Please use this identifier to cite or link to this item:
Appears in Collections:Biological and Environmental Sciences Journal Articles
Peer Review Status: Refereed
Title: Glucan, Water Dikinase Exerts Little Control over Starch Degradation in Arabidopsis Leaves at Night  
Author(s): Skeffington, Alastair W
Graf, Alexander
Duxbury, Zane
Gruissem, Wilhelm
Smith, Alison M
Contact Email:
Keywords: Plant Science
Issue Date: 2-Jun-2014
Date Deposited: 28-Jun-2023
Citation: Skeffington AW, Graf A, Duxbury Z, Gruissem W & Smith AM (2014) Glucan, Water Dikinase Exerts Little Control over Starch Degradation in Arabidopsis Leaves at Night  . <i>Plant Physiology</i>, 165 (2), pp. 866-879.
Abstract: The first step on the pathway of starch degradation in Arabidopsis (Arabidopsis thaliana) leaves at night is the phosphorylation of starch polymers, catalyzed by glucan, water dikinase (GWD). It has been suggested that GWD is important for the control of starch degradation, because its transcript levels undergo strong diel fluctuations, its activity is subject to redox regulation in vitro, and starch degradation is strongly decreased in gwd mutant plants. To test this suggestion, we analyzed changes in GWD protein abundance in relation to starch levels in wild-type plants, in transgenic plants in which GWD transcripts were strongly reduced by induction of RNA interference, and in transgenic plants overexpressing GWD. We found that GWD protein levels do not vary over the diel cycle and that the protein has a half-life of 2 d. Overexpression of GWD does not accelerate starch degradation in leaves, and starch degradation is not inhibited until GWD levels are reduced by 70%. Surprisingly, this degree of reduction also inhibits starch synthesis in the light. To discover the importance of redox regulation, we generated transgenic plants expressing constitutively active GWD. These plants retained normal control of degradation. We conclude that GWD exerts only a low level of control over starch degradation in Arabidopsis leaves.
DOI Link: 10.1104/pp.114.237016
Rights: This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Licence URL(s):

Files in This Item:
File Description SizeFormat 
plphys_v165_2_866.pdfFulltext - Published Version590.03 kBAdobe PDFView/Open

This item is protected by original copyright

A file in this item is licensed under a Creative Commons License Creative Commons

Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

The metadata of the records in the Repository are available under the CC0 public domain dedication: No Rights Reserved

If you believe that any material held in STORRE infringes copyright, please contact providing details and we will remove the Work from public display in STORRE and investigate your claim.