Post-translational processing of beta-d-xylanases and changes in extractability of arabinoxylans during wheat germination
Copyright 2009 Elsevier Masson SAS. All rights reserved.
| Publié dans: | Plant physiology and biochemistry : PPB. - 1991. - 48(2010), 2-3 vom: 15. Feb., Seite 90-7 |
|---|---|
| Auteur principal: | |
| Autres auteurs: | , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2010
|
| Accès à la collection: | Plant physiology and biochemistry : PPB |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Gibberellins Plant Growth Regulators Xylans arabinoxylan 9040-27-1 gibberellic acid BU0A7MWB6L Endo-1,4-beta Xylanases |
| Résumé: | Copyright 2009 Elsevier Masson SAS. All rights reserved. Endo-1,4-beta-d-xylanase (EC 3.2.1.8, beta-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 3-4 DPI). This increase was not accompanied by the discernible presence of homologues of the barley X-I beta-d-xylanase as established by immunodetection. This suggests that other, yet unidentified beta-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 beta-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 beta-d-xylanase activities and a further increase in WEAX level, pointing to in vivo activity of the unprocessed 67 kDa beta-d-xylanase. During the late stage (up to 24 DPI) gradual processing of the 67 kDa beta-d-xylanase occurred and was associated with a drastic increase in beta-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 beta-d-xylanase is processed into more active forms to achieve extensive AX breakdown |
|---|---|
| Description: | Date Completed 01.09.2010 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1873-2690 |
| DOI: | 10.1016/j.plaphy.2009.10.008 |