Title: Post-translational processing of β-D-xylanases and changes in extractability of arabinoxylans during wheat germination
Authors: De Backer, Evelien
Gebruers, Kurt ×
Van den Ende, Wim
Courtin, Christophe
Delcour, Jan #
Issue Date: 2010
Publisher: Gauthier-Villars
Series Title: Plant Physiology and Biochemistry vol:48 pages:90-97
Abstract: Endo-1,4-b-D-xylanase (EC, b-D-xylanase) activity, and arabinoxylan (AX) level and extractability
were monitored for the first time simultaneously in wheat kernels (Triticum aestivum cv. Glasgow) up to
24 days post-imbibition (DPI), both in the absence and presence of added gibberellic acid (GA). Roughly
three different stages (early, intermediate and late) can be discriminated. Addition of GA resulted in
a faster increase of water extractable arabinoxylan (WEAX) level in the early stage (up to 3e4 DPI). This
increase was not accompanied by the discernible presence of homologues of the barley X-I b-D-xylanase
as established by immunodetection. This suggests that other, yet unidentified b-D-xylanases operate in
this early time window. The intermediate stage (up to 13 DPI) was characterized by the presence of
unprocessed 67 kDa X-I like b-D-xylanase, which was much more abundant in the presence of GA. The
occurrence of higher levels of the unprocessed enzyme was related with higher b-D-xylanase activities
and a further increase in WEAX level, pointing to in vivo activity of the unprocessed 67 kDa b-D-xylanase.
During the late stage (up to 24 DPI) gradual processing of the 67 kDa b-D-xylanase occurred and was
associated with a drastic increase in b-D-xylanase activity. Up to 120-fold higher activity was recorded at
24 DPI, with approx. 85% thereof originating from the kernel remnants. The WEAX level decreased during
the late stage, suggesting that the b-D-xylanase is processed into more active forms to achieve extensive
AX breakdown.
ISSN: 0981-9428
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Centre for Food and Microbial Technology
Molecular Physiology of Plants and Micro-organisms Section - miscellaneous
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
De Backer 2010 Plant Physiol Biochem 48 90-97.pdf Published 477KbAdobe 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