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Domínguez-Lobo MT, Roldán M, Gutiérrez-Diánez AM, Florencio FJ, Muro-Pastor M. Double blocking of carbon metabolism causes a large increase of Calvin-Benson cycle compounds in cyanobacteria. Plant Physiol 2024:kiae083. [PMID: 38377468 DOI: 10.1093/plphys/kiae083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/08/2024] [Accepted: 01/19/2024] [Indexed: 02/22/2024]
Abstract
Carbon-flow-regulator A (CfrA) adapts carbon flux to nitrogen conditions in non-diazotrophic cyanobacteria. Under nitrogen deficiency, CfrA leads to the storage of excess carbon, which cannot combine with nitrogen, mainly as glycogen. cfrA overexpression from the arsenite-inducible, nitrogen-independent ParsB promoter allows analysis of the metabolic effects of CfrA accumulation. Considering that the main consequence of cfrA overexpression is glycogen accumulation, we examined carbon distribution in response to cfrA expression in Synechocystis sp. PCC 6803 strains impaired in synthesizing this polymer. We carried out a comparative phenotypic analysis to evaluate cfrA overexpression in the wild-type strain and in a mutant of ADP-glucose pyrophosphorylase (ΔglgC), which is unable to synthesize glycogen. The accumulation of CfrA in the wild-type background caused a photosynthetic readjustment although growth was not affected. However, in a ΔglgC strain, growth decreased depending on CfrA accumulation and photosynthesis was severely affected. An elemental analysis of the H, C, and N content of cells revealed that cfrA expression in the wildtype caused an increase in the C/N ratio, due to decreased nitrogen assimilation. Metabolomic study indicated that these cells store sucrose and glycosylglycerol, in addition to the previously described glycogen accumulation. However, cells deficient in glycogen synthesis accumulated large amounts of Calvin-Benson cycle intermediates as cfrA was expressed. These cells also showed increased levels of some amino acids, mainly alanine, serine, valine, isoleucine and leucine. The findings suggest that by controlling cfrA expression, in different conditions and strains, we could change the distribution of fixed carbon, with potential biotechnological benefits.
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Affiliation(s)
| | - Miguel Roldán
- Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), CSIC-Universidad de Sevilla, 41092 Sevilla, Spain
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología. Universidad de Sevilla, Profesor García González s/n, Sevilla, 41012, Spain
| | - Alba María Gutiérrez-Diánez
- Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), CSIC-Universidad de Sevilla, 41092 Sevilla, Spain
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología. Universidad de Sevilla, Profesor García González s/n, Sevilla, 41012, Spain
| | - Francisco Javier Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), CSIC-Universidad de Sevilla, 41092 Sevilla, Spain
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología. Universidad de Sevilla, Profesor García González s/n, Sevilla, 41012, Spain
| | - MaríaIsabel Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis (IBVF), CSIC-Universidad de Sevilla, 41092 Sevilla, Spain
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2
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Yin YG, Sanuki A, Goto Y, Suzui N, Kawachi N, Matsukura C. ADP-glucose pyrophosphorylase genes are differentially regulated in sugar-dependent or -independent manners in tomato ( Solanum lycopersicum L.) fruit. Plant Biotechnol (Tokyo) 2023; 40:345-351. [PMID: 38434118 PMCID: PMC10905566 DOI: 10.5511/plantbiotechnology.23.1004a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/04/2023] [Indexed: 03/05/2024]
Abstract
In early developing tomato (Solanum lycopersicum L.) fruit, starch accumulates at high levels and is used by various primary metabolites in ripening fruits. ADP-glucose pyrophosphorylase is responsible for the first key step of starch biosynthesis. Although it has been reported that AgpL1 and AgpS1 isoforms are mainly expressed in early developing fruit, their regulatory mechanism has not been elucidated. The present study investigated the transcriptional response of AgpL1 and AgpS1 to various metabolizable sugars, nonmetabolizable sugar analogues, hexokinase inhibitors and proline by an experimental system using half-cut fruits. AgpL1 was upregulated in response to sucrose and constituted hexoses such glucose, whereas the AgpS1 gene almost did not exhibit a prominent sugar response. Further analyses revealed that other disaccharides such maltose and trehalose did not show a remarkable effect on both AgpL1 and AgpS1 expressions. These results indicate that there are two distinct regulatory mechanisms, namely, sugar metabolism-dependent and -independent, for the regulation of AGPase gene expression. Interestingly, the ADP treatment, a hexokinase inhibitors, cancelled the sugar response of AgpL1, indicating that hexokinase-mediated sugar signaling should be involved in the sugar response of AgpL1. These results suggest that sugar-dependent (AgpL1) and sugar-independent (AgpS1) pathways coordinatively regulate starch biosynthesis in immature tomato fruit.
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Affiliation(s)
- Yong-Gen Yin
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology (QST), Takasaki, Gunma 370-1292, Japan
| | - Atsuko Sanuki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Yukihisa Goto
- Institute of Plant and Microbial Biology, Zurich-Basel Plant Science Center, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Nobuo Suzui
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology (QST), Takasaki, Gunma 370-1292, Japan
| | - Naoki Kawachi
- Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology (QST), Takasaki, Gunma 370-1292, Japan
| | - Chiaki Matsukura
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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3
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Nicolas P, Pattison RJ, Zheng Y, Lapidot-Cohen T, Brotman Y, Osorio S, Fernie AR, Fei Z, Catalá C. Starch deficiency in tomato causes transcriptional reprogramming that modulates fruit development, metabolism, and stress responses. J Exp Bot 2023; 74:6331-6348. [PMID: 37279327 DOI: 10.1093/jxb/erad212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 06/02/2023] [Indexed: 06/08/2023]
Abstract
Tomato (Solanum lycopersicum) fruit store carbon as starch during early development and mobilize it at the onset of ripening. Starch accumulation has been suggested to buffer fluctuations in carbon supply to the fruit under abiotic stress, and contribute to sugar levels in ripe fruit. However, the role of starch accumulation and metabolism during fruit development is still unclear. Here we show that the tomato mutant adpressa (adp) harbors a mutation in a gene encoding the small subunit of ADP-glucose pyrophosphorylase that abolishes starch synthesis. The disruption of starch biosynthesis causes major transcriptional and metabolic remodeling in adp fruit but only minor effects on fruit size and ripening. Changes in gene expression and metabolite profiles indicate that the lack of carbon flow into starch increases levels of soluble sugars during fruit growth, triggers a readjustment of central carbohydrate and lipid metabolism, and activates growth and stress protection pathways. Accordingly, adp fruits are remarkably resistant to blossom-end rot, a common physiological disorder induced by environmental stress. Our results provide insights into the effects of perturbations of carbohydrate metabolism on tomato fruit development, with potential implications for the enhancement of protective mechanisms against abiotic stress in fleshy fruit.
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Affiliation(s)
| | | | - Yi Zheng
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
| | - Taly Lapidot-Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm 14476, Germany
| | - Yariv Brotman
- Department of Life Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm 14476, Germany
| | - Sonia Osorio
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento de Biología Molecular y Bioquímica, Campus de Teatinos, 29071 Málaga, Spain
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam-Golm 14476, Germany
| | - Zhangjun Fei
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
- U.S. Department of Agriculture-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY 14853, USA
| | - Carmen Catalá
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
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4
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Patel HP, Martinez‐Ramirez G, Dobrzynski E, Iglesias AA, Liu D, Ballicora MA. A critical inter-subunit interaction for the transmission of the allosteric signal in the Agrobacterium tumefaciens ADP-glucose pyrophosphorylase. Protein Sci 2023; 32:e4747. [PMID: 37551561 PMCID: PMC10461462 DOI: 10.1002/pro.4747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/20/2023] [Accepted: 08/04/2023] [Indexed: 08/09/2023]
Abstract
ADP-glucose pyrophosphorylase is a key regulatory enzyme involved in starch and glycogen synthesis in plants and bacteria, respectively. It has been hypothesized that inter-subunit communications are important for the allosteric effect in this enzyme. However, no specific interactions have been identified as part of the regulatory signal. The enzyme from Agrobacterium tumefaciens is a homotetramer allosterically regulated by fructose 6-phosphate and pyruvate. Three pairs of distinct subunit-subunit interfaces are present. Here we focus on an interface that features two symmetrical interactions between Arg11 and Asp141 from one subunit with residues Asp141 and Arg11 of the neighbor subunit, respectively. Previously, scanning mutagenesis showed that a mutation at the Arg11 position disrupted the activation of the enzyme. Considering the distance of these residues from the allosteric and catalytic sites, we hypothesized that the interaction between Arg11 and Asp141 is critical for allosteric signaling rather than effector binding. To prove our hypothesis, we mutated those two sites (D141A, D141E, D141N, D141R, R11D, and R11K) and performed kinetic and binding analysis. Mutations that altered the charge affected the regulation the most. To prove that the interaction per se (rather than the presence of specific residues) is critical, we partially rescued the R11D protein by introducing a second mutation (R11D/D141R). This could not restore the activator effect on kcat , but it did rescue the effect on substrate affinity. Our results indicate the critical functional role of Arg11 and Asp141 to relay the allosteric signal in this subunit interface.
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Affiliation(s)
- Hiral P. Patel
- Department of Chemistry and BiochemistryLoyola University ChicagoChicagoIllinoisUSA
| | | | - Emily Dobrzynski
- Department of Chemistry and BiochemistryLoyola University ChicagoChicagoIllinoisUSA
| | | | - Dali Liu
- Department of Chemistry and BiochemistryLoyola University ChicagoChicagoIllinoisUSA
| | - Miguel A. Ballicora
- Department of Chemistry and BiochemistryLoyola University ChicagoChicagoIllinoisUSA
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5
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Fan W, Wang Y, Zhang L, Fang Y, Yan M, Yuan L, Yang J, Wang H. Sweet potato ADP-glucose pyrophosphorylase small subunit affects vegetative growth, starch content and storage root yield. Plant Physiol Biochem 2023; 200:107796. [PMID: 37269824 DOI: 10.1016/j.plaphy.2023.107796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 06/05/2023]
Abstract
The development of storage roots is a key factor determining the yields of crop plants, including sweet potato. Here, using combined bioinformatic and genomic approaches, we identified a sweet potato yield-related gene, ADP-glucose pyrophosphorylase (AGP) small subunit (IbAPS). We found that IbAPS positively affects AGP activity, transitory starch biosynthesis, leaf development, chlorophyll metabolism, and photosynthesis, ultimately affecting the source strength. IbAPS overexpression in sweet potato led to increased vegetative biomass and storage root yield. RNAi of IbAPS resulted in reduced vegetative biomass, accompanied with a slender stature and stunted root development. In addition to the effects on root starch metabolism, we found that IbAPS affects other storage root development-associated events, including lignification, cell expansion, transcriptional regulation, and production of the storage protein sporamins. A combinatorial analysis based on transcriptomes, as well as morphological and physiological data, revealed that IbAPS affects several pathways that determine development of vegetative tissues and storage roots. Our work establishes an important role of IbAPS in concurrent control of carbohydrate metabolism, plant growth, and storage root yield. We showed that upregulation of IbAPS results in superior sweet potato with increased green biomass, starch content, and storage root yield. The findings expand our understanding of the functions of AGP enzymes and advances our ability to increase the yield of sweet potato and, perhaps, other crop plants.
