphatase (PPase) treatment. The activity of OsGBSS1 affects the ratio of amylose to amylopectin and therefore the eating quality of rice. Understanding the regulation of OsGBSS1 activity may lead to the improvement of rice eating quality.
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Affiliation(s)
- De-Rui Liu
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
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158
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Wang JC, Xu H, Zhu Y, Liu QQ, Cai XL. OsbZIP58, a basic leucine zipper transcription factor, regulates starch biosynthesis in rice endosperm. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:3453-66. [PMID: 23846875 PMCID: PMC3733163 DOI: 10.1093/jxb/ert187] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Starch composition and the amount in endosperm, both of which contribute dramatically to seed yield, cooking quality, and taste in cereals, are determined by a series of complex biochemical reactions. However, the mechanism regulating starch biosynthesis in cereal seeds is not well understood. This study showed that OsbZIP58, a bZIP transcription factor, is a key transcriptional regulator controlling starch synthesis in rice endosperm. OsbZIP58 was expressed mainly in endosperm during active starch synthesis. osbzip58 null mutants displayed abnormal seed morphology with altered starch accumulation in the white belly region and decreased amounts of total starch and amylose. Moreover, osbzip58 had a higher proportion of short chains and a lower proportion of intermediate chains of amylopectin. Furthermore, OsbZIP58 was shown to bind directly to the promoters of six starch-synthesizing genes, OsAGPL3, Wx, OsSSIIa, SBE1, OsBEIIb, and ISA2, and to regulate their expression. These findings indicate that OsbZIP58 functions as a key regulator of starch synthesis in rice seeds and provide new insights into seed quality control.
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Affiliation(s)
- Jie-Chen Wang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, PR China
| | - Heng Xu
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Zhejiang 310021, PR China
| | - Ying Zhu
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Zhejiang 310021, PR China
| | - Qiao-Quan Liu
- Key Laboratories of Crop Genetics and Physiology of the Jiangsu Province and Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, PR China
| | - Xiu-Ling Cai
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, PR China
- * To whom correspondence should be addressed.
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159
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Higgins JE, Kosar-Hashemi B, Li Z, Howitt CA, Larroque O, Flanagan B, Morell MK, Rahman S. Characterization of starch phosphorylases in barley grains. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2013; 93:2137-2145. [PMID: 23288583 DOI: 10.1002/jsfa.6019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 11/13/2012] [Accepted: 11/28/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Starch is synthesized in both leaves and storage tissues of plants. The role of starch syntheses and branching enzymes is well understood; however, the role of starch phosphorylase is not clear. RESULTS A gene encoding Pho1 from barley was characterized and starch phosphorylases from both developing and germinating grain were characterized and purified. Two activities were detected: one with a molecular mass of 110 kDa and the other of 95 kDa. It was demonstrated through the use of antisera that the 110 kDa activity was located in the amyloplast and could correspond to the polypeptide encoded by the Pho1 gene cloned. The 95 kDa activity was localized to the cytoplasm, most strongly expressed in germinating grain, and was classified as a Pho2-type sequence. Using RNAi technology to reduce the content of Pho1 in the grain to less than 30% of wild type did not lead to any visible phenotype, and no dramatic alterations in the structure of the starch were observed. CONCLUSION Two starch phosphorylase activities were identified and characterized in barley grains, and shown to be present during starch synthesis. However, their role in starch synthesis still remains to be elucidated.
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160
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Matsushima R, Yamashita J, Kariyama S, Enomoto T, Sakamoto W. A Phylogenetic Re-evaluation of Morphological Variations of Starch Grains among Poaceae Species. J Appl Glycosci (1999) 2013. [DOI: 10.5458/jag.jag.jag-2012_006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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161
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162
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Brust H, Orzechowski S, Fettke J, Steup M. Starch Synthesizing Reactions and Paths: in vitro and in vivo Studies. J Appl Glycosci (1999) 2013. [DOI: 10.5458/jag.jag.jag-2012_018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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163
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Chen Y, Wang M, Ouwerkerk PBF. Molecular and environmental factors determining grain quality in rice. Food Energy Secur 2012. [DOI: 10.1002/fes3.11] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Yi Chen
- Sylvius Laboratory Department of Molecular and Developmental Genetics Institute of Biology Leiden University Sylviusweg 72 PO Box 9505 2300 RA Leiden The Netherlands
| | - Mei Wang
- Sylvius Laboratory Department of Molecular and Developmental Genetics Institute of Biology Leiden University Sylviusweg 72 PO Box 9505 2300 RA Leiden The Netherlands
- SU BioMedicine‐TNO Utrechtseweg 48 3704 HE Zeist PO Box 360 3700 AJ Zeist The Netherlands
| | - Pieter B. F. Ouwerkerk
- Sylvius Laboratory Department of Molecular and Developmental Genetics Institute of Biology Leiden University Sylviusweg 72 PO Box 9505 2300 RA Leiden The Netherlands
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164
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Chen J, Zhang J, Liu H, Hu Y, Huang Y. RETRACTED: Molecular strategies in manipulation of the starch synthesis pathway for improving storage starch content in plants (review and prospect for increasing storage starch synthesis). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 61:1-8. [PMID: 23023581 DOI: 10.1016/j.plaphy.2012.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 08/27/2012] [Indexed: 06/01/2023]
Abstract
Starch is the most widespread and abundant storage carbohydrate in plants. We depend upon starch for our nutrition, exploit its unique properties in industry, and use it as a feedstock for bioethanol production. In recent decades, enormous progress has been made in understanding the genetic and biochemical mechanisms of starch synthesis in plants. Yet, despite this remarkable progress and its obvious economic importance, very little has been achieved in terms of adding value to starch or increasing starch content, particularly in cereal crops. In this paper, we first review recent advances in understanding the biochemistry of starch synthesis, particularly in identifying key enzymes involved in starch assembly. We then assess the progress in molecular strategies for improving storage starch content in plants. Finally, we discuss the problems faced in our profession and present ideas to effectively increase storage starch content in the future.
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Affiliation(s)
- Jiang Chen
- Maize Research Institute, Sichuan Agricultural University, 211 Huiming Road, Chengdu 611130, China
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165
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Abstract
Starch is the major non-structural carbohydrate in plants. It serves as an important store of carbon that fuels plant metabolism and growth when they are unable to photosynthesise. This storage can be in leaves and other green tissues, where it is degraded during the night, or in heterotrophic tissues such as roots, seeds and tubers, where it is stored over longer time periods. Arabidopsis accumulates starch in many of its tissues, but mostly in its leaves during the day. It has proven to be a powerful genetic system for discovering how starch is synthesised and degraded, and new proteins and processes have been discovered. Such work has major significance for our starch crops, whose yield and quality could be improved by the application of this knowledge. Research into Arabidopsis starch metabolism has begun to reveal how its daily turnover is integrated into the rest of metabolism and adapted to the environmental conditions. Furthermore, Arabidopsis mutant lines deficient in starch metabolism have been employed as tools to study other biological processes ranging from sugar sensing to gravitropism and flowering time control. This review gives a detailed account of the use of Arabidopsis to study starch metabolism. It describes the major discoveries made and presents an overview of our understanding today, together with some as-yet unresolved questions.
