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Responses of individual stomata in Ipomoea pes‐caprae to various CO 2 concentrations
Author(s) -
Kamakura Mai,
Furukawa Akio
Publication year - 2008
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2007.01003.x
Subject(s) - guard cell , ipomoea , botany , stomatal density , convolvulaceae , biology , chemistry , horticulture , photosynthesis
The responses of individual stomata to CO 2 concentrations ranging from 0 to 900 μmol mol −1 air were analysed in Ipomoea pes‐caprae L. Sweet (Convolvulaceae). The stomata were directly observed using a measurement system that permitted continuous observation of stomatal movement under controlled light and CO 2 conditions. A CO 2 concentration of 350 μmol mol −1 or higher induced stomatal closure, whereas concentrations below 350 μmol mol −1 did not. The time lag before stomatal closure decreased with increasing CO 2 concentration, as did the steady‐state aperture of the stomata after a change in CO 2 concentration. However, the rate of stomatal closure increased with increasing CO 2 concentration. Therefore, not only the stomatal closure rate but also the time from the CO 2 concentration change to the beginning of stomatal closure changed with increasing CO 2 concentration. These results suggest that atmospheric CO 2 may be the stimulus for the closure of guard cells. No significant differences were observed between adaxial and abaxial stomata in terms of their responses to CO 2 . However, heterogeneous responses were detected between neighbouring stomata on each leaf surface.