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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PDF
934kB |
Abstract
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 | ||||||||||||
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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: | 2015:72 | ||||||||||||
Number of Pages: | 58 | ||||||||||||
Papers/manuscripts: |
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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 | ||||||||||||
ISSN: | 1652-6880 | ||||||||||||
Language: | English | ||||||||||||
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 | ||||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-2687 | ||||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2687 | ||||||||||||
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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