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Affiliation(s)
- Sebastian Streb
- Institute of Agricultural Sciences, Department of Biology, ETH
Zurich, Universitätstrasse 2, Zurich, Switzerland
| | - Samuel C. Zeeman
- Institute of Agricultural Sciences, Department of Biology, ETH
Zurich, Universitätstrasse 2, Zurich, Switzerland
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166
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Streb S, Zeeman SC. Starch metabolism in Arabidopsis. THE ARABIDOPSIS BOOK 2012; 10:e0160. [PMID: 23393426 DOI: 10.199/tab.e0160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Starch is the major non-structural carbohydrate in plants. It serves as an important store of carbon that fuels plant metabolism and growth when they are unable to photosynthesise. This storage can be in leaves and other green tissues, where it is degraded during the night, or in heterotrophic tissues such as roots, seeds and tubers, where it is stored over longer time periods. Arabidopsis accumulates starch in many of its tissues, but mostly in its leaves during the day. It has proven to be a powerful genetic system for discovering how starch is synthesised and degraded, and new proteins and processes have been discovered. Such work has major significance for our starch crops, whose yield and quality could be improved by the application of this knowledge. Research into Arabidopsis starch metabolism has begun to reveal how its daily turnover is integrated into the rest of metabolism and adapted to the environmental conditions. Furthermore, Arabidopsis mutant lines deficient in starch metabolism have been employed as tools to study other biological processes ranging from sugar sensing to gravitropism and flowering time control. This review gives a detailed account of the use of Arabidopsis to study starch metabolism. It describes the major discoveries made and presents an overview of our understanding today, together with some as-yet unresolved questions.
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Affiliation(s)
- Sebastian Streb
- Institute of Agricultural Sciences, Department of Biology, ETH Zurich, Universitätstrasse 2, Zurich, Switzerland
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167
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Fettke J, Leifels L, Brust H, Herbst K, Steup M. Two carbon fluxes to reserve starch in potato (Solanum tuberosum L.) tuber cells are closely interconnected but differently modulated by temperature. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3011-29. [PMID: 22378944 PMCID: PMC3350916 DOI: 10.1093/jxb/ers014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Parenchyma cells from tubers of Solanum tuberosum L. convert several externally supplied sugars to starch but the rates vary largely. Conversion of glucose 1-phosphate to starch is exceptionally efficient. In this communication, tuber slices were incubated with either of four solutions containing equimolar [U-¹⁴C]glucose 1-phosphate, [U-¹⁴C]sucrose, [U-¹⁴C]glucose 1-phosphate plus unlabelled equimolar sucrose or [U-¹⁴C]sucrose plus unlabelled equimolar glucose 1-phosphate. C¹⁴-incorporation into starch was monitored. In slices from freshly harvested tubers each unlabelled compound strongly enhanced ¹⁴C incorporation into starch indicating closely interacting paths of starch biosynthesis. However, enhancement disappeared when the tubers were stored. The two paths (and, consequently, the mutual enhancement effect) differ in temperature dependence. At lower temperatures, the glucose 1-phosphate-dependent path is functional, reaching maximal activity at approximately 20 °C but the flux of the sucrose-dependent route strongly increases above 20 °C. Results are confirmed by in vitro experiments using [U-¹⁴C]glucose 1-phosphate or adenosine-[U-¹⁴C]glucose and by quantitative zymograms of starch synthase or phosphorylase activity. In mutants almost completely lacking the plastidial phosphorylase isozyme(s), the glucose 1-phosphate-dependent path is largely impeded. Irrespective of the size of the granules, glucose 1-phosphate-dependent incorporation per granule surface area is essentially equal. Furthermore, within the granules no preference of distinct glucosyl acceptor sites was detectable. Thus, the path is integrated into the entire granule biosynthesis. In vitro C¹⁴C-incorporation into starch granules mediated by the recombinant plastidial phosphorylase isozyme clearly differed from the in situ results. Taken together, the data clearly demonstrate that two closely but flexibly interacting general paths of starch biosynthesis are functional in potato tuber cells.
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Affiliation(s)
- Joerg Fettke
- Mass Spectrometry of Biopolymers, University of Potsdam, D-14476 Potsdam-Golm, Germany.
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168
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Nakamura Y, Ono M, Utsumi C, Steup M. Functional interaction between plastidial starch phosphorylase and starch branching enzymes from rice during the synthesis of branched maltodextrins. PLANT & CELL PHYSIOLOGY 2012; 53:869-78. [PMID: 22414443 DOI: 10.1093/pcp/pcs030] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The present study established the way in which plastidial α-glucan phosphorylase (Pho1) synthesizes maltodextrin (MD) which can be the primer for starch biosynthesis in rice endosperm. The synthesis of MD by Pho1 was markedly accelerated by branching enzyme (BE) isozymes, although the greatest effect was exhibited by the presence of branching isozyme I (BEI) rather than by isozyme IIa (BEIIa) or isozyme IIb (BEIIb). The enhancement of the activity of Pho1 by BE was not merely due to the supply of a non-reducing ends. At the same time, Pho1 greatly enhanced the BE activity, possibly by generating a branched carbohydrate substrate which is used by BE with a higher affinity. The addition of isoamylase to the reaction mixture did not prevent the concerted action of Pho1 and BEI. Furthermore, in the product, the branched structure was, at least to some extent, maintained. Based on these results we propose that the interaction between Pho1 and BE is not merely due to chain-elongating and chain-branching reactions, but occurs in a physically and catalytically synergistic manner by each activating the mutual capacity of the other, presumably forming a physical association of Pho1, BEI and branched MDs. This close interaction might play a crucial role in the synthesis of branched MDs and the branched MDs can act as a primer for the biosynthesis of amylopectin molecules.
