Stomatal sensitivity to abscisic acid following water deficit stress

Abstract

Short- and medium-term stresses (1 and 24 h, respectively) were applied to detached leaves of Commelina communis L., resulting in both cases in a final leaf cell water potential (ψ w ) of about -1.0 MPa and relative water content (RWC) of about 74%. A long-term stress (14 d), applied to intact plants, resulted in a final leaf cell Ψ w of -0.57 MPa and RWC of 90%. All the stresses resulted in lower leaf conductances (g i ) compared to controls, although temporary increases in g i were observed early in the short- and medium term stresses. When epidermal strips were incubated in vitro, the stomatal opening potential was reduced by the stresses, possibly due to lower initial apertures caused by the stress