Two types of segments (intact leaf tissue and isolated mesophyll tissue respectively) were isolated from basal (still growing) and tip (non-growing) maize leaf regions. The leaf segments were exposed to different light qualities (blue or red light) and quantities, and net fluxes of K+, Ca 2+ and H+ were measured non-invasively using ion-selective vibrating microelectrodes (the MIFE technique). A clear dose dependency of all ion flux responses on both red (RL) and blue (BL) light fluence rate was found. We provide evidence that light-induced K+ flux kinetics are different between growing and non-growing tissues and attribute this difference to the direct involvement of RL-induced K+ flux in turgor-driven leaf expansion growth controlled by the epidermis, as well as to the charge-balancing role of K+ in the leaf mesophyll. Generally, BL was much more efficient in stimulating K+ uptake in the growing basal region compared with RL. We also show a much stronger influence of RL on Ca 2+ fluxes in the basal region compared with BL, which argues in favor of the importance of RL in Ca2+ signaling during leaf growth. © The Author 2007. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved.

Item Type:	Refereed Article
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 Environmental Sciences
Author:	Zivanovic, B (Dr Branka Zivanovic)
Author:	Cuin, TA (Dr Tracey Cuin)
Author:	Shabala, SN (Professor Sergey Shabala)
ID Code:	48797
Year Published:	2007
Web of Science® Times Cited:	5
Deposited By:	Agricultural Science
Deposited On:	2007-08-01
Last Modified:	2009-08-06
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