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169
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Lin YC, Chen HM, Chou IM, Chen AN, Chen CP, Young GH, Lin CT, Cheng CH, Chang SC, Juang RH. Plastidial starch phosphorylase in sweet potato roots is proteolytically modified by protein-protein interaction with the 20S proteasome. PLoS One 2012; 7:e35336. [PMID: 22506077 PMCID: PMC3323651 DOI: 10.1371/journal.pone.0035336] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 03/15/2012] [Indexed: 01/27/2023] Open
Abstract
Post-translational regulation plays an important role in cellular metabolism. Earlier studies showed that the activity of plastidial starch phosphorylase (Pho1) may be regulated by proteolytic modification. During the purification of Pho1 from sweet potato roots, we observed an unknown high molecular weight complex (HX) showing Pho1 activity. The two-dimensional gel electrophoresis, mass spectrometry, and reverse immunoprecipitation analyses showed that HX is composed of Pho1 and the 20S proteasome. Incubating sweet potato roots at 45°C triggers a stepwise degradation of Pho1; however, the degradation process can be partially inhibited by specific proteasome inhibitor MG132. The proteolytically modified Pho1 displays a lower binding affinity toward glucose 1-phosphate and a reduced starch-synthesizing activity. This study suggests that the 20S proteasome interacts with Pho1 and is involved in the regulation of the catalytic activity of Pho1 in sweet potato roots under heat stress conditions.
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Affiliation(s)
- Yi-Chen Lin
- Department of Biochemical Science and Technology, and Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
| | - Han-Min Chen
- Department of Life Science, and Institute of Applied Science and Engineering, Catholic Fu-Jen University, Taipei, Taiwan
| | - I-Min Chou
- Department of Biochemical Science and Technology, and Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
| | - An-Na Chen
- Department of Biochemical Science and Technology, and Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
| | - Chia-Pei Chen
- Department of Biochemical Science and Technology, and Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
| | - Guang-Huar Young
- Division of Nephrology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Tsai Lin
- Institute of Bioscience and Biotechnology, and Marine Center for Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
| | - Chiung-Hsiang Cheng
- Animal Cancer Research Center, Department of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
| | - Shih-Chung Chang
- Department of Biochemical Science and Technology, and Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
- * E-mail: (SCC); (RHJ)
| | - Rong-Huay Juang
- Department of Biochemical Science and Technology, and Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
- * E-mail: (SCC); (RHJ)
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170
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Fujita N. Analyses of Function of Starch Biosynthesis-related Isozymes in Rice and Production of Novel Starches. J Appl Glycosci (1999) 2012. [DOI: 10.5458/jag.jag.jag-2011_026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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171
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Han X, Wang Y, Liu X, Jiang L, Ren Y, Liu F, Peng C, Li J, Jin X, Wu F, Wang J, Guo X, Zhang X, Cheng Z, Wan J. The failure to express a protein disulphide isomerase-like protein results in a floury endosperm and an endoplasmic reticulum stress response in rice. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:121-30. [PMID: 21984651 PMCID: PMC3245461 DOI: 10.1093/jxb/err262] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The rice somaclonal mutant T3612 produces small grains with a floury endosperm, caused by the loose packing of starch granules. The positional cloning of the mutation revealed a deletion in a gene encoding a protein disulphide isomerase-like enzyme (PDIL1-1). In the wild type, PDIL1-1 was expressed throughout the plant, but most intensely in the developing grain. In T3612, its expression was abolished, resulting in a decrease in the activity of plastidial phosphorylase and pullulanase, and an increase in that of soluble starch synthase I and ADP-glucose pyrophosphorylase. The amylopectin in the T3612 endosperm showed an increase in chains with a degree of polymerization 8-13 compared with the wild type. The expression in the mutant's endosperm of certain endoplasmic reticulum stress-responsive genes was noticeably elevated. PDIL1-1 appears to play an important role in starch synthesis. Its absence is associated with endoplasmic reticulum stress in the endosperm, which is likely to underlie the formation of the floury endosperm in the T3612 mutant.
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Affiliation(s)
- Xiaohua Han
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Yihua Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Xi Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Ling Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Yulong Ren
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Feng Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Cheng Peng
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Jingjing Li
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Ximing Jin
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Fuqing Wu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiulin Wang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiuping Guo
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xin Zhang
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhijun Cheng
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- To whom correspondence should be addressed. E-mail:
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172
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Chen J, Huang B, Li Y, Du H, Gu Y, Liu H, Zhang J, Huang Y. Synergistic influence of sucrose and abscisic acid on the genes involved in starch synthesis in maize endosperm. Carbohydr Res 2011; 346:1684-91. [PMID: 21640984 DOI: 10.1016/j.carres.2011.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 04/20/2011] [Accepted: 05/03/2011] [Indexed: 11/27/2022]
Abstract
Starch is the major carbon reserve in plant storage organs, the synthesis of which is orchestrated by four major enzymes, ADP-glucose pyrophosphorylase, starch synthase, starch-branching enzyme and starch-debranching enzyme. There is much information available on the function of these key enzymes; however, little is known about their transcriptional regulation. In order to understand the transcriptional regulation of starch biosynthesis, the expression profiles of 24 starch genes were investigated in this work. The results showed major transcriptional changes for 15 of the 24 starch genes observed in maize endosperm, most of which are elevated at the early and middle stages of the developing endosperm. Sucrose, abscisic acid (ABA) and indole-3-acetic acid (IAA) had a significant correlation with the expression of 15 genes, indicating that sugars and phytohormones might take part in the regulation of starch synthesis. Also, we found that there is interaction of abscisic acid and sucrose on the regulation of the expression of these genes.
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Affiliation(s)
- Jiang Chen
- Maize Research Institute, Sichuan Agricultural University, Chengdu, China
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173
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Fettke J, Malinova I, Albrecht T, Hejazi M, Steup M. Glucose-1-phosphate transport into protoplasts and chloroplasts from leaves of Arabidopsis. PLANT PHYSIOLOGY 2011; 155:1723-34. [PMID: 21115809 PMCID: PMC3091119 DOI: 10.1104/pp.110.168716] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 11/25/2010] [Indexed: 05/18/2023]
Abstract
Almost all glucosyl transfer reactions rely on glucose-1-phosphate (Glc-1-P) that either immediately acts as glucosyl donor or as substrate for the synthesis of the more widely used Glc dinucleotides, ADPglucose or UDPglucose. In this communication, we have analyzed two Glc-1-P-related processes: the carbon flux from externally supplied Glc-1-P to starch by either mesophyll protoplasts or intact chloroplasts from Arabidopsis (Arabidopsis thaliana). When intact protoplasts or chloroplasts are incubated with [U-(14)C]Glc-1-P, starch is rapidly labeled. Incorporation into starch is unaffected by the addition of unlabeled Glc-6-P or Glc, indicating a selective flux from Glc-1-P to starch. However, illuminated protoplasts incorporate less (14)C into starch when unlabeled bicarbonate is supplied in addition to the (14)C-labeled Glc-1-P. Mesophyll protoplasts incubated with [U-(14)C]Glc-1-P incorporate (14)C into the plastidial pool of adenosine diphosphoglucose. Protoplasts prepared from leaves of mutants of Arabidopsis that lack either the plastidial phosphorylase or the phosphoglucomutase isozyme incorporate (14)C derived from external Glc-1-P into starch, but incorporation into starch is insignificant when protoplasts from a mutant possessing a highly reduced ADPglucose pyrophosphorylase activity are studied. Thus, the path of assimilatory starch biosynthesis initiated by extraplastidial Glc-1-P leads to the plastidial pool of adenosine diphosphoglucose, and at this intermediate it is fused with the Calvin cycle-driven route. Mutants lacking the plastidial phosphoglucomutase contain a small yet significant amount of transitory starch.
