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Water Channels Are Involved in Stomatal Oscillations Encoded by Parameter‐Specific Cytosolic Calcium Oscillations
Author(s) -
Yang HuiMin,
Zhang XiaoYan,
Wang GenXuan,
Zhang JianHua
Publication year - 2006
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/j.1744-7909.2006.00261.x
Subject(s) - guard cell , oscillation (cell signaling) , chemistry , inhibitory postsynaptic potential , biophysics , calcium , biochemistry , biology , endocrinology , organic chemistry
Earlier studies have shown that various stimuli can induce specific cytosolic calcium ([Ca 2+ ] cyt ) oscillations in guard cells and various oscillations in stomatal apertures. Exactly how [Ca 2+ ] cyt oscillation signaling functions in stomatal oscillation is not known. In the present study, the epidermis of broad bean ( Vicia faba L.) was used and a rapid ion‐exchange treatment with two shifting buffers differing in K + and Ca 2+ concentrations was applied. The treatment for five transients at a 10‐min transient period induced clear and regular stomatal oscillation. However, for other transient numbers and periods, the treatments induced some irregular oscillations or even no obvious oscillations in stomatal aperture. The results indicate that stomatal oscillation is encoded by parameter‐specific [Ca 2+ ] cyt oscillation: the parameters of [Ca 2+ ] cyt oscillation affected the occurrence rate and the parameters of stomatal oscillation. The water channel inhibitor HgCl 2 completely inhibited stomatal oscillation and the inhibitory effect could be partially reversed by β‐mercaptoethanol (an agent capable of reversing water channel inhibition by HgCl 2 ). Other inhibitory treatments against ion transport (i.e. the application of LaCl 3 , EGTA, or tetraethylammonium chloride (TEACI)) weakly impaired stomatal oscillation when the compounds were added after rapid ion‐exchange treatment. If these compounds were added before rapid‐ion exchange treatment, the inhibitory effect was much more apparent (except in the case of TEACI). The results of the present study suggest that water channels are involved in stomatal oscillation as a downstream element of [Ca 2+ ] cyt oscillation signaling. (Managing editor: Wei Wang)