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Discovering the roles of debranching enzymes in starch metabolism in arabidopsis

English title Discovering the roles of debranching enzymes in starch metabolism in arabidopsis
Applicant Zeeman Samuel C.
Number 131074
Funding scheme Project funding (Div. I-III)
Research institution Departement Umweltsystemwissenschaften ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Botany
Start/End 01.04.2010 - 30.09.2013
Approved amount 433'896.00
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All Disciplines (4)

Discipline
Botany
Genetics
Molecular Biology
Biochemistry

Keywords (7)

arabidopsis; starch metabolism; amylopectin structure; debranching enzyme; functional genomics; structural biology; bonus-of-excellence

Lay Summary (English)

Lead
Lay summary
Starch is a vital substance produced by plants. It is the major component of our staple crops (cereals, potatoes, legumes) and accounts for half of mankind's food. Starch is also a raw material for many industrial applications and for the production of bioethanol - a renewable substitute for petroleum. Starch is composed of polymers of the simple sugar, glucose. The major polymer is called 'amylopectin'. It contains about 100'000 glucosyl units linked to make long chains. These chains are branched in a precisely-defined way, giving amylopectin a special tree-like structure. This branching pattern enables amylopectin molecules to crystallise, resulting in dense insoluble starch granules, which are chemically stable. To make starch granules, plants possess a set of enzymes to elongate chains, to insert branch points, and to remove miss-placed branches. Our SNF-funded research project aims to determine the contributions of each class of enzyme using the model plant Arabidopsis thaliana - the plant equivalent to the 'laboratory rat'. We will test which enzyme combinations permit starch synthesis by selectively disrupting the plant genes that encodes them and analysing if starch is made normally using biochemical techniques. We will introduce the plant genes into organisms (e.g. yeast) that do not normally make starch. This will tell us if we have discovered all the factors needed for starch production. Because starch is made in the same way in most plants, including crops, this research will be directly relevant to agriculture, enabling future crop improvement in terms of altered starch properties and/or yields
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Loss of Starch Granule Initiation Has a Deleterious Effect on the Growth of Arabidopsis Plants Due to an Accumulation of ADP-Glucose
Ragel Paula, Streb Sebastian, Feil Regina, Sahrawy Mariam, Annunziata Maria Grazia, Lunn John E, Zeeman Samuel, Merida Angel (2013), Loss of Starch Granule Initiation Has a Deleterious Effect on the Growth of Arabidopsis Plants Due to an Accumulation of ADP-Glucose, in Plant Physiology, 163, 75-85.
Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion
Crumpton-Taylor Matilda, Pike Marilyn, Lu Kuan-Jen, Hylton Christopher M., Feil Regina, Eicke Simona, Lunn John E., Zeeman Samuel C., Smith Alison M. (2013), Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion, in New Phytologist, 200, 1064-1075.
The Heteromultimeric Debranching Enzyme Involved in Starch Synthesis in Arabidopsis Requires Both Isoamylase1 and Isoamylase2 Subunits for Complex Stability and Activity
Sundberg Maria, Pfister Barbara, Fulton Daniel, Bischof Sylvain, Delatte Thierry, Eicke Simona, Stettler Michaela, Smith Steven M., Streb Sebastian, Zeeman Samuel C. (2013), The Heteromultimeric Debranching Enzyme Involved in Starch Synthesis in Arabidopsis Requires Both Isoamylase1 and Isoamylase2 Subunits for Complex Stability and Activity, in PLoS ONE, 8(9), e75223.
Starch Metabolism in Arabidopsis
Streb Sebastian, Zeeman Samuel C (2012), Starch Metabolism in Arabidopsis, in The Arabidopsis Book, 10, e0160.
The Simultaneous Abolition of Three Starch Hydrolases Blocks Transient Starch Breakdown in Arabidopsis
Streb Sebastian, Eicke Simona, Zeeman Samuel C (2012), The Simultaneous Abolition of Three Starch Hydrolases Blocks Transient Starch Breakdown in Arabidopsis, in Journal of Biological Chemistry, 287(50), 41745-41756.

Collaboration

Group / person Country
Types of collaboration
University of Copenhagen Denmark (Europe)
- in-depth/constructive exchanges on approaches, methods or results

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Starch Round Table Talk given at a conference THE ROLE OF REVERSIBLE GLUCAN PHOSPHORYLATION IN THE CONTROL OF STARCH DEGRADATION 14.10.2011 Palm Springs, CA,, United States of America Zeeman Samuel C.;
Joint Meeting of AGI (Italian Genetics Association) - SIBV (Italian Society of Plant Biology) - SIGA (Italian Society of Agricultural Genetics) Talk given at a conference UNDERSTANDING STARCH METABOLISM IN PLANTS AND THE POTENTIAL TO IMPROVE STARCH CROPS. 19.09.2011 Assisi, Italy Zeeman Samuel C.;
24th Scandinavian Plant Physiology Congress Talk given at a conference THE ROLE OF REVERSIBLE GLUCAN PHOSPHORYLATION IN THE CONTROL OF STARCH DEGRADATION 21.08.2011 Stavangar, Norway Zeeman Samuel C.;
9th Carbohydrate Bioengineering Meeting Talk given at a conference Understanding starch biosynthesis in plants: the potential to improve starch crops. 15.05.2011 Lisbon, Portugal Zeeman Samuel C.;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions ETH unterwegs Italian-speaking Switzerland German-speaking Switzerland Rhaeto-Romanic Switzerland Western Switzerland 2011

Associated projects

Number Title Start Funding scheme
145021 Advancing Quantitative and Post-Translational Modification Proteomics by Latest Generation Mass Spectrometry 01.07.2013 R'EQUIP
148857 Discovery of factors regulating carbohydrate storage in plants: implications for biotechnological improvement of crops for food and for clean, green technologies. 01.08.2014 Bilateral programmes
67312 Discovering the role of debranching enzymes in starch metabolism in Arabidopsis 01.11.2002 Project funding (Div. I-III)
153144 Understanding the Mechanism of Starch Biosynthesis in Plants 01.04.2014 Project funding (Div. I-III)
116434 Discovering the roles of debranching enzymes in starch metabolism in arabidopsis 01.04.2007 Project funding (Div. I-III)

Abstract

This work aims to understand the biosynthesis and degradation of starch, the predominant storage carbohydrate in plants. Starch is important because it is the single largest component of our nutrition, and a large fraction of our arable land is given over to the growth of starch crops. Starch is made primarily of branched glucans that form insoluble glucans. In the previous granting periods we have conducted an extensive analysis of starch debranching enzyme (DBE) functions in the model plant Arabidopsis, which makes starch in its leaves. We have shown that one specific heteromultimeric DBE facilitates starch biosynthesis, while two other monomeric DBEs function primarily in starch breakdown. Mutants lacking the heteromultimeric DBE accumulate a soluble glycogen-like polymer rather than starch. This proposal aims to further our understanding of the starch biosynthetic process and the structure-functional relationship of the heteromultimeric DBE.
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