Stimulus-induced oscillations in guard cell cytosolic free calcium
Ca2+ is implicated as a second messenger in the response of stomata to a range of stimuli. However, the mechanism by which stimulus-induced increases in guard cell cytosolic free Ca2+ ([Ca2+]i) are transduced into different physiological responses remains to be explained. Oscillations in [Ca2+]i may...
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Published in | The Plant cell Vol. 7; no. 8; pp. 1207 - 1219 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society of Plant Physiologists
01.08.1995
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Subjects | |
Online Access | Get full text |
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Summary: | Ca2+ is implicated as a second messenger in the response of stomata to a range of stimuli. However, the mechanism by which stimulus-induced increases in guard cell cytosolic free Ca2+ ([Ca2+]i) are transduced into different physiological responses remains to be explained. Oscillations in [Ca2+]i may provide one way in which this can occur. We used photometric and imaging techniques to examine this hypothesis in guard cells of Commelina communis. External Ca2+ ([Ca2+]e), which causes an increase in [Ca2+]i, was used as a closing stimulus. The total increase in [Ca2+]i was directly related to the concentration of [Ca2+]e, both of which correlated closely with the degree of stomatal closure. Increases were oscillatory in nature, with the pattern of the oscillations dependent on the concentration of [Ca2+]e. At 0.1 mM, [Ca2+]e induced symmetrical oscillations. In contrast, 1.0 mM [Ca2+]e induced asymmetric oscillations. Oscillations were stimulus dependent and modulated by changing [Ca2+]e. Experiments using Ca2+ channel blockers and Mn2+-quenching studies suggested a role for Ca2+ influx during the oscillatory behavior without excluding the possible involvement of Ca2+ release from intracellular stores. These data suggest a mechanism for encoding the information required to distinguish between a number of different Ca2+-mobilizing stimuli in guard cells, using stimulus-specific patterns of oscillations in [Ca2+]i |
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Bibliography: | F60 9611408 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1040-4651 1532-298X |
DOI: | 10.1105/tpc.7.8.1207 |