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Affiliation(s)
- Joerg Fettke
- Mass Spectrometry of Biopolymers, University of Potsdam, 14476 Potsdam-Golm, Germany.
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174
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Howard T, Rejab NA, Griffiths S, Leigh F, Leverington-Waite M, Simmonds J, Uauy C, Trafford K. Identification of a major QTL controlling the content of B-type starch granules in Aegilops. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2217-28. [PMID: 21227932 PMCID: PMC3060699 DOI: 10.1093/jxb/erq423] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 11/25/2010] [Accepted: 11/26/2010] [Indexed: 05/19/2023]
Abstract
Starch within the endosperm of most species of the Triticeae has a unique bimodal granule morphology comprising large lenticular A-type granules and smaller near-spherical B-type granules. However, a few wild wheat species (Aegilops) are known to lack B-granules. Ae. peregrina and a synthetic tetraploid Aegilops with the same genome composition (SU) were found to differ in B-granule number. The synthetic tetraploid had normal A- and B-type starch granules whilst Ae. peregrina had only A-granules because the B-granules failed to initiate. A population segregating for B-granule number was generated by crossing these two accessions and was used to study the genetic basis of B-granule initiation. A combination of Bulked Segregant Analysis and QTL mapping identified a major QTL located on the short arm of chromosome 4S that accounted for 44.4% of the phenotypic variation. The lack of B-granules in polyploid Aegilops with diverse genomes suggests that the B-granule locus has been lost several times independently during the evolution of the Triticeae. It is proposed that the B-granule locus is susceptible to silencing during polyploidization and a model is presented to explain the observed data based on the assumption that the initiation of B-granules is controlled by a single major locus per haploid genome.
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Affiliation(s)
- Thomas Howard
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | | | - Simon Griffiths
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Fiona Leigh
- National Institute of Agricultural Botany, Huntingdon Road, Cambridge CB3 0LE, UK
| | | | - James Simmonds
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Cristobal Uauy
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- National Institute of Agricultural Botany, Huntingdon Road, Cambridge CB3 0LE, UK
| | - Kay Trafford
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- To whom correspondence should be addressed: E-mail:
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175
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She KC, Kusano H, Koizumi K, Yamakawa H, Hakata M, Imamura T, Fukuda M, Naito N, Tsurumaki Y, Yaeshima M, Tsuge T, Matsumoto K, Kudoh M, Itoh E, Kikuchi S, Kishimoto N, Yazaki J, Ando T, Yano M, Aoyama T, Sasaki T, Satoh H, Shimada H. A novel factor FLOURY ENDOSPERM2 is involved in regulation of rice grain size and starch quality. THE PLANT CELL 2010; 22:3280-94. [PMID: 20889913 PMCID: PMC2990130 DOI: 10.1105/tpc.109.070821] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 09/02/2010] [Accepted: 09/15/2010] [Indexed: 05/18/2023]
Abstract
Rice (Oryza sativa) endosperm accumulates a massive amount of storage starch and storage proteins during seed development. However, little is known about the regulatory system involved in the production of storage substances. The rice flo2 mutation resulted in reduced grain size and starch quality. Map-based cloning identified FLOURY ENDOSPERM2 (FLO2), a member of a novel gene family conserved in plants, as the gene responsible for the rice flo2 mutation. FLO2 harbors a tetratricopeptide repeat motif, considered to mediate a protein-protein interactions. FLO2 was abundantly expressed in developing seeds coincident with production of storage starch and protein, as well as in leaves, while abundant expression of its homologs was observed only in leaves. The flo2 mutation decreased expression of genes involved in production of storage starch and storage proteins in the endosperm. Differences between cultivars in their responsiveness of FLO2 expression during high-temperature stress indicated that FLO2 may be involved in heat tolerance during seed development. Overexpression of FLO2 enlarged the size of grains significantly. These results suggest that FLO2 plays a pivotal regulatory role in rice grain size and starch quality by affecting storage substance accumulation in the endosperm.
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Affiliation(s)
- Kao-Chih She
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
- Research Center for RNA Science, Research Institute for Science and Technology, Tokyo University of Science, Noda 278-8510 Japan
| | - Hiroaki Kusano
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Kazuyoshi Koizumi
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | | | - Makoto Hakata
- National Agricultural Research Center, Joetsu 943-0193, Japan
| | - Tomohiro Imamura
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
- Research Center for RNA Science, Research Institute for Science and Technology, Tokyo University of Science, Noda 278-8510 Japan
| | - Masato Fukuda
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Natsuka Naito
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Yumi Tsurumaki
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Mitsuhiro Yaeshima
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Tomohiko Tsuge
- Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
| | - Ken'ichiro Matsumoto
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Mari Kudoh
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Eiko Itoh
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Shoshi Kikuchi
- National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan
| | - Naoki Kishimoto
- National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan
| | - Junshi Yazaki
- National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan
| | - Tsuyu Ando
- STAFF Institute, Tsukuba 305-0854, Japan
| | - Masahiro Yano
- National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan
| | - Takashi Aoyama
- Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan
| | - Tadamasa Sasaki
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
- Research Center for RNA Science, Research Institute for Science and Technology, Tokyo University of Science, Noda 278-8510 Japan
| | - Hikaru Satoh
- Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
| | - Hiroaki Shimada
- Department of Biological Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
- Research Center for RNA Science, Research Institute for Science and Technology, Tokyo University of Science, Noda 278-8510 Japan
- Address correspondence to
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176
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D'Hulst C, Mérida A. The priming of storage glucan synthesis from bacteria to plants: current knowledge and new developments. THE NEW PHYTOLOGIST 2010; 188:13-21. [PMID: 20618917 DOI: 10.1111/j.1469-8137.2010.03361.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Starch is the main polymer in which carbon and energy are stored in land plants, algae and some cyanobacteria. It plays a crucial role in the physiology of these organisms and also represents an important polymer for humans, in terms of both diet and nonfood industry uses. Recent efforts have elucidated most of the steps involved in the synthesis of starch. However, the process that initiates the synthesis of the starch granule remains unclear. Here, we outline the similarities between the synthesis of starch and the synthesis of glycogen, the other widespread and abundant glucose-based polymer in living cells. We place special emphasis on the mechanisms of initiation of the glycogen granule and current knowledge concerning the initiation of the starch granule. We also discuss recent discoveries regarding the function of starch synthases in the priming of the starch granule and possible interactions with other elements of the starch synthesis machinery.