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Affiliation(s)
- Weijuan Fan
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Yuqin Wang
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China; College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Li Zhang
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China; College of Environmental Science and Engineering, China West Normal University, Nanchong, 637002, China
| | - Yijie Fang
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China; College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Mengxiao Yan
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Ling Yuan
- Department of Plant and Soil Sciences and Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY, 40546, USA.
| | - Jun Yang
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Hongxia Wang
- Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
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6
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Alghamdi MA, Hussien RA, Zheng Y, Patel HP, Asencion Diez MD, A Iglesias A, Liu D, Ballicora MA. Site-directed mutagenesis of Serine-72 reveals the location of the fructose 6-phosphate regulatory site of the Agrobacterium tumefaciens ADP-glucose pyrophosphorylase. Protein Sci 2022; 31:e4376. [PMID: 35762722 PMCID: PMC9234290 DOI: 10.1002/pro.4376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/27/2022] [Accepted: 06/05/2022] [Indexed: 11/10/2022]
Abstract
The allosteric regulation of ADP-glucose pyrophosphorylase is critical for the biosynthesis of glycogen in bacteria and starch in plants. The enzyme from Agrobacterium tumefaciens is activated by fructose 6-phosphate (Fru6P) and pyruvate (Pyr). The Pyr site has been recently found, but the site where Fru6P binds has remained unknown. We hypothesize that a sulfate ion previously found in the crystal structure reveals a part of the regulatory site mimicking the presence of the phosphoryl moiety of the activator Fru6P. Ser72 interacts with this sulfate ion and, if the hypothesis is correct, Ser72 would affect the interaction with Fru6P and activation of the enzyme. Here, we report structural, binding, and kinetic analysis of Ser72 mutants of the A. tumefaciens ADP-glucose pyrophosphorylase. By X-ray crystallography, we found that when Ser72 was replaced by Asp or Glu side chain carboxylates protruded into the sulfate-binding pocket. They would present a strong steric and electrostatic hindrance to the phosphoryl moiety of Fru6P, while being remote from the Pyr site. In agreement, we found that Fru6P could not activate or bind to S72E or S72D mutants, whereas Pyr was still an effective activator. These mutants also blocked the binding of the inhibitor AMP. This could potentially have biotechnological importance in obtaining enzyme forms insensitive to inhibition. Other mutations in this position (Ala, Cys, and Trp) confirmed the importance of Ser72 in regulation. We propose that the ADP-glucose pyrophosphorylase from A. tumefaciens have two distinct sites for Fru6P and Pyr working in tandem to regulate glycogen biosynthesis.
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Affiliation(s)
- Mashael A Alghamdi
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois.,Department of Chemistry, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Rania A Hussien
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois.,Department of Chemistry, Al Baha University, Al Baha, Saudi Arabia
| | - Yuanzhang Zheng
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois
| | - Hiral P Patel
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois
| | - Matías D Asencion Diez
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois.,Instituto de Agrobiotecnología del Litoral (UNL-CONICET), FBCB Paraje "El Pozo", CCT-Santa Fe, Santa Fe, Argentina
| | - Alberto A Iglesias
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), FBCB Paraje "El Pozo", CCT-Santa Fe, Santa Fe, Argentina
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois
| | - Miguel A Ballicora
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois
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7
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Okamura M, Hirai MY, Sawada Y, Okamoto M, Oikawa A, Sasaki R, Arai-Sanoh Y, Mukouyama T, Adachi S, Kondo M. Analysis of carbon flow at the metabolite level reveals that starch synthesis from hexose is a limiting factor in a high-yielding rice cultivar. J Exp Bot 2021; 72:2570-2583. [PMID: 33481019 DOI: 10.1093/jxb/erab016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 01/20/2021] [Indexed: 06/12/2023]
Abstract
Understanding the limiting factors of grain filling is essential for the further improvement of grain yields in rice (Oryza sativa). The relatively slow grain growth of the high-yielding cultivar 'Momiroman' is not improved by increasing carbon supply, and hence low sink activity (i.e. the metabolic activity of assimilate consumption/storage in sink organs) may be a limiting factor for grain filling. However, there is no metabolic evidence to corroborate this hypothesis, partly because there is no consensus on how to define and quantify sink activity. In this study, we investigated the carbon flow at a metabolite level from photosynthesis in leaves to starch synthesis in grains of three high-yielding cultivars using the stable isotope 13C. We found that a large amount of newly fixed carbon assimilates in Momiroman was stored as hexose instead of being converted to starch. In addition, the activity of ADP-glucose pyrophosphorylase and the expression of AGPS2b, which encodes a subunit of the ADP-glucose pyrophosphorylase enzyme, were both lower in Momiroman than in the other two cultivars in grains in superior positions on panicle branches. Hence, slower starch synthesis from hexose, which is partly explained by the low expression level of AGPS2b, may be the primary metabolic reason for the lower sink activity observed in Momiroman.
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Affiliation(s)
- Masaki Okamura
- Institute of Crop Science, NARO, 2-1-2 Kannondai, Tsukuba, Ibaraki, Japan
- Central Region Agricultural Research Center, NARO, 1-2-1, Inada, Joetsu, Niigata, Japan
| | - Masami Yokota Hirai
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Yuji Sawada
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Mami Okamoto
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Akira Oikawa
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan
- Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata, Japan
| | - Ryosuke Sasaki
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Yumiko Arai-Sanoh
- Institute of Crop Science, NARO, 2-1-2 Kannondai, Tsukuba, Ibaraki, Japan
| | - Takehiro Mukouyama
- Institute of Crop Science, NARO, 2-1-2 Kannondai, Tsukuba, Ibaraki, Japan
- Yamanashi Prefectural Agritechnology Center 1100, Shimoimai, Kai, Yamanashi, Japan
| | - Shunsuke Adachi
- Institute of Crop Science, NARO, 2-1-2 Kannondai, Tsukuba, Ibaraki, Japan
- College of Agriculture, Ibaraki University, 3-21-1, Chuo, Ami, Inashiki, Ibaraki, Japan
| | - Motohiko Kondo
- Institute of Crop Science, NARO, 2-1-2 Kannondai, Tsukuba, Ibaraki, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, Japan
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8
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Shi HD, Zhang WQ, Lu HY, Zhang WQ, Ye H, Liu DD. Functional characterization of a starch synthesis-related gene AmAGP in Amorphophallus muelleri. Plant Signal Behav 2020; 15:1805903. [PMID: 32799608 PMCID: PMC7588197 DOI: 10.1080/15592324.2020.1805903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/23/2020] [Accepted: 07/26/2020] [Indexed: 06/11/2023]
Abstract
has attracted tremendous interest because of its high contents of glucomannan and starch. Very few genes regulating glucomannan and starch were reported in Amorphophallus. In this study, an ADP-glucose pyrophosphorylase (AGP) gene that plays a significant role in plant starch synthesis was cloned from Amorphophallus muelleri. It was shown that it encoded a predicted protein containing a conserved plant ADP-Glucose-PP repeat domain and seven potential ligand-binding sites. The real-time quantitative PCR showed that AmAGP was most abundant in tubers, and it was positively correlated with starch content. Additionally, its influencers about temperature and exogenous plant hormone were also discussed, showing that AmAGP expressed highly in tubers under treatments using 25°C and IAA. Furthermore, starch content was closely related to AmAGP expression level, suggesting that AmAGP was involved in the regulation of starch synthesis in A. muelleri. Therefore, identifying the sequence of AmAGP and its expression pattern during tuber enlarging and the changes of its transcript levels in response to temperature and plant hormones would contribute to a better understanding of starch synthesis, and also providing a reference information for future preferable breeding for obtaining more starch or more glucomannan in Amorphophallus.
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Affiliation(s)
- Hong-Di Shi
- School of Agriculture, Yunnan University, Kunming, China
| | - Wan-Qiao Zhang
- School of Agriculture, Yunnan University, Kunming, China
| | - Hong-Ye Lu
- School of International Education, Baise University, Baise, China
| | - Wen-Qian Zhang
- Department of Science and Education, Xintai Modern Agricultural Development Service Center, Xintai, China
| | - Hui Ye
- School of Agriculture, Yunnan University, Kunming, China
| | - Dan-Dan Liu
- School of Agriculture, Yunnan University, Kunming, China
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9
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Kleczkowski LA, Igamberdiev AU. Optimization of nucleotide sugar supply for polysaccharide formation via thermodynamic buffering. Biochem J 2020; 477:341-56. [PMID: 31967651 DOI: 10.1042/BCJ20190807] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023]
Abstract
Plant polysaccharides (cellulose, hemicellulose, pectin, starch) are either direct (i.e. leaf starch) or indirect products of photosynthesis, and they belong to the most abundant organic compounds in nature. Although each of these polymers is made by a specific enzymatic machinery, frequently in different cell locations, details of their synthesis share certain common features. Thus, the production of these polysaccharides is preceded by the formation of nucleotide sugars catalyzed by fully reversible reactions of various enzymes, mostly pyrophosphorylases. These 'buffering' enzymes are, generally, quite active and operate close to equilibrium. The nucleotide sugars are then used as substrates for irreversible reactions of various polysaccharide-synthesizing glycosyltransferases ('engine' enzymes), e.g. plastidial starch synthases, or plasma membrane-bound cellulose synthase and callose synthase, or ER/Golgi-located variety of glycosyltransferases forming hemicellulose and pectin backbones. Alternatively, the irreversible step might also be provided by a carrier transporting a given immediate precursor across a membrane. Here, we argue that local equilibria, established within metabolic pathways and cycles resulting in polysaccharide production, bring stability to the system via the arrangement of a flexible supply of nucleotide sugars. This metabolic system is itself under control of adenylate kinase and nucleoside-diphosphate kinase, which determine the availability of nucleotides (adenylates, uridylates, guanylates and cytidylates) and Mg2+, the latter serving as a feedback signal from the nucleotide metabolome. Under these conditions, the supply of nucleotide sugars to engine enzymes is stable and constant, and the metabolic process becomes optimized in its load and consumption, making the system steady and self-regulated.
