Influence of the mesophyll on stomatal opening

This study shows that stomata in the isolated epidermis do not behave like those in the intact leaf and that the mesophyll plays an important role in the mechanism of stomatal opening over short periods. The results suggested that the opening of stomata in isolated epidermis was inferior to that in...

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Bibliographic Details
Main Author: Lee, Joonsang
Published: University of Aberdeen 1992
Subjects:
580
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314415
Description
Summary:This study shows that stomata in the isolated epidermis do not behave like those in the intact leaf and that the mesophyll plays an important role in the mechanism of stomatal opening over short periods. The results suggested that the opening of stomata in isolated epidermis was inferior to that in the intact leaf and was influenced by the concentration of KCl in the medium rather than by light. Stomatal opening in isolated epidermis of <i>Commelina</i> was not only insensitive to light but also unaffected by CO<sub>2</sub> in the medium containing 100 mol m<sup>-3</sup> KCl. The absence of an effect of light and CO<sub>2</sub> on the stomata in isolated epidermis and the evidence that they possessed the potential of those in the intact leaf to open wide, suggested that the mesophyll could be important in influencing stomatal opening in the intact leaf. The solution in which the mesophyll cells were incubated was separated by centrifugation. The medium from cells previously incubated in the light caused the stomata in the isolated epidermis to open but that from cells kept in the dark had no effect. Thus the stimulatory influence of the mesophyll cells in bringing about stomatal opening could be separated from the cells into solution. For ease of description it is tentatively suggested that the putative factor which promotes stomatal opening indicated by the results be called stomatin. Stomatin will be produced when the chloroplasts in the mesophyll are exposed to white light.