Project

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Quantitative analysis of seed carbohydrate metabolism and its impact on seed development

Applicant Köhler Claudia
Number 127506
Funding scheme Sinergia
Research institution Departement Umweltsystemwissenschaften ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Biochemistry
Start/End 01.10.2009 - 31.03.2013
Approved amount 1'000'000.00
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Keywords (8)

seed development; carbohydrate metabolism; FRET nanosensors; metabolomics; flux analysis; Seed metabolism; Carbon flux; Metabolite sensing

Lay Summary (English)

Lead
Lay summary
Seed development is a pivotal process in the life cycle of higher plants. In angiosperms it is initiated by the process of double fertilization, which leads to the development of the embryo and endosperm that are surrounded by the maternally derived seed coat. The physiological as well as genetic balance between the endosperm, embryo and maternal tissues is important for proper seed development. The major carbohydrate imported into developing seeds is sucrose, which is metabolized for the production of structural and storage compounds. The switch from the phase of rapid cell division to the phase of storage compound deposition has been correlated with a change in the metabolism of imported sucrose, and led to the concept that sugars contribute to the developmental switch by acting as signals as well as substrates for metabolism. One aim of this proposal is to test this hypothesis by localizing the pools of sugar, the fluxes through them as well as analysing the developmental consequences of disturbed carbohydrate metabolism. One of the major obstacles to understanding the carbon fluxes in complex plant organs is the difficulty of measuring the cellular and subcellular concentrations of metabolites and the fluxes through the different metabolic pathways. Through collaborative efforts of all applicants in this Synergia proposal, we will tackle this challenge by combining recent developments in metabolomics and metabolite sensing with mutational and transgenic studies. The main aim of this proposal is to gain a thorough understanding of carbohydrate metabolism in plant seeds by employing and developing novel detection tools and exploiting the advantages of available genetic resources and mutants in the model system Arabidopsis thaliana. Understanding carbohydrate metabolism and bottlenecks in its regulation are central requirements for improvements by rational design, therefore, the outcome of our activities will not merely be of significant scientific interest, but will have a substantial economic impact as well.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Examining strategies to facilitate vitamin B1 biofortification of plants by genetic engineering.
Pourcel Lucille, Moulin Michael, Fitzpatrick Teresa B (2013), Examining strategies to facilitate vitamin B1 biofortification of plants by genetic engineering., in Frontiers in plant science, 4, 160-160.
Endosperm cellularization defines an important developmental transition for embryo development.
Hehenberger Elisabeth, Kradolfer David, Köhler Claudia (2012), Endosperm cellularization defines an important developmental transition for embryo development., in Development (Cambridge, England), 139(11), 2031-9.
Loss of Cytosolic Phosphoglucomutase Compromises Gametophyte Development in Arabidopsis
Egli Barbara, Koeling Katharina, Koehler Claudia, Zeeman Samuel C., Streb Sebastian (2010), Loss of Cytosolic Phosphoglucomutase Compromises Gametophyte Development in Arabidopsis, in PLANT PHYSIOLOGY, 154(4), 1659-1671.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Scandinavian Society of Plant Physiology 12.09.2012 Laulasmaa, Estonia
Meeting of the French Society for Plant Biology 14.12.2011 Clerment-Ferand, France
Botanikertagung 18.09.2011 Berlin, Germany
International Congress on Plant Sexual Reproduction 05.08.2010 Bristol, UK
Federal European Society of Plant Biology meeting 05.07.2010 Valencia, Spain
International conference on Plant Molecular Cell Biology 23.02.2010 Vienna, Austria


Abstract

IntroductionSeed development is a pivotal process in the life cycle of an angiosperm. It is initiated by the process of double fertilization, which leads to the development of the embryo and endosperm that are surrounded by the maternally derived seed coat. The physiological as well as genetic balance between the endosperm, embryo and maternal tissues is important for proper seed development. The major carbohydrate imported into developing seeds is sucrose, which is metabolized for the production of structural and storage compounds. The switch from the phase of rapid cell division to the phase of storage compound deposition has been correlated with a change in the metabolism of imported sucrose, and led to the concept that sugars contribute to the developmental switch by acting as signals as well as substrates for metabolism. One aim of this proposal is to test this hypothesis by localizing the pools of sugar, the fluxes through them as well as analysing the developmental consequences of disturbed carbohydrate metabolism. One of the major obstacles to understanding the carbon fluxes in complex plant organs is the difficulty of measuring the cellular and subcellular concentrations of metabolites and the fluxes through the different metabolic pathways. Through collaborative efforts of all applicants in this Synergia proposal, we will tackle this challenge by combining recent developments in metabolomics and metabolite sensing with mutational and transgenic studies. We will apply existing as well as develop novel nanosensors for tracing the in vivo dynamics and spatial distribution of metabolites during seed development. Main objectives, benefit of collaboration and significance of planned research:The main aim of this proposal is to gain a thorough understanding of carbohydrate metabolism in plant seeds by employing and developing novel detection tools and exploiting the advantages of available genetic tools and mutants in the model system Arabidopsis thaliana. This main objective will by achieved by the following intermediate objectives:•Develop FRET sensors for realtime detection of carbohydrate substrates and intermediates in embryo and endosperm. •Establish MS-based metabolomics and integrate thermodynamic information to investigate dynamic fluxes over time in seed mutants.•Define the precise localization and dynamics of carbohydrates in the endosperm of wild type and seed development mutants using nanosensors.•Define the cause and effect of increased hexose content in seed development mutants.•Define the fate of carbon imported into developing seeds.•Define the requirement of starch synthesis for storage oil synthesis in mature embryos.•Define the distribution of key metabolites within the tissues and cellular compartments of the seed.•Define the impact of B1 and B6 vitamins on the carbohydrate status of seeds.•Define the in vivo B1 and B6 vitamin distribution in seeds.To reach our ambitious goals, there is an evident mutual dependency that requires the combination of complementary research expertise and tools available in each of the participating groups to synergistically promote individual subprojects. The participants of this proposal have extensive expertise in: (i) metabolomics, flux analysis, and FRET sensors (Zamboni group), (ii) plant reproductive development (Köhler group), and (iii) primary plant metabolism (Zeeman and Fitzpatrick groups). Therefore, the successful achievement of the main research aim requires the collaborative effort of all four groups that will share results, experience, tools and materials. Thus far, the impact of primary metabolism on plant seed development has not yet been thoroughly investigated, the availability of novel tools and technologies makes this endeavor possible and within the frame of this proposal it is likely to be successful. Understanding carbohydrate metabolism and bottlenecks in its regulation are central requirements for improvements by rational design. Thus, our proposed activities will provide a conceptional basis for the improvement of oil crops such as rapeseed, and therefore, the outcome of our activities will not merely be of significant scientific interest, but will have a substantial economic impact as well.
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