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An extra-plastidial α-glucan, water dikinase from Arabidopsis phosphorylates amylopectin in vitro and is not necessary for transient starch degradation
Citation
Glaring, MA and Zygadlo, A and Thorneycroft, D and Schulz, A and Smith, SM and Blennow, A and Baunsgaard, L, An extra-plastidial α-glucan, water dikinase from Arabidopsis phosphorylates amylopectin in vitro and is not necessary for transient starch degradation, Journal of Experimental Botany, 58, (14) pp. 3949-3960. ISSN 0022-0957 (2007) [Refereed Article]
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Copyright Statement
Copyright 2007 The Author. Licensed under Creative Commons Attribution-NonCommercial 2.0 UK: England & Wales (CC BY-NC 2.0 UK) http://creativecommons.org/licenses/by-nc/2.0/uk/
Abstract
Starch phosphorylation catalysed by the α-glucan, water dikinases (GWD) has profound effects on starch degradation in plants.
The Arabidopsis thaliana genome encodes three isoforms of GWD, two of which are localized in the chloroplast and are involved in the degradation of
transient starch. The third isoform, termed AtGWD2 (At4g24450), was heterologously expressed and purified and shown to have
a substrate preference similar to potato GWD. Analyses of AtGWD2 null mutants did not reveal any differences in growth or starch and sugar levels, when compared to the wild type. Subcellular
localization studies in Arabidopsis leaves and in vitro chloroplast import assays indicated that AtGWD2 was not targeted to the chloroplasts. The AtGWD2 promoter showed a highly restricted pattern of activity, both spatially and temporally. High activity was observed in the
companion cells of the phloem, with expression appearing just before the onset of senescence. Taken together, these data indicate
that, although AtGWD2 is capable of phosphorylating α-glucans in vitro, it is not directly involved in transient starch degradation.
Item Details
Item Type: | Refereed Article |
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Keywords: | Arabidopsis, dikinase, GWD, phloem, starch degradation, starch phosphorylation. |
Research Division: | Biological Sciences |
Research Group: | Plant biology |
Research Field: | Plant physiology |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the biological sciences |
UTAS Author: | Smith, SM (Professor Steven Smith) |
ID Code: | 101508 |
Year Published: | 2007 |
Web of Science® Times Cited: | 22 |
Deposited By: | Plant Science |
Deposited On: | 2015-06-25 |
Last Modified: | 2015-09-24 |
Downloads: | 218 View Download Statistics |
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