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10
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Li D, Yang Z, Liu X, Song Z, Feng Z, He Y. Cloning and expression analysis of cDNAs encoding ADP-glucose pyrophosphorylase large and small subunits from hulless barley (Hordeum vulgare L. var. nudum). ACTA ACUST UNITED AC 2019; 73:191-197. [PMID: 29455192 DOI: 10.1515/znc-2017-0154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/20/2018] [Indexed: 11/15/2022]
Abstract
As an important plateau cereal crop, hulless barley is the principal food for the Tibetan people in China. ADP-glucose pyrophosphorylase (AGPase) is considered as the key enzyme for starch biosynthesis in plants. In this study, cDNAs encoding the small subunit (SSU I) and large subunit (LSU I) of AGPase were isolated from hulless barley. The results showed that SSU I and LSU I were 1438 and 1786 bp in length with a complete open reading frame (ORF) of 1419 and 1572 bp. The ORF-encoded polypeptides of 472 and 523 amino acids were having calculated molecular masses of 52.01 and 58.23 kDa, and the pI values were 5.59 and 6.30. In addition, phylogenetic analysis showed that SSU I and LSU I had the same phylogenetic trends with some species. Furthermore, expression levels in different growth periods and tissues of two hulless barley varieties were analyzed by quantitative reverse transcription-polymerase chain reaction. Gene expression levels of SSU I and LSU I were consistent with the total starch accumulation rate in endosperm. In conclusion, our data confirmed that SSU I and LSU I played an important role in hulless barley starch synthesis.
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Affiliation(s)
- Dongmei Li
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, P.R. China
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P.R. China
| | - Zhimin Yang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Xinchun Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Zhen Song
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P.R. China
| | - Zongyun Feng
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Yang He
- College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P.R. China
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Xu X, Vanhercke T, Shrestha P, Luo J, Akbar S, Konik-Rose C, Venugoban L, Hussain D, Tian L, Singh S, Li Z, Sharp PJ, Liu Q. Upregulated Lipid Biosynthesis at the Expense of Starch Production in Potato ( Solanum tuberosum) Vegetative Tissues via Simultaneous Downregulation of ADP-Glucose Pyrophosphorylase and Sugar Dependent1 Expressions. Front Plant Sci 2019; 10:1444. [PMID: 31781148 PMCID: PMC6861213 DOI: 10.3389/fpls.2019.01444] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/17/2019] [Indexed: 05/05/2023]
Abstract
Triacylglycerol is a major component of vegetable oil in seeds and fruits of many plants, but its production in vegetative tissues is rather limited. It would be intriguing and important to explore any possibility to expand current oil production platforms, for example from the plant vegetative tissues. By expressing a suite of transgenes involved in the triacylglycerol biosynthesis, we have previously observed substantial accumulation of triacylglycerol in tobacco (Nicotiana tabacum) leaf and potato (Solanum tuberosum) tuber. In this study, simultaneous RNA interference (RNAi) downregulation of ADP-glucose pyrophosphorylase (AGPase) and Sugar-dependent1 (SDP1), was able to increase the accumulation of triacylglycerol and other lipids in both wild type potato and the previously generated high oil potato line 69. Particularly, a 16-fold enhancement of triacylglycerol production was observed in the mature transgenic tubers derived from the wild type potato, and a two-fold increase in triacylglycerol was observed in the high oil potato line 69, accounting for about 7% of tuber dry weight, which is the highest triacylglycerol accumulation ever reported in potato. In addition to the alterations of lipid content and fatty acid composition, sugar accumulation, starch content of the RNAi potato lines in both tuber and leaf tissues were also substantially changed, as well as the tuber starch properties. Microscopic analysis further revealed variation of lipid droplet distribution and starch granule morphology in the mature transgenic tubers compared to their parent lines. This study reflects that the carbon partitioning between lipid and starch in both leaves and non-photosynthetic tuber tissues, respectively, are highly orchestrated in potato, and it is promising to convert low-energy starch to storage lipids via genetic manipulation of the carbon metabolism pathways.
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Affiliation(s)
- Xiaoyu Xu
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
- Plant Breeding Institute and Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Thomas Vanhercke
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Pushkar Shrestha
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Jixun Luo
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Sehrish Akbar
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Christine Konik-Rose
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Lauren Venugoban
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Dawar Hussain
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Lijun Tian
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Surinder Singh
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Zhongyi Li
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
- *Correspondence: Zhongyi Li, ; Peter J. Sharp, ; Qing Liu,
| | - Peter J. Sharp
- Plant Breeding Institute and Sydney Institute of Agriculture, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
- *Correspondence: Zhongyi Li, ; Peter J. Sharp, ; Qing Liu,
| | - Qing Liu
- Research Program of Traits, CSIRO Agriculture and Food, Canberra, ACT, Australia
- *Correspondence: Zhongyi Li, ; Peter J. Sharp, ; Qing Liu,
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12
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Na G, Aryal N, Fatihi A, Kang J, Lu C. Seed-specific suppression of ADP-glucose pyrophosphorylase in Camelina sativa increases seed size and weight. Biotechnol Biofuels 2018; 11:330. [PMID: 30568730 PMCID: PMC6297958 DOI: 10.1186/s13068-018-1334-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/07/2018] [Indexed: 05/23/2023]
Abstract
BACKGROUND Camelina (Camelina sativa L.) is a promising oilseed crop that may provide sustainable feedstock for biofuel production. One of the major drawbacks of Camelina is its smaller seeds compared to other major oil crops such as canola, which limit oil yield and may also pose challenges in successful seedling establishment, especially in dryland cultivation. Previous studies indicate that seed development may be under metabolic control. In oilseeds, starch only accumulates temporarily during seed development but is almost absent in mature seeds. In this study, we explored the effect of altering seed carbohydrate metabolism on Camelina seed size through down-regulating ADP-glucose pyrophosphorylase (AGPase), a major enzyme in starch biosynthesis. RESULTS An RNAi construct comprising sequences of the Camelina small subunit of an AGPase (CsAPS) was expressed in Camelina cultivar Suneson under a seed-specific promoter. The RNAi suppression reduced AGPase activities which concurred with moderately decreased starch accumulation during seed development. Transcripts of genes examined that are involved in storage products were not affected, but contents of sugars and water were increased in developing seeds. The transgenic seeds were larger than wild-type plants due to increased cell sizes in seed coat and embryos, and mature seeds contained similar oil but more protein contents. The larger seeds showed advantages on seedling emergence from deep soils. CONCLUSIONS Changing starch and sugar metabolism during seed development may increase the size and mass of seeds without affecting their final oil content in Camelina. Increased seed size may improve seedling establishment in the field and increase seed yield.
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Affiliation(s)
- GunNam Na
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150 USA
| | - Niranjan Aryal
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150 USA
| | - Abdelhak Fatihi
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150 USA
- Present Address: IJPB, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78026 Versailles Cedex, France
| | - Jinling Kang
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150 USA
| | - Chaofu Lu
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150 USA
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13
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Boehlein SK, Shaw JR, Boehlein TJ, Boehlein EC, Hannah LC. Fundamental differences in starch synthesis in the maize leaf, embryo, ovary and endosperm. Plant J 2018; 96:595-606. [PMID: 30062763 DOI: 10.1111/tpj.14053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 07/23/2018] [Indexed: 05/25/2023]
Abstract
Enzymological and starch analyses of various ADP-glucose pyrophosphorylase (AGPase) null mutants point to fundamental differences in the pathways for starch synthesis in the maize leaf, embryo, ovary and endosperm. Leaf starch is synthesized via the AGPase encoded by the small and large subunits shown previously to be expressed at abundant levels in the leaf, whereas more than one AGPase isoform functions in the embryo and in the ovary. Embryo starch content is also dependent on genes functioning in the leaf and in the endosperm. AGPase encoded by shrunken-2 and brittle-2 synthesizes ~75% of endosperm starch. The gene, agpsemzm, previously shown to encode the small subunit expressed in the embryo, and agpllzm, the leaf large subunit gene, are here shown to encode the endosperm, plastid-localized AGPase. Loss of this enzyme does not reduce endosperm starch. Rather, the data suggest that AGPase-independent starch synthesis accounts for ~25% of endosperm starch. Three maize genes encode the small subunit of the AGPase. Data here show that the triple mutant lacking all three small subunits is lethal in early seed development but can be viable in both male and female gametes. Seed and plant viability is restored by any one of the three small subunit genes, including one previously thought to function only in the cytosol of the endosperm. Data herein also show the functionality of a fourth gene encoding the large subunit of this enzyme. Although adenosine diphosphate glucose pyrophosphorylase is shown here to be essential for maize viability, strong evidence for starch synthesis in the endosperm that is independent of this enzyme is also presented. Starch synthesis is distinct in the maize embryo, ovary, leaf and endosperm, and is coordinated among the various tissues.
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Affiliation(s)
- Susan K Boehlein
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Janine R Shaw
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Timothy J Boehlein
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Emily C Boehlein
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - L Curtis Hannah
- Program in Plant Molecular and Cellular Biology, Genetics Institute and the Department of Horticultural Sciences, University of Florida, Gainesville, FL, 32611, USA
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14
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Yao C, Jiang J, Cao X, Liu Y, Xue S, Zhang Y. Phosphorus Enhances Photosynthetic Storage Starch Production in a Green Microalga (Chlorophyta) Tetraselmis subcordiformis in Nitrogen Starvation Conditions. J Agric Food Chem 2018; 66:10777-10787. [PMID: 30270616 DOI: 10.1021/acs.jafc.8b04798] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Microalgae are potential starch producers as alternatives to agricultural crops. This study disclosed the effects and mechanism of phosphorus availability exerted on storage starch production in a starch-producing microalga Tetraselmis subcordiformis in nitrogen starvation conditions. Excessive phosphorus supply facilitated starch production, which differed from the conventional cognition that phosphorus would inhibit transitory starch biosynthesis in plants. Phosphorus enhanced energy utilization efficiency for biomass and storage starch production. ADP-glucose pyrophosphorylase (AGPase), conventionally known to be critical for starch biosynthesis, was negatively correlated to storage starch biosynthesis. Excessive phosphorus supply maintained large cell volumes, enhanced activities of starch phosphorylases (SPs) along with branching enzymes and isoamylases, and increased phosphoenolpyruvate and trehalose-6-phosphate levels to alleviate the inhibition of high phosphate availability to AGPase, all of which improved starch production. This work highlighted the importance of phosphorus in the production of microalgal starch and provided further evidence for the SP-based storage starch biosynthesis pathway.
