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Puzanskiy RK, Romanyuk DA, Kirpichnikova AA, Yemelyanov VV, Shishova MF. Plant Heterotrophic Cultures: No Food, No Growth. PLANTS (BASEL, SWITZERLAND) 2024; 13:277. [PMID: 38256830 PMCID: PMC10821431 DOI: 10.3390/plants13020277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 01/10/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024]
Abstract
Plant cells are capable of uptaking exogenous organic substances. This inherited trait allows the development of heterotrophic cell cultures in various plants. The most common of them are Nicotiana tabacum and Arabidopsis thaliana. Plant cells are widely used in academic studies and as factories for valuable substance production. The repertoire of compounds supporting the heterotrophic growth of plant cells is limited. The best growth of cultures is ensured by oligosaccharides and their cleavage products. Primarily, these are sucrose, raffinose, glucose and fructose. Other molecules such as glycerol, carbonic acids, starch, and mannitol have the ability to support growth occasionally, or in combination with another substrate. Culture growth is accompanied by processes of specialization, such as elongation growth. This determines the pattern of the carbon budget. Culture ageing is closely linked to substrate depletion, changes in medium composition, and cell physiological rearrangements. A lack of substrate leads to starvation, which results in a decrease in physiological activity and the mobilization of resources, and finally in the loss of viability. The cause of the instability of cultivated cells may be the non-optimal metabolism under cultural conditions or the insufficiency of internal regulation.
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Affiliation(s)
- Roman K. Puzanskiy
- Laboratory of Analytical Phytochemistry, Komarov Botanical Institute of the Russian Academy of Sciences, 197022 St. Petersburg, Russia;
| | - Daria A. Romanyuk
- Laboratory of Genetics of Plant-Microbe Interactions, All-Russia Research Institute for Agricultural Microbiology, 196608 St. Petersburg, Russia;
| | | | - Vladislav V. Yemelyanov
- Faculty of Biology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.A.K.); (V.V.Y.)
| | - Maria F. Shishova
- Faculty of Biology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.A.K.); (V.V.Y.)
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2
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Zhang Q, Hua X, Liu H, Yuan Y, Shi Y, Wang Z, Zhang M, Ming R, Zhang J. Evolutionary expansion and functional divergence of sugar transporters in Saccharum (S. spontaneum and S. officinarum). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:884-906. [PMID: 33179305 DOI: 10.1111/tpj.15076] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 10/27/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Abstract
The sugar transporter (ST) family is considered to be the most important gene family for sugar accumulation, but limited information about the ST family in the important sugar-yielding crop Saccharum is available due to its complex genetic background. Here, 105 ST genes were identified and clustered into eight subfamilies in Saccharum spontaneum. Comparative genomics revealed that tandem duplication events contributed to ST gene expansions of two subfamilies, PLT and STP, in S. spontaneum, indicating an early evolutionary step towards high sugar content in Saccharum. The analyses of expression patterns were based on four large datasets with a total of 226 RNA sequencing samples from S. spontaneum and Saccharum officinarum. The results clearly demonstrated 50 ST genes had different spatiotemporal expression patterns in leaf tissues, 10 STs were specifically expressed in the stem, and 10 STs responded to the diurnal rhythm. Heterologous expression experiments in the defective yeast strain EBY.VW4000 indicated STP13, pGlcT2, VGT3, and TMT4 are the STs with most affinity for glucose/fructose and SUT1_T1 has the highest affinity to sucrose. Furthermore, metabolomics analysis suggested STP7 is a sugar starvation-induced gene and STP13 has a function in retrieving sugar in senescent tissues. PLT11, PLT11_T1, TMT3, and TMT4 contributed to breaking the limitations of the storage sink. SUT1, SUT1_T1, PLT11, TMT4, pGlcT2, and VGT3 responded for different functions in these two Saccharum species. This study demonstrated the evolutionary expansion and functional divergence of the ST gene family and will enable the further investigation of the molecular mechanism of sugar metabolism in Saccharum.
