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Acetylation of polysaccharides in plant cell wall

with a focus on woody species

Pawar, Prashant Mohan-Anupama (2015). Acetylation of polysaccharides in plant cell wall. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2015:72
ISBN 978-91-576-8342-7
eISBN 978-91-576-8343-4
[Doctoral thesis]

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Plant cell wall in woody tissues is a complex matrix, which consists of cellulose, matrix polysaccharides and lignin. The matrix polysaccharides are substituted with acetyl group that are hypothesised to play important roles in determining properties of these polysaccharides. The aim of this thesis was to understand the role of O-acetylation in plants and investigate possibilities for improvement of woody lignocellulose for biorefinery applications by reducing wood O-acetylation.

To alter acetylation specifically in woody tissues, a promoter from Glycosyl Transferase 43 family (GT43) in Populus was isolated that had a very specific expression in secondary cell wall forming cells. This xylem specific promoter (pGT43B) was more effective in modification of wood acetylation by overexpression and suppression strategies as compared to 35S promoter (Paper I).

To reduce xylan acetylation using transgenic approach, acetyl xylan esterase from Aspergillus niger, AnAXE1, was targetted specifically to the cell wall in Arabidopsis (Paper II) and in Populus (Paper III). Plants expressing AnAXE1 grew as well as wild type and had increased acetyl esterase activity. This has led to reduction in cell wall acetyl content and in xylan O-acetylation. Moreover, transgenic Arabidopsis exhibited increased resistance against a biotrophic pathogen Hyaloperonospora arabidopsidis. Both transgenic plants had improved sugar yields in saccharification with different pretreatments and without pretreatment.

To reduce acetylation using cisgenic approach, Populus Reduced Wall Acetylation (RWA) gene family was characterised by suppression of the two clades RWA-AB, and RWA-CD (Paper IV). Both clades were shown to be involved in xylan acetylation in the wood. Both clades were therefore suppressed under control of xylem specific promoter pGT43B to improve wood saccharification potential. Transgenic plants had reduced wood acetyl content, normal growth, and increased sugar yield and glucose conversion % in saccharification without pretreatment. Glucose yield was also slightly increased in saccharification after acid pretreatment.

These results show that reduction of cell wall acetylation by 10-30% does not alter plant growth and development, but improves yields in lignocellulose saccharification (with and without pretreatment) (Papers II, III and IV).

To identify Quantitative Trait Loci (QTLs) related to cell wall acetyl content and other chemical traits in Salix, the mapping population of 463 progenies of S. viminalis and S. schwerinii was analysed by FT-IR and acetyl content assay (Paper V). 28 QTLs were identified for different cell wall chemical traits, which were co-located with several cell wall related genes and gene clusters. These QTLs and genes can be used in the future to improve wood chemical traits in Salix and Populus for biofuel production by breeding.

Authors/Creators:Pawar, Prashant Mohan-Anupama
Title:Acetylation of polysaccharides in plant cell wall
Subtitle:with a focus on woody species
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :4 June 2015
Depositing date:4 June 2015
Number of Pages:58
IChristine Ratke, Prashant Mohan-Anupama Pawar, Vimal K. Balasubramanian, Marcel Naumann, Mathilda Lönnäs Duncranz, Marta Derba-Maceluch, András Gorzsás, Satoshi Endo, Ines Ezcurra and Ewa J. Mellerowicz (2015). Populus GT43 family members group into distinct sets required for primary and secondary wall xylan biosynthesis and include useful promoters for wood modification. Plant Biotechnology Journal 13, 26-37.
IIPrashant Mohan-Anupama Pawar, Marta Derba-Maceluch, Sun-Li Chong, Leonardo D. Gómez, Eva Miedes, Alicja Banasiak, Christine Ratke, Cyril Gaertner, Grégory Mouille, Simon J. McQueen-Mason, Antonio Molina, Anita Sellstedt, Maija Tenkanen and Ewa J. Mellerowicz (2015). Expression of fungal acetyl xylan esterase in Arabidopsis thaliana improves saccharification of stem lignocellulose. Plant Biotechnology Journal in press.
IIIPrashant Mohan-Anupama Pawar, Marta Derba-Maceluch, Sun-Li Chong, Madhavi Latha Gandla, Shamrat Shafiul Bashar, Tobias Sparrman, Patrik Ahvenainen, Mattias Hedenström, Ritva Serimaa, Martin Lawoko, Maija Tenkanen, Leif J. Jönsson and Ewa J. Mellerowicz. Expression of xylan acetyl esterase AnAXE1 improves saccharification potential and lignin solubility in aspen (Manuscript).
IVPrashant Mohan-Anupama Pawar, Christine Ratke, Vimal K. Balasubramanian, Sun-Li Chong, Madhavi Latha Gandla, Tobias Sparrman, Mathilda Lönnäs Duncranz, Ines Ezcurra, Maija Tenkanen, Leif J. Jönsson and Ewa J. Mellerowicz. Downregulation of RWA genes in hybrid aspen affects xylan acetylation and improves wood saccharification properties. (Manuscript).
VPrashant Mohan-Anupama Pawar, Anna Schnürer, Ewa J. Mellerowicz, Ann Christin Rönnberg-Wästljung. QTL mapping of wood FT-IR chemotypes and acetyl content shows promise for improving biofuel potential in short rotation coppice willow (Salix spp.) (Manuscript)
Place of Publication:Umeå
Publisher:Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-8342-7
ISBN for electronic version:978-91-576-8343-4
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 > F60 Plant physiology and biochemistry
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) > Cell Biology
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Wood Science
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 404 Agricultural Biotechnology > Genetics and Breeding
Agrovoc terms:wood, woody plants, polysaccharides, cell walls, acetylation, populus, aspen, salix, arabidopsis, quantitative trait loci, genetic engineering
Keywords:Populus, acetylation, QTL, saccharification, secondary cell wall, xylan, Arabidopsis, aspen, Salix, RWA, acetyl xylan esterase, cell wall acetylation, acetyl esterification
Permanent URL:
ID Code:12329
Faculty:S - Faculty of Forest Sciences
Department:(S) > Dept. of Forest Genetics and Plant Physiology
Deposited By: Mr Prashant Mohan Pawar
Deposited On:08 Jun 2015 06:38
Metadata Last Modified:10 Sep 2020 13:41

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