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Affiliation(s)
- Changhong Yao
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering , Sichuan University , Chengdu , Sichuan 610065 , China
| | - Junpeng Jiang
- Marine Bioengineering Group , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
- University of Chinese Academy of Sciences , Beijing 100039 , China
| | - Xupeng Cao
- Marine Bioengineering Group , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Yinghui Liu
- Marine Bioengineering Group , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Song Xue
- Marine Bioengineering Group , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Yongkui Zhang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering , Sichuan University , Chengdu , Sichuan 610065 , China
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Ma P, Chen X, Liu C, Xia Z, Song Y, Zeng C, Li Y, Wang W. MePHD1 as a PHD-Finger Protein Negatively Regulates ADP-Glucose Pyrophosphorylase Small Subunit1a Gene in Cassava. Int J Mol Sci 2018; 19:E2831. [PMID: 30235813 DOI: 10.3390/ijms19092831] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/11/2018] [Accepted: 09/15/2018] [Indexed: 11/17/2022] Open
Abstract
ADP-glucose pyrophosphorylase (AGPase) is an important enzyme in the starch synthesis pathway. Its enzyme activity can determine the efficiency of starch biosynthesis. Cassava (Manihot esculenta Crantz) is the main staple crop worldwide and has a high starch content in its storage root. However, the inner regulatory mechanism of AGPase gene family is unclear. MePHD1; a plant homeodomain transcription factor; was isolated through a yeast one-hybrid screening using the promoter of ADP-glucose pyrophosphorylase small subunit1a (MeAGPS1a) as bait, and cassava storage root cDNA library as prey. This factor could bind to the MeAGPS1a promoter in vitro and in vivo, and its predicted binding region ranged from −400 bp to −201 bp, at the translation initiation site. The transcript level of MePHD1 could be induced by five plant hormones, and a temperature of 42 °C. This was down-regulated during the maturation process of the storage root. MePHD1 protein could repress the promoter activity of MeAGPS1a gene by a dual-luciferase assay; which indicated that MePHD1 is a negative regulator for the transcript level of MeAGPS1a gene.
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16
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Cereijo AE, Asencion Diez MD, Ballicora MA, Iglesias AA. Regulatory Properties of the ADP-Glucose Pyrophosphorylase from the Clostridial Firmicutes Member Ruminococcus albus. J Bacteriol 2018; 200:e00172-18. [PMID: 29941423 DOI: 10.1128/JB.00172-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/19/2018] [Indexed: 11/20/2022] Open
Abstract
ADP-glucose pyrophosphorylase from Firmicutes is encoded by two genes (glgC and glgD) leading to a heterotetrameric protein structure, unlike those in other bacterial phyla. The enzymes from two groups of Firmicutes, Bacillales and Lactobacillales, present dissimilar kinetic and regulatory properties. Nevertheless, no ADP-glucose pyrophosphorylase from Clostridiales, the third group in Firmicutes, has been characterized. For this reason, we cloned the glgC and glgD genes from Ruminococcus albus Different quaternary forms of the enzyme (GlgC, GlgD, and GlgC/GlgD) were purified to homogeneity and their kinetic parameters were analyzed. We observed that GlgD is an inactive monomer when expressed alone but increased the catalytic efficiency of the heterotetramer (GlgC/GlgD) compared to the homotetramer (GlgC). The heterotetramer is regulated by fructose-1,6-bisphosphate, phosphoenolpyruvate, and NAD(P)H. The first characterization of the Bacillales enzyme suggested that heterotetrameric ADP-glucose pyrophosphorylases from Firmicutes were unregulated. Our results, together with data from Lactobacillales, indicate that heterotetrameric Firmicutes enzymes are mostly regulated. Thus, the ADP-glucose pyrophosphorylase from Bacillales seems to have distinctive insensitivity to regulation.IMPORTANCE The enzymes involved in glycogen synthesis from Firmicutes have been less characterized in comparison with other bacterial groups. We performed kinetic and regulatory characterization of the ADP-glucose pyrophosphorylase from Ruminococcus albus Our results showed that this protein that belongs to different groups from Firmicutes (Bacillales, Lactobacillales, and Clostridiales) presents dissimilar features. This study contributes to the understanding of how this critical enzyme for glycogen biosynthesis is regulated in the Firmicutes group, whereby we propose that these heterotetrameric enzymes, with the exception of Bacillales, are allosterically regulated. Our results provide a better understanding of the evolutionary relationship of this enzyme family in Firmicutes.
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Figueroa CM, Kuhn ML, Hill BL, Iglesias AA, Ballicora MA. Resurrecting the Regulatory Properties of the Ostreococcus tauri ADP-Glucose Pyrophosphorylase Large Subunit. Front Plant Sci 2018; 9:1564. [PMID: 30425723 PMCID: PMC6218581 DOI: 10.3389/fpls.2018.01564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/05/2018] [Indexed: 05/09/2023]
Abstract
ADP-glucose pyrophosphorylase (ADP-Glc PPase) catalyzes the first committed step for the synthesis of glycogen in cyanobacteria and starch in green algae and plants. The enzyme from cyanobacteria is homotetrameric (α4), while that from green algae and plants is heterotetrameric (α2β2). These ADP-Glc PPases are allosterically regulated by 3-phosphoglycerate (3PGA, activator) and inorganic orthophosphate (Pi, inhibitor). Previous studies on the cyanobacterial and plant enzymes showed that 3PGA binds to two highly conserved Lys residues located in the C-terminal domain. We observed that both Lys residues are present in the small (α) subunit of the Ostreococcus tauri enzyme; however, one of these Lys residues is replaced by Arg in the large (β) subunit. In this work, we obtained the K443R and R466K mutants of the O. tauri small and large subunits, respectively, and co-expressed them together or with their corresponding wild type counterparts. Our results show that restoring the Lys residue in the large subunit enhanced 3PGA affinity, whereas introduction of an Arg residue in the small subunit reduced 3PGA affinity of the heterotetramers. Inhibition kinetics also showed that heterotetramers containing the K443R small subunit mutant were less sensitive to Pi inhibition, but only minor changes were observed for those containing the R466K large subunit mutant, suggesting a leading role of the small subunit for Pi inhibition of the heterotetramer. We conclude that, during evolution, the ADP-Glc PPase large subunit from green algae and plants acquired mutations in its regulatory site. The rationale for this could have been to accommodate sensitivity to particular metabolic needs of the cell or tissue.
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Affiliation(s)
- Carlos M. Figueroa
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, CONICET, Facultad de Bioquímica y Ciencias Biológicas, Santa Fe, Argentina
| | - Misty L. Kuhn
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States
| | - Benjamin L. Hill
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States
| | - Alberto A. Iglesias
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, CONICET, Facultad de Bioquímica y Ciencias Biológicas, Santa Fe, Argentina
- *Correspondence: Alberto A. Iglesias, Miguel A. Ballicora,
| | - Miguel A. Ballicora
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States
- *Correspondence: Alberto A. Iglesias, Miguel A. Ballicora,
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18
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Hou J, Li T, Wang Y, Hao C, Liu H, Zhang X. ADP-glucose pyrophosphorylase genes, associated with kernel weight, underwent selection during wheat domestication and breeding. Plant Biotechnol J 2017; 15:1533-1543. [PMID: 28371241 PMCID: PMC5698054 DOI: 10.1111/pbi.12735] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/23/2017] [Accepted: 03/26/2017] [Indexed: 05/04/2023]
Abstract
ADP-glucose pyrophosphorylase, comprising two small subunits and two large subunits, is considered a key enzyme in the endosperm starch synthesis pathway in wheat (Triticum aestivum L.). Two genes, TaAGP-S1-7A and TaAGP-L-1B, were investigated in this study. Haplotypes of these genes were associated with thousand kernel weight (TKW) in different populations. Mean TKWs of favoured haplotypes were significantly higher than those of nonfavoured ones. Two molecular markers developed to distinguish these haplotypes could be used in molecular breeding. Frequencies of favoured haplotypes were dramatically increased in cultivars released in China after the 1940s. These favoured haplotypes were also positively selected in six major wheat production regions globally. Selection of AGP-S1 and AGP-L-1B in wheat mainly occurred during and after hexaploidization. Strong additive effects of the favoured haplotypes of with other genes for starch synthesis were also detected in different populations.
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Affiliation(s)
- Jian Hou
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Tian Li
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Yamei Wang
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Chenyang Hao
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Hongxia Liu
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Xueyong Zhang
- Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
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Dorion S, Clendenning A, Rivoal J. Engineering the expression level of cytosolic nucleoside diphosphate kinase in transgenic Solanum tuberosum roots alters growth, respiration and carbon metabolism. Plant J 2017; 89:914-926. [PMID: 27880021 DOI: 10.1111/tpj.13431] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/14/2016] [Accepted: 11/17/2016] [Indexed: 05/06/2023]
Abstract
Nucleoside diphosphate kinase (NDPK) is a ubiquitous enzyme that catalyzes the transfer of the γ-phosphate from a donor nucleoside triphosphate to an acceptor nucleoside diphosphate. In this study we used a targeted metabolomic approach and measurement of physiological parameters to report the effects of the genetic manipulation of cytosolic NDPK (NDPK1) expression on physiology and carbon metabolism in potato (Solanum tuberosum) roots. Sense and antisense NDPK1 constructs were introduced in potato using Agrobacterium rhizogenes to generate a population of root clones displaying a 40-fold difference in NDPK activity. Root growth, O2 uptake, flux of carbon between sucrose and CO2 , levels of reactive oxygen species and some tricarboxylic acid cycle intermediates were positively correlated with levels of NDPK1 expression. In addition, NDPK1 levels positively affected UDP-glucose and cellulose contents. The activation state of ADP-glucose pyrophosphorylase, a key enzyme in starch synthesis, was higher in antisense roots than in roots overexpressing NDPK1. Further analyses demonstrated that ADP-glucose pyrophosphorylase was more oxidized, and therefore less active, in sense clones than antisense clones. Consequently, antisense NDPK1 roots accumulated more starch and the starch to cellulose ratio was negatively affected by the level of NDPK1. These data support the idea that modulation of NDPK1 affects the distribution of carbon between starch and cellulose biosynthetic pathways.
