Title: Towards a better understanding of the generation of fructan structure diversity in plants: molecular and functional characterization of a sucrose:fructan 6-fructosyltransferase (6-SFT) cDNA from perennial ryegrass (Lolium perenne)
Authors: Lasseur, Bertrand ×
Lothier, Jérémy
Wiemken, Andres
Van Laere, André
Morvan-Bertrand, Annette
Van den Ende, Wim
Prud'homme, Marie-Pascale #
Issue Date: Mar-2011
Publisher: Oxford University Press
Series Title: Journal of Experimental Botany vol:62 issue:6 pages:1871-1885
Abstract: The main storage compounds in Lolium perenne are fructans with prevailing b(2–6) linkages. A cDNA library of
L. perenne was screened using Poa secunda sucrose:fructan 6-fructosyltransferase (6-SFT) as a probe. A full-length
Lp6-SFT clone was isolated as shown by heterologous expression in Pichia pastoris. High levels of Lp6-SFT
transcription were found in the growth zone of elongating leaves and in mature leaf sheaths where fructans are
synthesized. Upon fructan synthesis induction, Lp6-SFT transcription was high in mature leaf blades but with no
concomitant accumulation of fructans. In vitro studies with the recombinant Lp6-SFT protein showed that both
1-kestotriose and 6G-kestotriose acted as fructosyl acceptors, producing 1- and 6-kestotetraose (bifurcose) and
6G,6-kestotetraose, respectively. Interestingly, bifurcose formation ceased and 6G,6-kestotetraose was formed
instead, when recombinant fructan:fructan 6G-fructosyltransferase (6G-FFT) of L. perenne was introduced in
the enzyme assay with sucrose and 1-kestotriose as substrates. The remarkable absence of bifurcose in L. perenne
tissues might be explained by a higher affinity of 6G-FFT, as compared with 6-SFT, for 1-kestotriose, which is the
first fructan formed. Surprisingly, recombinant 6-SFT from Hordeum vulgare, a plant devoid of fructans with internal
glucosyl residues, also produced 6G,6-kestotetraose from sucrose and 6G-kestotriose. In the presence of
recombinant L. perenne 6G-FFT, it produced 6G,6-kestotetraose from 1-kestotriose and sucrose, like L. perenne
6-SFT. Thus, we demonstrate that the two 6-SFTs have close catalytic properties and that the distinct fructans
formed in L. perenne and H. vulgare can be explained by the presence of 6G-FFT activity in L. perenne and its
absence in H. vulgare.
ISSN: 0022-0957
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Molecular Physiology of Plants and Micro-organisms Section - miscellaneous
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
Lasseuretal6-SFT2011.pdf Published 901KbAdobe PDFView/Open Request a copy

These files are only available to some KU Leuven Association staff members


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science