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Affiliation(s)
- Christophe D'Hulst
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR8576 CNRS/USTL, IFR 147, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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177
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Hirabaru C, Izumo A, Fujiwara S, Tadokoro Y, Shimonaga T, Konishi M, Yoshida M, Fujita N, Nakamura Y, Yoshida M, Kuroiwa T, Tsuzuki M. The primitive rhodophyte Cyanidioschyzon merolae contains a semiamylopectin-type, but not an amylose-type, alpha-glucan. PLANT & CELL PHYSIOLOGY 2010; 51:682-693. [PMID: 20385610 DOI: 10.1093/pcp/pcq046] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The storage glucans of Cyanidioschyzon merolae [clade L-1 (cyanidian algae), order Porphyridiales, subclass Bangiophycidae], which is considered to be one of the most primitive rhodophytes, were analyzed to understand the early evolution of the glucan structure in the Rhodophyta. Chain-length distribution analysis of the glucans of cyanidian algae demonstrated that while the glucans of Cyanidium caldarium and Galdieria sulphuraria are of the glycogen type, those of C. merolae are of the semiamylopectin type, as in other lineages of the Rhodophyta. Gel permeation chromatography, however, showed that the glucans of C. merolae do not include amylose, being different from those of other Bangiophycidae species. Identification by MALDI-TOF-MS and enzyme assaying of glucan granule-bound proteins indicated that phosphorylase, but not starch synthase, is included. Thus, C. merolae has an unusual glucan and bound-protein composition for the Bangiophycidae, appearing to be a member of the Florideophycidae. The finding that the alga does not contain amylose or the related enzyme, granule-bound starch synthase, is, however, consistent with previously reported results of molecular phylogenetic analysis of starch synthases. Our results support an evolutionary scenario defined by the loss of starch and reversion to glycogen synthesis during the evolution of cyanidian algae, and suggest the possibility that a C. merolae-like primitive rhodophyte might have evolved into the Florideophycidae.
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Affiliation(s)
- Chika Hirabaru
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392 Japan
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178
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Matsushima R, Maekawa M, Fujita N, Sakamoto W. A rapid, direct observation method to isolate mutants with defects in starch grain morphology in rice. PLANT & CELL PHYSIOLOGY 2010; 51:728-41. [PMID: 20360021 DOI: 10.1093/pcp/pcq040] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Starch forms transparent grains, referred to as starch grains (SGs), in amyloplasts. Despite the simple glucose polymer composition of starch, SGs exhibit different morphologies depending on plant species, especially in the endosperm of the Poaceae family. This study reports a novel method for preparing thin sections of endosperm without chemical fixation or resin embedding that allowed us to visualize subcellular SGs clearly. Using this method, we observed the SG morphologies of >5,000 mutagenized rice seeds and were able to isolate mutants in which SGs were morphologically altered. In five mutants, named ssg (substandard starch grain), increased numbers of small SGs (ssg1-ssg3), enlarged SGs (ssg4) and abnormal interior structures of SGs (ssg5) were observed. Amylopectin chain length distribution analysis and identification of the mutated gene suggested a possible allelic relationship between ssg1, ssg2, ssg3 and the previously isolated amylose-extender (ae) mutants, while ssg4 and ssg5 seemed to be novel mutants. Compared with conventional observation methods, the methods developed here are more effective for obtaining fine images of subcellular SGs and are suitable for the observation of a large number of samples.
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Affiliation(s)
- Ryo Matsushima
- Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046 Japan.
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179
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Yamakawa H, Hakata M. Atlas of rice grain filling-related metabolism under high temperature: joint analysis of metabolome and transcriptome demonstrated inhibition of starch accumulation and induction of amino acid accumulation. PLANT & CELL PHYSIOLOGY 2010; 51:795-809. [PMID: 20304786 PMCID: PMC2871029 DOI: 10.1093/pcp/pcq034] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Accepted: 03/12/2010] [Indexed: 05/18/2023]
Abstract
High temperature impairs grain filling by inhibiting the deposition of storage materials such as starch and protein. To comprehend its impact on grain filling metabolism in rice (Oryza sativa), levels of metabolites and transcripts related to central pathways of metabolism were simultaneously determined in developing caryopses exposed to high temperature (33 degrees C/28 degrees C) and a control temperature (25 degrees C/20 degrees C) during the milky stage. A capillary electrophoresis-based metabolomic analysis revealed that high temperature increased the accumulation of sucrose and pyruvate/ oxaloacetate-derived amino acids and decreased levels of sugar phosphates and organic acids involved in glycolysis/gluconeogenesis and the tricarboxylic acid (TCA) cycle, respectively. A transcriptomic analysis using a whole genome-covering microarray unraveled the possible metabolic steps causing the shortage of storage materials under the elevated temperature. Starch deposition might be impaired by down-regulation of sucrose import/degradation and starch biosynthesis, and/or up-regulation of starch degradation as well as inefficient ATP production by an inhibited cytochrome respiration chain, as indicated by the response of gene expression to high temperature. Amino acid accumulation might be attributed to the heat-stable import of amino acids into the caryopsis and/or repression of protein synthesis especially the tRNA charging step under high temperature. An atlas showing the effect of high temperature on levels of metabolites and gene expression in the central metabolic pathways is presented.
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Affiliation(s)
- Hiromoto Yamakawa
- National Agricultural Research Center, Joetsu, Niigata, 943-0193 Japan.