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Affiliation(s)
- Sonia Dorion
- Institut de Recherche en Biologie Végétale, Université de Montréal, 4101 Sherbrooke Est, Montréal, QC, H1X 2B2, Canada
| | - Audrey Clendenning
- Institut de Recherche en Biologie Végétale, Université de Montréal, 4101 Sherbrooke Est, Montréal, QC, H1X 2B2, Canada
| | - Jean Rivoal
- Institut de Recherche en Biologie Végétale, Université de Montréal, 4101 Sherbrooke Est, Montréal, QC, H1X 2B2, Canada
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Ma P, Chen X, Liu C, Meng Y, Xia Z, Zeng C, Lu C, Wang W. MeSAUR1, Encoded by a Small Auxin-Up RNA Gene, Acts as a Transcription Regulator to Positively Regulate ADP-Glucose Pyrophosphorylase Small Subunit1a Gene in Cassava. Front Plant Sci 2017; 8:1315. [PMID: 28824663 PMCID: PMC5534448 DOI: 10.3389/fpls.2017.01315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/12/2017] [Indexed: 05/11/2023]
Abstract
Cassava, being one of the top three tuberous crops, features highly efficient starch accumulation in the storage root to adapt the tropical resources and environments. The molecular mechanism for the process, however, is still unclear. ADP-glucose pyrophosphorylase, the first and rate-limited enzyme in starch biosynthesis pathway, is a heterotetramer comprised of two small/catalytic and two large/modulatory subunits. To understand the regulation of MeAGPase, the promoter of a highly expressed small subunit, MeAGPs1a, was used as bait for a yeast one-hybrid assay to screen storage root cDNA library. One cDNA, coding for a small auxin-up RNA protein, named MeSAUR1, was isolated from cassava. MeSAUR1 could bind to the promoter of MeAGPS1a in yeast one-hybrid test and in vitro, and was located in cell nucleus. MeSAUR1 displayed a higher transcript level in cassava root cortex, and its expression was induced by indole-3-acetic acid, gibberellin and ethylene, but repressed by abscisic acid. A dual-luciferase interaction test further convinced that MeSAUR1 could bind to the promoter of MeAGPS1a, and positively regulate the transcription of MeAGPS1a in cassava.
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Affiliation(s)
- Ping’an Ma
- Institute of Tropical Agriculture and Forestry, Hainan UniversityHaikou, China
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
| | - Xin Chen
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
- *Correspondence: Xin Chen, Wenquan Wang,
| | - Chen Liu
- Institute of Tropical Agriculture and Forestry, Hainan UniversityHaikou, China
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
| | - Yuhong Meng
- Institute of Tropical Agriculture and Forestry, Hainan UniversityHaikou, China
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
| | - Zhiqiang Xia
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
| | - Changying Zeng
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
| | - Cheng Lu
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
| | - Wenquan Wang
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of AgricultureHaikou, China
- *Correspondence: Xin Chen, Wenquan Wang,
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Cheng L, Liu X, Yin J, Yang J, Li Y, Hui L, Li S, Li L. Activity and expression of ADP-glucose pyrophosphorylase during rhizome formation in lotus (Nelumbo nucifera Gaertn.). Bot Stud 2016; 57:26. [PMID: 28597436 PMCID: PMC5432948 DOI: 10.1186/s40529-016-0140-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/20/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Lotus root is a traditional and popular aquatic vegetable in China. Starch is an important component of the rhizome and directly affects the quality of processed products. ADP -glucose pyrophosphorylase (AGPase) is a rate-limiting enzyme associated with starch biosynthesis in plants. Therefore, in the present study, AGPase activity and NnAGP expression during rhizome development of lotus were analyzed. RESULTS Among 15 cultivars analyzed, the contents of amylose and total starch in the rhizome were highest in 'Mei Ren Hong'. 'Su Zhou' and 'Zhen Zhu' showed the lowest amylose, amylopectin and total starch contents. In the rhizome, activity of AGPase was highest at the middle swelling stage of development, and higher activity was observed in the 'Hou ba' leaf and terminational leaf at the same stage. Three AGPase genes, comprising two large subunit genes (NnAGPL1 and NnAGPL2) and one small subunit gene (NnAGPS), were isolated and identified. The deduced amino acid sequences showed 40.5 % similarity among the three genes. Full-length genomic DNA sequences of NnAGPL1, NnAGPL2, and NnAGPS were 4841, 11,346 and 4169 bp, respectively. Analysis of the temporal and spatial expression patterns revealed that the transcription levels of NnAGPL1 and NnAGPS were higher in the rhizome, followed by the 'Hou ba' leaf, whereas NnAGPL2 was significantly detected in the 'Hou ba' leaf and terminational leaf. The initial swelling stage of rhizome development was accompanied by the highest accumulation of mRNAs of NnAGPL1, whereas expression of NnAGPL2 was not detected during rhizome development. The transcript level of NnAGPS was highest at the initial swelling stage compared with the other rhizome developmental stages. Transcription of NnAGPL1, NnAGPL2, and NnAGPS was induced within 24 h after treatment with exogenous sucrose. The mRNA level of NnAGPL1 and NnAGPS was increased by exogenous ABA, whereas transcription of NnAGPL2 was not affected by ABA. CONCLUSIONS The three AGPase genes display marked differences in spatial and temporal expression patterns. Regulation of AGPase in relation to starch synthesis in lotus is indicated to be complex.
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Affiliation(s)
- Libao Cheng
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
| | - Xian Liu
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
| | - Jingjing Yin
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
| | - Jianqiu Yang
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
| | - Yan Li
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
| | - Linchong Hui
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
| | - Shuyan Li
- College of Guangling, Yangzhou University, Yangzhou, Jiangsu China
| | - Liangjun Li
- School of Horticulture and Plant Protection of Yangzhou University, Yangzhou, Jiangsu China
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Seferoglu AB, Gul S, Dikbas UM, Baris I, Koper K, Caliskan M, Cevahir G, Kavakli IH. Glu-370 in the large subunit influences the substrate binding, allosteric, and heat stability properties of potato ADP-glucose pyrophosphorylase. Plant Sci 2016; 252:125-132. [PMID: 27717448 DOI: 10.1016/j.plantsci.2016.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 06/06/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is a key allosteric enzyme in plant starch biosynthesis. Plant AGPase is a heterotetrameric enzyme that consists of large (LS) and small subunits (SS), which are encoded by two different genes. In this study, we showed that the conversion of Glu to Gly at position 370 in the LS of AGPase alters the heterotetrameric stability along with the binding properties of substrate and effectors of the enzyme. Kinetic analyses revealed that the affinity of the LSE370GSSWT AGPase for glucose-1-phosphate is 3-fold less than for wild type (WT) AGPase. Additionally, the LSE370GSSWT AGPase requires 3-fold more 3-phosphogyceric acid to be activated. Finally, the LSE370GSSWTAGPase is less heat stable compared with the WT AGPase. Computational analysis of the mutant Gly-370 in the 3D modeled LS AGPase showed that this residue changes charge distribution of the surface and thus affect stability of the LS AGPase and overall heat stability of the heterotetrameric AGPase. In summary, our results show that LSE370 intricately modulate the heat stability and enzymatic activity of potato the AGPase.
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Affiliation(s)
- Ayse Bengisu Seferoglu
- Koc University, Department of Chemical and Biological Engineering, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey
| | - Seref Gul
- Koc University, Department of Chemical and Biological Engineering, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey
| | - Ugur Meric Dikbas
- Koc University, Department of Molecular Biology and Genetics, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey
| | - Ibrahim Baris
- Koc University, Department of Molecular Biology and Genetics, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey
| | - Kaan Koper
- Koc University, Department of Chemical and Biological Engineering, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey
| | - Mahmut Caliskan
- Istanbul University, Department of Biology, 34134 Suleymaniye, Istanbul, Turkey
| | - Gul Cevahir
- Istanbul University, Department of Biology, 34134 Suleymaniye, Istanbul, Turkey
| | - Ibrahim Halil Kavakli
- Koc University, Department of Chemical and Biological Engineering, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey; Koc University, Department of Molecular Biology and Genetics, Rumelifeneri Yolu, Sariyer, Istanbul, Turkey.
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23
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Lee SK, Eom JS, Hwang SK, Shin D, An G, Okita TW, Jeon JS. Plastidic phosphoglucomutase and ADP-glucose pyrophosphorylase mutants impair starch synthesis in rice pollen grains and cause male sterility. J Exp Bot 2016; 67:5557-5569. [PMID: 27588462 PMCID: PMC5049399 DOI: 10.1093/jxb/erw324] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
To elucidate the starch synthesis pathway and the role of this reserve in rice pollen, we characterized mutations in the plastidic phosphoglucomutase, OspPGM, and the plastidic large subunit of ADP-glucose (ADP-Glc) pyrophosphorylase, OsAGPL4 Both genes were up-regulated in maturing pollen, a stage when starch begins to accumulate. Progeny analysis of self-pollinated heterozygous lines carrying the OspPGM mutant alleles, osppgm-1 and osppgm-2, or the OsAGPL4 mutant allele, osagpl4-1, as well as reciprocal crosses between the wild type (WT) and heterozygotes revealed that loss of OspPGM or OsAGPL4 caused male sterility, with the former condition rescued by the introduction of the WT OspPGM gene. While iodine staining and transmission electron microscopy analyses of pollen grains from homozygous osppgm-1 lines produced by anther culture confirmed the starch null phenotype, pollen from homozygous osagpl4 mutant lines, osagpl4-2 and osagpl4-3, generated by the CRISPR/Cas system, accumulated small amounts of starch which were sufficient to produce viable seed. Such osagpl4 mutant pollen, however, was unable to compete against WT pollen successfully, validating the important role of this reserve in fertilization. Our results demonstrate that starch is mainly polymerized from ADP-Glc synthesized from plastidic hexose phosphates in rice pollen and that starch is an essential requirement for successful fertilization in rice.
