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...
Gespeichert in:
Veröffentlicht in: | The Plant cell 1995-08, Vol.7 (8), p.1207-1219 |
---|---|
Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | 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 |
---|---|
ISSN: | 1040-4651 1532-298X |
DOI: | 10.1105/tpc.7.8.1207 |