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180
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Affiliation(s)
- Peter L. Keeling
- NSF Engineering Research Center for Biorenewable Chemicals and Iowa State University, Ames, Iowa 50011;
| | - Alan M. Myers
- NSF Engineering Research Center for Biorenewable Chemicals and Iowa State University, Ames, Iowa 50011;
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181
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Rice endosperm-specific plastidial α-glucan phosphorylase is important for synthesis of short-chain malto-oligosaccharides. Arch Biochem Biophys 2010; 495:82-92. [DOI: 10.1016/j.abb.2009.12.023] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 12/24/2009] [Accepted: 12/29/2009] [Indexed: 11/18/2022]
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182
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Qiao Y, Lee SI, Piao R, Jiang W, Ham TH, Chin JH, Piao Z, Han L, Kang SY, Koh HJ. Fine mapping and candidate gene analysis of the floury endosperm gene, FLO(a), in rice. Mol Cells 2010; 29:167-74. [PMID: 20016946 DOI: 10.1007/s10059-010-0010-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 10/19/2009] [Accepted: 10/28/2009] [Indexed: 10/20/2022] Open
Abstract
In addition to its role as an energy source for plants, animals and humans, starch is also an environmentally friendly alternative to fossil fuels. In rice, the eating and cooking quality of the grain is determined by its starch properties. The floury endosperm of rice has been explored as an agronomical trait in breeding and genetics studies. In the present study, we characterized a floury endosperm mutant, flo(a), derived from treatment of Oryza sativa ssp. japonica cultivar Hwacheong with MNU. The innermost endosperm of the flo(a) mutant exhibited floury characteristics while the outer layer of the endosperm appeared normal. Starch granules in the flo(a) mutant formed a loosely-packed crystalline structure and X-ray diffraction revealed that the overall crystallinity of the starch was decreased compared to wild-type. The FLO(a) gene was isolated via a map-based cloning approach and predicted to encode the tetratricopeptide repeat domain-containing protein, OsTPR. Three mutant alleles contain a nucleotide substitution that generated one stop codon or one splice site, respectively, which presumably disrupts the interaction of the functionally conserved TPR motifs. Taken together, our map-based cloning approach pinpointed an OsTPR as a strong candidate of FLO(a), and the proteins that contain TPR motifs might play a significant role in rice starch biosynthetic pathways.
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Affiliation(s)
- Yongli Qiao
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-921, Korea
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183
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Fettke J, Albrecht T, Hejazi M, Mahlow S, Nakamura Y, Steup M. Glucose 1-phosphate is efficiently taken up by potato (Solanum tuberosum) tuber parenchyma cells and converted to reserve starch granules. THE NEW PHYTOLOGIST 2010; 185:663-75. [PMID: 20028468 DOI: 10.1111/j.1469-8137.2009.03126.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Reserve starch is an important plant product but the actual biosynthetic process is not yet fully understood. Potato (Solanum tuberosum) tuber discs from various transgenic plants were used to analyse the conversion of external sugars or sugar derivatives to starch. By using in vitro assays, a direct glucosyl transfer from glucose 1-phosphate to native starch granules as mediated by recombinant plastidial phosphorylase was analysed. Compared with labelled glucose, glucose 6-phosphate or sucrose, tuber discs converted externally supplied [(14)C]glucose 1-phosphate into starch at a much higher rate. Likewise, tuber discs from transgenic lines with a strongly reduced expression of cytosolic phosphoglucomutase, phosphorylase or transglucosidase converted glucose 1-phosphate to starch with the same or even an increased rate compared with the wild-type. Similar results were obtained with transgenic potato lines possessing a strongly reduced activity of both the cytosolic and the plastidial phosphoglucomutase. Starch labelling was, however, significantly diminished in transgenic lines, with a reduced concentration of the plastidial phosphorylase isozymes. Two distinct paths of reserve starch biosynthesis are proposed that explain, at a biochemical level, the phenotype of several transgenic plant lines.
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Affiliation(s)
- Joerg Fettke
- Institute of Biochemistry and Biology, Mass Spectrometry of Biopolymers, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, D-14476 Potsdam-Golm, Germany.
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184
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Rathore RS, Garg N, Garg S, Kumar A. Starch phosphorylase: role in starch metabolism and biotechnological applications. Crit Rev Biotechnol 2010; 29:214-24. [PMID: 19708823 DOI: 10.1080/07388550902926063] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The alpha-glucan phosphorylases of the glycosyltransferase family are important enzymes of carbohydrate metabolism in prokaryotes and eukaryotes. The plant alpha-glucan phosphorylase, commonly called starch phosphorylase (EC 2.4.1.1), is largely known for the phosphorolytic degradation of starch. Starch phosphorylase catalyzes the reversible transfer of glucosyl units from glucose-1-phosphate to the nonreducing end of alpha-1,4-D-glucan chains with the release of phosphate. Two distinct forms of starch phosphorylase, plastidic phosphorylase and cytosolic phosphorylase, have been consistently observed in higher plants. Starch phosphorylase is industrially useful and a preferred enzyme among all glucan phosphorylases for phosphorolytic reactions for the production of glucose-1-phosphate and for the development of engineered varieties of glucans and starch. Despite several investigations, the precise functional mechanisms of its characteristic multiple forms and the structural details are still eluding us. Recent discoveries have shed some light on their physiological substrates, precise biological functions, and regulatory aspects. In this review, we have highlighted important developments in understanding the role of starch phosphorylases and their emerging applications in industry.
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Affiliation(s)
- R S Rathore
- School of Biotechnology, Devi Ahilya University, Indore, India
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185
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Zeeman SC, Kossmann J, Smith AM. Starch: its metabolism, evolution, and biotechnological modification in plants. ANNUAL REVIEW OF PLANT BIOLOGY 2010; 61:209-34. [PMID: 20192737 DOI: 10.1146/annurev-arplant-042809-112301] [Citation(s) in RCA: 576] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Starch is the most widespread and abundant storage carbohydrate in plants. We depend upon starch for our nutrition, exploit its unique properties in industry, and use it as a feedstock for bioethanol production. Here, we review recent advances in research in three key areas. First, we assess progress in identifying the enzymatic machinery required for the synthesis of amylopectin, the glucose polymer responsible for the insoluble nature of starch. Second, we discuss the pathways of starch degradation, focusing on the emerging role of transient glucan phosphorylation in plastids as a mechanism for solubilizing the surface of the starch granule. We contrast this pathway in leaves with the degradation of starch in the endosperm of germinated cereal seeds. Third, we consider the evolution of starch biosynthesis in plants from the ancestral ability to make glycogen. Finally, we discuss how this basic knowledge has been utilized to improve and diversify starch crops.
