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Production of amylopectin and high-amylose starch in separate potato genotypes

Hofvander, Per (2004). Production of amylopectin and high-amylose starch in separate potato genotypes. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae. Agraria, 1401-6249 ; 495
ISBN 91-576-6775-6
[Doctoral thesis]

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Starch is one of the most important processed products from agriculture. Two main outlets can be identified; starch is either enzymatically processed for the production of sweeteners and as raw material for fermentation or channelled to various applications as dry starch. Native or chemically modified starches are utilized in food as well as non-food applications, where the specific physicochemical properties are main determinants for their respective use. Starch consists of two different molecules, amylose and amylopectin. To be able to take the full benefit of the unique properties of either component it is of interest to divide the production of amylose and amylopectin into separate plant genotypes. In the presented work, potatoes producing either amylopectin or high-amylose starch were achieved using genetic modification. For potato transformation a highly efficient protocol was developed for a herbicide selection gene instead of the commonly used nptII antibiotic selection gene. In order to achieve respective starch qualities, the expression of genes important for amylopectin or amylose synthesis was silenced. Antisense technology as well as the expression of dsRNA was investigated where the expression of dsRNA was determined to be at least ten-fold more efficient for gene silencing. An added benefit of dsRNA expression was that a higher fraction of silenced transgenic lines compared to the use antisense were associated with single copy T-DNA integrations. One amylopectin potato line was furthermore characterized regarding genetic and chemical composition. The T-DNA was found integrated as an inverted repeat with the inverted repeat region extending into potato chromosomal DNA. This transgenic locus was found to be more consistent with integration into a double-stranded chromosomal break than insertion by a mechanism nicking one strand of the locus. The high-amylose trait generally resulted in a higher tuber fresh weight yield, much elevated sugar levels and a decreased starch content. Amylose levels were obtained where very limited amounts of material recognizable as amylopectin could be found. The production of amylopectin and amylose was divided into separate genotypes but additional factors are needed to be able to produce amylose at levels comparable to starch contents of cultivated potatoes.

Authors/Creators:Hofvander, Per
Title:Production of amylopectin and high-amylose starch in separate potato genotypes
Series Name/Journal:Acta Universitatis Agriculturae Sueciae. Agraria
Year of publishing :November 2004
Number of Pages:63
ALLI. Hofvander, P., Andersson, M., Larsson, C.-T. and Larsson, H. (2004) Field performance and starch characteristics of high-amylose potatoes obtained by antisense gene targeting of two branching enzymes. Plant Biotechnology Journal 2, 311-320. II. Andersson, M., Melander, M., Pojmark, P., Larsson, H. Bülow, L., Hofvander, P. Targeted gene suppression by RNA interference: an efficient method for production of high amylose potato lines. (Submitted) III. Larsson, C.-T., Hofvander, P., Khoshnoodi, J., Ek, B., Rask, L. and Larsson, H. (1996) Three isoforms of starch synthase and two isoforms of branching enzyme are present in potato tuber starch. Plant Science 117, 9-16. IV. Andersson, M., Turesson, H., Strömdahl, A.-C., Pojmark, P., Bülow, L., Larsson, H. and Hofvander, P. Molecular and compositional analysis of an amylopectin potato. (Submitted) V. Andersson, M., Trifanova, A., Andersson, A.-B., Johansson, M., Bülow, L. and Hofvander, P. 2003. A novel selection system for potato transformation using a mutated AHAS gene. Plant Cell Reports 22, 261-267.
Place of Publication:Uppsala
Associated Programs and Other Stakeholders:Z - SLU - Library > Odla mera
ISBN for printed version:91-576-6775-6
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
Subjects:Not in use, please see Agris categories
Agrovoc terms:solanum tuberosum, amylose, amylopectin, potato starch, genetic engineering, genes, genotypes
Keywords:Solanum tuberosum, gene inhibition, amylose, amylopectin, granule bound starch synthase, starch branching enzyme, selection gene
Permanent URL:
ID Code:688
Department:(NL, NJ) > Dept. of Plant Biology and Forest Genetics (until 131231)
Deposited By: Per Hofvander
Deposited On:11 Nov 2004 00:00
Metadata Last Modified:22 Mar 2015 15:14

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