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Affiliation(s)
- Qing Zhang
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Provincial Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiuting Hua
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Provincial Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Hong Liu
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Provincial Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yuan Yuan
- College of Life Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Yan Shi
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Provincial Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhengchao Wang
- College of Life Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Muqing Zhang
- Guangxi key lab for sugarcane biology, Guangxi University, Nanning, Guangxi, 530005, China
| | - Ray Ming
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Provincial Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jisen Zhang
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, Fujian Provincial Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Guangxi key lab for sugarcane biology, Guangxi University, Nanning, Guangxi, 530005, China
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3
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Fugate KK, Eide JD, Martins DN, Grusak MA, Deckard EL, Finger FL. Colocalization of sucrose synthase expression and sucrose storage in the sugarbeet taproot indicates a potential role for sucrose catabolism in sucrose accumulation. JOURNAL OF PLANT PHYSIOLOGY 2019; 240:153016. [PMID: 31400718 DOI: 10.1016/j.jplph.2019.153016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/08/2019] [Accepted: 07/13/2019] [Indexed: 06/10/2023]
Abstract
Sucrose metabolism is believed to have a central role in promoting sink strength and sucrose storage in the sugarbeet taproot. How sucrose accumulation is increased by sucrose-degrading enzymes, however, is a paradox. To elucidate roles for sucrose-degrading activities in sucrose accumulation, relationships between the intercellular location of sucrose-catabolizing enzymes and sites of sucrose accumulation were determined in the sugarbeet taproot. Sucrose storage was evident in parenchyma cells of the outer cortex, rays, and rings of parenchyma tissue, but was absent in phloem, the vascular cambium, cells surrounding these tissues, or cells surrounding xylem. Sucrose synthase, which was primarily responsible for sucrose catabolism throughout the taproot, was expressed in similar cell and tissue types to those accumulating sucrose. Colocalization of sucrose synthase with sucrose accumulation, as well as sucrose synthase localization near the tonoplast, suggests a role for the enzyme in generating metabolic energy to fuel sucrose sequestration in the vacuole. Localization near the plasma membrane also suggests a role for sucrose synthase in supplying substrates for cell wall biosynthesis. By utilizing sucrose for ATP or cell wall biosynthesis, sucrose synthase likely maintains the source-to-sink sucrose gradient that drives sucrose transport into the root, thereby promoting sugarbeet root sink strength.
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Affiliation(s)
- Karen K Fugate
- USDA-ARS, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N., Fargo, ND, 58102-2765, USA.
| | - John D Eide
- USDA-ARS, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N., Fargo, ND, 58102-2765, USA.
| | - Daniel N Martins
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36571-000, Viçosa, MG, Brazil.
| | - Michael A Grusak
- USDA-ARS, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N., Fargo, ND, 58102-2765, USA.
| | - Edward L Deckard
- Department of Plant Sciences, North Dakota State University, P.O. Box 6050, Fargo, ND, 58108, USA.
| | - Fernando L Finger
- Departamento de Fitotecnia, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.
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4
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Characteristics of fermented coffee inoculated with yeast starter cultures using different inoculation methods. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2018.02.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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5
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Robaina-Estévez S, Daloso DM, Zhang Y, Fernie AR, Nikoloski Z. Resolving the central metabolism of Arabidopsis guard cells. Sci Rep 2017; 7:8307. [PMID: 28814793 PMCID: PMC5559522 DOI: 10.1038/s41598-017-07132-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 06/23/2017] [Indexed: 12/22/2022] Open
Abstract
Photosynthesis and water use efficiency, key factors affecting plant growth, are directly controlled by microscopic and adjustable pores in the leaf-the stomata. The size of the pores is modulated by the guard cells, which rely on molecular mechanisms to sense and respond to environmental changes. It has been shown that the physiology of mesophyll and guard cells differs substantially. However, the implications of these differences to metabolism at a genome-scale level remain unclear. Here, we used constraint-based modeling to predict the differences in metabolic fluxes between the mesophyll and guard cells of Arabidopsis thaliana by exploring the space of fluxes that are most concordant to cell-type-specific transcript profiles. An independent 13C-labeling experiment using isolated mesophyll and guard cells was conducted and provided support for our predictions about the role of the Calvin-Benson cycle in sucrose synthesis in guard cells. The combination of in silico with in vivo analyses indicated that guard cells have higher anaplerotic CO2 fixation via phosphoenolpyruvate carboxylase, which was demonstrated to be an important source of malate. Beyond highlighting the metabolic differences between mesophyll and guard cells, our findings can be used in future integrated modeling of multi-cellular plant systems and their engineering towards improved growth.
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Affiliation(s)
- Semidán Robaina-Estévez
- Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Golm, Germany
- Bioinformatics Group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Golm, Germany
| | - Danilo M Daloso
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Golm, Germany
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Youjun Zhang
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Golm, Germany
| | - Alisdair R Fernie
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Golm, Germany
| | - Zoran Nikoloski
- Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Golm, Germany.
- Bioinformatics Group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Golm, Germany.