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Affiliation(s)
- Sang-Kyu Lee
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea
| | - Joon-Seob Eom
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea
| | - Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
| | - Dongjin Shin
- Department of Southern Area Crop Science, National Institute of Crop Science, Rural Development Administration, Milyang 50424, Korea
| | - Gynheung An
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
| | - Jong-Seong Jeon
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea
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Bhattacharya S, Das N, Maiti MK. Cumulative effect of heterologous AtWRI1 gene expression and endogenous BjAGPase gene silencing increases seed lipid content in Indian mustard Brassica juncea. Plant Physiol Biochem 2016; 107:204-213. [PMID: 27314514 DOI: 10.1016/j.plaphy.2016.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/10/2016] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
The production of vegetable oil in many countries of the world, including India has not been able to keep pace with the increasing requirement, leading to a very large gap in the demand-supply chain. Thus, there is an urgent need to increase the yield potential of the oilseed crops so as to enhance the storage lipid productivity. The present study describes a novel metabolic engineering ploy involving the constitutive down-regulation of endogenous ADP-glucose pyrophosphorylase (BjAGPase) enzyme and the seed-specific expression of WRINKLED1 transcription factor (AtWRI1) from Arabidopsis thaliana in Indian mustard (Brassica juncea) with an aim to divert the photosynthetically fixed carbon pool from starch to lipid synthesis in the seeds for the enhanced production of storage lipids in the seeds of transgenic mustard plants. The starch content, in both the vegetative leaf and developing seed tissues of the transgenic B. juncea lines exhibited a reduction by about 45-53% compared to the untransformed control, whereas the soluble sugar content was increased by 2.4 and 1.3-fold in the leaf and developing seed tissues, respectively. Consequently, the transgenic lines showed a significant enhancement in total seed lipid content ranging between 7.5 and 16.9%. The results indicate that the adopted metabolic engineering strategy was successful in significantly increasing the seed oil content. Therefore, findings of our research suggest that the metabolic engineering strategy adopted in this study for shifting the anabolic carbon flux from starch synthesis to lipid biosynthesis can be employed for increasing the storage lipid content of seeds in other plant species.
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Affiliation(s)
- Surajit Bhattacharya
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Natasha Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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Cereijo AE, Asencion Diez MD, Dávila Costa JS, Alvarez HM, Iglesias AA. On the Kinetic and Allosteric Regulatory Properties of the ADP-Glucose Pyrophosphorylase from Rhodococcus jostii: An Approach to Evaluate Glycogen Metabolism in Oleaginous Bacteria. Front Microbiol 2016; 7:830. [PMID: 27313571 PMCID: PMC4890535 DOI: 10.3389/fmicb.2016.00830] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/17/2016] [Indexed: 01/29/2023] Open
Abstract
Rhodococcus spp. are oleaginous bacteria that accumulate glycogen during exponential growth. Despite the importance of these microorganisms in biotechnology, little is known about the regulation of carbon and energy storage, mainly the relationship between glycogen and triacylglycerols metabolisms. Herein, we report the molecular cloning and heterologous expression of the gene coding for ADP-glucose pyrophosphorylase (EC 2.7.7.27) of Rhodococcus jostii, strain RHA1. The recombinant enzyme was purified to electrophoretic homogeneity to accurately characterize its oligomeric, kinetic, and regulatory properties. The R. jostii ADP-glucose pyrophosphorylase is a homotetramer of 190 kDa exhibiting low basal activity to catalyze synthesis of ADP-glucose, which is markedly influenced by different allosteric effectors. Glucose-6P, mannose-6P, fructose-6P, ribose-5P, and phosphoenolpyruvate were major activators; whereas, NADPH and 6P-gluconate behaved as main inhibitors of the enzyme. The combination of glucose-6P and other effectors (activators or inhibitors) showed a cross-talk effect suggesting that the different metabolites could orchestrate a fine regulation of ADP-glucose pyrophosphorylase in R. jostii. The enzyme exhibited some degree of affinity toward ATP, GTP, CTP, and other sugar-1P substrates. Remarkably, the use of glucosamine-1P was sensitive to allosteric activation. The relevance of the fine regulation of R. jostii ADP-glucose pyrophosphorylase is further analyzed in the framework of proteomic studies already determined for the bacterium. Results support a critical role for glycogen as a temporal reserve that provides a pool of carbon able of be re-routed to produce long-term storage of lipids under certain conditions.
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Affiliation(s)
- Antonela E Cereijo
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral, CONICET, Centro Científico Tecnológico, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina
| | - Matías D Asencion Diez
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral, CONICET, Centro Científico Tecnológico, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina
| | - José S Dávila Costa
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales Universidad Nacional de la Patagonia San Juan Bosco Comodoro Rivadavia, Argentina
| | - Héctor M Alvarez
- Centro Regional de Investigación y Desarrollo Científico Tecnológico, Facultad de Ciencias Naturales Universidad Nacional de la Patagonia San Juan Bosco Comodoro Rivadavia, Argentina
| | - Alberto A Iglesias
- Laboratorio de Enzimología Molecular, Instituto de Agrobiotecnología del Litoral, CONICET, Centro Científico Tecnológico, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral Santa Fe, Argentina
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26
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Seng S, Wu J, Sui J, Wu C, Zhong X, Liu C, Liu C, Gong B, Zhang F, He J, Yi M. ADP-glucose pyrophosphorylase gene plays a key role in the quality of corm and yield of cormels in gladiolus. Biochem Biophys Res Commun 2016; 474:206-212. [PMID: 27107698 DOI: 10.1016/j.bbrc.2016.04.103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 04/19/2016] [Indexed: 11/29/2022]
Abstract
Starch is the main storage compound in underground organs like corms. ADP-glucose pyrophosphorylase (AGPase) plays a key role in regulating starch biosynthesis in storage organs and is likely one of the most important determinant of sink strength. Here, we identify an AGPase gene (GhAGPS1) from gladiolus. The highest transcriptional levels of GhAGPS1 were observed in cormels and corms. Transformation of GhAGPS1 into Arabidopsis rescued the phenotype of aps1 mutant. Silencing GhAGPS1 in gladiolus corms by virus-induced gene silencing (VIGS) decreased the transcriptional levels of two genes and starch content. Transmission electron microscopy analyses of leaf and corm sections confirmed that starch biosynthesis was inhibited. Corm weight and cormel number reduced significantly in the silenced plants. Taken together, these results indicate that inhibiting the expression of AGPase gene could impair starch synthesis, which results in the lowered corm quality and cormel yield in gladiolus.
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Affiliation(s)
- Shanshan Seng
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China.
| | - Jian Wu
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Juanjuan Sui
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China; College of Biology, Fuyang Normal College, Qinghe Western Road 100#, Fuyang 236037, Anhui, China
| | - Chenyu Wu
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Xionghui Zhong
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Chen Liu
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Chao Liu
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Benhe Gong
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Fengqin Zhang
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Junna He
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China
| | - Mingfang Yi
- Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Yuan Mingyuan Western Road 2#, Beijing 100193, China.
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Liu N, Xue Y, Guo Z, Li W, Tang J. Genome-Wide Association Study Identifies Candidate Genes for Starch Content Regulation in Maize Kernels. Front Plant Sci 2016; 7:1046. [PMID: 27512395 PMCID: PMC4961707 DOI: 10.3389/fpls.2016.01046] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/04/2016] [Indexed: 05/18/2023]
Abstract
Kernel starch content is an important trait in maize (Zea mays L.) as it accounts for 65-75% of the dry kernel weight and positively correlates with seed yield. A number of starch synthesis-related genes have been identified in maize in recent years. However, many loci underlying variation in starch content among maize inbred lines still remain to be identified. The current study is a genome-wide association study that used a set of 263 maize inbred lines. In this panel, the average kernel starch content was 66.99%, ranging from 60.60 to 71.58% over the three study years. These inbred lines were genotyped with the SNP50 BeadChip maize array, which is comprised of 56,110 evenly spaced, random SNPs. Population structure was controlled by a mixed linear model (MLM) as implemented in the software package TASSEL. After the statistical analyses, four SNPs were identified as significantly associated with starch content (P ≤ 0.0001), among which one each are located on chromosomes 1 and 5 and two are on chromosome 2. Furthermore, 77 candidate genes associated with starch synthesis were found within the 100-kb intervals containing these four QTLs, and four highly associated genes were within 20-kb intervals of the associated SNPs. Among the four genes, Glucose-1-phosphate adenylyltransferase (APS1; Gene ID GRMZM2G163437) is known as an important regulator of kernel starch content. The identified SNPs, QTLs, and candidate genes may not only be readily used for germplasm improvement by marker-assisted selection in breeding, but can also elucidate the genetic basis of starch content. Further studies on these identified candidate genes may help determine the molecular mechanisms regulating kernel starch content in maize and other important cereal crops.
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Affiliation(s)
- Na Liu
- College of Biological Engineering, Henan University of TechnologyZhengzhou, China
- State Key Laboratory of Wheat and Maize Crop Science/Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural UniversityZhengzhou, China
| | - Yadong Xue
- State Key Laboratory of Wheat and Maize Crop Science/Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural UniversityZhengzhou, China
| | - Zhanyong Guo
- State Key Laboratory of Wheat and Maize Crop Science/Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural UniversityZhengzhou, China
| | - Weihua Li
- State Key Laboratory of Wheat and Maize Crop Science/Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural UniversityZhengzhou, China
| | - Jihua Tang
- State Key Laboratory of Wheat and Maize Crop Science/Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural UniversityZhengzhou, China
- Hubei Collaborative Innovation Center for Grain Industry, Yangtze UniversityJinzhou, China
- *Correspondence: Jihua Tang,
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Cakir B, Tuncel A, Green AR, Koper K, Hwang SK, Okita TW, Kang C. Substrate binding properties of potato tuber ADP-glucose pyrophosphorylase as determined by isothermal titration calorimetry. FEBS Lett 2015; 589:1444-9. [PMID: 25953126 DOI: 10.1016/j.febslet.2015.04.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 04/14/2015] [Accepted: 04/21/2015] [Indexed: 11/15/2022]
Abstract
Substrate binding properties of the large (LS) and small (SS) subunits of potato tuber ADP-glucose pyrophosphorylase were investigated by using isothermal titration calorimetry. Our results clearly show that the wild type heterotetramer (S(WT)L(WT)) possesses two distinct types of ATP binding sites, whereas the homotetrameric LS and SS variant forms only exhibited properties of one of the two binding sites. The wild type enzyme also exhibited significantly increased affinity to this substrate compared to the homotetrameric enzyme forms. No stable binding was evident for the second substrate, glucose-1-phosphate, in the presence or absence of ATPγS suggesting that interaction of glucose-1-phosphate is dependent on hydrolysis of ATP and supports the Theorell-Chance bi bi reaction mechanism.
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Affiliation(s)
- Bilal Cakir
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Abigail R Green
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
| | - Kaan Koper
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA.
| | - ChulHee Kang
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA.
