Other hormones gibberellins, cytokinins, methyl jasmonate and ethylene

Other hormones gibberellins, cytokinins, methyl jasmonate, and ethylene 

ABA and auxins are the only two hormones to date that have been studied in detail as ion transport regulators in the guard cell system. A short summary of the effects of other hormones on stomatal control is given below. 

There is little evidence from either in vivo [57,126,127] or electrophysiological studies for a role of gibberellic acid (GA) in modulation of stomatal response. Gibberellin [28] has been tested and found to be ineffective in modulating the R-type anion channel of Vida guard cells other transporters have yet to be investigated. 

The literature on cytokinin regulation of stomatal activity has been reviewed by Incoll and fewer [130]. Cytokinins such as kinetin, zeatin, and benzyladenine typically promote opening of grass stomata. Similar effects have been observed in several dicots [130], although Catsky et al. recently reported no effect on transpiration resulting from a 

10-20% increase in endogenous cytokinins accomplished via transformation of tobacco with gene 4 of cytokinin synthesis [131], Conflicting reports also exist in the literature for 

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