CDeT6โ19 is an ABAโregulated gene which has been isolated from Craterostigma plantagineum. The CDeT6โ19 gene promoter has been fused to the ฮฒโglucuronidase reporter gene (GUS) and used to stably transform Arabidopsis thaliana and Nicotiana tabacum. This construct has been shown to be expressed in stomatal guard cells and often in the adjacent epidermal cells of both species in response to both exogenous ABA and drought stress. These results indicate that the stomatal guard cell is competent to relay an ABA signal to the nucleus. In contrast GUS expression directed by the promoter from a predominantly seedโspecific, ABAโregulated gene, Em, or the promoter from the ABAโregulated CDeT27โ45 gene is not detectable in the epidermal or guard cells of tobacco or Arabidopsis in response to ABA. The fact that not all ABAโregulated gene promoters are active in stomatal guard cells suggests that effective transduction of the signal is dependent upon particular regions within the gene promoter or that guard cells lack all or part of the specific transduction apparatus required to couple the ABA signal to these promoters. This suggests that there are multiple ABA stimulus response coupling pathways. The identification of a regulatory sequence from an ABAโinduced gene which is expressed in stomatal guard cells creates the possibility of examining the role of Ca^2+^ and other second messengers in ABAโinduced gene expression.