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6
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Mullet JE. High-biomass C 4 grasses-Filling the yield gap. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 261:10-17. [PMID: 28554689 DOI: 10.1016/j.plantsci.2017.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/22/2017] [Accepted: 05/09/2017] [Indexed: 05/24/2023]
Abstract
A significant increase in agricultural productivity will be required by 2050 to meet the needs of an expanding and rapidly developing world population, without allocating more land and water resources to agriculture, and despite slowing rates of grain yield improvement. This review examines the proposition that high-biomass C4 grasses could help fill the yield gap. High-biomass C4 grasses exhibit high yield due to C4 photosynthesis, long growth duration, and efficient capture and utilization of light, water, and nutrients. These C4 grasses exhibit high levels of drought tolerance during their long vegetative growth phase ideal for crops grown in water-limited regions of agricultural production. The stems of some high-biomass C4 grasses can accumulate high levels of non-structural carbohydrates that could be engineered to enhance biomass yield and utility as feedstocks for animals and biofuels production. The regulatory pathway that delays flowering of high-biomass C4 grasses in long days has been elucidated enabling production and deployment of hybrids. Crop and landscape-scale modeling predict that utilization of high-biomass C4 grass crops on land and in regions where water resources limit grain crop yield could increase agricultural productivity.
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Affiliation(s)
- John E Mullet
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, United States.
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Cunha CP, Roberto GG, Vicentini R, Lembke CG, Souza GM, Ribeiro RV, Machado EC, Lagôa AMMA, Menossi M. Ethylene-induced transcriptional and hormonal responses at the onset of sugarcane ripening. Sci Rep 2017; 7:43364. [PMID: 28266527 PMCID: PMC5339719 DOI: 10.1038/srep43364] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/23/2017] [Indexed: 12/14/2022] Open
Abstract
The effects of ethephon as a sugarcane ripener are attributed to ethylene. However, the role of this phytohormone at the molecular level is unknown. We performed a transcriptome analysis combined with the evaluation of sucrose metabolism and hormone profiling of sugarcane plants sprayed with ethephon or aminoethoxyvinylglycine (AVG), an ethylene inhibitor, at the onset of ripening. The differential response between ethephon and AVG on sucrose level and sucrose synthase activity in internodes indicates ethylene as a potential regulator of sink strength. The correlation between hormone levels and transcriptional changes suggests ethylene as a trigger of multiple hormone signal cascades, with approximately 18% of differentially expressed genes involved in hormone biosynthesis, metabolism, signalling, and response. A defence response elicited in leaves favoured salicylic acid over the ethylene/jasmonic acid pathway, while the upper internode was prone to respond to ethylene with strong stimuli on ethylene biosynthesis and signalling genes. Besides, ethylene acted synergistically with abscisic acid, another ripening factor, and antagonistically with gibberellin and auxin. We identified potential ethylene target genes and characterized the hormonal status during ripening, providing insights into the action of ethylene at the site of sucrose accumulation. A molecular model of ethylene interplay with other hormones is proposed.
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Affiliation(s)
- Camila P. Cunha
- Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, 13083-862, Campinas, Brasil
| | - Guilherme G. Roberto
- Centro de Ecofisiologia e Biofísica, Instituto Agronômico de Campinas, 13001-970, Campinas, Brasil
| | - Renato Vicentini
- Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, 13083-862, Campinas, Brasil
| | - Carolina G. Lembke
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, Brasil
| | - Glaucia M. Souza
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, Brasil
| | - Rafael V. Ribeiro
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, 13083-862, Campinas, Brasil
| | - Eduardo C. Machado
- Centro de Ecofisiologia e Biofísica, Instituto Agronômico de Campinas, 13001-970, Campinas, Brasil
| | - Ana M. M. A. Lagôa
- Centro de Ecofisiologia e Biofísica, Instituto Agronômico de Campinas, 13001-970, Campinas, Brasil
| | - Marcelo Menossi
- Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, 13083-862, Campinas, Brasil
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8
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Baslam M, Baroja-Fernández E, Ricarte-Bermejo A, Sánchez-López ÁM, Aranjuelo I, Bahaji A, Muñoz FJ, Almagro G, Pujol P, Galarza R, Teixidor P, Pozueta-Romero J. Genetic and isotope ratio mass spectrometric evidence for the occurrence of starch degradation and cycling in illuminated Arabidopsis leaves. PLoS One 2017; 12:e0171245. [PMID: 28152100 PMCID: PMC5289593 DOI: 10.1371/journal.pone.0171245] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/17/2017] [Indexed: 11/20/2022] Open
Abstract
Although there is a great wealth of data supporting the occurrence of simultaneous synthesis and breakdown of storage carbohydrate in many organisms, previous 13CO2 pulse-chase based studies indicated that starch degradation does not operate in illuminated Arabidopsis leaves. Here we show that leaves of gwd, sex4, bam4, bam1/bam3 and amy3/isa3/lda starch breakdown mutants accumulate higher levels of starch than wild type (WT) leaves when cultured under continuous light (CL) conditions. We also show that leaves of CL grown dpe1 plants impaired in the plastidic disproportionating enzyme accumulate higher levels of maltotriose than WT leaves, the overall data providing evidence for the occurrence of extensive starch degradation in illuminated leaves. Moreover, we show that leaves of CL grown mex1/pglct plants impaired in the chloroplastic maltose and glucose transporters display a severe dwarf phenotype and accumulate high levels of maltose, strongly indicating that the MEX1 and pGlcT transporters are involved in the export of starch breakdown products to the cytosol to support growth during illumination. To investigate whether starch breakdown products can be recycled back to starch during illumination through a mechanism involving ADP-glucose pyrophosphorylase (AGP) we conducted kinetic analyses of the stable isotope carbon composition (δ13C) in starch of leaves of 13CO2 pulsed-chased WT and AGP lacking aps1 plants. Notably, the rate of increase of δ13C in starch of aps1 leaves during the pulse was exceedingly higher than that of WT leaves. Furthermore, δ13C decline in starch of aps1 leaves during the chase was much faster than that of WT leaves, which provides strong evidence for the occurrence of AGP-mediated cycling of starch breakdown products in illuminated Arabidopsis leaves.