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Asención Diez MD, Demonte AM, Syson K, Arias DG, Gorelik A, Guerrero SA, Bornemann S, Iglesias AA. Allosteric regulation of the partitioning of glucose-1-phosphate between glycogen and trehalose biosynthesis in Mycobacterium tuberculosis. Biochim Biophys Acta Gen Subj 2014; 1850:13-21. [PMID: 25277548 PMCID: PMC4331664 DOI: 10.1016/j.bbagen.2014.09.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/20/2014] [Accepted: 09/22/2014] [Indexed: 11/16/2022]
Abstract
Background Mycobacterium tuberculosis is a pathogenic prokaryote adapted to survive in hostile environments. In this organism and other Gram-positive actinobacteria, the metabolic pathways of glycogen and trehalose are interconnected. Results In this work we show the production, purification and characterization of recombinant enzymes involved in the partitioning of glucose-1-phosphate between glycogen and trehalose in M. tuberculosis H37Rv, namely: ADP-glucose pyrophosphorylase, glycogen synthase, UDP-glucose pyrophosphorylase and trehalose-6-phosphate synthase. The substrate specificity, kinetic parameters and allosteric regulation of each enzyme were determined. ADP-glucose pyrophosphorylase was highly specific for ADP-glucose while trehalose-6-phosphate synthase used not only ADP-glucose but also UDP-glucose, albeit to a lesser extent. ADP-glucose pyrophosphorylase was allosterically activated primarily by phosphoenolpyruvate and glucose-6-phosphate, while the activity of trehalose-6-phosphate synthase was increased up to 2-fold by fructose-6-phosphate. None of the other two enzymes tested exhibited allosteric regulation. Conclusions Results give information about how the glucose-1-phosphate/ADP-glucose node is controlled after kinetic and regulatory properties of key enzymes for mycobacteria metabolism. General significance This work increases our understanding of oligo and polysaccharides metabolism in M. tuberculosis and reinforces the importance of the interconnection between glycogen and trehalose biosynthesis in this human pathogen. Nucleotide-glucose synthesis in Mycobacterium tuberculosis was analyzed. The characterization of four enzymes involved in glucose-1P partitioning is reported. Mycobacterial ADP-glucose pyrophosphorylase is allosterically regulated. Trehalose-6P synthase exhibits higher catalytic efficiency for ADP-glucose. Trehalose-6P synthase is activated by fructose-6P.
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Affiliation(s)
- Matías D Asención Diez
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, Paraje El Pozo, S3000ZAA Santa Fe, Argentina
| | - Ana M Demonte
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, Paraje El Pozo, S3000ZAA Santa Fe, Argentina
| | - Karl Syson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Diego G Arias
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, Paraje El Pozo, S3000ZAA Santa Fe, Argentina
| | - Andrii Gorelik
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Sergio A Guerrero
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, Paraje El Pozo, S3000ZAA Santa Fe, Argentina
| | - Stephen Bornemann
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Alberto A Iglesias
- Instituto de Agrobiotecnología del Litoral (UNL-CONICET), Facultad de Bioquímica y Ciencias Biológicas, Paraje El Pozo, S3000ZAA Santa Fe, Argentina.
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Tuncel A, Cakir B, Hwang SK, Okita TW. The role of the large subunit in redox regulation of the rice endosperm ADP-glucose pyrophosphorylase. FEBS J 2014; 281:4951-63. [PMID: 25204204 DOI: 10.1111/febs.13041] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/08/2014] [Accepted: 09/04/2014] [Indexed: 01/31/2023]
Abstract
The starch regulatory enzyme ADP-glucose pyrophosphorylase is activated by 3-phosphoglyceric acid (3-PGA) and inhibited by inorganic phosphate (Pi ). The activity of the plastid-localized enzyme is also subject to fine regulation by redox control in response to changing light and sugar levels. The less active oxidized form of the enzyme contains an inter-subunit disulfide bond formed between the pair of small subunit's Cys12 residues of the heterotetrameric enzyme. Although this cysteine residue is not conserved in the small subunits of cereal endosperm cytosolic AGPases, biochemical studies of the major rice endosperm enzyme indicate that the cytosolic isoform, like the plastidial enzymes, is subject to redox control. Kinetic analysis revealed that the reduced forms of the partially purified native and purified recombinant AGPases have 6- and 3.4-fold, respectively, more affinity to 3-PGA, rendering the enzymes more active at lower 3-PGA concentration than the non-reduced enzyme. Truncation of the large subunit by removal of N-terminal peptide resulted in a decrease in 3-PGA affinity and loss of redox response of the enzyme. Site-directed mutagenesis of the conserved cysteine residues at the N-terminal of the large subunit showed that C47 and C58, but not C12, are essential for proper redox response of the enzyme. Overall, our results show that the major rice endosperm AGPase activity is controlled by a combination of allosteric regulation and redox control, the latter through modification of the large subunit instead of the small subunit as evident in the plastid-localized enzyme.
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Affiliation(s)
- Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
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Seferoglu AB, Koper K, Can FB, Cevahir G, Kavakli IH. Enhanced heterotetrameric assembly of potato ADP-glucose pyrophosphorylase using reverse genetics. Plant Cell Physiol 2014; 55:1473-1483. [PMID: 24891561 DOI: 10.1093/pcp/pcu078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is a key allosteric enzyme in plant starch biosynthesis. Plant AGPase is a heterotetrameric enzyme that consists of large (LS) and small subunits (SS), which are encoded by two different genes. Computational and experimental studies have revealed that the heterotetrameric assembly of AGPase is thermodynamically weak. Modeling studies followed by the mutagenesis of the LS of the potato AGPase identified a heterotetramer-deficient mutant, LS(R88A). To enhance heterotetrameric assembly, LS(R88A) cDNA was subjected to error-prone PCR, and second-site revertants were identified according to their ability to restore glycogen accumulation, as assessed with iodine staining. Selected mutations were introduced into the wild-type (WT) LS and co-expressed with the WT SS in Escherichia coli glgC(-). The biochemical characterization of revertants revealed that LS(I90V)SS(WT), LS(Y378C)SS(WT) and LS(D410G)SS(WT) mutants displayed enhanced heterotetrameric assembly with the WT SS. Among these mutants, LS(Y378C)SS(WT) AGPase displayed increased heat stability compared with the WT enzyme. Kinetic characterization of the mutants indicated that the LS(I90V)SS(WT) and LS(Y378C)SS(WT) AGPases have comparable allosteric and kinetic properties. However, the LS(D410G)SS(WT) mutant exhibited altered allosteric properties of being less responsive and more sensitive to 3-phosphoglyceric acid activation and inorganic phosphate inhibition. This study not only enhances our understanding of the interaction between the SS and the LS of AGPase but also enables protein engineering to obtain enhanced assembled heat-stable variants of AGPase, which can be used for the improvement of plant yields.
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Affiliation(s)
- A Bengisu Seferoglu
- Department of Chemical and Biological Engineering, Koc University, Rumeli Feneri Yolu, 34450 Sariyer, Turkey
| | - Kaan Koper
- Department of Chemical and Biological Engineering, Koc University, Rumeli Feneri Yolu, 34450 Sariyer, Turkey
| | - F Betul Can
- Department of Molecular Biology and Genetics, Koc University, Rumeli Feneri Yolu, 34450 Sariyer, Turkey
| | - Gul Cevahir
- Istanbul University, Department of Biology, 34134 Suleymaniye, Istanbul, Turkey
| | - I Halil Kavakli
- Department of Chemical and Biological Engineering, Koc University, Rumeli Feneri Yolu, 34450 Sariyer, TurkeyDepartment of Molecular Biology and Genetics, Koc University, Rumeli Feneri Yolu, 34450 Sariyer, Turkey
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Tuncel A, Kawaguchi J, Ihara Y, Matsusaka H, Nishi A, Nakamura T, Kuhara S, Hirakawa H, Nakamura Y, Cakir B, Nagamine A, Okita TW, Hwang SK, Satoh H. The rice endosperm ADP-glucose pyrophosphorylase large subunit is essential for optimal catalysis and allosteric regulation of the heterotetrameric enzyme. Plant Cell Physiol 2014; 55:1169-83. [PMID: 24747952 DOI: 10.1093/pcp/pcu057] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Although an alternative pathway has been suggested, the prevailing view is that starch synthesis in cereal endosperm is controlled by the activity of the cytosolic isoform of ADPglucose pyrophosphorylase (AGPase). In rice, the cytosolic AGPase isoform is encoded by the OsAGPS2b and OsAGPL2 genes, which code for the small (S2b) and large (L2) subunits of the heterotetrameric enzyme, respectively. In this study, we isolated several allelic missense and nonsense OsAGPL2 mutants by N-methyl-N-nitrosourea (MNU) treatment of fertilized egg cells and by TILLING (Targeting Induced Local Lesions in Genomes). Interestingly, seeds from three of the missense mutants (two containing T139I and A171V) were severely shriveled and had seed weight and starch content comparable with the shriveled seeds from OsAGPL2 null mutants. Results from kinetic analysis of the purified recombinant enzymes revealed that the catalytic and allosteric regulatory properties of these mutant enzymes were significantly impaired. The missense heterotetramer enzymes and the S2b homotetramer had lower specific (catalytic) activities and affinities for the activator 3-phosphoglycerate (3-PGA). The missense heterotetramer enzymes showed more sensitivity to inhibition by the inhibitor inorganic phosphate (Pi) than the wild-type AGPase, while the S2b homotetramer was profoundly tolerant to Pi inhibition. Thus, our results provide definitive evidence that starch biosynthesis during rice endosperm development is controlled predominantly by the catalytic activity of the cytoplasmic AGPase and its allosteric regulation by the effectors. Moreover, our results show that the L2 subunit is essential for both catalysis and allosteric regulatory properties of the heterotetramer enzyme.
