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Xylan biosynthesis and modification

characterisation of a glycosyltransferase and a glycoside hydrolase in hybrid aspen

Ratke, Christine (2014). Xylan biosynthesis and modification. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2014:41
ISBN 978-91-576-8030-3
eISBN 978-91-576-8031-0
[Doctoral thesis]

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Wood is an important renewable material used by humans for a variety of downstream applications. The basic subcellular structure in wood is the cell wall, mainly consisting of the cross-linked polymers cellulose, hemicellulose, and lignin. Xylan is the main hemicellulose found in angiosperm wood, and its biosynthesis and effects on wood properties in hybrid aspen (Populus tremula x tremuloides) were the object of the present study. We identified a glycoside hydrolase in developing wood, PtxtXyn10A—a previously suggested xylanase—and found that it rather has xylan transglycosylase activity. This xylan transglycosylase probably rearranges xylan chains during secondary wall deposition. Interestingly, it affected the orientation of cellulose microfibrils, giving new insights into the interaction of cell wall polymers and their control during deposition into the wall. To study genes involved in secondary wall formation and to modify wood properties using transgenic approaches, it is essential to efficiently target transgene expression to the secondary wall forming cells. We isolated and tested a promoter, pGT43B, which proved to be very effective in altering gene expression and in generating intended chemical modifications in woody cells. We applied this GT43B promoter to modify xylan acetylation and polymerisation in hybrid aspen wood. Furthermore, it enabled the identification of the sucrose transporter SUT3, elucidating how sucrose is transported from ray to developing fiber and vessel cells. Glycosyltransferases (GTs) are enzymes involved in polysaccharide biosynthesis. We characterised the xylan biosynthetic GT43 gene family in hybrid aspen and found that reduced GT43 expression levels positively affected overall plant growth, wood mechanical strength, and saccharification efficiency, indicating potential applications for engineering bioenergy feedstocks. We conclude that cell specific modification of xylan properties in hybrid aspen can alter cellulose deposition and result in activation of cambial proliferation which has a positive impact on overall biomass yield and properties for downstream woodutilisation.

Authors/Creators:Ratke, Christine
Title:Xylan biosynthesis and modification
Subtitle:characterisation of a glycosyltransferase and a glycoside hydrolase in hybrid aspen
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :May 2014
Number of Pages:63
I.Marta Derba-Maceluch, Tatsuya Awano, Junko Takahashi, Jessica Lucenius, Christine Ratke, Inkeri Kontro, Ondrej Kosik, Ryo Tanaka, Anders Winzéll, Åsa Kallas, Joanna Leśniewska, Tarek Elhasi, Fredrik Berthold, Peter Immerzeel, Tuula T. Teeri, Ines Ezcurra, Paul Dupree, Ritva Serimaa and Ewa J. Mellerowicz. Suppression of a xylan transglycosylase PtxtXyn10A affects cellulose microfibril angle in secondary wall in aspen wood. Manuscript.
II.Christine Ratke, Prashant Pawar, Vimal Kumar Balasubramanian, Mathilda Lönnäs Duncranz, Ines Ezcurra and Ewa J. Mellerowicz. Populus GT43 family gene members show differential expression and include promoters useful for wood modification. Submitted.
III.Amir Mahboubi, Christine Ratke, András Gorzsás, Manoj Kumar, Ewa J. Mellerowicz and Totte Niittylä. (2013) Aspen SUCROSE TRANSPORTER 3 allocates carbon into wood fibres. Plant Physiology 163 (4): 1729-1740.
IV.Christine Ratke, Barbara Terebieniec, Sandra Winestrand, Thomas Grahn, Jennifer C. Mortimer, Bastian Schiffthaler, Thomas Ulvcrona, Paul Dupree, Nathaniel R. Street, Leif Jönsson and Ewa J. Mellerowicz. Altering xylan biosynthetic GT43 glycosyltransferases in hybrid aspen leads to increased growth and improved wood mechanical properties and saccharification. Manuscript.
Place of Publication:Umeå
Publisher:Institutionen för skoglig genetik och växtfysiologi, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-8030-3
ISBN for electronic version:978-91-576-8031-0
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
F Plant production > F50 Plant structure
F Plant production > F62 Plant physiology - Growth and development
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Biochemistry and Molecular Biology
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Botany
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 404 Agricultural Biotechnology > Plant Biotechnology
Agrovoc terms:wood, populus tremula, populus tremuloides, hybrids, cell walls, cell structure, xylans, glycosyltransferases, hydrolases, biosynthesis, lignification, genetic engineering
Keywords:Wood, Cell wall, Xylan
Permanent URL:
ID Code:11167
Faculty:S - Faculty of Forest Sciences
Department:(S) > Dept. of Forest Genetics and Plant Physiology
External funders:FORMAS
Deposited By: Christine Ratke
Deposited On:12 May 2014 07:44
Metadata Last Modified:14 Dec 2014 20:02

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