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Affiliation(s)
- Marouane Baslam
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Edurne Baroja-Fernández
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Adriana Ricarte-Bermejo
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Ángela María Sánchez-López
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Iker Aranjuelo
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Abdellatif Bahaji
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Francisco José Muñoz
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Goizeder Almagro
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
| | - Pablo Pujol
- Servicio de Apoyo a la Investigación, Universidad Pública de Navarra, Campus de Arrosadia, Iruña, Nafarroa, Spain
| | - Regina Galarza
- Servicio de Apoyo a la Investigación, Universidad Pública de Navarra, Campus de Arrosadia, Iruña, Nafarroa, Spain
| | - Pilar Teixidor
- Centres Científics i Tecnològics, Universitat de Barcelona, C/ Lluís Solé I Sabarís 1–3, Barcelona, Spain
| | - Javier Pozueta-Romero
- Instituto de Agrobiotecnología (CSIC/UPNA/Gobierno de Navarra). Iruñako etorbidea 123, Mutiloabeti, Nafarroa, Spain
- * E-mail:
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9
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Kruger NJ, Le Lay P, Ratcliffe RG. Vacuolar compartmentation complicates the steady-state analysis of glucose metabolism and forces reappraisal of sucrose cycling in plants. PHYTOCHEMISTRY 2007; 68:2189-96. [PMID: 17524437 DOI: 10.1016/j.phytochem.2007.04.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 03/30/2007] [Accepted: 04/03/2007] [Indexed: 05/02/2023]
Abstract
Steady-state stable isotope labelling provides a method for generating flux maps of the compartmented network of central metabolism in heterotrophic plant tissues. Theoretical analysis of the contribution of the vacuole to the regeneration of glucose by endogenous processes shows that numerical fitting of isotopomeric data will only generate an accurate map of the fluxes involving intracellular glucose if information is available on the labelling of both the cytosolic and vacuolar glucose pools. In the absence of this information many of the calculated fluxes are at best unreliable or at worst indeterminate. This result suggests that the anomalously high rates of sucrose cycling and glucose resynthesis that have been reported in earlier steady-state analyses of tissues labelled with (13)C-glucose precursors may be an artefact of assuming that the labelling pattern of extracted glucose reflected the labelling of the cytosolic pool. The analysis emphasises that although subcellular information can sometimes be deduced from a steady-state analysis without recourse to subcellular fractionation, the success of this procedure depends critically on the structure of the metabolic network. It is concluded that methods need to be implemented that will allow measurement of the subcellular labelling pattern of glucose and other metabolites, as part of the routine analysis of the redistribution of label in steady-state stable isotope labelling experiments, if the true potential of network flux analysis for generating metabolic phenotypes is to be realized.
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Affiliation(s)
- Nicholas J Kruger
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
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Roby C, Cortès S, Gromova M, Le Bail JL, Roberts JKM. Sucrose cycling in heterotrophic plant cell metabolism: first step towards an experimental model. Mol Biol Rep 2003; 29:145-9. [PMID: 12241046 DOI: 10.1023/a:1020309309045] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Sucrose is the cornerstone of higher plant metabolism. Produced by photosynthesis, sucrose is the main substrate for respiration and biosynthesis. The emerging idea is that sucrose may act as regulator of its own metabolism, characterized in particular by a permanent process of degradation and formation. This sucrose turnover may control several important physiological functions. Of particular concern is an energy dependent cycle involving the hexokinase. This report presents an experimental approach to define quantitatively physiological states of suspension-cultured plant cells wih reference to their sucrose content and respiration rate. Sucrose depletion of normal cells incubated in a medium devoid of sugar is measured in vivo using 13C and respiration is simultaneously recorded. Results obtained with sucrose-storing cells and Arabidopsis thaliana show that respiration rate is closely linked to the available sucrose. Sucrose-depleted cells offer a stable model to study the bioenergetics of the process.
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Affiliation(s)
- Claude Roby
- CEA, CNRS and UJF, UMR 5019 Physiologie Cellulaire Végétale, Grenoble, France.
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