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Affiliation(s)
- Aytug Tuncel
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USAThese authors contributed equally to this work
| | - Joe Kawaguchi
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 JapanThese authors contributed equally to this work
| | - Yasuharu Ihara
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | | | - Aiko Nishi
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | | | - Satoru Kuhara
- Department of Genetic Resources Technology, Kyushu University, Fukuoka, 812-8581 Japan
| | - Hideki Hirakawa
- Kazusa DNA Research Institute, Department of Plant Genome Research, Kisarazu, Japan
| | - Yasunori Nakamura
- Faculty of Bioresource Sciences, Akita Prefectural University, Akita City, 010-0195 Japan
| | - Bilal Cakir
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Ai Nagamine
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USAFaculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Seon-Kap Hwang
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
| | - Hikaru Satoh
- Faculty of Agriculture, Kyushu University, Fukuoka, 812-8581 Japan
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Li FP, Yoon MY, Li G, Ra WH, Park JW, Kwon SJ, Kwon SW, Ahn IP, Park YJ. Transcriptome analysis of grain-filling caryopses reveals the potential formation mechanism of the rice sugary mutant. Gene 2014; 546:318-26. [PMID: 24875416 DOI: 10.1016/j.gene.2014.05.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 05/14/2014] [Accepted: 05/26/2014] [Indexed: 11/17/2022]
Abstract
A sugary mutant with low total starch and high sugar contents was compared with its wild type Sindongjin for grain-filling caryopses. In the present study, developing seeds of Sindongjin and sugary mutant from the 11th day after flowering (DAF) were subjected to RNA sequencing (RNA-Seq). A total of 30,385 and 32,243 genes were identified in Sindongjin and sugary mutant. Transcriptomic change analysis showed that 7713 differentially expressed genes (DEGs) (log₂ fold change ≥1, false discovery rate (FDR)≤0.001) were identified based on our RNA-Seq data, with 7239 genes up-regulated and 474 down-regulated in the sugary mutant. A large number of DEGs were found related to metabolic, biosynthesis of secondary metabolites, plant-pathogen interaction, plant hormone signal transduction and starch/sugar metabolism. Detailed pathway dissection and quantitative real time PCR (qRT-PCR) demonstrated that most genes involved in sucrose to starch synthesis are up-regulated, whereas the expression of the ADP-glucose pyrophosphorylase small subunit (OsAGPS2b) catalyzing the first committed step of starch biosynthesis was specifically inhibited during the grain-filling stage in sugary mutant. Further analysis suggested that the OsAGPS2b is a considerable candidate gene responsible for phenotype of sugary mutant.
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Affiliation(s)
- Feng-peng Li
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan 340-702, Republic of Korea
| | - Min-Young Yoon
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan 340-702, Republic of Korea
| | - Gang Li
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan 340-702, Republic of Korea
| | - Won-Hee Ra
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan 340-702, Republic of Korea
| | - Jae-Wan Park
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan 340-702, Republic of Korea
| | - Soon-Jae Kwon
- Advanced Radiation Technology Institute, Atomic Energy Research Institute, Jeongeup 580-185, Republic of Korea
| | - Soon-Wook Kwon
- Department of Plant Bioscience, College of Natural Resources and Life Science, Pusan National University, Milyang 627-706, Republic of Korea
| | - Il-Pyung Ahn
- National Academy of Agricultural Science, Rural Development Administration, Suwon 441-107, Republic of Korea
| | - Yong-Jin Park
- Department of Plant Resources, College of Industrial Sciences, Kongju National University, Yesan 340-702, Republic of Korea.
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Boehlein SK, Shaw JR, Georgelis N, Hannah LC. Enhanced heat stability and kinetic parameters of maize endosperm ADPglucose pyrophosphorylase by alteration of phylogenetically identified amino acids. Arch Biochem Biophys 2013; 543:1-9. [PMID: 24378757 DOI: 10.1016/j.abb.2013.12.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 12/12/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Abstract
ADP-glucose pyrophosphorylase (AGPase) controls the rate-limiting step in starch biosynthesis and is regulated at various levels. Cereal endosperm enzymes, in contrast to other plant AGPases, are particularly heat labile and transgenic studies highlight the importance of temperature for cereal yield. Previously, a phylogenetic approach identified Type II and positively selected amino acid positions in the large subunit of maize endosperm AGPase. Glycogen content, kinetic parameters and heat stability were measured in AGPases having mutations in these sites and interesting differences were observed. This study expands on our earlier evolutionary work by determining how all Type II and positively selected sites affect kinetic constants, heat stability and catalytic rates at increased temperatures. Variants with enhanced properties were identified and combined into one gene, designated Sh2-E. Enhanced properties include: heat stability, enhanced activity at 37 °C, activity at 55 °C, reduced Ka and activity in the absence of activator. The resulting enzyme exhibited all improved properties of the various individual changes. Additionally, Sh2-E was expressed with a small subunit variant with enhanced enzyme properties resulting in an enzyme that has exceptional heat stability, a high catalytic rate at increased temperatures and significantly decreased Km values for both substrates in the absence of the activator.
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Affiliation(s)
- Susan K Boehlein
- 1253 Fifield Hall, University of Florida, Gainesville, FL 32611, USA
| | - Janine R Shaw
- 1253 Fifield Hall, University of Florida, Gainesville, FL 32611, USA
| | | | - L Curtis Hannah
- 1253 Fifield Hall, University of Florida, Gainesville, FL 32611, USA.
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Lepistö A, Pakula E, Toivola J, Krieger-Liszkay A, Vignols F, Rintamäki E. Deletion of chloroplast NADPH-dependent thioredoxin reductase results in inability to regulate starch synthesis and causes stunted growth under short-day photoperiods. J Exp Bot 2013; 64:3843-54. [PMID: 23881397 PMCID: PMC3745738 DOI: 10.1093/jxb/ert216] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plastid-localized NADPH-dependent thioredoxin reductase C (NTRC) is a unique NTR enzyme containing both reductase and thioredoxin domains in a single polypeptide. Arabidopsis thaliana NTRC knockout lines (ntrc) show retarded growth, especially under short-day (SD) photoperiods. This study identified chloroplast processes that accounted for growth reduction in SD-acclimated ntrc. The strongest reduction in ntrc growth occurred under photoperiods with nights longer than 14 h, whereas knockout of the NTRC gene did not alter the circadian-clock-controlled growth of Arabidopsis. Lack of NTRC modulated chloroplast reactive oxygen species (ROS) metabolism, but oxidative stress was not the primary cause of retarded growth of SD-acclimated ntrc. Scarcity of starch accumulation made ntrc leaves particularly vulnerable to photoperiods with long nights. Direct interaction of NTRC and ADP-glucose pyrophosphorylase, a key enzyme in starch synthesis, was confirmed by yeast two-hybrid analysis. The ntrc line was not able to maximize starch synthesis during the light period, which was particularly detrimental under SD conditions. Acclimation of Arabidopsis to SD conditions also involved an inductive rise of ROS production in illuminated chloroplasts that was not counterbalanced by the activation of plastidial anti-oxidative systems. It is proposed that knockout of NTRC challenges redox regulation of starch synthesis, resulting in stunted growth of the mutant lines acclimated to the SD photoperiod.
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Affiliation(s)
- Anna Lepistö
- Molecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
| | - Eveliina Pakula
- Molecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
| | - Jouni Toivola
- Molecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
| | - Anja Krieger-Liszkay
- Commissariat à l’Energie Atomique, Institut de Biologie et Technologies de Saclay, CNRS Unité Mixte de Recherche 8221, F-91191 Gif-sur-Yvette cedex, France
| | - Florence Vignols
- Institut de Recherche et Développement, Equipe Effecteurs-Cibles des pathosystèmes du Riz, UMR186 IRD.UM2.CIRAD Résistance des Plantes aux Bioagresseurs, 911 Avenue Agropolis BP64501, 34394 Montpellier Cedex 5, France
| | - Eevi Rintamäki
- Molecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Gothenburg, Sweden
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Liu DR, Huang WX, Cai XL. Oligomerization of rice granule-bound starch synthase 1 modulates its activity regulation. Plant Sci 2013; 210:141-50. [PMID: 23849121 DOI: 10.1016/j.plantsci.2013.05.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Boehlein SK, Shaw JR, McCarty DR, Hwang SK, Stewart JD, Hannah LC. The potato tuber, maize endosperm and a chimeric maize-potato ADP-glucose pyrophosphorylase exhibit fundamental differences in Pi inhibition. Arch Biochem Biophys 2013; 537:210-6. [PMID: 23906662 DOI: 10.1016/j.abb.2013.07.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/09/2013] [Accepted: 07/16/2013] [Indexed: 10/26/2022]
Abstract
ADP-glucose pyrophosphorylase (AGPase) is highly regulated by allosteric effectors acting both positively and negatively. Enzymes from various sources differ, however, in the mechanism of allosteric regulation. Here, we determined how the effector, inorganic phosphate (Pi), functions in the presence and absence of saturating amounts of the activator, 3-phosphoglyceric acid (3-PGA). This regulation was examined in the maize endosperm enzyme, the oxidized and reduced forms of the potato tuber enzyme as well as a small subunit chimeric AGPase (MP), which contains both maize endosperm and potato tuber sequences paired with a wild-type maize large subunit. These data, combined with our previous kinetic studies of these enzymes led to a model of Pi inhibition for the various enzymes. The Pi inhibition data suggest that while the maize enzyme contains a single effector site that binds both 3-PGA and Pi, the other enzymes exhibit more complex behavior and most likely have at least two separate interacting binding sites for Pi. The possible physiological implications of the differences in Pi inhibition distinguishing the maize endosperm and potato tuber AGPases are discussed.
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Affiliation(s)
- Susan K Boehlein
- Program in Plant Molecular and Cellular Biology and Horticultural Sciences, University of Florida, 1253 Fifield Hall, Gainesville, FL 32611, USA
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Danishuddin M, Chatrath R, Singh R. Insights of interaction between small and large subunits of ADP-glucose pyrophosphorylase from bread wheat (Triticum aestivum L.). Bioinformation 2011; 6:144-8. [PMID: 21572880 PMCID: PMC3092947 DOI: 10.6026/97320630006144] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 01/29/2011] [Indexed: 11/23/2022] Open
Abstract
Lack of knowledge of three dimensional structures of small and large subunits of ADP- glucose pyrophosphorylase (AGPase) in wheat has hindered efforts to understand the binding specifities of substrate and catalytic mechanism. Thus, to understand the structure activity relationship, 3D structures were built by homology modelling based on crystal structure of potato tuber ADP-glucose pyrophosphorylase. Selected models were refined by energy minimization and further validated by Procheck and Prosa-web analysis. Ramachandran plot showed that overall main chain and side chain parameters are favourable. Moreover, Z-score of the models from Prosa-web analysis gave the conformation that they are in the range of the template. Interaction analysis depicts the involvement of six amino acids in hydrogen bonding (AGP-SThr422-AGP-LMet138, AGP- SArg420-AGP-LGly47, AGP-SSer259-AGP-LSer306, AGP-SGlu241-AGP-LIle311, AGPSGln113- AGP-LGlu286 and AGP-SGln70-AGP-LLys291). Fifteen amino acids of small subunit were able to make hydrophobic contacts with seventeen amino acids of large subunit. Furthermore, decrease in the solvent accessible surface area in the amino acids involved in interaction were also reported. All the distances were formed in between 2.27 to 3.78Å. The present study focussed on heterodimeric structure of (AGPase). This predicted complex not only enhance our understanding of the interaction mechanism between these subunits (AGP-L and AGP-S) but also enable to further study to obtain better variants of this enzyme for the improvement of the plant yield.
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Affiliation(s)
- Mohd Danishuddin
- Directorate of Wheat Research, Post Box 158, Karnal - 132001, India
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