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186
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Liu L, Ma X, Liu S, Zhu C, Jiang L, Wang Y, Shen Y, Ren Y, Dong H, Chen L, Liu X, Zhao Z, Zhai H, Wan J. Identification and characterization of a novel Waxy allele from a Yunnan rice landrace. PLANT MOLECULAR BIOLOGY 2009; 71:609-26. [PMID: 19760367 DOI: 10.1007/s11103-009-9544-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Accepted: 08/24/2009] [Indexed: 05/04/2023]
Abstract
Low amylose content (AC) is a desirable trait for rice (Oryza sativa L.) cooking quality and is selected in soft rice breeding. To gain a better understanding of the molecular mechanism controlling AC formation, we screened 83 Yunnan rice landraces in China and identified a rice variety, Haopi, with low AC. Genetic analyses and transgenic experiments revealed that low AC in Haopi was controlled by a novel allele of the Wx locus, Wx(hp), encoding a granule-bound starch synthase (GBSSI). Sequence comparisons of Wx(hp) and Wx(b) alleles (from Nipponbare) showed several nucleotide changes in the upstream regulatory regions (including the promoter, 5'-untranslated region, and first intron 5' splicing junction site). Interestingly, these changes had no obvious effect on the expression level and splicing efficiency of Wx transcripts. In addition, an examination of the coding region revealed that the Wx(hp) allele carries an A-to-G change at nucleotide position +497 from the start codon, resulting in an Asp(165)/Gly(165) substitution. The amino acid substitution had no detectable effects on GBSSI activity in vitro; however, it notably reduced the binding of GBSSI to starch granules, resulting in a reduction of AC in rice seeds. Moreover, three other Yunnan landraces with low AC also carry a nucleotide substitution identical to Haopi at the +497 position of the Wx gene, suggesting common ancestry. Based on the single-nucleotide polymorphism, we have developed a new derived cleaved amplified polymorphic sequence marker for use in breeding practice to manipulate AC in rice endosperm.
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Affiliation(s)
- Linglong Liu
- State Key Laboratory for Crop Genetics & Germplasm Enhancement, Jiangsu Provincial Center of Plant Gene Engineering, Nanjing Agricultural University, Weigang 1, 210095 Nanjing, China
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187
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Tickle P, Burrell MM, Coates SA, Emes MJ, Tetlow IJ, Bowsher CG. Characterization of plastidial starch phosphorylase in Triticum aestivum L. endosperm. JOURNAL OF PLANT PHYSIOLOGY 2009; 166:1465-78. [PMID: 19524321 DOI: 10.1016/j.jplph.2009.05.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 02/09/2009] [Accepted: 05/01/2009] [Indexed: 05/10/2023]
Abstract
Starch phosphorylase (Pho) catalyses the reversible transfer of glucosyl units from glucose1-phosphate to the non-reducing end of an alpha-1,4-linked glucan chain. Two major isoforms of Pho exist in the plastid (Pho1) and cytosol (Pho2). In this paper it is proposed that Pho1 may play an important role in recycling glucosyl units from malto-oligosaccharides back into starch synthesis in the developing wheat endosperm. Pho activity was observed in highly purified amyloplast extracts prepared from developing wheat endosperms, representing the first direct evidence of plastidial Pho activity in this tissue. A full-length cDNA clone encoding a plastidial Pho isoform, designated TaPho1, was also isolated from a wheat endosperm cDNA library. The TaPho1 protein and Pho1 enzyme activity levels were shown to increase throughout the period of starch synthesis. These observations add to the growing body of evidence which indicates that this enzyme class has a role in starch synthesis in wheat endosperm and indeed all starch storing tissues.
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Affiliation(s)
- Paul Tickle
- Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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188
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Yan HB, Pan XX, Jiang HW, Wu GJ. Comparison of the starch synthesis genes between maize and rice: copies, chromosome location and expression divergence. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2009; 119:815-25. [PMID: 19593540 DOI: 10.1007/s00122-009-1091-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 06/08/2009] [Indexed: 05/10/2023]
Abstract
Gene duplication and divergence are important evolutionary processes. It has been suggested that a whole genome duplication (WGD) event occurred in the Gramineae, predating its divergence, and a second WGD occurred in maize during its evolution. In this study we compared the fate of the genes involved in the core pathway of starch biosynthesis following the ancient and second WGDs in maize and rice. In total, thirty starch synthesis genes were detected in the maize genome, which covered all the starch synthesis gene families encoded by 27 genes in rice. All of these genes, except ZmGBSSIIb and ZmBEIII, are anchored within large-scale synteny blocks of rice and maize chromosomes. Previous findings and our results indicate that two of the current copies of many starch synthesis genes (including AGPL, AGPS, GBSS, SSII, SSIII, and BEII) probably arose from the ancient WGD in the Gramineae and are still present in the maize and rice genome. Furthermore, two copies of at least six genes (AGPS1, SSIIb, SSIIIb, GBSSII, BEI, and ISA3) appear to have been retained in the maize genome after its second WGD, although complete coding regions were only detected among the duplicate sets of AGPS1, SSIIb, and SSIIIb. The expression patterns of the remaining duplicate sets of starch synthesis genes (AGPL1/2, AGPS1/2, SSIIa/b, SSIIIa/b, GBSSI/II, and BEIIa/b) differ in their expression and could be classified into two groups in maize. The first group is mainly expressed in the endosperm, whereas the second is expressed in other organs and the early endosperm development. The four duplicate sets of ZmGBSSII, ZmSSIIb, ZmSSIIIb and AGPS1, which arose from the second WGD diverged in gene structure and/or expression patterns in maize. These results indicated that some duplicated starch synthesis genes were remained, whereas others diverged in gene structure and/or expression pattern in maize. For most of the duplicated genes, one of the copies has disappeared in the maize genome after the WGD and the subsequent "diploidization".
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Affiliation(s)
- Hong-Bo Yan
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Tianhe District, 510650 Guangzhou, People's Republic of China
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189
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Szydlowski N, Ragel P, Raynaud S, Lucas MM, Roldán I, Montero M, Muñoz FJ, Ovecka M, Bahaji A, Planchot V, Pozueta-Romero J, D'Hulst C, Mérida A. Starch granule initiation in Arabidopsis requires the presence of either class IV or class III starch synthases. THE PLANT CELL 2009; 21:2443-57. [PMID: 19666739 PMCID: PMC2751949 DOI: 10.1105/tpc.109.066522] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 07/13/2009] [Accepted: 07/21/2009] [Indexed: 05/18/2023]
Abstract
The mechanisms underlying starch granule initiation remain unknown. We have recently reported that mutation of soluble starch synthase IV (SSIV) in Arabidopsis thaliana results in restriction of the number of starch granules to a single, large, particle per plastid, thereby defining an important component of the starch priming machinery. In this work, we provide further evidence for the function of SSIV in the priming process of starch granule formation and show that SSIV is necessary and sufficient to establish the correct number of starch granules observed in wild-type chloroplasts. The role of SSIV in granule seeding can be replaced, in part, by the phylogenetically related SSIII. Indeed, the simultaneous elimination of both proteins prevents Arabidopsis from synthesizing starch, thus demonstrating that other starch synthases cannot support starch synthesis despite remaining enzymatically active. Herein, we describe the substrate specificity and kinetic properties of SSIV and its subchloroplastic localization in specific regions associated with the edges of starch granules. The data presented in this work point to a complex mechanism for starch granule formation and to the different abilities of SSIV and SSIII to support this process in Arabidopsis leaves.
