Present address: UPR28 Génetique Palmier, CIRAD, Avenue Agropolis, 34398 Montpellier Cedex 5, France.
A grapevine Shaker inward K+ channel activated by the calcineurin B-like calcium sensor 1–protein kinase CIPK23 network is expressed in grape berries under drought stress conditions
Article first published online: 27 OCT 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd
The Plant Journal
Volume 61, Issue 1, pages 58–69, January 2010
How to Cite
Cuéllar, T., Pascaud, F., Verdeil, J.-L., Torregrosa, L., Adam-Blondon, A.-F., Thibaud, J.-B., Sentenac, H. and Gaillard, I. (2010), A grapevine Shaker inward K+ channel activated by the calcineurin B-like calcium sensor 1–protein kinase CIPK23 network is expressed in grape berries under drought stress conditions. The Plant Journal, 61: 58–69. doi: 10.1111/j.1365-313X.2009.04029.x
- Issue published online: 18 DEC 2009
- Article first published online: 27 OCT 2009
- Received 19 June 2009; revised 15 September 2009; accepted 18 September 2009; published online 27 October 2009.
- Shaker K+ channel;
- K+ uptake;
- CIPK–CBL network;
- drought stress;
- in situ hybridization;
- expression pattern
Grapevine (Vitis vinifera), the genome sequence of which has recently been reported, is considered as a model species to study fleshy fruit development and acid fruit physiology. Grape berry acidity is quantitatively and qualitatively affected upon increased K+ accumulation, resulting in deleterious effects on fruit (and wine) quality. Aiming at identifying molecular determinants of K+ transport in grapevine, we have identified a K+ channel, named VvK1.1, from the Shaker family. In silico analyses indicated that VvK1.1 is the grapevine counterpart of the Arabidopsis AKT1 channel, known to dominate the plasma membrane inward conductance to K+ in root periphery cells, and to play a major role in K+ uptake from the soil solution. VvK1.1 shares common functional properties with AKT1, such as inward rectification (resulting from voltage sensitivity) or regulation by calcineurin B-like (CBL)-interacting protein kinase (CIPK) and Ca2+-sensing CBL partners (shown upon heterologous expression in Xenopus oocytes). It also displays distinctive features such as activation at much more negative membrane voltages or expression strongly sensitive to drought stress and ABA (upregulation in aerial parts, downregulation in roots). In roots, VvK1.1 is mainly expressed in cortical cells, like AKT1. In aerial parts, VvK1.1 transcripts were detected in most organs, with expression levels being the highest in the berries. VvK1.1 expression in the berry is localized in the phloem vasculature and pip teguments, and displays strong upregulation upon drought stress, by about 10-fold.VvK1.1 could thus play a major role in K+ loading into berry tissues, especially upon drought stress.