Open AccessPectin engineering to modify product quality in potato
Author(s) -
Ross Heather A.,
Morris Wayne L.,
Ducreux Laurence J.M.,
Hancock Robert D.,
Verrall Susan R.,
Morris Jenny A,
Tucker Gregory A.,
Stewart Derek,
Hedley Pete E.,
McDougall Gordon J.,
Taylor Mark A.
Publication year - 2011
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2011.00591.x
Subject(s) - pectin , biology , gene isoform , methylation , transgene , gene , food science , biochemistry
Summary Although processed potato tuber texture is an important trait that influences consumer preference, a detailed understanding of tuber textural properties at the molecular level is lacking. Previous work has identified tuber pectin methyl esterase (PME) activity as a potential factor impacting on textural properties, and the expression of a gene encoding an isoform of PME ( PEST1 ) was associated with cooked tuber textural properties. In this study, a transgenic approach was undertaken to investigate further the impact of the PEST1 gene. Antisense and over‐expressing potato lines were generated. In over‐expressing lines, tuber PME activity was enhanced by up to 2.3‐fold; whereas in antisense lines, PME activity was decreased by up to 62%. PME isoform analysis indicated that the PEST1 gene encoded one isoform of PME. Analysis of cell walls from tubers from the over‐expressing lines indicated that the changes in PME activity resulted in a decrease in pectin methylation. Analysis of processed tuber texture demonstrated that the reduced level of pectin methylation in the over‐expressing transgenic lines was associated with a firmer processed texture. Thus, there is a clear link between PME activity, pectin methylation and processed tuber textural properties.