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Affiliation(s)
- Nicolas Szydlowski
- Unité de Glycobiologie Structurale et Fonctionelle, Unité Mixte de Recherche 8576, Centre National de la Recherche Scientifique, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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190
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Radchuk VV, Borisjuk L, Sreenivasulu N, Merx K, Mock HP, Rolletschek H, Wobus U, Weschke W. Spatiotemporal profiling of starch biosynthesis and degradation in the developing barley grain. PLANT PHYSIOLOGY 2009; 150:190-204. [PMID: 19321714 PMCID: PMC2675734 DOI: 10.1104/pp.108.133520] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 03/19/2009] [Indexed: 05/19/2023]
Abstract
Barley (Hordeum vulgare) grains synthesize starch as the main storage compound. However, some starch is degraded already during caryopsis development. We studied temporal and spatial expression patterns of genes coding for enzymes of starch synthesis and degradation. These profiles coupled with measurements of selected enzyme activities and metabolites have allowed us to propose a role for starch degradation in maternal and filial tissues of developing grains. Early maternal pericarp functions as a major short-term starch storage tissue, possibly ensuring sink strength of the young caryopsis. Gene expression patterns and enzyme activities suggest two different pathways for starch degradation in maternal tissues. One pathway possibly occurs via alpha-amylases 1 and 4 and beta-amylase 1 in pericarp, nucellus, and nucellar projection, tissues that undergo programmed cell death. Another pathway is deducted for living pericarp and chlorenchyma cells, where transient starch breakdown correlates with expression of chloroplast-localized beta-amylases 5, 6, and 7, glucan, water dikinase 1, phosphoglucan, water dikinase, isoamylase 3, and disproportionating enzyme. The suite of genes involved in starch synthesis in filial starchy endosperm is much more complex than in pericarp and involves several endosperm-specific genes. Transient starch turnover occurs in transfer cells, ensuring the maintenance of sink strength in filial tissues and the reallocation of sugars into more proximal regions of the starchy endosperm. Starch is temporally accumulated also in aleurone cells, where it is degraded during the seed filling period, to be replaced by storage proteins and lipids.
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Affiliation(s)
- Volodymyr V Radchuk
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung, D-06466 Gatersleben, Germany.
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191
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Taliercio EW, Romano G, Scheffler J, Ayre BG. Expression of genes associated with carbohydrate metabolism in cotton stems and roots. BMC PLANT BIOLOGY 2009; 9:11. [PMID: 19161628 PMCID: PMC2639587 DOI: 10.1186/1471-2229-9-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Accepted: 01/22/2009] [Indexed: 05/27/2023]
Abstract
BACKGROUND Cotton (Gossypium hirsutum L) is an important crop worldwide that provides fiber for the textile industry. Cotton is a perennial plant that stores starch in stems and roots to provide carbohydrates for growth in subsequent seasons. Domesticated cotton makes these reserves available to developing seeds which impacts seed yield. The goals of these analyses were to identify genes and physiological pathways that establish cotton stems and roots as physiological sinks and investigate the role these pathways play in cotton development during seed set. RESULTS Analysis of field-grown cotton plants indicated that starch levels peaked about the time of first anthesis and then declined similar to reports in greenhouse-grown cotton plants. Starch accumulated along the length of the stem and the shape and size of the starch grains from stems were easily distinguished from transient starch. Microarray analyses compared gene expression in tissues containing low levels of starch with tissues rapidly accumulating starch. Statistical analysis of differentially expressed genes indicated increased expression among genes associated with starch synthesis, starch degradation, hexose metabolism, raffinose synthesis and trehalose synthesis. The anticipated changes in these sugars were largely confirmed by measuring soluble sugars in selected tissues. CONCLUSION In domesticated cotton starch stored prior to flowering was available to support seed production. Starch accumulation observed in young field-grown plants was not observed in greenhouse grown plants. A suite of genes associated with starch biosynthesis was identified. The pathway for starch utilization after flowering was associated with an increase in expression of a glucan water dikinase gene as has been implicated in utilization of transient starch. Changes in raffinose levels and levels of expression of genes controlling trehalose and raffinose biosynthesis were also observed in vegetative cotton tissues as plants age.
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Affiliation(s)
| | - Gabriela Romano
- USDA/ARS, 141 Experiment Station Road, Stoneville, Mississippi 38776, USA
| | - Jodi Scheffler
- USDA/ARS, 141 Experiment Station Road, Stoneville, Mississippi 38776, USA
| | - Brian G Ayre
- University of North Texas, Department of Biological Sciences, 1504 W. Mulberry, SRB Rm 120, P.O. Box 305220, Denton, TX 76203 5220, USA
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192
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Liu F, Makhmoudova A, Lee EA, Wait R, Emes MJ, Tetlow IJ. The amylose extender mutant of maize conditions novel protein-protein interactions between starch biosynthetic enzymes in amyloplasts. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:4423-40. [PMID: 19805395 DOI: 10.1093/jxb/erp297] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The amylose extender (ae(-)) mutant of maize lacks starch branching enzyme IIb (SBEIIb) activity, resulting in amylopectin with reduced branch point frequency, and longer glucan chains. Recent studies indicate isozymes of soluble starch synthases form high molecular weight complexes with SBEII isoforms. This study investigated the effect of the loss of SBEIIb activity on interactions between starch biosynthetic enzymes in maize endosperm amyloplasts. Results show distinct patterns of protein-protein interactions in amyloplasts of ae(-) mutants compared with the wild type, suggesting functional complementation for loss of SBEIIb by SBEI, SBEIIa, and SP. Coimmunoprecipitation experiments and affinity chromatography using recombinant proteins showed that, in amyloplasts from normal endosperm, protein-protein interactions involving starch synthase I (SSI), SSIIa, and SBEIIb could be detected. By contrast, in ae(-) amyloplasts, SSI and SSIIa interacted with SBEI, SBEIIa, and SP. All interactions in the wild-type were strongly enhanced by ATP, and broken by alkaline phosphatase, indicating a role for protein phosphorylation in their assembly. Whilst ATP and alkaline phosphatase had no effect on the stability of the protein complexes from ae(-) endosperm, radiolabelling experiments showed SP and SBEI were both phosphorylated within the mutant protein complex. It is proposed that, during amylopectin biosynthesis, SSI and SSIIa form the core of a phosphorylation-dependent glucan-synthesizing protein complex which, in normal endosperm, recruits SBEIIb, but when SBEIIb is absent (ae(-)), recruits SBEI, SBEIIa, and SP. Differences in stromal protein complexes are mirrored in the complement of the starch synthesizing enzymes detected in the starch granules of each genotype, reinforcing the hypothesis that the complexes play a functional role in starch biosynthesis.
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Affiliation(s)
- Fushan Liu
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Canada
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